EPA/600/R-14/148 | July 2014 | www.epa.gov/research
United States
Environmental Protection
Agency
Field Demonstration of Innovative
Condition Assessment Technologies for
Water Mains: Acoustic Pipe Wall
Assessment, Internal Inspection, and
External Inspection
Volume 1:Technical Report
Volume 2: Appendices
Office of Research and Development
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FINAL REPORT
FIELD DEMONSTRATION OF INNOVATIVE CONDITION ASSESSMENT TECHNOLOGIES
FOR WATER MAINS: ACOUSTIC PIPE WALL ASSESSMENT, INTERNAL INSPECTION,
AND EXTERNAL INSPECTION
VOLUME 1: TECHNICAL REPORT
by
Bruce Nestleroth, Stephanie Flamberg, Vivek Lai, Wendy Condit, and John Matthews
Battelle
Abraham Chen and Lili Wang
Alsa Tech, LLC
Contract No. EP-C-05-057
Task Order No. 0062
for
Michael Royer
Task Order Manager
Water Supply and Water Resources Division
National Risk Management Research Laboratory
2890 Woodbridge Avenue (MS-104)
Edison, NJ 08837
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
September 2013
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DISCLAIMER
The U.S. Environmental Protection Agency, through its Office of Research and Development, funded and
managed, or partially funded and collaborated in, the research described herein under Task Order (TO)
0062 of Contract No. EP-C-05-057 to Battelle. It has been subjected to the Agency's peer and
administrative review and has been approved for publication. Any opinions expressed in this report are
those of the author (s) and do not necessarily reflect the views of the Agency, therefore, no official
endorsement should be inferred. Any mention of trade names or commercial products does not constitute
endorsement or recommendation for use. The quality of secondary data referenced in this document was
not independently evaluated by EPA and Battelle.
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ABSTRACT
Nine pipe wall integrity assessment technologies were demonstrated on a 76-year-old, 2,057-ft-long
portion of a cement-lined, 24-in. cast iron water main in Louisville, KY. This activity was part of a series
of field demonstrations of innovative leak detection/location and condition assessment technologies
sponsored by the U.S. Environmental Protection Agency (EPA). The main goal of the demonstrations
was to acquire a snapshot of the current performance capability and cost of these innovative technologies
under real-world pipeline conditions so that technology developers, technology vendors, research support
organizations, and the user community can make more informed decisions about the strengths,
weaknesses, and need for further advancement of these technologies.
Pipe wall integrity assessment was one part of a comprehensive water pipeline condition assessment
demonstration where six inspection companies operated 12 technologies (nine for pipe wall integrity
assessment and three for leak detection) that were at various stages of development and provided different
types and levels of leak and/or structural condition data. Technologies were included for wall-thickness
screening (i.e., average wall loss over many tens of feet), for video screening of internal pipe condition,
for detailed mapping of wall thickness, and for leak detection. Both in-line and external inspection
technologies were demonstrated. The inspection technologies used visual, mechanical, acoustic,
ultrasonic, and electromagnetic methods for acquiring leak and pipe condition data.
This report presents the results of the following nine pipe wall integrity assessment technologies:
Three technologies for average wall thickness screening are discussed including Sahara® Wall Thickness
Testing (WTT), SmartBall™Pipe Wall Assessment (PWA), and ThicknessFinder. These inspection
technologies acquire pipe condition data in the form of general pipeline condition or average wall loss
over a specified interval.
Three technologies are discussed that use inline inspection of the entire pipeline length including Sahara
Video®, PipeDiver® remote field eddy current (RFEC), and See Snake® RFT. These inspection
technologies can acquire pipe condition data, such as metal loss, size of defects, and/or cracks.
Three technologies are discussed that use external inspection at selected excavation points including
External Condition Assessment Tool (ECAT), Hand Scanning Kit (HSK) and Crown Assessment Probe
(CAP). These inspection technologies can acquire pipe condition data within an excavation and use
models to predict the condition of portions of the pipeline that remain buried.
Upon completion of the field demonstration effort, the 24-in. diameter test pipe was removed by
Louisville Water Company (LWC) to prepare for installation of a 30-in. diameter replacement line. As
the 24-in. line was being removed, the EPA's contractor selected 12 pipe lengths for post-demonstration
confirmation of the reported condition assessment technology results. Pipe segments were selected using
the inspection results reported by each technology vendor and visual assessment of the pipe condition as it
was removed. The pipes were grit blasted to remove coating, corrosion and graphitization and the amount
of metal loss was quantified manually and with a laser scanner. For each technology, inspection results
were compared to the dimensions and locations of machined defects and/or of naturally-occurring defects
found after excavation to evaluate the performance of the pipe wall integrity assessment technologies.
Each company provided a written report on the condition of the test pipe, with some reporting anomalous
pipe segments and others reporting the size, depth, and location of specific defects along the test pipe.
This report covers acoustic pipe wall assessment, internal inspection, and external inspection. Volume II
includes assessment data for excavated pipe and vendor reports. A companion report (Nestleroth et al.,
2012) provides information on the leak detection and location portion of the technology demonstration.
The field demonstration phase was conducted in 2009. The post-demonstration ex situ pipe
characterization, and report preparation and review was conducted in 2010, 2011, 2012, and 2013.
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ACKNOWLEDGMENTS
The authors wish to express their sincere appreciation for the excellent cooperation and support provided
by Andy Williams, Keith Coombs, Dennis Pike, and other Louisville Water Company (LWC) colleagues,
as well as the LWC contractor, MAC Construction and Excavating, Inc. We would also like to
acknowledge the following technology vendors for their participation and in-kind support to this
demonstration:
Echologics Engineering Inc.
The Pressure Pipe Inspection Company
Pure Technologies, Ltd.
Russell NDE Systems Inc.
Advanced Engineering Solutions Limited
Rock Solid Group Pty. Ltd.
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EXECUTIVE SUMMARY
The state of the art in condition assessment technologies for water mains is still developing and water
utilities are interested in third-party, independent sources of information on the capabilities of innovative
inspection technologies. Technology demonstrations with a range of real-life defects and conditions are
particularly valuable to water utilities and can play a vital role in accelerating the adoption of appropriate,
innovative condition assessment technologies. A field demonstration program was conducted to evaluate
condition assessment technologies applicable to the inspection of cast iron water mains. It is critical that
utilities have the capability to undertake reliable condition assessment of cast iron pipelines in order to
prevent failures and/or premature rehabilitation or replacement.
The main goal of the demonstration program was to acquire a snapshot of the performance capability and
cost of applicable inspection technologies under real-world pipeline conditions so that technology
developers, technology vendors, research organizations, and the user community can make more
informed decisions about the strengths, weaknesses, and need for further advancement of these
technologies. As part of this research effort, several emerging and innovative inspection technologies
were demonstrated on a 76-year-old, 2,057-ft-long portion of a cement-lined, 24-in. cast iron water main
in Louisville, KY. This report presents the results from the acoustic pipe wall assessment, the internal
inspection, and the external inspection technology demonstrations. A companion report (Nestleroth, B. et
al., 2012) discusses the results of the leak detection technologies. The field demonstration phase was
conducted in 2009. The post-demonstration ex situ pipe characterization, report preparation, and review
was conducted in 2010, 2011, 2012, and 2013.
This report presents the results of a total of nine pipe wall integrity assessment technologies including:
Average wall thickness screening with Pressure Pipe Inspection Company's (PPIC) Sahara® Wall
Thickness Testing (WTT), Pure's SmartBall™ Pipe Wall Assessment (PWA), and Echologics'
ThicknessFinderRT. The methods used sensors and data recording equipment from their leak detection
platforms, along with a method to introduce sound energy into the pipeline.
In-line inspection of the entire pipeline length with two remote field eddy current (RFEC) methods called
PPIC PipeDiver® RFEC and Russell NDE Systems Inc. See Snake® Remote Field Technology (RFT), and
a video system called Sahara Video®.
External inspection at selected excavation points using Advanced Engineering Solutions, Ltd. (AESL)
External Condition Assessment Tool (ECAT), Rock Solid Group's (RSG) Hand Scanning Kit (HSK), and
RSG's Crown Assessment Probe (CAP).
All of the technologies are commercially available and most have been reported to have been improved
since the demonstration was conducted in 2009. Many of the companies have recently been acquired or
merged. PPIC is now part of Pure. Echologics is a subsidiary of Mueller Water Products. Rock Solid
Group has successfully licensed their technology globally including a number of U.S.-based licensees that
offer broadband electromagnetic (BEM) inspections locally. The See Snake® demonstrated by Russell
NDE Systems Inc. is now provided by a subsidiary, Pipeline Inspection and Condition Analysis (PICA).
AESL technology was developed and operated in the United Kingdom and has been leased for operation
in Europe and Australasia for several years, and more recently in North America.
These nine technologies were demonstrated to evaluate their capabilities to assess the structural condition
of a straight, cement-lined, 24-in. cast iron water main with bell and spigot joints that are sealed with
leadite. The test pipe had a burial depth between 3.5 and 6.0 ft and wall thicknesses ranging from 0.68 to
0.78-in., as measured periodically during routine maintenance activities. The test pipe historically
operated at pressures between 45 and 50 pounds per square inch (psi), while transmitting 4 to 6 million
gallons per day (MGD) of flow. Under the Louisville Water Company's (LWC) Main Replacement and
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Rehabilitation Program, a portion of 24-in. diameter cast iron transmission water main along Westport
Road was scheduled for replacement. LWC agreed to make this portion of the pipe available for field
demonstration, as well as provide necessary on-site assistance. Immediately after the field demonstration
was completed, the 24-in. water main was replaced with a 30-in. line in the same location. This allowed
for the opportunity to exhume portions of the pipeline in individual 12-ft lengths for further assessment.
Many logistical, operational, and performance aspects of these nine technologies were observed over the
course of the demonstration. The logistical and operational requirements affect the feasibility and
complexity of use for the various inspection tools. Several steps, which varied depending on the
technology function, were involved in demonstrating technology performance. The vendors provided
their assessment of the test pipe condition, with some reporting average or effective wall thickness for
various spans of pipe; others reporting anomalous pipe segments; and still others reporting the size, depth,
and location of specific defects along the test pipe. Pipe segments were then selected for detailed ex situ
evaluation based upon the vendor inspection results, and visual assessment of the pipe condition as it was
removed from the ground by the utility. The technology inspection results were compared to the
dimensions and locations of machined defects and/or naturally-occurring defects to evaluate the
performance of the pipe wall integrity assessment technologies. The amount of metal loss from 12
exhumed pipes was quantified manually and/or with a laser scanner and compared, where applicable, to
the vendors' in situ inspection results. In addition, cost estimates to implement the various technologies
for the inspection of a 24-in. cast iron pipe were also requested and are documented in this report, along
with estimated site preparation costs for those activities typically conducted by the utility.
With respect to pipe deterioration measuring capabilities of the innovative technologies, the main focus
was on the capability of the devices to measure metal loss, primarily due to pitting, graphitization, general
corrosion, and machined defects. An exception is Sahara Video, which provided visual data only on the
location and condition of the cement mortar liner defects, valves, and connections.
The pipe wall integrity inspection demonstrations did not evaluate technology capability for all types of
failure modes. For example:
• Interior metal loss was not evaluated. The pipe had a cement mortar liner, which appeared to be
in good condition based on CCTV and visual observation of excavated pipes. It was assumed that a
sound cement liner indicated little or no corrosion in the adjacent pipe wall. Removing the cement mortar
liner to assess the inner pipe wall was not within the project scope.
Cracks were not a priority, and were not generally present. Significant cracking was not observed
in the 12 excavated pipes that were characterized in detail, nor were cracks included in the set of
machined defects, nor did the technologies with crack-detection capability report cracks. The leak
detection demonstration previously conducted indicated few through-wall cracks.
• Detection of mis-aligned joints was not a capability of the demonstrated technologies, nor was
mis-alignment found during documentation of the pipe characteristics.
Machined Defects
A milling machine on a magnetic base was used to create 18 machined metal loss defects that were
installed in Pits 2, 4, 5, and F. The manufactured defect sizes ranged from approximately 1- to 6-in. in
length with depths varying between 20% up to 70% wall loss. The intent of installing machined
corrosion defects was: (a) to provide three defects for vendors to calibrate their inspection devices, and
(b) to create a set of 15 "hidden" defects whose characteristics were only known by the EPA contractor,
not the inspection vendor. In this way, the demonstration could help to define both the current capability
and future challenges for each of the inspection technologies. For technologies that report the average
wall thickness over tens or hundreds of feet, detection of the machined defects in this demonstration is not
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a relevant parameter, since the machined defects cause only a minuscule change in average wall thickness
for even a single length of pipe.
Condition Assessment of Exhumed Pipes
A post-demonstration confirmation study was conducted in order to select, characterize, and compare the
condition of exhumed pipe samples to the pipe inspection data that was collected by the inspection
technology vendors during the field demonstration in Louisville, KY. The confirmation study included
an assessment of the original wall thickness, inside cement coating thickness, and pipe outer diameter
(OD) and wall loss measurements for 12 exhumed pipes. Prior to measuring external wall loss, the pipes
were sandblasted to a NACE-2 Near-White Blast Cleaning to expose degradation. While this method will
remove a small amount of good cast material, a less aggressive NACE-3 preparation did not remove all of
the graphitization in the deepest pits. Therefore, measured metal loss may be slightly greater than actual
condition. The exhumed pipes were assessed manually and/or with a laser scanner in order to determine
the extent of metal loss. The extent of metal loss was characterized by total volume loss, number of pits
(with loss greater than 50% of depth), maximum pit depth, and largest corrosion patch dimensions. This
report presents the rationale for selection of the 12 exhumed pipe segments and the methodologies used
for the pipe condition assessment during the post-demonstration confirmation study.
The wall thickness was measured at undeteriorated locations around the circumference at the spigot,
center and bell; the inside cement coating thickness was measured at the spigot; and the circumference
was measured at three undeteriorated locations. In general, the pipe wall thickness at the spigot was the
same around the circumference, confirming that the pipe is spun cast iron. For the 12 exhumed pipe
samples, the average wall thickness of the undeteriorated portions of the exhumed pipes was 0.786-in.,
the standard deviation was about 3%, and the pipes tended to be slightly thicker at the bell than at the
spigot. The average outside diameter of the 12 pipes was 25.82 inches with a standard deviation of 0.03
inches. Thus, the average inside diameter of the pipe was 24.25-in. The cement liner had an average
thickness of 0.25-in, but it was thicker at the top (average 0.33 inches) than at the bottom (average 0.14
inches) with a standard deviation of 0.06-in..
For the areas of the 12 exhumed pipes with corrosion and graphitization, the remaining metal was
calculated by subtracting the anomaly depth from the local wall thickness. The depth of the pits was
measured by two methods. For the eight pipes with the least corrosion, corrosion was mapped in a 1A x 1A
in. grid using a micrometer and bridging bar. For the four pipes selected for verification judged to be in
the worst condition, a laser-based coordinate-measuring machine (CMM) was used for automated
measurement of the metal loss. This method uses laser beams that are projected against the surface of the
pipe. Many thousands of points in a 0.040 x 0.080 in. grid are then taken and used to determine the size
and position of corrosion by creating a three-dimensional (3D) image of the pipe. An area on one pipe
was assessed with both methods to ensure comparable results were attained.
While each of the 12 pipes had some amount of metal loss, the pipe condition was generally good. The
greatest average wall loss was calculated for all of the pipes and was less than three percent. The number
of pits greater than 50% deep was also counted; one pipe had 13 pits, four pipes had four to six pits, four
pipes had one or two pits, and three pipes had none greater than 50% deep. The deepest pit was 85
percent through the wall. Also, the cement mortar liner appeared in generally good condition. Based on
the above information, EPA's contractor considered the exhumed pipes to have minimal deterioration.
While none of the pipes appeared to have significant degradation, the pipes were assigned a relative
condition assessment score based upon volume loss and number of deep pits as described in the report.
Condition Assessment with Non-Destructive Technologies
As noted above, many aspects of the wall thickness assessment technologies were observed and
documented over the course of the demonstrations. This section provides an overview of the
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demonstration results and their significance.
Ten logistical and operational requirements are documented for each demonstrated technology. The
requirements addressed are: equipment logistics, utility preparation, number of technicians needed, pipe
access or contact points, sterilization of components that contact water, real-time data, condition
assessment, on-site report, and operator intervention. This information provides insight into the ability of
the tools to mobilize, access the pipe, and operate under various field conditions for a 24-in. cast iron
pipe. This information will help utilities to gauge the logistical and operational feasibility of using these
technologies at their sites.
Most of the technologies were in the early stages of commercial deployment. For some of the
technologies, this demonstration was the initial or early use of the inspection tool or procedure. The
inspection technologies are not strictly comparable since, for example, they are designed to meet various
water pipeline operators' needs with respect to inspection goals, levels of intrusion, complexity of
operation, resolution of results, and implementation approaches. The lowest resolution system provided
average wall thickness measurements at intervals of a few hundred feet; this system required one person
with two suitcases about a half a day to perform the task and required seven excavations to the top of the
pipe. The highest resolution system measured the location as well as depth, length, and width of
individual metal loss anomalies along the pipe length and circumference. This was also an intrusive
technology, since it was an internal inspection system that was nearly full circumference and for this use
the pipe had to be drained, eight ft of pipe had to be removed at each end, and a dedicated winch truck
employed.
For the average wall thickness screening assessments (that used sensors and data recording components
from leak detection platforms, along with a method to introduce sound energy into the pipeline), the
following observations were found.
• ThicknessFinder worked from the outside of the pipe at excavations and had the coarsest
resolution. It provided average wall thickness readings for seven segments of pipe that averaged
293 ft in length. Numerical values of average effective wall thickness were provided, along with
a qualitative description of the pipe condition. The results of the inspection classified the pipes as
in good condition, but estimated the average effective wall thickness loss at 14% to 20%,
reflecting more severe deterioration than the exhumed pipes, which were found to have <2.6%
wall loss. The capability of the technology to identify large areas of significant corrosion could
not be evaluated, since the test pipe was in overall good condition, i.e., < 2.6% wall loss in the 12
pipe lengths characterized in detail. The inspection tool was able to be successfully deployed
under site conditions. ThicknessFinder was operated in the demonstration with the pipe full, but
not flowing, and hence not producing a noisy discharge to the sewer. One person and two
suitcases of equipment required about a half a day to perform the task. Eight excavations were
needed. The water was not contacted. Longer distances would require more excavation points.
This technology was in an emerging technology status at the time of the demonstration.
• Sahara® WTT provided measurements over 33 ft intervals using a sensor in the pipe and
excitation at excavations. The inspection results were reported as an average wall thickness loss
ratio. The inspection tool was successfully deployed under site conditions. The inspection report
indicated that a wide range of conditions were present in the pipe with degradation, in terms of
wall thickness loss, exceeding 30% for three intervals. However, in the assessment of 12
exhumed pipes, only minimal wall loss was observed. Sahara® WTT provided data for about
1040-ft out of the 2057-ft test pipe due to reasons such as the close proximity of the internal and
external sensors, presence of large air pockets, or noise from the pipeline discharge, which
masked acoustic activity. Flow in the test pipe was necessary to transport the tethered sensor
through the pipe. For this demonstration the flow had to be discharged to the sewer, which likely
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would be unnecessary for an in-service line or could be done sufficiently far from the tested pipe
to prevent interference. A dedicated winch truck with two operators was needed; the inspection
was completed in a day. One excavation point and installation of a 2-in. fitting were required; a
second excavation point and fitting would be needed if length increased significantly. A
sterilized sensor and tether was inserted in the pipe; disinfection efficacy assessment was not
within the project scope for any internal technologies. This was a very early use of this emerging
technology and tool performance could be improved with further calibration to pipe excavation
and characterization information from the field. For example, a utility could perform a few
excavations in areas of suspected wall loss to confirm the condition of the pipe and subsequently
work with the vendor to improve the calibration and post-analysis of the Sahara® WTT results
with excavation information from their site. This confirmation of inspection results is a common
practice in other industries (e.g., oil and gas pipeline inspections) where typically up to five
locations are dug to confirm and better calibrate inspection results.
• SmartBall™ Pipe Wall Assessment made acoustic velocity measurements approximately every 2
ft using a sensor inserted in the pipe and a sound source at the ends and middle of the main. The
measurements were analyzed and twelve spans of pipe, from 14 to 102 ft in length were identified
as having acoustic anomalies with the designation of regions noted to have reduced stiffness.
Four of the exhumed pipes fell within regions designated as having "reduced stiffness" and three
fell within regions designated as "normal" via SmartBall™ inspection; the worst of the exhumed
pipes were in spans identified as having reduced stiffness. Two operators were needed with
equipment delivered by overnight package delivery. Two excavation points (each end) were
required with a 4-in. fitting installed; greater distances than those demonstrated can be done with
one insertion. A sterilized sensor and catching equipment were inserted in the pipe. SmartBall™
PWA provided data for about 1050-ft out of the 2057-ft test pipe. It had difficulties assessing the
second half of the test pipe potentially due to SmartBall™ PWA being unable to detect the
acoustic signal from the third pulser, which was nearest the large amount of noise produced by
discharge of water from the test pipe, which would likely be unnecessary or avoidable in an in-
service line. This was a very early use of this emerging technology and tool performance could
be improved with further calibration to excavation information from the field. For example, a
utility could perform a few excavations in areas of suspected wall loss to confirm the condition of
the pipe and subsequently work with the vendor to improve the calibration and post-analysis of
the SmartBall™ results with excavation information from their site. This confirmation of
inspection results is a common practice in other industries.
For the in-line inspection of the entire pipeline length with two remote field eddy current (RFEC)
methods, and one video method, the following observations were found.
• PipeDiver® RFEC made measurements in fine intervals along the full length of the pipeline;
signal analysis yielded prediction of anomalous or good condition for each of the 12-ft pipe
lengths, including those that were subsequently exhumed and characterized in detail. It
successfully identified pipes independently determined to be in good condition. PipeDiver®
results were mixed compared to the EPA contractor's assessment when attempting to discriminate
between levels of degradation in pipe that was in overall good condition (i.e., < 4% overall wall
loss). In those pipes, some substantial corrosion patches, deep corrosion pits, and up to 6 pits >
50% did not cause pipes to be reported as anomalous. This may or may not be a concern,
depending on inspection goals and criteria. PipeDiver® results indicated more anomalies in the
second half of the test pipe, whereas See Snake® indicated significantly more, and more severe,
metal loss anomalies in the first half of the pipe (Figure 2-2). The bell and spigot joint made a
clear pattern in the raw data; one method used to identify anomalous pipe was observing
disruptions in this pattern. The inspection tool was able to be successfully deployed under site
conditions, although the initial launching process was modified due to pipeline obstructions (e.g.,
gaps in a downstream joint). Two excavation points (each end) were required with a 12-in. fitting
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installed; greater distances than those demonstrated can be done with one deployment. Complex
equipment was used to launch and receive the sterilized inspection tool. The tool was half the
diameter of the pipe. This was the first use of this technology for wall thickness assessment in a
cast iron main and tool performance could be improved with further calibration to pipe condition
information from field excavations. Additional sensors may enable more detailed resolution of
pipe defects.
• See Snake® RFT provided the axial and circumferential location of individual metal loss
anomalies as well as the dimensions (depth, length and width). While each reported defect does
not map directly to each actual defect, of the 12 pipes that underwent detailed examinations, the
pipe lengths with the largest number of metal loss indications were also reported by See Snake®
to have a large number of pits. Additionally, the pipe lengths that showed minimal degradation in
the detailed examinations were also correctly identified by See Snake® as having few or small
anomalies. As noted above, See Snake® indicated significantly more, and more severe, metal loss
anomalies in the first half of the pipe, whereas PipeDiver® reported more anomalies in the second
half of the pipe (Figure 2-2). The bell and spigot joints could be seen in the raw data, but not
characterized in detail. Eight joints were identified as anomalous. See Snake® was not able to
characterize any of the machined calibration or test defects, and the vendor identified the
potential cause for the problem as magnetic permeability noise. The vendor identified four
potential causes of the interference arising from either the installation process for the artificial
defects or the previous operation of other electromagnetic inspection devices in the vicinity. The
inspection tool was able to be successfully deployed under site conditions. The implementation
was intrusive for the demonstration as the pipe had to be dewatered, cut, and a pull cable had to
be threaded for this inspection. Ultimately, the See Snake® is designed to be launched in a live
pipeline; however this was not possible for the demonstration because it was a prototype system.
Two excavation points (each end) were required with the pipe cut to launch and receive the tool.
The pipe had to be drained and water swabbed out. The tool was somewhat less than the inside
diameter of the pipe. This was the first use of this version of the technology for a 24-in. cast iron
water main.
• Sahara Video® is used to detect corrosion on the inside pipe surface. The camera provided an
image of a portion of the inside of the pipe. Sahara Video® provided results that confirmed that
the pipe lining was in generally good condition and had minimal degradation or delamination.
Air pockets, ranging from small to large in size, were also discovered during the video inspection,
but could not be further verified as the air pockets dissipated with flow. Operations are similar to
the Sahara® WTT tool. The results of the video were not independently verified, although the
inner lining was found to be in good condition based upon visual examination of the excavated
pipe.
Technologies for external inspection at selected excavation points are usually significantly simpler to
implement than in-line inspection devices. The demonstration showed the following differences
among the external inspection technologies in implementation approach and potential results.
• The AESL ECAT device provided axial and circumferential location of individual metal loss
anomalies, as well as the dimensions (depth, length and width) for defects at specific excavation
locations. In addition to the pipe condition data from the ECAT magnetic flux inspection tool,
AESL collected ultrasonic wall thickness measurements, and coating assessments and soil data
(i.e., soil resistivity, redox, pipe-to-soil potential, and pH;) from the three pits. They also
collected the soil data from seven other pits along the test pipe. AESL also used an extensive
analysis procedure to derive the general pipe condition along the entire length of the test pipe.
o The AESL ECAT detection rate for the machined defects in one test pit was 100%,
detecting six of six of the machined defects within their scan range. On average, AESL
located anomalies within a small distance of the recorded defect location. The location
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differences could be attributed to differences in the vendor's and the EPA contractor's
coordinate reference systems. The ECAT device was used to collect pipe wall data on
0.5% of the test pipe, i.e., 1-m circumferential bands at three locations. In addition to the
pipe condition data from the ECAT magnetic flux inspection tool, AESL also collected
ultrasonic wall thickness measurements, and coating assessments and soil data (i.e., soil
resistivity, redox, pipe-to-soil potential, and pH;) from the three pits. They also collected
the soil data from seven other pits along the test pipe. AESL also used an extensive
analysis procedure to derive the general pipe condition along the entire length of the test
pipe.
o With regard to corrosion pits greater than 50% deep, the ECAT MFL method used by
AESL reported for Pit L (Pipe 30), a substantially larger number of corrosion pits greater
than the size measured manually after grit blasting. For Pit F, a similar number (5 vs. 3)
of corrosion pits greater than 50% deep were identified by both methods. For Pit L,
AESL reported that for the 20 deepest pits, 18 of these were greater than 50% deep. The
post assessment by EPA's contractor found one deep pit, at 68%, two pits near 50% (i.e.,
46% and 47%), and many smaller pits. AESL may or may not remove the corrosion
product within natural defects. While done for the first pipe assessed, AESL was asked
not to do it for this pipe because this could possibly influence results for subsequent tests
in the demonstration. Per AESL, removal or non-removal of corrosion does not affect
AESL's calibration or sizing of defects, since the MFL inspection tools are calibrated
prior to arrival on site and sizing models are based on a database of defects at AESL.
The pipes in Pits 2 were not subjected to detailed assessment after the demonstration, so
there is no data for direct comparison with AESL data.
o AESL used models, e.g., stress analysis, fracture analysis, and extreme value statistics, to
extrapolate results from three pits for the entire pipe length. AESL estimated that > 65
potential through-wall defects would be present along the pipeline length. For the 2/3 of
the pipeline representative of Pit 2 and Pit F, AESL estimated there are potentially 15
through-wall defects and for the 1/3 of pipeline representative of Pit L, there are
potentially >50 through-wall defects along the pipeline. The confirmation results are
ambiguous regarding AESL's projected number of through-wall holes in the test pipe.
The available data from the 12 exhumed, characterized pipes found no through-wall
holes, and leak detection studies indicated a maximum of 20 leaks. However, there are
insufficient data to eliminate the possibility that a substantial number of through-wall
holes, or near- through-wall holes, do exist. For example: (a) since only 12 of 171 (7%)
of pipe lengths were measured in detail for wall loss and corrosion pits, the actual number
of through-wall holes in the remaining 93% of the test pipe is not known; (b) AESL
collected metal loss data on only 0.5% of the test pipe, but they augmented their direct
measurements with other relevant data, and then subjected the data to a logical and
systematic analysis in order to generate their predictions of potential through-wall defects
in the remainder of the pipe, and a comparable assessment was not within the EPA
contractors' scope of work; (c) some through-wall holes may be present, but not leak due
to plugging; (d) AESL was given 2500-ft as the length of the test pipe, instead of 2057-ft,
so this elevated their extrapolated number of potential through-wall holes; the EPA
contractor's numbers were extrapolated to 2500-ft for the comparisons above; and (e)
the constraint of a multiple vendor demonstration did not permit AESL to decide the
location of each excavation, which they would normally decide themselves based on soil
tests.
o AESL also conducted a pipeline stress analysis assuming various loading regimes (soil
overburden and traffic), membrane and bending stress, structural significance of the
corrosion, and fracture mechanics models to predict critical defect sizes for the risk of
structural pipeline failure. AESL estimated that > 63 potential critical wall defects
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existed. For the 2/3 of the pipeline representative of Pit 2 and Pit F, there are potentially
13 critical defects ( >0.57-in.) and for the 1/3 of pipeline representative of Pit L, there are
potentially >50 critical defects (>0.67-in.) along the pipeline. Based on the estimated
maximum stresses, defect distribution models, and assumed pipe material properties,
AESL concluded that defects of sufficient depth to cause structural failure of the pipe
may be present. The EPA project scope did not include a critical defect analysis by
EPA's contractor, so no direct comparison was possible.
o A number of factors that can influence AESL's findings were identified. Because
detailed pipeline material property data could not be provided to AESL due to the age of
the pipeline system, there are uncertainties in the stress analysis and critical defect depth
predictions. The identification of a historic American pipe standard for cast iron pipe, as
opposed to the British Standard that was used, would allow AESL to reduce the
uncertainty in their assessment of original dimensions, material properties, and test
pressures. AESL also notes that there may be variations in the soil properties and hence
corrosion drivers along the pipeline length, which may affect the validity of the statistical
predictions. The fracture mechanics modeling conducted by AESL is based on a singular
defect being present at a point of maximum stress to determine critical defects. Defects
found in close proximity to each other are likely to give rise to higher stress concentration
and therefore a further increase in the risk of structural failure. One excavated pipe
location used by AESL was near a large leak, which may have contributed to higher
corrosion rates that may have biased the extrapolations towards larger defects. AESL
would normally select the assessment points, but the selection options were limited by the
test program requirements. Additionally, the sizing software used by AESL is based on
calibration scans of flat-bottomed corrosion defects from different pipes of different wall
thicknesses and potentially different magnetic properties. As such, this demonstration
provides a unique opportunity for AESL to improve their sizing algorithms based on the
more complex geometry of natural defects found in the test pipe.
o The wall thickness data from ultrasonic devices was in good agreement from both AESL
and EPA's contractor.
o The inspection with the ECAT device identified fifteen internal defects. No independent
data were collected to confirm the internal metal loss anomalies identified by AESL.
RSG HSK provided axial and circumferential location of average depth of metal loss anomalies
over the 2x2-in. sensor aperture for defects at specific excavation locations. RSG's CAP
provided axial and circumferential location of average depth of metal loss anomalies over the
Ixl-in. sensor aperture for defects at specific excavation locations. CAP provided local wall
thickness values at nominally 250-ft intervals on the top of the pipe and HSK provided full pipe
circumference measurements in three locations. These readings did not discover significant metal
loss, which therefore indicated a good condition for the pipeline as observed in the 12 exhumed
pipes, representing 7% of the test pipe. The HSK and CAP sensor sizes did not provide sufficient
resolution to accurately measure the machined defects. HSK and CAP did not inspect where
obstacles are encountered, such as valves and joints. However, the HSK can be used to
specifically inspect joints if required. This was not attempted as part of the demonstration. While
a prototype at the demonstration, a more advanced commercial version of the CAP tool is
reported to exist, as is a full circumferential scan capability in a keyhole excavation.
All of the technologies accomplished the first goal of any demonstration, being able to collect data on
site, within the time window provided, and analyzing the data to provide results that are consistent with
their reported methods and procedures. The generally good condition of the 12 exhumed sections of the
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test pipe and small range of sizes of pipeline anomalies did not enable a full evaluation of the sensitivity
of the individual technologies. Each technology targets a specific market niche, resolution, ease of use
and other factors. One conclusion drawn from this study is that the technologies tested would benefit
from further calibration to a wider range of excavated pipe data from the field. Also, although all of the
exhumed pipes had metal loss, their condition with regard to overall metal loss was generally good. The
average wall loss was calculated for each of the 12 exhumed pipes, and highest wall loss observed for a
12-ft length of pipe was 2.6%.
Vendors were provided an opportunity to summarize any advances in tool configuration and performance
since the field demonstration in Appendix H to this report. The technologies have, in some cases, been
substantially modified since the completion of the field demonstration in September 2009. The most
current information about the state of these technologies can be found at:
AESL (http://www.aesengs.co.uk/')
Echologics (http://echologics.com/)
Pressure Pipe Inspection Company (PPIC) (see Pure Technologies)
Pure Technologies
(http://www.puretechltd.com/applications/pipelines/water_wastewater_pipelines.shtml)
Rock Solid Group (http://www.rocksolidgroup.com/Non-Destructive-Testing.aspx)
Russell NDE Systems Inc., (http://www.russelltech.com/; http://www.picacorp.com/).
One key gap is a better understanding of the cost of obtaining data for water main inspections compared
to the benefit in terms of reducing failure risks. As novel technologies develop and competition grows, it
is anticipated that non-destructive inspections will become more cost-effective even for pipes with
moderate consequences of failure. This demonstration involved the collection of cost data in order to
help to address this issue. The cost of inspection is dependent on a number of variables including the
length and diameter of pipe to be inspected, pipe accessibility, and number of services requested (some
vendors offer volume discounts). The cost of an inspection has two main components: (1) the cost of the
service provided by the inspection vendor; and (2) the cost for the water company to prepare the line and
run the inspection tool, which is often more difficult to quantify.
The estimated inspection costs were developed based upon vendor quotes for inspecting, in 2009, a
10,000 ft section of 24-in. cast iron pipe along the same route as the demonstration site in Louisville, KY.
The cost for a wall thickness survey alone ranges from $3 to $7/ft; the cost for both leak detection and a
pipe wall thickness survey ranges from $3 to $9/ft. Cost savings can be achieved when combining the
leak detection with pipe wall thickness survey due to reduced time, labor, and equipment costs. The cost
for internal inspection is estimated to range from $15 to $19/ft and the cost for external inspection is
estimated to range from $3 to $4/ft. Site-specific factors and technology development will change costs.
The site preparation costs for line modification and field support are highly site-specific and for this
reason the estimates provided are order of magnitude estimates based upon typical construction costs. It
is estimated that the site preparation costs to conduct a wall thickness survey of 10,000 ft of 24-in.
diameter cast iron pipe may range in magnitude from $0.48/ft to $0.69/ft (including traffic control,
pit/pothole excavation, tapping, backfill, and restoration). It is estimated that site preparation costs for an
internal inspection of 10,000 ft of 24-in. diameter cast iron pipe are approximately $0.58/ft (including
traffic control, pit excavation, tapping, backfill, and restoration). It is estimated that site preparation costs
for an external inspection of 10,000 ft of 24-in. diameter cast iron pipe may range in magnitude from
$0.94/ft to $1.63/ft (with 9 to 13 excavated locations, respectively).
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CONTENTS
DISCLAIMER ii
ABSTRACT iii
ACKNOWLEDGMENTS iv
EXECUTIVE SUMMARY v
FIGURES xv
TABLES xvii
APPENDICES xviii
ABBREVIATIONS AND ACRONYMS xix
1.0: INTRODUCTION 1
1.1 Background 1
1.2 Organization of Report 3
2.0: SUMMARY AND CONCLUSIONS 4
2.1 Technology Summary 4
2.2. Technology Demonstration 6
2.2.1 Logistical and Operational Requirements 7
2.2.2 Technology Assessment 10
2.2.2.1 Acoustic Pipe Wall Assessment Technologies 10
2.2.2.2 Internal Inspection Technologies 14
2.2.2.3 External Inspection Technologies 17
2.3. Costs 21
2.4 Conclusions and Research Needs 22
3.0: MATERIALS AND METHODS FOR FIELD DEMONSTRATION 27
3.1 Site Description 27
3.1.1 Site Location 27
3.1.2 Test Pipe Condition 27
3.1.3 Leak History 29
3.2 Technology/Vendor Selection 31
3.3 Technology Description 32
3.3.1 Acoustic Pipe Wall Assessment Technology Description 32
3.3.2 Internal Inspection Technology Description 39
3.3.3 External Inspection Technology Description 45
3.4 Site/Test Preparation 49
3.4.1 Access Requirements 49
3.4.2 Safety, Logistics, Excavation, and Tapping 53
3.4.3 Machined Defects 59
3.5 Test Configuration 68
3.5.1 Pipe Wall Assessment 68
3.5.2 Internal Inspection 72
3.5.3 External Inspection 79
4.0: MATERIALS AND METHODS FOR POST-DEMONSTRATION CONFIRMATION
STUDY 85
4.1 Selection of Pipe Segments for Removal 85
4.2 Selection of Pipe Segments for Post-Demonstration Wall Thickness Assessment 86
4.3 Transportation, Storage, and Surface Preparation 88
4.4 General Pipe Parameter Measurements 89
4.5 Assessment of Metal Loss Regions 93
4.6 Summary of the Extent of Corrosion on Pipes Selected for Post-Demonstration
Verification 101
5.0: RESULTS AND DISCUSSION 103
5.1 Acoustic Pipe Wall Thickness Assessment 103
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5.1.1 Sahara® Wall Thickness Testing 103
5.1.2 SmartBall™ Pipe Wall Assessment 106
5.1.3 ThicknessFinder 114
5.2 Internal Inspection 115
5.2.1 Sahara® Video 118
5.2.2 PipeDiver® 118
5.2.3 See Snake® 126
5.3. External Assessment 130
5.3.1 AESLECAT 131
5.3.2 RSGHSKandCAP 144
5.4 Cost of Technologies 154
5.4.1 Acoustic Pipe Wall Survey Costs 154
5.4.2 Internal Inspection Technology Costs 158
5.4.3 External Inspection Technology Costs 159
5.4.4 Site Preparation Costs 160
6.0: REFERENCES 164
FIGURES
Figure 2-1. Defect Histogram 15
Figure 2-2. Defect Scatter Graph for See Snake® vs. Anomalous Pipe Locations for PipeDiver® 16
Figure 3-1. Location Map of Westport Road Transmission Main Replacement Project 28
Figure 3-2. Locations and Details of Pipe and Joint Breaks and Leaks 30
Figure 3-3. Pipe Break along Westport Road Adjacent to Test Area in August 2008 31
Figure 3-4. Sahara Wall Thickness Technology 33
Figure 3 -5. Accelerometer Acoustic Sensor Attached to the Sahara® Insertion Tube 34
Figure 3-6. Aluminum Case and Foam Housing for SmartBall™ Acoustic Acquisition Device, Data
Storage, and Power Supply 36
Figure 3-7. SmartBall™ Insertion and Extraction Tubes 36
Figure 3-8. SmartBall™ PWA Insertion Stack with Pulser 37
Figure 3-9. Sahara® Video System 39
Figure 3-10. PipeDiver® Inspection Vehicle (left) and Insertion Tube (right) 41
Figure 3-11. Schematic of PipeDiver® Inspection Vehicle 41
Figure 3-12. The PipeDiver® Inspection System 42
Figure 3-13. PipeDiver® Extraction Tube and Robotic Claw 42
Figure 3-14. RFEC Signal Paths 43
Figure 3-15. Schematic of Magnetic Interaction between RFTTool and Pipe 43
Figure 3-16. See Snake® (One of three modules) 44
Figure 3-17. Schematic of Magnetic Interaction between RFTTool and Pipe 44
Figure 3-18. Grid Pattern Used for Ultrasonic Wall Thickness Measurements and Coating Assessment 46
Figure 3-19. AESLECAT 47
Figure 3-20. RSG Hand Scanning Kit (HSK) 48
Figure 3-21. RSG Crown Assessment Probe (CAP) 48
Figure 3-22. Construction Trailer for Equipment Storage and Work Space 54
Figure 3-23. Location of Pits for Demonstration 55
Figure 3-24. Location of Pit 1 -Near Chenoweth Lane 57
Figure 3-25. Location of Pit 2 -Near St. Matthews Ave 57
Figure 3-26. Approximate Location of Pit 3 - Near Ridgeway Avenue 58
Figure 3-27. Test Pipe Discharge to Storm Sewer Configuration 58
Figure 3-28. Magnetic Base End Mill Used to Create Machined Defects 59
Figure 3-29. Machined Defect Locations in Pit 2 64
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Figure 3-30. Machined Defect Locations in Pit 4 65
Figure 3-31. Machined Defect Locations in Pit 5 66
Figure 3-32. Machined Defect Locations in Pit F 67
Figure 3-33. PipeDiver® Coil Locations 75
Figure 3-34. Sahara® Video of the Joint Gap 76
Figure 3-35. PipeDiver® Insertion Schematic 76
Figure 3-36. Wireline Truck and Hydrant Set-up 78
Figure 3-37. Pipe Grid Diagram for Visual Coating Assessment 80
Figure 3-38. Typical Survey Grid Along a Pipe Section 81
Figure 3-39. Plan View of Specific Referencing for Pipe Section Survey 82
Figure 3-40. Representation of Sensors Responding to Flaw 83
Figure 3-41. Typical CAP Scan Set-up and Design 84
Figure 4-1. Hardware Cloth on Pipe Sample with Corrosion Used to Establish the !/2-x!/2-in., Grid 95
Figure 4-2. Bridging Bar Used to Establish a Reference for Measurements 96
Figure 4-3. Data Recording System for Making Depth Measurements 96
Figure 4-4. Corrosion Area on Pipe 69: 95-in. from the spigot, 129-degrees from the top of the pipe, 27-
in. in axial extent and 109-degrees in circumferential extent 97
Figure 4-5. Map of Corrosion Area on Pipe 69: 95-in. from the spigot, 129-degrees from the top of the
pipe, 27-in. in axial extent and 109-degrees in circumferential extent 97
Figure 4-6. CMM Laser Scanning of Pipe 63 99
Figure 4-7. CMM Laser Scan Image of Pipe 63 99
Figure 4-8. Photograph of Pipe 63 100
Figure 5-1. Acoustic Profiles from 0 ft to 150 ft 108
Figure 5-2. Acoustic Profiles from 130 ft to 300 ft 108
Figure 5-3. Acoustic Profiles from 300 ft to 465 ft 109
Figure 5-4. Acoustic Profiles from 480 ft to 630 ft 109
Figure 5-5. Acoustic Profiles from 630 ft to 775 ft 110
Figure 5-6. Acoustic Profiles from 780 ft to 900 ft 110
Figure 5-7. Acoustic Profiles from 900 ft to 1,050ft Ill
Figure 5-8. Joint Locations 112
Figure 5-9. Drain Valve Location as Seen by Acoustic Pulses 112
Figure 5-10. PipeDiver RFEC Anomalous Pipes (for Reference Distance in Feet and Pipe Length
Number are Given) 120
Figure 5-11. Calibration Defects in Pit F 121
Figure 5-12. Comparing RFEC Data Before and After Defects 122
Figure 5-13. Defect Histogram 127
Figure 5-14. Defect Scatter Graph 127
Figure 5-15. Visual Coating Failure Distribution - Pit F 133
Figure 5-16. Visual Coating Failure Distribution - Pit 2 134
Figure 5-17. Visual Coating Failure Distribution - Pit L 135
Figure 5-18. Defect Plot for Pit F (20 Largest Defect Depths) 136
Figure 5-19. Defect Plot for Pit 2 (20 Largest Defect Depths) 137
Figure 5-20. Machined Defect Plot for Pit 2 138
Figure 5-21. Defect Plot for Pit L (20 Largest Defect Depths) 139
Figure 5-22. Measured Depth vs. Predicted Depth for the AESL ECAT for Machined Defects in Pit 2 143
Figure 5-23. Measured Length vs. Predicted Length for the AESL ECAT for Machined Defects in Pit 2
143
Figure 5-24. HSK Data Plot - Pit L 146
Figure 5-25. HSK Data Plot - Pit F 147
Figure 5-26. CAP Data Plot - Pit A 148
Figure 5-27. CAP Data Plot - Pit B 149
Figure 5-28. CAP Data Plot - Pit C 150
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Figure 5-29. CAP Data Plot-Pit D and a photograph of the area 151
Figure 5-30. HSK Data Plot - Pit 2 152
Figure 5-31. HSK Data Plot - Pit F 153
Figure 5-32. CAP Data Plot - Pit E 154
TABLES
Table 2-1. Comparison Data for the Logistical and Operational Variables 9
Table 2-2. Summary of Acoustic Pipe Wall Assessments' Average Wall Thickness Results by Sahara®,
SmartBall™ PWA, and ThicknessFinder 11
Table 2-3. Summary of Condition Assessment Results for AESL ECAT 19
Table 2-4. Summary of Condition Assessment Results for RSG 21
Table 2-5. Summary of Implementation Factors, Format of Inspection Results, and Costs 23
Table 3 -1. Summary of Historical, Operational, and Environmental Characteristics of Test Pipe 29
Table 3-2. Summary of Test Pipe Access Requirements for LWC Demonstration for Wall Thickness
Screening Technologies 50
Table 3-3. Summary of Test Pipe Access Requirements for LWC Demonstration for Internal Inspection
Technologies 52
Table 3-4. Summary of Test Pipe Access Requirements for LWC Demonstration for External Inspection
Technologies 53
Table 3-5. Summary of Access Pits - Description and Purpose 56
Table 3-6. Calibration Defects Provided to Technology Vendors 60
Table 3-7. Hidden Defects for Inspection - Pit 2 60
Table 3-8. Hidden Defects for Inspection - Pit 4 62
Table 3-9. Hidden Defects for Inspection - Pit 5 63
Table 3-10. Daily Activities for Each Wall Thickness Assessment Technology Vendor 68
Table 3-11. SmartBall™ Receiver (SBR) Locations 71
Table 3-12. Daily Activities for Each Inline Inspection Technology Vendor 72
Table 3-13. PipeDiver® Insertion Details 74
Table 3-14. Daily Activities for Each External Condition Assessment Technology Vendor 79
Table 3-15. Principal Structural Details for Water Main Based on BS1211-1945 Class D 80
Table 4-1. Consolidated List of Pipe Sections Removed for Post-Demonstration Verification 87
Table 4-2. Pipes Selected for Full Assessment during Post-Demonstration Verification 88
Table 4-3. Blast Finish Considered for Preparation of Pipe for Assessment 89
Table 4-4. Spigot Wall Thickness as Measured by a Caliper at Four Locations 90
Table 4-5. Spatial Averaging Methods Were Used to Estimate Wall Thickness 91
Table 4-6. Wall Thickness Measurements of Cast Iron Using an Ultrasonic Thickness Gauge 91
Table 4-7. Calculation of Thickness of Cement Liner at Spigot with Caliper for Pipe 30 92
Table 4-8. Thickness Measurements of Cement Liner at Spigot for All Pipe Samples 92
Table 4-9. Outer Diameter Measurements Using a Pi Tape 93
Table 4-10. Depth of 20 Pits Measured on Pipe 63 by Laser and Manual Methods 101
Table 4-11. Summary of Metal Loss for Each Destructively Assessed Pipe Sample 102
Table 5-1. Sahara® Wall Thickness Results 104
Table 5-2. Sahara® Wall Thickness Results for Seven Included, Destructively Assessed Pipes 105
Table 5-3. PWA Wall Thickness Results - Summary of Acoustic Anomalies Ill
Table 5-4. Results for Pure SmartBall™ Pipe Wall Assessment (PWA) and Seven Included,
Destructively Assessed Pipes 113
Table 5 -5. Guidelines for Interpreting ThicknessFinder Wall Thickness Data 114
Table 5-6. Echologics ThicknessFinder Condition Assessment Results 115
Table 5-7. Echologics ThicknessFinder Condition Assessment Results for Eleven Destructively Assessed
Pipes 116
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Table 5-8. Sahara Video Observation Details 118
Table 5-9. PipeDiver® Anomalous Pipes 119
Table 5-10. PPIC PipeDiver® Results for Eleven Destructively Assessed Pipes 124
Table 5-11. See Snake® Results for Eleven Destructively Assessed Pipes 128
Table 5-12. Soil Corrosivity Results 131
Table 5-13. Summarized Condition Assessment Results for Pit F, Pit 2, and Pit L 132
Table 5-14. Defect Depth to Cause Fracture 140
Table 5-15. Summarized RSG Condition Assessment Results for Pit A to F, Pit 2, and Pit L 144
Table 5-16. PPIC Sahara® Cost Estimates for Inspection of a 24-in. Diameter, 10,000 ft Long Cast Iron
Pipeline 155
Table 5-17. Pure SmartBall™ Cost Estimates for Inspection of a 24-in. Diameter, 10,000 ft Long Cast
Iron Pipeline 156
Table 5-18. Echologics LeakfmderRT Cost Estimates for Inspection of a 24-in. Diameter, 10,000 ft Long
Cast Iron Pipeline 158
Table 5-19. Russell NDE Systems Inc. See Snake Cost Estimates for Inspection of a 24-in. Diameter,
10,000 ft Long Cast Iron Pipeline 159
Table 5-20. AESL ECAT Cost Estimates for Inspection of a 24-in. Diameter, 10,000 ft Long Cast Iron
Pipeline 159
Table 5-21. Rock Solid HSK Cost Estimates for Inspection of a 24-in Diameter, 10,000 ft Long Cast Iron
Pipeline 160
Table 5-22. Estimated Site Preparation Costs for Sahara® WTT Pipe Wall Survey of 10,000 ft pipe.... 161
Table 5-23. Estimated Site Preparation Costs for SmartBall™ Pipe Wall Survey of 10,000 ft pipe 161
Table 5-24. Estimated Site Preparation Costs for ThicknessFinder Pipe Wall Survey of 10,000 ft pipe 162
Table 5-25. Estimated Site Preparation Costs for See Snake® Pipe Wall Survey of 10,000 ft pipe 162
Table 5-26. Estimated Site Preparation Costs for ECAT Pipe Wall Survey of 10,000 ft pipe 163
Table 5-27. Estimated Site Preparation Costs for HSK Pipe Wall Survey of 10,000 ft pipe 163
APPENDICES
APPENDIX A: Assessment Data for Excavated Pipe Volume 2
APPENDIX B: Sahara® Report Volume 2
APPENDIX C: Pure SmartBall™ Report Volume 2
APPENDIX D: Echologics ThicknessFinder Report Volume 2
APPENDIX E: Russell NDE Systems Inc. Report Volume 2
APPENDIX F: AESL Report Volume 2
APPENDIX G: RSG Report Volume 2
APPENDIX H: Technology Vendor Letters Volume 2
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ABBREVIATIONS AND ACRONYMS
3D three-dimensional
AC alternating current
A/D analog-to-digital
AESL Advanced Engineering Solutions, Ltd
ANSI American National Standards Institute
BEM Broadband Electro-Magnetic
CAP Crown Assessment Probe
CCTV closed-circuit television
CMM coordinate-measuring machine
DSP digital signal processor
EC AT External Condition Assessment Tool
EPA U.S. Environmental Protection Agency
FAD failure assessment diagram
gpm gallons per minute
GPS global positioning system
HOPE high density polyethylene
HF high flux
HSK Hand Scanning Kit
ksi kilopounds per square inch
ID inner diameter
LWC Louisville Water Company
MGD million gallons per day
MJ mechanical joint
MRRP Main Replacement and Rehabilitation Program
MSD Municipal Sewer Department
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NDE non-destructive evaluation
NDT non-destructive testing
NPT National Pipe Thread
NRC National Research Council
NRMRL National Risk Management Research Laboratory
OD
outer diameter
PICA
PPIC
psi
PVC
PWA
Pipeline Inspection and Condition Analysis Corporation
Pressure Pipe Inspection Company
pounds per square inch
polyvinyl chloride
Pipe Wall Assessment
QA/QC quality assurance/quality control
QAPP Quality Assurance Project Plan
RFEC
RF
RFT
RSG
remote field eddy current
radio frequency
remote field technology
Rock Solid Group
SBR
SOTR
SmartBall™ receiver
State of the Technology Review
TO
Task Order
WERF Water Environment Research Foundation
WTT Wall Thickness Testing (Sahara®)
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1.0: INTRODUCTION
Nine pipe wall integrity assessment technologies were demonstrated on a 76-year-old, 2,057-ft-long
portion of a cement-lined, 24-in. cast iron water main in Louisville, KY. This activity was part of a series
of field demonstrations of innovative leak detection/location and condition assessment technologies
sponsored by the U.S. Environmental Protection Agency (EPA) from July through September 2009. The
main goal of the demonstrations was to acquire a snapshot of the current performance capability and cost
of these innovative technologies under real-world pipeline conditions so that technology developers,
technology vendors, research-support organizations, and the user community can make more informed
decisions about the strengths, weaknesses, and need for further advancement of these technologies.
Pipe wall integrity assessment was one part of a comprehensive water pipeline condition assessment
demonstration where six inspection companies operated 12 technologies that were at various stages of
development and provided different types and levels of leak and/or structural condition data.
Technologies were included for wall-thickness screening (i.e., average wall loss over many tens of feet),
for detailed mapping of wall thickness, and for leak detection. Both in-line and external inspection
technologies were demonstrated. The inspection technologies used visual, mechanical, acoustic,
ultrasonic, and electromagnetic methods for acquiring leak and pipe condition data. The inspection
results for each technology were compared to the leak rates or dimensions of introduced and/or naturally
occurring anomalies, as well as their location along the pipeline.
This report presents the results of a total of nine pipe wall integrity assessment technologies including:
Average wall thickness screening with PPIC1 Sahara® Wall Thickness Testing (WTT), Pure's
SmartBall™, and Echologics'2 ThicknessFinder;
Inline inspection of the entire pipeline length with PPIC1 Sahara Video® , which inspected only the inner
wall, and two remote field eddy current (RFEC) methods called PPIC1 PipeDiver® RFEC and Russell3
NDE Systems Inc. See Snake® Remote Field Technology (RFT), which detect both internal and external
metal loss; and
External inspection at selected excavation points using Advanced Engineering Solutions, Ltd. (AESL)
External Condition Assessment Tool (ECAT), Rock Solid Group's (RSG) Hand Scanning Kit (HSK), and
RSG's Crown Assessment Probe (CAP). Different approaches are used to estimate the condition of the
pipe in sections that are not inspected.
Each of the three innovative average wall thickness screening tools demonstrated (and listed in the first
bullet above) uses a platform that is also used for an established leak detection technology. The
demonstration of the leak detection technologies is described in a companion report (Nestleroth, B. et al.,
2012).
1.1 Background
To gain a better understanding of the available technologies for condition assessment of water mains, a
Technology Forum was held on September 9 and 10, 2008, in Edison, NJ under Task Order (TO) 62. The
1 The Pressure Pipe Inspection Company's (PPIC) is now part of Pure Technologies, Inc.
2 Echologics is now a subsidiary of Mueller Water Products.
3 Russell NDE Systems, Inc. has transferred its water and waste water inspection business to its subsidiary: Pipeline
Inspection and Condition Analysis Corporation (PICA)
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Forum indicated that the state of the art in condition assessment technologies is still developing and that
water utilities could benefit from third-party, independent sources of information on the capabilities of
innovative inspection technologies. Technology demonstrations on real systems are particularly valued
by water utilities and can play a vital role in accelerating the adoption of appropriate, innovative condition
assessment technologies. A range of real-life defects and conditions should be present when undertaking
these types of demonstrations to maximize the benefit to utilities.
After participating in the Forum, the Louisville Water Company (LWC) offered a section of 24-in.
diameter, cement-lined, cast iron pipe for field demonstrations of water main inspection technologies.
LWC treats 135 million gallons per day (MOD) of water and transmits water to 270,000 service taps
through 3,500 miles of water main ranging in diameter from 1 to 60-in. Under its Main Replacement and
Rehabilitation Program (MRRP), the company annually replaces over 35 miles of water mains to
maintain the water transmission system. A 2,500-ft portion of 24-in. diameter cast iron transmission
water main along Westport Road was scheduled for replacement in September 2009. LWC agreed to
make all or part of this pipe available for field demonstrations and provide necessary on-site assistance.
A continuous 2057-ft section of the pipe was used for the demonstrations.
The field demonstration occurred between July 6 and September 4, 2009. This program presented an
opportunity to (1) apply inspection technologies under nearly normal operating conditions, (2) compare
parameter measurements from non-destructive testing (NDT) with direct measurements, and (3) remove
sections of the pipe for comparative testing with other technologies at a later date.
Cast iron pipe is the oldest and largest part of the water network (Thomson and Wang, 2009). It is critical
that utilities have the capability to undertake reliable condition assessment of cast iron pipes to prevent
failures and premature rehabilitation or replacement. Innovative technologies are available for condition
assessment of cast iron mains, but limited third-party performance and cost data inhibit their effective
consideration by the user community.
The suite of technologies considered for demonstration was based on a state of the technology review
report prepared under TO 62 on inspection technologies of water mains for ferrous pipes (Thomson and
Wang, 2009) and Forum input. Consistent with the focus of the state of the technology review and the
Forum, only leak detection/location and structural condition assessment technologies for ferrous pipes
were considered for the field demonstrations. Six vendors providing 12 different technologies including
leak detection/location and condition assessment technologies (both internal and external) agreed to
participate in the field demonstration program with substantial in-kind support.
The EPA contractor, in coordination with the participating vendors and the LWC, was responsible for the
planning, coordination, oversight, and execution of this field demonstration project. The major tasks
associated with the field demonstration project are described below:
• Task 6.1: Pre-Demonstration Activities. Pre-demonstration activities included planning and
coordination of project activities among EPA, LWC, and participating technology vendors;
preparation of a Quality Assurance Project Plan (QAPP); development of test protocols (with
vendor input); and communication of project schedules and testing requirements to all project
participants.
• Task 6.2: Field Demonstration. EPA's contractor coordinated with the participating vendors and
LWC for all on-site demonstration activities, communicated safety requirements, planned/
adjusted test schedules, monitored test progress, and documented field observations. In
performing the field demonstration, the technical and quality assurance/quality control (QA/QC)
procedures were followed as specified in the EPA-endorsed QAPP.
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• Task 6.3: Post-Demonstration Evaluation and Reporting. Post-demonstration activities
included exhuming 200+ ft of pipe, shipping the pipe to EPA contractor's lab, preparing pipe
segments for wall thickness assessment, and assessing pipe wall thickness both manually and
with a laser scanner. In performing the post-demonstration pipe verification, the QA/QC
procedures were followed as specified in the addendum to the EPA-endorsed QAPP. This task
also included the preparation of technical reports and photo documentation to summarize the
results of the field demonstration.
The main goal of the demonstrations was to acquire a snapshot of the current performance capability and
cost of these innovative technologies under real-world pipeline conditions so that technology developers,
technology vendors, research support organizations, and the user community can make more informed
decisions about the strengths, weaknesses, and need for further advancement of these technologies.
The ultimate desired outcome from these demonstrations is to detect problems in large diameter, cast iron
water mains prior to their failure, as well as to reduce premature replacement of sound buried water
infrastructure. These outcomes are expected to arise, in part, due to expanded and accelerated acceptance
and use of effective condition assessment devices, systems, and procedures, and better decisions
regarding development and use of innovative condition assessment devices, systems, and procedures.
1.2 Organization of Report
This report is divided into five main sections that include introductory material (Section 1.0), summary
and conclusions from the results of the field demonstration (Section 2.0), description of the materials and
methods used to manage the field demonstration (Section 3.0), description of the materials and methods
used to conduct the post-demonstration confirmation study (Section 4.0), and discussion of results
provided by each technology vendor (Section 5.0). This report covers acoustic pipe wall assessment,
internal inspection, and external inspection. Volume 2 of this report contains appendices with EPA
contractor assessment data for excavated pipe plus the vendor inspection reports and vendor letters
identifying post-demonstration technology status or changes. A companion report (Nestleroth, B. et al.,
2012) covers the demonstration results for the leak detection and location technologies.
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2.0: SUMMARY AND CONCLUSIONS
The state of the art in condition assessment technologies for water mains is still developing and water
utilities are interested in third-party, independent sources of information on the capabilities of innovative
inspection technologies. Technology demonstrations with a range of real-life defects and conditions are
particularly valuable to water utilities and can play a vital role in accelerating the adoption of appropriate,
innovative condition assessment technologies. A field demonstration program was conducted in 2009 to
evaluate condition assessment technologies applicable to the inspection of cast iron water mains. All nine
condition assessment technologies were demonstrated on a 76-year-old, 2,057-ft-long portion of a
straight, cement-lined, 24-in. diameter cast iron water main in Louisville, KY. These technologies
included acoustic pipe wall assessment, internal inspection, and external inspection tools. This section
provides an overview of the technologies, reviews the complexity of site logistical and operational
requirements, summarizes the condition assessment results from each inspection tool, and presents
available cost information for inspection and site preparation.
2.1 Technology Summary
Acoustic Pipe Wall Assessment. The acoustic pipe wall thickness assessment technologies that were
demonstrated included the PPIC Sahara® (now part of Pure) Wall Thickness Testing (WTT), Pure
SmartBall™ Pipe Wall Assessment (PWA), and Echologics ThicknessFinder. Each of these technologies
measures the speed of sound through consecutive sections of the pipeline, and then uses a formula to
relate acoustic velocity changes to the wall thickness for the associated length of pipe. While each
technology used some form of acoustic device, the implementations were quite different as follows:
• Sahara® WTT has a truck-mounted reel of neutrally buoyant cable, and attached near the end of
the cable is a small parachute with a hydrophone. The cable is fed into the water main, which is
typically under pressure. The parachute-hydrophone-cable assembly is pulled in the direction of
flow, and the hydrophone is stopped at intervals (e.g., 33-ft). For each interval a sound pulse is
introduced into the pipe, and the pulse arrival time at the hydrophone is determined. The
differences in travel times of the acoustic pulses over the consecutive pipe intervals enables
acoustic velocity and average pipe wall thickness to be calculated for the associated interval.
• SmartBall™ PWA utilizes a non-tethered, in-line sensor to measure the acoustic velocity of
sound pulses injected into the pipe. SmartBall™ is comprised of a spherical, sealed package of
electronics for detecting and recording acoustic emissions, position (e.g., rotation, acceleration),
and time data. The spherical package is placed inside a foam ball to reduce noise as it moves
through the pipeline. The SmartBall ™ is inserted into the pipeline through a special tube while
the pipeline is under pressure, then it rolls along the bottom of the pipe until it is captured
downstream by a special extraction net that is deployed through another tube. Timed sound pulses
from known locations along the pipeline are also used to help determine the location of the
SmartBall™ vs. time. Other timed sound pulses are put into the pipe to enable acoustic velocity
determinations every 1 to 2 ft. as the SmartBall™ travels the pipe. After the SmartBall™ is
retrieved, the time, location, and acoustic emission data are correlated to determine acoustic
velocity, to estimate the average effective wall thickness along the pipeline, and to identify
anomalous sections.
• Echologics' ThicknessFinder Technology uses paired accelerometers mounted on the outside of
the pipe at discrete locations to determine travel time of an out-of-bracket sound from one
transducer to the other. This enables the acoustic velocity to be determined and the effective
average wall thickness to be calculated for the associated pipe interval. In the demonstrations the
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distance between sensors ranged from 250 to 360 feet per determination of effective wall
thickness.
Knowledge of average wall thickness in a pipe section does not identify specific defects, but can be
valuable for focusing subsequent, more detailed and expensive structural inspections on the most
problematic areas.
Internal Inspection. The internal inspection technologies that were demonstrated included the Sahara
Video®, PipeDiver® RFEC, and See Snake® RFT. Sahara Video® used closed circuit television (CCTV)
to conduct an internal inspection of the pipeline, while PipeDiver® and See Snake® used a form of RFEC
technology to conduct the inspection:
• Sahara Video® uses a video camera at the end of a cable tether. The camera, which was inserted
and pulled through the pipeline using the water flow, provided real-time, in-service, CCTV
inspection of the test pipe. The camera was also tracked by an operator from ground level to
mark items of interest on the pavement.
• PipeDiver® RFEC is a non-tethered, free swimming platform for inspection of in-service water
mains and includes an electronics module, battery module, and transmitter module for above
ground tracking. PipeDiver® is inserted and extracted from the water pipe via large, vertical
tubes designed to launch or receive the tool at pipeline pressures.
• See Snake® RFT is designed to be launched in a live pipeline. However, the demonstrated tool
was a tethered prototype unit designed to be pulled through a dry line. This prototype was
customized for the demonstration in order to adapt the technology to a 24-in. diameter line. The
hard diameter of the tool is smaller than the inner diameter (ID) of the pipe to allow for passage
around protrusions, lining, and scale within the pipe.
External Inspection. The AESL ECAT, RSG HSK and RSG CAP external inspection technologies were
demonstrated on the same cast iron water main in Louisville, KY as described above.
• AESL attaches the ECAT system to the exterior of the pipe using high strength magnets. The
ECAT is manually operated and uses magnetic flux leakage (MFL) technology to locate and size
defects. ECAT only scans a portion of the exposed pipe at one time and then must be
repositioned. This process continues until the entire circumference and length of the exposed
pipe has been scanned. The ECAT system is used in combination with commercial ultrasonic
instruments, visual inspection of coating condition, and soil properties to statistically predict the
condition of long lengths of un-inspected pipe from the results of the few local inspections.
• RSG HSK is a handheld device that uses a patented Broadband Electro-Magnetic (BEM)
technology to assess the localized pipeline condition in select excavations. The HSK is manually
moved around the exposed pipe in a grid pattern to collect pipe defect data (e.g., remaining wall
thickness, areas of metal loss, and fractures). The HSK system is designed to inspect the full pipe
circumference, or any part of it, along the entire excavated length, dependent on accessibility.
The condition of the entire water main segment is inferred from these local measurements.
• RSG CAP also uses the BEM technology, but it is used for keyhole inspections. The device
operates with a down-hole, clamp-on device to affix the sensors to the pipe. The CAP system is
only designed to scan the top portion of the pipe exposed via the keyhole excavation, and is most
suitable for pipes where crown corrosion is a common problem, such as pressure sewer mains.
Further developments after the demonstration provide the capability for full-circumference scans,
which are more applicable to water mains. The condition of the entire water main segment is
then inferred from these local measurements.
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2.2. Technology Demonstration
Many aspects of these technologies were observed over the course of the demonstration. This included an
assessment of logistical and operational requirements in order to assess the feasibility and complexity of
use for the various inspection tools. The vendors provided their assessment of the test pipe condition,
with some reporting average or effective wall thickness for various spans of pipe; others reporting
anomalous pipe segments; and still others reporting the size, depth, and location of specific defects along
the test pipe. Pipe segments were then selected for excavation based upon these inspection results and
visual assessment of the pipe condition as it was removed. For each technology, inspection results were
compared to the dimensions and locations of machined defects and/or naturally-occurring defects to
evaluate the performance of the pipe wall integrity assessment technologies. The amount of metal loss
was quantified manually or with a laser scanner and compared to the vendor inspection results for these
exhumed pipes. Cost estimates to implement the various technologies for the inspection of a 24-in. cast
iron pipe were also requested and are documented in this report, along with estimated site preparation
costs for those activities typically conducted by the utility.
Based on data collected by EPA's contractor independently of the vendors, a semi-quantitative
assessment was made that the pipe was in overall good condition. Twelve lengths of pipe, out of 171
(i.e., 7%) in the full test pipe, were excavated and evaluated off-site by methods described elsewhere in
the report. In those twelve pipes, no through-wall pits were found. The cement mortar liner was in good
condition, which was considered an indication of minimal inner wall corrosion. The maximum external
wall volume loss was 2.6%, with seven pipe lengths at < 1% volume wall loss. The deepest pit was 85%
of wall thickness. One pipe had 13 pits deeper than 50%; four pipes had between four and six pits >50%;
and the other seven had between zero and two pits >50%. The largest pitted area was 25-in. long and
48% deep. A detailed statistical and structural condition assessment of the pipe was not done to, for
example, estimate the size and number of critical defects subject to fracture. A conclusive comparison
between this semi-quantitative assessment, and direct or extrapolated condition assessments by the
vendors was not always possible.
The pipe wall integrity inspection demonstrations did not evaluate technology capability for all types of
failure modes. Interior metal loss was not evaluated. The pipe had a cement mortar liner, which appeared
to be in good condition based on CCTV and visual observation of excavated pipes. It was assumed that a
sound cement liner indicated little or no corrosion in the adjacent pipe wall. Removing the cement mortar
liner to assess the inner pipe wall was not within the project scope. Cracks were not a priority, and were
not generally present. Significant cracking was not observed in the 12 excavated pipes that were
characterized in detail, nor were cracks included in the set of machined defects, nor did the technologies
with crack-detection capability report cracks. The leak detection demonstration previously conducted
indicated few through-wall cracks. Detection of mis-aligned joints was not a capability of the
demonstrated technologies, nor was mis-alignment found during documentation of the pipe
characteristics.
Preliminary reports were requested within one week and final reports within five weeks of the
demonstration. These vendor reports are an important source of data presented in this summary report.
Users of this report can refer to these appendices to review the original format and organization of the
inspection data as issued by the individual vendors. The vendor reports are presented in Volume 2 of this
report including Appendix B (Sahara® Video, Sahara®WTT, and PipeDiver®), Appendix C (SmartBall™
PWA), Appendix D (ThicknessFinder), Appendix E (See Snake®), Appendix F (ECAT), and Appendix G
(HSK and CAP).
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Because this demonstration was a snapshot in time, new developments may have taken place since
completion of the demonstration. For this reason, the vendors were asked to provide formal comments on
this report to highlight advancements since completion of the demonstration and/or clarification on what
was reported. These comment letters are contained in Appendix H. Additional technology modifications
have occurred since the field demonstration was completed in September 2009. Information about the
current state of these technologies can be found at:
AESL (http://www.aesengs.co.uk/)
Echologics (http://echologics .com/)
Pressure Pipe Inspection Company (PPIC) (see Pure Technologies)
Pure Technologies
(http://www.puretechltd.com/applications/pipelines/water wastewater_pipelines.shtml)
Rock Solid Group (http://www.rocksolidgroup.com/Non-Destructive-Testing.aspx)
Russell NDE Systems Inc. (http://www.russelltech.com/ ; http://www.picacorp.com/).
2.2.1 Logistical and Operational Requirements. The logistical and operational requirements
encountered during the demonstration were documented and are summarized in the report including the
number of technicians needed, any need for operator intervention, the number and spacing of pipe contact
points, access requirements, and more. Tracking this information provides insight into the ability of the
tools to mobilize, access the pipe, and operate under various field conditions for a 24-in. cast iron pipe.
This information will help utilities to gauge the feasibility of using these technologies at their site.
Comparison data for the logistical and operational variables encountered during the demonstration are
provided in Table 2-1 for the acoustic pipe wall assessment, internal assessment technologies, and
external assessment technologies. In addition, further discussion is provided below of the transportation
and installation requirements and implementation of the technologies.
Acoustic Pipe Wall Assessment. Sahara® WTT and SmartBall™ PWA require internal pipe access, but
are minimally-disruptive in nature and can be performed while the pipeline is in service. ThicknessFinder
does not require internal pipe access, is non-disruptive, and can be performed on a live main with or
without flow. Sahara® WTT required a dedicated truck to handle the cable tether and data-processing
equipment; SmartBall™ equipment arrived in seven cases via overnight shipment; and ThicknessFinder
equipment arrived at the site in a passenger vehicle with the equipment operator. Installing the Sahara®
WTT tethered system was the most complicated operation, requiring a minimum of two technicians, but a
third made operations run more smoothly. Deploying and retrieving the SmartBall™ was accomplished
with two technicians, while ThicknessFinder could conduct its assessment with one technician. Each
vendor was capable of configuring their equipment to inspect the full 2,057 ft of pipe.
Internal Inspection. Installing the Sahara Video® tethered system required a minimum of two
technicians, but a third made operations run more smoothly. The initial PipeDiver® deployment was
slow; however as the demonstration continued and the technicians gained familiarity in the operation, tool
deployment and retrieval became more efficient. Three operators were needed to set-up the pipeline for
PipeDiver® and another three operators were needed during the actual PipeDiver® inspection. At the time
of the demonstration, See Snake® was not yet designed to be launched in a live pipeline. As such a wire
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line was needed to pull the tool through the dewatered pipeline. See Snake® required 3 operators. Each
vendor was capable of configuring their equipment to inspect the full 2,057 ft of pipe.
External Inspection. Installing the AESL ECAT system required two technicians, while both the RSG
HSK and CAP systems required only one technician. Both AESL and RSG were capable of configuring
their equipment to inspect the entire circumference of the exposed pipe as long as there was sufficient
clearance for access; however they were not able to take data over the bell-and-spigot joints as part of the
pipe segment scan. The capacity to inspect the joints is now reported to exist. The RSG CAP is only
designed to scan the top portion of pipe exposed via a keyhole excavation.
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Table 2-1. Comparison Data for the Logistical and Operational Variables
Logistical and
Operational
Variables
Equipment logistics
Internal access?
Utility preparation
Number of
technicians needed
for operation
Pipe access or contact
points
Sterilization of
components that
contact water
Real-time data
Condition assessment
On- site report
Operator intervention
Acoustic Pipe Wall Assessment Tools
Sahara* WTT
Dedicated
truck
Yes
Requires one
access point
and a
controlled flow
rate.
2
One; 6,000 ft
max. cable
length (2,500
as supplied for
LWC); Contact
every 250 to
400 ft for
sound
generation.
Yes. All
components
tether cable.
Yes
Post-analysis
used to assess
average wall
thickness
No
Operator
impacts pipe to
create noise,
sensor indexed
at specific
intervals
SmartBall™
PWA
Overnight
shipping
Yes
Requires two
access points and
a controlled flow
rate. Large off
takes on the pipe
must be closed.
2
Two; Insertion
and extraction;
Distance depends
on flow rate;
Pulsers installed
approximately
every 1,000ft.
Yes. Ball,
launching and
catching
equipment.
No
Post-analysis
used to assess
average wall
thickness
No
No operator tasks
after ball is
launched until it
is received
ThicknessFinder
Operator transported
two cases
No
Requires two access
points but can be
accomplished with
hydrants or common
pipeline
appurtenances.
1
Two per test; Every
300 to 400 ft for
condition assessment
No water contact.
Accelerometers
mounted on pipe
surface.
Yes
Post-analysis used to
assess average wall
thickness
No
Trained technician
manually set filters to
eliminate site- specific
noise
Internal Inspection Tools
Sahara
Video®
Dedicated
truck
Yes
Requires one
access point
and a
controlled
flow rate.
2
One; 6,000 ft
max. cable
length (2,500
as supplied
for LWC);
Yes
Yes
On- site
analysis to
assess areas
with potential
defects
Yes
Operator had
to walk the
line to track
tool location
PipeDiver*
Overnight
shipping
Yes
Two access
points and a
controlled
flow rate.
Vertical
clearance of
40 ft needed
for launch
tube.
5-6
Two;
Distance
depends on
flow rate
Yes
No
Post-analysis
off-site used
to assess
general pipe
condition
No
Operator had
to walk the
line to track
tool location
See Snake®
Overnight
shipping
Yes
Demonstrated
system required
the pipeline to
be dewatered
and installation
of a cable with a
winch to pull the
tool through the
pipeline.
2-3
Two; pull
distance depends
on number of
bends. The
demonstration
was 2,000 ft.
Yes
No
Post-analysis
off-site used to
assess metal loss
defect sizes and
locations
No
Winch control
for speed and
distance
External Inspection Tools
ECAT
Overnight
shipping
No
Requires
full pipe
circum-
ference
excavation
for full
circumfer-
ence scan
2
External;
equipment
moved
manually to
inspect
entire
circum-
ference
No
Yes
Post-
analysis of
general
pipe
condition
On-site data
display
Manual
process
HSK
Overnight
shipping
No
Requires
full pipe
circum-
ference
excavation
for full
circumfer-
ence scan
1
External;
equipment
moved
manually to
inspect
entire
circum-
ference
No
Yes
Post-
analysis of
general pipe
condition
On-site data
display
Manual
process
CAP
Overnight
shipping
No
Requires
keyhole
excavation
1
External;
equipment
only scans
top of pipe
No
Yes
Post-analysis
of general
pipe
condition
On-site data
display
Manual
process
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2.2.2 Technology Assessment. The key to a demonstration of inspection technologies is the
presence of anomalies (e.g. a detectable deviation in the pipe material that may or may not be a defect
depending on size). Since the presence of corrosion anomalies in the pipe was unknown prior to the
demonstration, several local machined metal loss defects were installed at four locations with the intent of
ranging in size from simple to difficult to detect and quantify for each inspection vendor, except the
average wall thickness screening technologies, which are not intended for this purpose. In this way, the
demonstration results could be used to define both the current capability and future challenges for each of
the inspection technologies. Calibration defects were provided to the inspection vendors for system
verification and calibration to facilitate subsequent analysis and post-processing. The manufactured
defect sizes ranged from approximately 1- to 6-in. in length with depths varying between 20% up to 70%
wall loss. During installation of these defects several areas of natural corrosion were found in the line.
As such, the machined defects were placed so as to not disturb the natural corrosion.
2.2.2.1 Acoustic Pipe Wall Assessment Technologies. Sahara® WTT, SmartBall™ PWA, and
ThicknessFinder are emerging NOT methods that offer non- or minimally- intrusive options to screen
water mains for significant average wall loss. This screening information can help to reduce costs by
focusing subsequent, detailed inspection on pipe sections where accelerated deterioration is likely to be
occurring. The acoustic pipe wall assessment technologies only identify average changes in wall
thickness over a specified pipe length, and therefore are not intended to find individual defects, unless the
defect is large enough to cause a significant change in the pipe stress carrying capability. Therefore, the
machined anomalies described above were not used for calibrating the acoustic pipe wall assessment
technologies. For these technologies, the inspection results were compared with the calculated average
wall thickness derived from measurements of exhumed pipe samples by laser technology and manual
methods as described in Section 4.0. A summary of the average wall thickness inspection results is
provided in Table 2-2.
Sahara® WTT. Sahara® WTT presented the wall thickness measurement as an average wall thickness
loss ratio (%) in 33 ft intervals (see Table 2-2). It was noted that by utilizing the tethered Sahara system
and being able to stop the hydrophone at precise locations, the Sahara WTT technique could allow
flexible distance and selectable intervals for calculating average wall thickness loss. However, if finer
intervals (belter resolution) are selected, then longer inspection times will occur.
A pipe wall thickness loss of less than 2% is considered nominal. Three pipe sections, 295 to 328 ft, 328
to 361 ft, and 361 to 394 ft, showed the highest wall thickness loss (i.e., >30%). Five sections showed
15% to 30% of wall thickness loss. Eleven pipe sections showed <15% of wall thickness loss. The
remaining sections showed nominal loss. However, a wall thickness ratio could not be calculated for
several pipe sections (i.e., [230 to 295 ft], [787 to 1,640 ft], and [1,935 to 2,057 ft]) due to reasons such as
the close proximity of the internal and external sensors, presence of large air pockets, or the pipeline
discharge which masked acoustic activity after 1,935 ft.
Sahara® WTT provided average wall thickness results for pipe sections that included seven of the 12
pipes that were fully assessed by EPA's contractor. For the other 5 pipes, pipeline and inspection
variables (e.g., flow noise at discharge) adversely affected data collection and therefore Sahara® WTT
was unable to provide results. Of these seven pipes, Sahara® WTT predicted two pipes were in sections
with wall loss >30%, three pipes were in sections with wall loss between 15%-30%, and two pipes were
in sections with <15% wall loss. In comparison, these same pipes that were fully assessed by EPA's
contractor were noted to have limited variation with average wall loss of no more than 2.6% (considered
to be nominal wall loss). Therefore, Sahara® WTT conservatively estimated the remaining wall thickness
for six of the seven pipe sections (e.g., reported the pipe to have significant wall loss when only minimal
10
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wall loss was noted in exhumed pipe). This technology is emerging in status and would benefit from
additional vendor experience in correlating results with pipelines of varying degrees of wall loss. Further
technology development is needed to improve the accuracy and potentially reduce the amount of over
calls.
Table 2-2. Summary of Acoustic Pipe Wall Assessments' Average Wall Thickness Results by
Sahara®WTT, SmartBall™ PWA, and ThicknessFinder
Distance
from Start
(ft)
0-17
17-33
33-66
66-98
98-131
131-164
164-197
197-230
230-295
295-328
328-361
361-394
394-426
426-459
459-492
492-525
525-558
558-590
590-623
623-656
656-689
Exhumed Pipe Condition
as Assessed by EPA
Contractor4
Pipe visually assessed as it
came out of the ditch. No
corrosion or cracking was
observed.
Pipe 30 (339-35 1ft)
Minimal average wall loss;
minimal pitting
Pipe 32 (363-375 ft)
Minimal average wall loss;
locally moderate pitting
Pipe visually assessed as it
came out of the ditch. No
corrosion or cracking was
observed.
Pipe 49 (567-579 ft)
Minimal average wall loss;
locally heavy pitting
Pipe visually assessed as it
came out of the ditch. No
corrosion or cracking was
observed.
Pipe 56 (65 1-663 ft)
Minimal average wall loss;
locally light pitting
Pipe 56 (65 1-663 ft)
Minimal average wall loss;
locally light pitting
Sahara®
Average Wall
Thickness Loss
Ratio (%)
N/A
< 15%
Nominal
< 15%
Nominal
Nominal
Nominal
15-30%
N/A
> 30%
> 30%
> 30%
Nominal
< 15%
15-30%
< 15%
< 15%
< 15%
Nominal
< 15%
Nominal
SmartBall™ Pipe Wall
Thickness Assessment
Reduced pipe wall
stiffness (14 ft to 63 ft)
Nominal stiffness loss
(63 ft to 100ft)
Reduced pipe wall
stiffness (100 ft to 165 ft)
Reduced pipe wall
stiffness (100 ft to 165ft)
Nominal stiffness loss
(165 ft to 237 ft)
Reduced pipe wall
stiffness (237 ft to 292 ft)
Nominal stiffness loss
(292 ft to 3 94 ft)
Reduced pipe wall
stiffness (3 94 ft to 465 ft)
Nominal stiffness loss
(465 ft to 488 ft)
Reduced pipe wall
stiffness (488 ft to 535 ft)
Reduced pipe wall
stiffness (540 ft to 592 ft)
Nominal stiffness loss
(592 ft to 650)
Reduced pipe wall
stiffness (650 ft to 692 ft)
Reduced pipe wall
stiffness (650 ft to 692 ft)
ThicknessFinder
Pipe Wall Thickness
Assessment
Good condition
(0 ft to 250 ft)
Good condition
(250 ft to 5 10 ft)
Good condition
(5 10 ft to 8 10 ft)
Good condition
(5 10 ft to 8 10 ft)
4 Four categories of pipe condition were defined by EPA's contractor ranging from best to worst: minimal, light,
moderate, and heavy. See Section 4 for details.
11
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Table 2-2. Summary of Acoustic Pipe Wall Assessments' Average Wall Thickness Results by
Sahara*, SmartBall™ PWA, and ThicknessFinder (Continued)
Distance
from Start
(ft)
689-722
722-754
754-787
787-821
821-950
950-1034
1034-1174
1174-1439
1439-1640
1640-1673
1673-1706
1706-1738
1738-1771
1771-1804
1804-1837
1837-1870
1870-1902
Exhumed Pipe Condition
as Assessed by EPA
Contractor4
Pipe 6 1(7 11 -723 ft)
Minimal average wall loss;
locally moderate pitting
Pipe 63 (735-747 ft)
Minimal average wall loss;
locally heavy pitting
Pipe 64 (747-759 ft)
Minimal average wall loss;
locally heavy pitting
Pipe 64
(747.759 ft)
Minimal average wall loss;
locally heavy pitting
Pipe 69
(809-821 ft)
Minimal average wall loss;
locally moderate pitting
Pipe visually assessed as it
came out of the ditch. No
corrosion or cracking was
observed.
Pipe 98 (1162-1 174 ft)
Minimal average wall loss;
locally light pitting
Pipe visually assessed as it
came out of the ditch. No
corrosion or cracking was
observed.
Pipe 137 (1630-1642 ft)
Minimal average wall loss;
locally light pitting
Pipe 137 (1630-1642 ft)
Minimal average wall loss;
minimal pitting
Pipe visually assessed as it
came out of the ditch. No
corrosion or cracking was
observed.
Pipe 144
(1724-1750 ft)
Minimal average wall loss;
locally light pitting
Pipe 144
(1724-1750 ft)
Minimal average wall loss;
locally light pitting
Pipe visually assessed as it
came out of the ditch. No
corrosion or cracking was
observed.
Sahara®
Average Wall
Thickness Loss
Ratio (%)
15-30%
15-30%
Nominal
No assessment
provided
Nominal
Nominal
< 15%
< 15%
< 15%
< 15%
Nominal
Nominal
SmartBall™ Pipe Wall
Thickness Assessment
Reduced pipe wall
stiffness (650 ft to 692 ft)
Reduced pipe wall
stiffness (742 ft to 770 ft)
Reduced pipe wall
stiffness (742 ft to 770 ft)
Reduced pipe wall
stiffness (794 ft to 808 ft)
Reduced pipe wall
stiffness (900 ft to 950 ft)
Reduced pipe wall
stiffness
(990 ft to 1,034 ft)
No assessment provided
No assessment provided
ThicknessFinder
Pipe Wall Thickness
Assessment
Good with possibly
higher corrosion rate
(8 10 ft to 1080ft)
Good with possibly
higher corrosion rate
(1080 ft to 1439 ft)
Good condition
(1439 ft to 1750)
Good condition
(1439 ft to 1750)
Good with possibly
higher corrosion rate
(1750 ft to end)
12
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Table 2-2. Summary of Acoustic Pipe Wall Assessments' Average Wall Thickness Results by
Sahara*, SmartBall™ PWA, and ThicknessFinder (Continued)
Distance
from Start
(ft)
1902-1935
1935-2057
Exhumed Pipe Condition
as Assessed by EPA
Contractor4
Pipe 166
(1978-1990 ft)
Minimal average wall loss;
minimal pitting
Sahara®
Average Wall
Thickness Loss
Ratio (%)
15-30%
No assessment
provided
SmartBall™ Pipe Wall
Thickness Assessment
ThicknessFinder
Pipe Wall Thickness
Assessment
SmartBall11*1 PWA. SmartBall™ PWA made measurements every two ft; lengths of degraded pipes were
reported in ranges from 14 to 102 ft. SmartBall™ PWA reported the wall thickness assessment results as
pipe intervals of interest with reduced wall stiffness for the first 1,050 ft of the test pipe. It had
difficulties assessing the second half of the test pipe potentially due to the large amount of noise
generated by the water discharge. The data suggested that several interesting variations existed in the
apparent pulse velocity at different points along the pipeline. However, it was unclear whether the data
revealed actual changes in the hoop stiffness of the pipe wall, or if the data had been affected by the
presence or condition of the mortar lining or other pipe stiffness enhancements (such as previous repairs
on the pipe). This is a common issue for acoustic-based technologies. In addition, the PWA was able to
detect pipeline features such as valves and joints. For example, the acoustic profile showed the locations
of the joints at 12-ft intervals. The spatial resolution of the tool is related to the flow velocity and was
about one data point every two ft along the line. This technique is not designed to detect individual pits,
but may reveal areas where clusters of pitting or thinning produce weakening over several feet along the
pipe.
SmartBall™ PWA provided results for approximately the first half of the test section, which included
seven of the 12 pipes that were fully assessed by EPA's contractor. For the other five pipes, which were
in the second half of the pipeline, inspection variables (e.g., flow noise at discharge) adversely affected
data collection and therefore SmartBall™ PWA was unable to provide results. Of these seven pipes,
SmartBall™ PWA identified four pipes that were located within regions of reduced stiffness and three
pipes that were located within regions where the pipe was considered to have only nominal changes to
stiffness (e.g., normal condition).
While none of the exhumed pipes contained a large amount of metal loss, three of the pipes that EPA's
contractor identified as more corroded were identified as having reduced wall stiffness by SmartBall™
PWA. These three pipes had either had a larger volume of metal loss or larger area of corrosion with
deep pits as identified by EPA's contractor. The fourth pipe identified with reduced wall stiffness by
SmartBall™ PWA was later determined by EPA's contractor to have a low volume loss and relatively
moderate pitting.
Two of the three pipes identified as normal by SmartBall™ PWA were later confirmed to have minimal
volume loss and only a few deep pits. One of the three pipes identified as normal by SmartBall™ PWA
had increased volume loss over a large area, but none of the pit depths exceeded 40%.
Although all of the exhumed pipes had minimal average wall loss, SmartBall™ PWA was able to indicate
which pipe segments were in worse condition based upon local corrosion pitting. This was a very early
use of this emerging technology and tool performance could be improved with further calibration to
excavation information from the field.
13
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ThicknessFinder. Echologics' ThicknessFinder had the coarsest resolution with seven readings provided
for the 2,057 ft pipe. Numerical values of thickness were provided, along with a qualitative description of
the pipe condition. ThicknessFinder reported the wall thickness results as the remaining equivalent
thickness of the pipe, which also accounts for the presence of the cement lining. Since the cement lining
enhanced the structural stiffness of the pipe, the equivalent thickness of a metallic pipe without the lining,
was generally thicker than that of the base metal. The 2,057 ft long test pipe was divided into seven
sections, each ranging in length from approximately 250 to 360 ft. The results of the condition
assessment measurements indicated six sections in a row with remaining equivalent thickness greater than
0.70-in. with the seventh section just .01-in. below, at 0.69-in. Echologics concluded that although there
may be some deterioration in these sections, the pipe is in good structural condition, which they define as
having wall loss in the 10%-20% range. They more specifically estimated the effective wall thickness
loss to be approximately 14%-20%, which is more severe deterioration than the maximum average wall
loss of 2.6% found in the 12 pipe sections assessed in detail.
Echologics provided results for the entire pipe length used in the demonstration. ThicknessFinder
provided average wall thickness values over 250 to 360 ft intervals. ThicknessFinder is not intended to be
able to discriminate between slight variations in the condition of locally degraded pipe.
2.2.2.2 Internal Inspection Technologies. Internal inspection technologies were evaluated based upon
detection of natural corrosion areas and existing anomalies or defects. In addition, the electromagnetic
inspection devices' ability to detect machined metal loss defects was evaluated.
Sahara® Video. Sahara Video® presented the results of the video inspection as a sequence of
observations of only the internal surface of the test pipe. Several visible features were identified over the
length of the test pipe including outlets (branch connections, hydrants, etc.), air pockets, and corrosion.
Two fairly large areas of internal corrosion were found at 1,565 ft and 1,637 ft, but were not
independently verified. Sahara Video® provided results that confirmed that the pipe lining was in
generally good condition and had minimal degradation or delamination. Air pockets, ranging from small
to large in size, were also discovered during the video inspection, but could not be further verified as the
air pockets dissipated with flow. However, one week later, one of the leak detection systems being
demonstrated also noted that air pockets were present. No debris or tuberculation was found in the pipe.
This inspection was a valuable part of the demonstration as it was the first assessment of the ID of the
pipe and provided some assurance that subsequent internal condition assessment methods could be
successfully applied since an unobstructed path was available from end to end. Sahara Video® only
provides information about the condition of the pipe behind the liner if a pipe defect manifests itself on
the inside of the pipe visible via video.
PipeDiver9. The PipeDiver® RFEC results showed joint signals, known features and anomalous signals,
which were reportedly due to wall thickness loss. Forty-one of a total of 170 pipe segments showed
anomalous signals; the size of the anomalies was not quantified. Of the anomalous pipe segments, 14
were identified in the first half of the test pipe, while 27 were identified in the second half of the test pipe.
PipeDiver® testing was conducted as a pilot project to obtain field data for analysis and technology
improvements. PipeDiver® provided results for the entire pipe length used in the demonstration. Forty-
one of the 172 pipe lengths (24%) were identified as being anomalous. Of the 12 exhumed pipes, one
pipe length with the largest area of local corrosion pitting was identified as anomalous. Of the 12
exhumed pipes, five that were assessed and showed minimal degradation were correctly identified as not
degraded by PipeDiver®. The remaining six exhumed pipes that were determined by EPA's contractor to
be in a more degraded condition were not identified as anomalous by PipeDiver®.
14
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This is an emerging technology, and further verification and calibration data are needed by the vendor to
fully assess the nature of these anomalous signals and to improve the ability of the tool to more accurately
characterize pipeline condition. The detection and sizing sensitivity of PipeDiver® is limited by the
number of sensor channels. This was the first use of PipeDiver® for a cast iron water main; the vendor
reported that future developments will focus on improving the detectors and their placement (including
increasing the number of available detectors). In addition, the analysis process will be reviewed for new
techniques and improved software.
See Snake9. The See Snake® detected 367 wall loss indications. Figure 2-1 shows that a majority of the
defects are less than or equal to 50% deep, with a much smaller group in the 60% to 80% range, and only
a few defects 90% or deeper. More importantly, the results from See Snake® show that the deep defects
are concentrated within the first half of the line, leaving about half of the line with approximately original
wall thickness.
120
<20 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100
Defect Depth [in % of wall thickness]
(Courtesy of Russell NDE Systems Inc.)
Figure 2-1. Defect Histogram
Russell NDE Systems Inc. See Snake® provided detailed results for the entire pipe length examined in the
demonstration. Of the 12 exhumed pipes that underwent assessment by the EPA contractor, the pipes
with the largest number of metal loss indications were also reported by See Snake® to have a large
number of pits. Additionally, the pipes that showed minimal degradation in the detailed examinations
were also correctly identified by See Snake® as having few or small anomalies.
Of all of the condition assessment technologies demonstrated, See Snake® provided the most detailed
results for the entire pipe length. The total number of corrosion pits, as well as corrosion pit location with
respect to the pipe joint and clock position, were reported. The inspection results were found to correlate
with the post-demonstration assessment of the 12 exhumed pipe segments. The comparison approach is
described in Section 4. It should be noted that the implementation was intrusive, as the pipe had to be cut,
a pull cable had to be threaded from start to finish, and the pipe drained for this demonstration inspection.
15
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Detection of Anomalies-Comparison of See Snake® and PipeDiver®Results. See Snake® provided
detailed results that correlated well with the post-demonstration assessment of the 12 exhumed pipe
segments. The total number of corrosion pits, as well as corrosion pit location with respect to the pipe
joint and clock position, were reported. PipeDiver® indicated only the pipe length locations where the
pipe had anomalies. A summary of the internal inspection results reported by PipeDiver® and See Snake®
is provided in Figure 2-2.
From this comparison, it is evident that See Snake® found a much larger number of defects in the first half
of the test pipe with some locations corresponding to anomalous pipe found by PipeDiver®. On the other
hand, PipeDiver® found a greater number of anomalous pipe segments in the second half of the test pipe,
while See Snake® found far fewer and less severe anomalies. Verification of anomalies in specific pipe
samples using wall thickness measurements by EPA's contractor for selected pipe segments showed some
pitting, but generally the pipe was in good condition. See Snake® provided the most detailed inspection
results for the entire pipe length and the condition reported by See Snake® was found to correlate with the
post-demonstration assessment of the 12 exhumed pipe segments by EPA's contractor. The bell and
spigot joints could be seen in the raw data, but not characterized in detail. Eight joints were identified as
anomalous. Due to magnetic permeability noise, See Snake® was not able to characterize any of the
machined calibration or test defects. The vendor identified four potential causes of the interference
arising from either the installation process for the artificial defects or the previous operation of other
electromagnetic inspection devices in the vicinity.
Majority of anomalies
found in first half of pipe
Majority of anomalous pipe segments found in second half
Anomalies detected by See Snake
Manufactured defects
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
Distance [ft]
Figure 2-2. Defect Scatter Graph for See Snake® vs. Anomalous Pipe Locations for PipeDiver®
16
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2.2.2.3 External Inspection Technologies. The same machined metal loss defects as described above
were used for the external inspection technology demonstration, along with natural corrosion areas. Each
external condition assessment tool found a large number of anomalies in the excavated pipeline sections.
AESL ECAT. AESL's ECAT detected and characterized machined defects. AESL also used an
extensive analysis procedure to derive the general pipe condition along the entire length of the test pipe.
While on site, AESL conducted assessments of the relative soil corrosivity, pipe coating condition, pipe
wall thickness, and full circumference ECAT scans for three excavation locations (labeled as Pit L, Pit 2,
and Pit F). AESL integrated and analyzed this data to determine the pipe condition in these three
excavated pits. Subsequent statistical analyses were then performed to predict the condition of the un-
inspected portions of the pipeline based upon the detailed findings within the excavated pits.
The AESL ECAT MFL device successfully detected six of six machined defects. The measured defect
depths ranged from 0.13-in. to 0.53-in. with the ECAT device reporting -47% to + 96% of the measured
depths. The measured defect lengths ranged from 1-in. to 3.7-in. with the ECAT device reporting -45%
to +210% of the measured lengths. On average, AESL located anomalies within a small distance (2.6
inches) of the recorded defect location, but this apparent error may be attributed to differences between
AESL's and EPA contractor's coordinate reference systems.
AESL's analysis of external defects and other data indicated >65(5) potential through-wall defects and
>63(6) critical defects. The 2/3 of the pipeline representative of Pits 2 and F likely has 15 through-wall
defects and 13 critical defects (>0.57-in.). The 1/3 of the pipeline representative of Pit L likely has >50
through-wall defects and > 50 critical defects (> 0.67-in.). Based on the estimated maximum stresses,
defect distribution models, and assumed pipe material properties, AESL concluded that defects of
sufficient depth to cause structural failure of the pipe may be present.
While there are some indications that AESL's estimate of >65 potential through-wall holes may be a
significant overestimate, a definite conclusion about the accuracy of the estimate is not possible with
available data. Indicators that an estimate of >65 through-wall holes is high are: (a) no through-wall
defects were found in the 144-ft (i.e., 7% of actual test pipe length) that was sandblasted and evaluated in
detail; and (b) the leak detection phase of the study (Nestleroth, B. et al, 2012), reported approximately 8
possible through-wall leaks/1000 ft, which, assuming a uniform leak density across the pipe, projects to
20 through-wall leaks over 2500-ft. However, there are insufficient data to eliminate the possibility that a
substantial number of through-wall holes, or near- through-wall holes, do exist. For example: (a) since
only 12 of 171 (7%) of pipe lengths were measured in detail for wall loss and corrosion pits, the actual
number of through-wall holes in the remaining 93% of the test pipe is not known; (b) AESL collected
metal loss data on only 0.5% of the test pipe, but they augmented their direct measurements with other
relevant data, and then subjected the data to a logical and systematic analysis in order to generate their
predictions of through-wall defects in the remainder of the pipe, and a comparable assessment was not
within the EPA contractors' scope of work; (c) some through-wall holes may be present, but not leak due
to plugging; and (d) AESL was given 2500-ft as the length of the test pipe, instead of 2057-ft, so this
elevated their extrapolated number of potential through-wall holes; the EPA contractor's numbers were
extrapolated to 2500-ft for the comparisons above.
AESL also conducted a pipeline stress analysis assuming various loading regimes (soil overburden and
traffic), membrane and bending stress, structural significance of the corrosion, and fracture mechanics
models to predict critical defect sizes for the risk of structural pipeline failure. AESL estimated the likely
number of critical defects in the same pipeline locations. For 2/3 of the pipeline representative of Pit 2
and Pit F, there are potentially 13 critical defects (0.57-in. deep) and for the 1/3 of the pipeline
' This number is somewhat inflated due to AESL being given 2500-ft as the test pipe length instead of 2057-ft.
17
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representative of Pit L, there are potentially >50 critical defects (0.67-in. deep) along the pipeline. Based
on the estimated maximum stresses, defect distribution models, and assumed pipe material properties,
AESL concluded that defects of sufficient depth to cause structural failure of the pipe may be present.
The critical defect depth at the location of maximum stress for Pits L, 2 and F was reported at 0.67, 0.57,
and 0.62 in., respectively. Data are summarized in Table 2-3. The project scope did not include a similar
level of analysis by EPA's contractor, so no comparison of the number of critical defects was conducted.
Also, since the project is focused on the innovative pipe wall integrity measuring devices, EPA
contractor's scope did not include an assessment comparable to AESL's assessment of soil characteristics
or coating condition; nor did they perform modeling, statistical, or structural analyses to integrate and
extrapolate indirect and direct data into a condition assessment for the full length of the test pipe.
Under the demonstration program requirements, the ECAT MFL method used by AESL reported, in one
case (Pit L; Pipe 30), a substantially larger number of corrosion pits greater than the size measured
manually after grit blasting; and for Pit F, a similar number (5 vs. 3) of corrosion pits greater than 50%
deep. For Pit L, AESL reported that for the 20 deepest pits, 18 of these were greater than 50% deep. The
post assessment by EPA's contractor found one deep pit, at 68%, two pits near 50% (i.e., 46% and 47%),
and many smaller pits. AESL may or may not remove the corrosion product within natural defects.
While done for the first pipe assessed, AESL was asked not to do it for this pipe because this could
possibly influence results for subsequent tests in the demonstration. Per AESL, removal or non-removal
of corrosion does not affect AESL's calibration or sizing of defects, since the MFL inspection tools are
calibrated prior to arrival on site and sizing models are based on a database of defects at AESL. The
pipes in Pit 2 were not subjected to detailed assessment after the demonstration, so there is no data for
direct comparison with AESL pit depth data.
A number of factors that can influence AESL's findings were identified. Because detailed pipeline
material property data could not be provided to AESL due to the age of the pipeline system, there are
uncertainties in the stress analysis and critical defect depth predictions. The identification of a historic
American pipe standard for cast iron pipe, as opposed to the British Standard that was used, would allow
AESL to reduce the uncertainty in their assessment of original dimensions, material properties, and test
pressures. AESL also notes that there may be variations in the soil properties and hence corrosion
drivers along the pipeline length, which may affect the validity of the statistical predictions. The fracture
mechanics modeling conducted by AESL is based on a singular defect being present at a point of
maximum stress to determine critical defects. Defects found in close proximity to each other are likely to
give rise to higher stress concentration and therefore a further increase in the risk of structural failure.
One excavated pipe location used by AESL was near a large leak, which may have contributed to higher
corrosion rates that may have biased the extrapolations towards larger defects. AESL would normally
select the assessment points, but the selection options were limited by the test program requirements.
Additionally, the sizing software used by AESL is based on calibration scans of flat-bottomed corrosion
defects from different pipes of different wall thicknesses and potentially different magnetic properties.
As such, this demonstration provides a unique opportunity for AESL to improve their sizing algorithms
based on the more complex geometry of natural defects found in the test pipe.
The wall thickness data from ultrasonic devices was in good agreement from both AESL and EPA's
contractor.
The inspection with the ECAT device identified fifteen internal defects. No independent data were
collected to confirm the internal metal loss anomalies identified by AESL.
AESL's approach does not require entry into the pipe or disruption of flow. Only selected locations along
the pipe require excavation. The ECAT is equipped with GPS and blue tooth technology to enable data
transfer in real-time.
18
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RSG HSK and CAP. For RSG, the results generally indicate that there is metal loss in the sections of
pipe scanned during the demonstration. RSG did not find a common wall thinning trend for the entire
pipeline length and indicated that the trends appeared to be section specific. The minimum wall thickness
recorded was 0.627-in. in Pit C. A summary of the results is provided in Table 2-4.
RSG only provided relative wall thinning data averaged over the sensor area (1x1 in. for CAP and 2x2 in.
for HSK) and therefore did not offer the sensitivity needed to size the machined defects, which were
smaller than the sensor area. Therefore, only general observations can be made regarding possible
increased wall thinning in the location of the machined defects. The HSK scan of Pit F, which contained
fairly large machined defects (35% to 59% wall loss over a 6-in. length and 1-in. wide), did indicate areas
of reduced wall thickness over a 6-in. length near the crown of the pipe. However, since the results were
averaged there is not sufficient granularity to directly compare the scans with the actual depths of the
machined defects in Pit F where RSG reported a minimum wall thickness of 0.678-in. (and the measured
minimum of the machined defects was approximately 0.3-in.).
The RSG HSK and CAP results compared well with the general condition of the pipe. The method
provided local wall thickness values at nominally 250 ft intervals on the top of the pipe and full pipe
circumference measurements in three locations. These readings did not discover significant metal loss
that would indicate that the condition of the pipe was less than serviceable.
Table 2-3. Summary of Condition Assessment Results for AESL ECAT
Location
[ft]
338
(PitL)
Exhumed
Pipe
Condition as
Assessed by
EPA
Contractor6
* Minimal
average
wall loss;
Deepest pit
0.53 in.;
Avg. wall
thickness
was 0.76 in.
Soil
Corrosivity
* Fairly
Corrosive
*AFNOR
Score = 7
ECAT
Pipe Wall
Thickness
* Avg. wall
thickness
was 0.74
in.
Coating Condition
( ° from Top)
* Generally good with an
overall area of coating
failure of 6%.
* Coating between 245°
and 278° is in the
worst condition with
the highest % coating
failure at 31% at 278°
ECAT
Condition Assessment
Results
* -330 external defects
(Deepest was 0.57 in.)
* ~3 internal defects
(deepest was 0.41 in.)
* Excavator or mechanical
damage at -90° and
between 180° and 280°
6 Four categories of pipe condition were defined by EPA's contractor ranging from best to worst: minimal, light,
moderate, and heavy. See Section 4 for details.
19
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Location
[ft]
1,080
(Pit 2)
1,750
(PitF)
Exhumed
Pipe
Condition as
Assessed by
EPA
Contractor6
* Machined
defects -
not
sandblasted
for natural
anomalies
Deepest pit
70% (0.55
in.);
Avg. wall
thickness
not
measured.
* Minimal
average
wall loss;
Deepest pit
0.37 in.;
Avg. wall
thickness
was 0.77 in.
Soil
Corrosivity
* Fairly
Corrosive
*AFNOR
Score = 5
* Highly
Corrosive
* AFNOR
Score = 9
ECAT
Pipe Wall
Thickness
* Avg. wall
thickness
was 0.73
in.
* Avg. wall
thickness
was 0.75
in.
Coating Condition
( ° from Top)
* Generally poor with an
overall area of coating
failure of 70%.
* Coating between 115°
and 245° (bottom) is in
the worst condition
with several axial
locations having 100%
coating failure.
* Generally good with an
overall area of coating
failure of 11%
* Coating between 147°
and 295° is in the
worst condition with
the highest % coating
failure at 39% at 229°
ECAT
Condition Assessment
Results
* -225 external defects
(deepest was 0.59 in.)
* -1 1 internal defects
(deepest was 0.41 in.)
* -240 external defects
(deepest was 0.49 in.)
* -9 internal defects
(deepest was 0.39 in.)
* Mechanical damage
between 180° and 270°;
likely not to have
occurred recently
20
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Table 2-4. Summary of Condition Assessment Results for RSG
Location
[ft]
250
(Pit A)
338
(PitL)
510
(PitB)
809
(PitC)
1,080
(Pit 2)
1,173
(Pit D)
1,439
(PitE)
1,750
(PitF)
Exhumed Pipe
Condition as
Assessed by
EPA
Contractor7
Not assessed
Minimal
average wall
loss; locally
light pitting
Not assessed
Minimal
average wall
loss; locally
moderate
pitting seen on
site
Machined
defects - not
sandblasted for
natural
anomalies
Not assessed
Not assessed
Minimal
average wall
loss; locally
light pitting
Type
of
Scan
CAP
HSK
CAP
CAP
HSK
CAP
CAP
HSK
RSG
Minimum
Wall
Thickness
[in.]
0.662
0.654
0.680
0.627
0.688
0.666
0.704
0.678 to
0.711
RSG
Average
Wall
Thickness
[in.]
0.737
0.735
0.719
0.703
0.735
0.689
0.709
0.745 to
0.748
RSG
Condition Assessment
Results
* Moderate corrosion near the pipe crown
* Higher degree of wall thinning near the pipe
crown
* Moderate degree of wall thinning at the pipe
sides
* 90% of the pipe was examined. 5% could not
be scanned due to access restrictions; 5% could
not be analyzed for two sections due to noise
detected during post-analysis.
* Moderate corrosion near the pipe crown
* Most severe corrosion near the pipe crown
* Moderate to severe corrosion on the southern
side of the pipe
* Moderate corrosion at the bottom of the pipe
* Moderate corrosion near the pipe crown
* Negligible wall thickness variation
* Higher degree of wall thinning near pipe crown
* Moderate degree of wall thinning at the pipe
sides; more prevalent on northern side
* Thinning in isolated areas; therefore likely due
to pitting clusters or graphitization
2.3.
Costs
One key gap is a better understanding of the cost of obtaining data for water main inspections compared
to the benefit in terms of reducing failure risks. As novel technologies develop and competition grows, it
is anticipated that non-destructive inspections will become more cost-effective even for pipes with
moderate consequences of failure. This demonstration involved the collection of cost data in order to
help to address this issue.
7 Four categories of pipe condition were defined by EPA's contractor ranging from best to worst: minimal, light,
moderate, and heavy. See Section 4 for details.
21
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The cost of inspection is dependent on a number of variables including the length and diameter of pipe to
be inspected, pipe accessibility, and number of services requested (some vendors offer volume discounts).
The cost of an inspection has two main components: (1) the cost of the service provided by the inspection
vendor; and (2) the cost for the water company to prepare the line and conduct the inspection, which is
often more difficult to quantify. Table 2-5 summarizes the estimated inspection costs and site preparation
costs for the acoustic pipe wall surveys, internal inspection technologies, and external inspection
technologies. The cost of inspection is also likely to change as inspection technology develops.
The estimated inspection costs were developed based upon vendor quotes for inspecting 10,000 ft of 24-
in. cast iron pipe along the same route as the demonstration site in Louisville, KY. The cost for a wall
thickness survey ranges from $3 to $7/ft; the cost for both leak detection and pipe wall thickness survey
ranges from $3 to $9/ft. Cost savings can be achieved when combining the leak detection with pipe wall
thickness survey to reduce time, labor, and equipment costs for inspection. The cost for internal
inspection is estimated to range from $15 to $19/ft and the cost for external inspection is estimated to
range from $3 to $4/ft.
The site preparation costs for line modification and field support are highly site-specific and for this
reason the estimates provided are order of magnitude estimates based upon typical construction costs
(RSMeans, 2011). The actual site preparation costs for a given site will depend upon regional costs for
construction labor, along with factors such as the access requirements, availability and condition of
existing hydrants/valves, length of deployment, days on site, and more. It is estimated that the site
preparation costs to conduct a wall thickness survey of 10,000 ft of 24-in. diameter cast iron pipe may
range in magnitude from $0.48/ftto $0.69/ft (including traffic control, pit/pothole excavation, tapping,
backfill, and restoration). It is estimated that site preparation costs for an internal inspection of 10,000 ft
of 24-in. diameter cast iron pipe is approximately $0.58/ft (including traffic control, pit excavation,
tapping, backfill, and restoration). It is estimated that site preparation costs for an external inspection of
10,000 ft of 24-in. diameter cast iron pipe may range in magnitude from $0.94/ft to $1.63/ft (with 9 to 13
excavated locations, respectively).
2.4 Conclusions and Research Needs
The outcome of this demonstration is to provide water utilities with third-party, independent sources of
information on applying selected innovative condition assessment technologies for cast iron water mains.
Observations are summarized here on the maturity of these technologies for the inspection of cast iron
water mains, the complexity of logistical and operational requirements, overall technology performance in
predicting pipe condition, and technology costs.
Table 2-5 summarizes useful information on implementation factors, technology inspection results, and
costs. In addition, conclusions can be drawn regarding further research and technology development
needs and improved methodologies for evaluating pipe wall condition inspection technologies as
discussed below.
22
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Table 2-5. Summary of Implementation Factors, Format of Inspection Results, and Costs
Technology
Implementation Factors
Diameter
Range
Internal/
External
Flow
Requirements
Inspection
Interval
Format of Inspection Results
Provides
General
Assessment?
Finds
Specific
Defects?
Provides
Detailed
Measurements?
Cost Factors
Inspection
Cost
Site
Preparation
Cost
Acoustic Pipe Wall Assessment
Sahara® WTT
SmartBall™
PWA
ThicknessFinder
>4 in.
>6in.
N/A
Int.
Int.
Ext.
>lft/s
>0.5 ft/s
Flow/No Flow
Variable.
Demonstrated
at 33 ft.
Data every 2
feet. Sections
of pipe
grouped.
Variable.
Demonstrated
at293ftavg.
Yes
Yes
Yes
No
No
No
No
No
Yes
$3.30/ft
$6.00/ft
$2.71/ft
$0.66/ft
$0.69/ft
$0.48/ft
Internal Technologies
Sahara® Video
PipeDiver®
See Snake®
>4in.
24-60 in.
2-16 in. and
20-28 in.
(can be
adapted to a
custom
diameter)
Int.
Int.
Int.
>lft/s
>0. 7 to 1.5 ft/s
Dewatered;
Flow version
available.
Continuous
Pipe length
Continuous
Yes
Yes
No
Yes
No
Yes
No
No
Yes
N/A*
N/A*
$15-$19/ft
N/A*
N/A*
$0.58/ft
External Technologies
ECAT
HSK
CAP
>12-in.
No diameter
limit noted as
advantage.
No diameter
limit noted as
advantage.
Ext.
Ext.
Ext.
N/A
N/A
N/A
Every 1,200 ft
Every 900 ft
Every 300 ft
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
$3.60/ft
$2.95/ft
N/A*
$0.94/ft
$1.63/ft
N/A*
* Cost data not provided by vendor due to developmental status of technology, etc.
-------
Technology Maturity. The level of development differs substantially among the tools for the inspection
of a 24-in. cement lined, cast iron pipe. For PipeDiver® and See Snake®, this demonstration was the first
application of the technology for the inspection of a large diameter cast iron water main. Therefore, the
demonstration helped to accelerate the testing and development of these emerging technologies under
field conditions. For other technologies, this demonstration represented a very early application (e.g.
Sahara® WTT and SmartBall™ PWA) and the data will provide a source of information to the vendors for
improving tool performance with further calibration to excavation information from the field. Other
technologies such as Echologics® ThicknessFinder have been deployed at multiple sites and therefore
have more experience in calibrating inspection results to field conditions. All of the inspection vendors
planned to use the demonstration to facilitate new technology developments and improvements. All of
the technologies are still available as of the preparation of this report with improvements claimed since
the time of the demonstration (see Appendix H and vendor websites listed in Section 2).
Technology Implementation. Some technologies were simple to implement with minimal modification
to the water main and others required launching/retrieval of the tool. Water utilities can benefit from
information on the ease of use of inspection tools and/or the complexity of site logistical and operational
requirements. The access requirements, support equipment and number of personnel needed to deploy the
inspection technologies varied substantially with each vendor. The demonstration provided information
on the ability to mobilize, access the pipe, operate under given flow rates, and other site conditions for a
24-in., spun cast iron pipe with leadite bell and spigot joints, and a cement-lining. The logistical and
operational information was summarized in detail in Table 2-1 for each technology. This included the
number of technicians needed, any need for operator intervention, the number and spacing of pipe contact
points, access requirements, and more. Other implementation factors of interest to water utilities are
summarized in Table 2-5. For the internal inspection technologies, each vendor was capable of
configuring their equipment to inspect the full 2,057 ft of pipe. For the external technologies, the scans of
the exposed pipe were able to be completed.
Issues that were encountered for the acoustic pipe wall assessment technologies included signal
interference from large air pockets and signal interference from the noise generated by the discharge at
the end of the test pipe. However, these situations are unlikely to occur in a fully operational water main
and are due primarily to the test pipe configuration.
For internal inspection technologies, both PipeDiver® and See Snake® provided inspection results for the
entire pipe length used in the demonstration. For both vendors, this was the initial use of this technology
implementation on an operational cast iron water main. At the time of the demonstration, See Snake®
was a tethered prototype unit that was particularly intrusive, since it required the pipe to be dewatered and
cut, and then the See Snake® was pulled through a dry line. The full-scale commercial system is now
available to be launched in a live pipeline. There were some issues with control of the winch initially
causing velocity excursions (e.g., jerking, and surging), but this was resolved. The demonstration of
PipeDiver® showed that a large free swimming, in-line inspection tool could be launched and retrieved
from an operating pipeline. Live insertion and retrieval of inspection tools within a water main is a key
area for improvement and this demonstration assisted in acceleration of these efforts. No significant
implementation issues were encountered except for a minor issue with launching of the PipeDiver®,
which was overcome by modifying the tool so that it wouldn't get caught in a 4-in. gap in a joint
downstream of the inspection point. As a result, the vendor recommends using Sahara® Video prior to the
inspection to identify the exact layout of the insertion point.
No significant implementation issues were noted for the external technologies. Two of these technologies
typically require excavation of 5 ft sections every 1,200 ft for ECAT and every 900 ft for RSG HSK. A
keyhole excavation or pothole is used every 300 ft for RSG CAP. One excavation location used by AESL
was near a large leak, which may have contributed to higher corrosion rates in that pipe section that may
24
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have biased the statistical model towards predicting larger defects. This highlights the importance of the
selection of excavation locations to technology performance and the need for improvements in screening
approaches for selecting locations that are representative of the remaining portion of unexposed pipe.
Technology Inspection Results. The pipeline condition data provided by each vendor varied from
highly detailed defect location and sizing information to general pipe condition over larger areas of the
test pipe. Ultimately, it is the decision of the water utilities to determine the level of analysis needed to
make decisions regarding rehabilitation and replacement of a particular main. Familiarity with a variety
of tools can be valuable to a utility, as well as having options that accommodate specific situations
necessary to obtain a useful assessment of the pipe condition. Table 2-5 summarizes the format of the
inspection results that can be expected from each technology (e.g., the inspection technology provides for
general condition assessment information, identification of specific defects, and/or numerical results).
One conclusion drawn from this study is that the technologies tested would benefit from further
calibration to a wider range of excavated pipe data from the field. While all of the exhumed pipes had
metal loss, their condition with regard to overall metal loss was generally good. The average wall loss
was calculated for all of the exhumed pipes and the greatest amount observed was 2.6%.
Technology Costs. Table 2-5 summarizes the estimated inspection costs and site preparation costs for
the acoustic pipe wall surveys, internal inspection technologies, and external inspection technologies.
Summary and Research Needs. The inspection goal of each of the inspection technologies differed, as
they attempted to balance maximizing inspection performance, while minimizing intrusion on the pipe
and the direct cost of the inspection. The following conclusions can be drawn regarding further research
and technology development needs and improved methodologies for evaluating pipe wall condition
inspection technologies as discussed below.
The technologies tested would benefit from further calibration with field data to improve their accuracy
and reduce the amount of overcalls (e.g. prediction of pipe in worse condition than its actual condition).
The data from this field demonstration was provided to the vendors and will aid the developers in
improving their calibration to excavation results.
Although the acoustic pipe wall screening technology demonstration data suggests that several interesting
variations exist in the pulse velocity at different points along the pipeline, it was unclear whether the data
revealed actual changes in the hoop stiffness of the pipe wall, or if the data had been affected by the
presence or condition of the mortar lining or other pipe stiffness enhancements (such as previous repairs
on the pipe). Improved capability to identify the causes of these acoustic velocity changes would be
useful. Good construction and maintenance records may be a critical source of useful data.
The test pipe at LWC was being replaced for capacity issues and overall the pipe appeared to be in good
condition (defined as average wall loss less than 4% and no detected through-wall defects) both from a
visual assessment of the pipe as it was excavated and based upon the 12 exhumed pipes that were selected
for further manual and/or laser assessment. A future field demonstration where the test pipe had a larger
variation in condition along its length, including larger defects and more significant wall loss would
provide for an improved understanding of the detection capabilities of the inspection technologies.
Each technology provides different types of inspection results at widely varying resolutions. For water
utilities, this can make a one-to-one comparison of the technologies and inspection results difficult to
achieve. Vendors may provide an evaluation that does not yield quantitative, numerical data (e.g., wall
thickness) along the full length of the pipe. Instead, a qualitative pipe condition may be provided, the
basis of which is not well defined and/or proprietary to the vendor.
25
-------
Because of the inherent uncertainty in the condition of an operational water main (prior to a
demonstration), there is a need to simulate key pipe scenarios under controlled conditions to further test
inspection technologies and their ability to accurately characterize pipe condition. The size of the
machined defects in this study ranged from 1- to 6-in. in length and 20% to 70% wall loss. Many of the
external inspection methods averaged over large areas and there was not sufficient granularity to directly
compare the scans with the actual dimensions of the machined defects. Future controlled condition
testing in a test bed could be conducted with a larger range of calibration and test defect sizes (while
minimizing any stress on the pipe that could cause local changes to its magnetic properties).
26
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3.0: MATERIALS AND METHODS FOR FIELD DEMONSTRATION
3.1 Site Description
3.1.1 Site Location. Louisville is located in the north-central portion of Kentucky, immediately
south of Indiana along the Ohio River. Its climate can be described as humid sub-tropical with yearly
temperatures ranging from 0°C in January to 25°C in July. The city's estimated population, as of 2006,
was just fewer than 600,000; the Louisville Metropolitan Area's population was approximately
1,250,000. Supplied by the Ohio River, the source water is treated and transmitted to service taps by
LWC, which was granted a charter from the Kentucky Legislature in 1854. Under this charter, water was
first provided to the citizens of Louisville by LWC in 1860. Currently, LWC treats and transmits 135
MGD of water to 270,000 service taps through 3,500 miles of water mains, ranging in diameter from 1 to
60-in. Under its MRRP, the company replaces over 35 miles of pipe every year as either a preventive or
reactionary effort to maintain the water transmission and distribution system.
As part of LWC's pipe replacement and rehabilitation program, a 2,500-ft length of 24-in. diameter pipe
that was scheduled for replacement was made available for the demonstrations of inspection and
condition assessment technologies. A continuous 2,057-ft section of this pipe was used for the
demonstrations. The pipeline right-of-way is in the north lane of Westport Road, from the intersection of
Westport Road and Chenoweth Lane, to the intersection of Ridgeway Avenue and Westport Road (see
Figure 3-1). At Ridgeway Avenue, the 24-in. diameter line goes under a set of CSX railroad tracks.
3.1.2 Test Pipe Condition. The portion of the 24-in. diameter transmission main along Westport
Road between Chenoweth Lane and Ridgeway Avenue was made available for the field demonstration
project (referred to herein as "the test pipe"). The test pipe is Class 150 deLavaud spun cast iron that is
lined with a factory-installed cement mortar and represents approximately 2,500 ft of transmission line.
The test pipe was installed in September 1933 and had a burial depth between 3.5 and 6.0 ft. Wall
thicknesses of the pipe range from 0.68 to 0.73-in., as measured periodically during routine maintenance
and inspections or during repairs. During a site visit in May 2009, wall thicknesses of pipe samples
removed during the installation of a 24-in. by 12-in. tee were measured and ranged from 0.76 to 0.78-in.
The test pipe typically operates at pressures between 45 and 50 pounds per square inch (psi), while
transmitting 4 to 6 MGD of flow. Table 3-1 summarizes the historical, operational, and environmental
characteristics of the test pipe.
In preparation for the new installation and prior to the demonstration, all taps and offtakes on the 24-in.
diameter test pipe were moved to a 12 in. diameter parallel service line. The test pipe was bypassed and
taken offline, but could be filled or drained as needed for each demonstration. During the demonstration,
traffic was restricted to a single lane and traffic flow was sporadic. The amount of traffic during the
demonstration was not separately measured or recorded.
27
-------
m
Pit #2 (1080' from Pit #1; St. Matthews Ave.)
Corp Valve 3 4 5 & 6, machine defects
PitF
(1750'from Pit #1)
Pit #4 (581'from Pit #1)
Corp Valve 1 & 2, machine defects
^
Pit#1)
One 24" x 12" tee (with a
"te f-—
I " E3^q--J-^l
Pit #5 (1580' from Pit #1)
Corp Valve 7 & 8, machine defects
PitE
(1439' from
Pit #1 (near Chenoweth Ln.)
One 24" x 12" tee (with adapters to 2" and 6")
V
PitB
(510'from Pit #1)
PitL
(338'from Pit #1)
Machine defects
PitC
(809'from Pit #1)
(A.
12" Discharge to
Sanitary Sewer
Pit #3 (2057' from Pit #1 near Ridgeway Ave.)
- 24" Pipe
— 30" Pipe
I I 1 0' W x 1 6' L Trench Box
D 6' x 6' Sensor Pit
0 Fire Hydrant
^ Discharge Point
© Pressure Gauge
SCALE IN FEET
DATE: 10/22/08
WESTPORT RD
Chenoweth Ln
to
Ridgeway Ave
HLOJIC
Figure 3-1. Location Map of Westport Road Transmission Main Replacement Project
-------
Table 3-1. Summary of Historical, Operational, and Environmental Characteristics of Test Pipe
Historical
Pipe Material
Installation Date
Pipe Segment Length (ft)
Pipe Inner Diameter (in.)
Pipe Class
Pipe Thickness (in.)
Approximate Total Pipe Length (ft)
Burial Depth (ft)
Pipe Lining
Pipe Lining Thickness (in.)
External Coating
Type of Joints
Land Use over Main
Leak History (recorded)
Date of First Joint Leak (recorded)
Date of First Pipe Break (recorded)
Cast iron
09/1933
12
24
deLavaud Spun Cast; Cement lined; Class 150
0.68-0.78
2,000
3.5-6.0
Factory Applied Cement Mortar
Variable, on the order of 0.25
Bitumen paint
Leadite
Residential traffic; bituminous paving
Eight leaks since 1973 (see Figure 3-2)
05/22/1973
08/29/2008 (not within 2,057-ft test pipe)
Operational
Typical Operating Flow (MOD)
Typical Operating Pressure (psi)
Water pH (S.U.)
4-6
• Flow throttled due to concerns of main breaks
• Available flow for inspection ranging from 1,400 to 2,800 gpm (or 1 to
2 ft/sec) due to sewer restrictions
45-50
8.2
Environmental
Soil Parameters (moisture, pH,
resistivity, redox potential, etc.)
Average Monthly Temperature (°C)
No historical data(a)
January through December: 0, 2, 8, 14, 19, 23, 25, 24, 21, 14, 8, 3
Minimum - 0 (January)
Maximum - 25 (July)
(a) Soil characterization was performed during the demonstration project.
3.1.3 Leak History. Seven joint leaks and one pipe break have been reported along the test pipe
from May 1973 to August 2008; however, no information exists regarding the test pipe leak history prior
to 1973. Figure 3-2 shows the location and date of the recorded leaks and breaks: two near the
intersection of Ridgeway Avenue and Westport Road on May 22, 1973 and March 2, 1977; three near the
intersection of St. Matthews Avenue and Westport Road on December 14, 1995, August 23, 2001, and
February 17, 2002; and two near the intersection of Sherrin Avenue and Westport Road on November 18,
1985 and December 27, 2003. All of the seven joint leaks occurred at leadite joints.
Since no evidence of wall loss was noted at the time of the repairs, most of these joint leaks are assumed
to have been induced by settling/consolidation of underlying fill material or natural soils or as a result of
the freeze/thaw cycle causing differential movement of pipe segments attached to the common joint. The
exception to this was the December 14, 1995 joint leak at the intersection of St. Matthews Avenue and
Westport Road in which evidence of corrosion was observed.
29
-------
ugusl 29. 2008
Exact LoL-ation: 40 ft. E C/L Westport Rd. and 12 ft. N C/L Ridgeway Ave.
Leakjryrjc: Pipe
th 10 Pipe: 6 ft.
Evidence of Corrosion: Yes
Date: November IS. 1985
Exact Location: Westport Rd. and Shcrrin Avc
Leak Type: Joint
Depth to Pipe: 4ft.
Lvuk'iice of Corrosion: N
Date: December 14, 1995
Exact Location: Westport Rd. and St. Matthews Avc.
Leak Type: Joint
Depth to Pipe: 4 ft,
|-\ Kk'nLV of Corrosion: V
Dale: May 22, 1973
Exact Location: West noil Rd. and Riducway Avc.
Leak Type: Joint
Depth to Pipe: 4 ft.
Evidence of Corrosion; Nt
Date: August 23. 2001
•xact Location: 10 ft. N C/L Westport Rd. and 88 ft. W. C/L St. Matthews A
,eak/Typc: Joint
Depth to Pine: 5ft.
Evidence of Corrosion: No
Date: March 2. 1977
Exact Location: Westport Rd. and Ridgeway Ave.
•ilk Type: Joint
Depth to Pipe: 4ft.
H\ idenee of Corrosion: No
Date: December 27. 2003
Exact Location: 6 ft. N C/L Westporl Rd. and 46 ft. W C/L Sherrin Ave
Leak Type: Joint
th to Pipe: 3ft,
Evidence- of Corrosion: No
Dale: February 17. 2002
Exacl Location: 9 ft. N. C/L Weslpott Rd. and 139 ft. E. C/L Si. Matthews Ave
kJTyjje: Joint
Depth tu Pipe: 3.5ft.
lence of Corrosion: No
WESTPORT RD
ACTIVE SERVICE PRESSURIZED MAINS SYSTEM VALVES
DIAMETER VALVE TYPE. OPEN DIRECTION
ByPjsa
Chenoweth Ln
to
Ridgeway Ave
Figure 3-2. Locations and Details of Pipe and Joint Breaks and Leaks
-------
The only recorded pipe break occurred on August 29, 2008, approximately 12 ft north of the centerline of
Ridgeway Avenue and 40 ft east of the centerline of Westport Road. The break appears to have occurred
near a joint and propagated longitudinally along the pipe (see Figure 3-3), resulting in complete failure.
The pipe break was caused by an attempt to operate the line at its full capacity, which indicated that the
pipe might have lost part of its original structural integrity due to aging. It should be noted that the
location of the pipe break is outside the test area (that is, not strictly part of the test pipe). However, it is
noteworthy because of the nature of the break and because it occurred just a few days before the EPA
Forum, which prompted LWC to offer the pipe for this demonstration.
Note arrow pointing to longitudinal propagation of crack
Figure 3-3. Pipe Break along Westport Road Adjacent to Test Area in August 2008
3.2
Technology/Vendor Selection
The TO 62 State of the Technology Review (SOTR) report (Thomson and Wang, 2009) provides an
overview of the state of inspection technologies for ferrous pipes. The technologies selected for
demonstration at Louisville, KY were based on the TO 62 SOTR report, feedback from the Technology
Forum, and an additional literature search on relevant reports prepared by organizations such as Water
Research Foundation (formerly American Water Works Association Research Foundation), Water
Environment Research Foundation (WERF), and EPA, as well as vendors' Web sites. A list of potential
candidate technologies was compiled, which included acoustic-, magnetic-, electromagnetic-, and
ultrasonic-based technologies. Technologies that require the removal of coatings and preparation of the
pipe surface (such as ultrasonic tools for wall thickness measurement) are well established and were not
31
-------
considered in this field demonstration. Innovative and emerging ultrasonic tools can be demonstrated
offsite after the pipe is exhumed.
The candidate technologies were further screened based on (1) suitability of the technologies for the test
pipe diameter and material, (2) readiness of the technologies within the field demonstration timeline, and
(3) potential to yield useful data for interested utilities. It is also important that the technologies
considered not only represent those that are commercially available, but also those that are in the stage of
development that could be demonstrated in the field. An added benefit of this demonstration project is to
bring new technologies to the forefront of condition assessment research and allow utilities to become
familiar with these technologies.
After the technology screening, an e-mail transmittal was sent to prospective vendors in February 2009 to
solicit expression of interest. Most vendors responded promptly and expressed their keen interest in
participating in the demonstration. Several vendors were eliminated from further consideration due to
either lack of interest or financial constraints. Six vendors agreed to participate in and provide partial in-
kind contributions to the field demonstration project.
3.3 Technology Description
3.3.1 Acoustic Pipe Wall Assessment Technology Description. Relatively new, non-destructive
technologies are available for providing the estimates of the wall thickness averaged over an interval that
does not require taking pipes out of service. These methods typically work by inducing an acoustic signal
in pipes either by releasing water at a hydrant or inducing vibrations in the pipe wall (e.g. tapping,
electro-mechanical shaker, acoustic pulses, etc.) and measuring how quickly acoustic waves travel along a
section of pipe. The acoustic signals are measured either by external sensors positioned at locations along
the pipe such as at fire hydrants, control valves, and/or excavated holes or by internal sensors such as
hydrophones. The velocity of the acoustic vibration is then calculated based on the sensor spacing and
time delay between the measured acoustic signals. Average wall thickness of the pipe section is then
estimated based on its relationship to the acoustic velocity and the hoop stiffness of the pipe.
Systems can be fully external or used for a combination of internal and external components. For entirely
external systems, the length of the pipe section over which the acoustic velocity is measured is chosen
based on the local water main configurations, but usually ranges from about 300 to 700 ft between
sensors. If a higher thickness resolution is needed, the acoustic sensors can be moved closer together by
using keyhole vacuum excavations to access the pipe or by inserting arrays of closely spaced sensors. In
the case of wall thickness assessment systems with internal components, data can be collected by
positioning the movable sensor at specific distance intervals or by continuously collecting data over the
length of the pipeline.
The pipe wall thickness determined by these methods represents an average value for the pipe section
over which acoustic velocity is measured. In the development of this technology, research has shown
pipes will have a more-or-less uniform thickness profile over significant lengths (-150 ft to 300 ft) as soil
and bedding conditions are unlikely to change significantly over such distances (Hunaidi et al, 2004) .
Also, the average general wall thickness is believed by some to be a better indicator of the general
structural condition and remaining life of pipes than the depth of individual corrosion pits, especially for
the purpose of long-term planning of rehabilitation and replacement needs (Hunaidi, 2006).
The following average wall thickness assessment technologies participated in the demonstration at LWC:
Sahara® Wall Thickness Testing. The Sahara® WTT system, provided by PPIC (now part of Pure), is a
non-destructive inspection technology that estimates the average pipe wall thickness over a range of pipe
32
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segments in large diameter water transmission mains. Sahara® WTT can be performed in conjunction
with a Sahara® Leak Detection inspection under the same operating pressure, flow velocity, and
inspection distance constraints (pressure range from 7 to 230 psi; flow range from 1 to 5 ft/s; survey
length -6,000 ft depending on pipeline geometry, flow conditions, and internal pipe conditions).
Operation of the Sahara® WTT system is similar to the Sahara® Leak Detection system in which a 1 in.
diameter hydrophone is inserted into a live pipeline through any standard tap that is 2 in. in diameter or
greater. A drogue (parachute) is attached in front of the hydrophone to capture water flow and carry the
sensor and cable down the pipeline. However, wall thickness testing requires installation of a secondary
acoustic sensor (either an external accelerometer attached to the pipe surface or an additional internal
hydrophone) and generation of reference signals (e.g., test strikes at access points or sounds produced by
a speaker) within the pipe to facilitate testing as shown in Figures 3-4 and 3-5.
The sound waves generated by the reference signal propagate through the pipeline; the propagation speed
is affected by the condition of the pipe wall over the interval. Pairs of acoustic sensors separated by a
known distance are used to estimate the time that the reference signal arrives. This information is used to
calculate the speed of sound within the pipe and thus the average wall thickness over the specific
intervals. Detailed pipe information and fluid parameters are needed to calculate the average wall
thickness. Current testing procedures require access to the pipe (i.e. hydrant, flange, or exposed pipe
surface) a minimum of every 400 ft to generate reference acoustic signals.
Accelerometer
and Acoustic Unit
for Reference
Reference
Signal
Sahara^
Hydrophone"
Time Delay
(Courtesy of vendor)
Figure 3-4. Sahara Wall Thickness Technology
33
-------
(Courtesy of vendor)
Figure 3-5. Accelerometer Acoustic Sensor Attached to the Sahara® Insertion Tube
The tethered control of the Sahara® system allows the hydrophone to stop at precise locations for each
interval. Since the wall thickness average intervals are defined by hydrophone location, a high resolution
can be attained by indexing the hydrophone a short distance and repeating the data acquisition. However
incrementing the hydrophone in fine intervals will take increased time and hence costs. For these tests,
the travel times for sound pulses were determined at 33-ft intervals, and then the sound velocity was
calculated for the same interval.
Sahara® WTT has the same inspection limitations as the leak detection system. Like the leak detection
system, air pockets can significantly interfere with the wall thickness measurements by affecting the
acoustic signal propagation. Some factors affecting average wall thickness accuracy include: length of a
given section over which acoustic velocity is measured (the shorter, the more uncertain); distance
readings of the sections; accuracy of the pipeline and fluid parameters; unknown pipe features and
rehabilitation; large stationary air pockets; and, background noise. Each deployment at a site includes:
calibration of Sahara® WTT sensor's sensitivity and distance reading; calibration of reference acoustic
sensor for synchronization with Sahara® WTT; and, repeatability tests. A relative result is obtained based
on all calculated results in every 33 ft interval. A baseline pipe wall thickness would be calculated from a
group of intervals that show similar wall thickness results (< 2% difference from the mean), and the result
of other portions would show the wall thickness change ratio to this baseline value. This relative result is
provided instead of a calculated wall thickness to account for possible uncertainties introduced by
composite pipe material and fluid parameters.
SmartBall™ Pipe Wall Assessment (PWA). SmartBall™ (PWA) uses acoustic technology to assess
general pipeline condition. SmartBall™ (PWA) system is the SmartBall™ Leak and Gas Pocket
Location tool (Nestleroth, 2012) plus the additional capability of determining pipe wall stiffness. The
SmartBall™ (PWA) system components include: (1) the SmartBall™ , which travels through the full
pipe; (2) insertion and extraction devices for the SmartBall™; (3) SmartBall™ Receivers (SBR) that are
placed at fixed locations along the pipeline to receive acoustic pulses from the SmartBall™ that are used
to help track its position vs. time; and, (4) pulsers. also positioned along the pipeline, that send into the
pipeline low frequency acoustic pulses whose velocity varies with, and can be correlated to, the local
hoop strength of the pipe.
The SmartBall™ contains an acoustic acquisition device for leak sounds, etc.; an acoustic pulse generator
for transmitting acoustic signals to the SBRs for determining SmartBall™ location; accelerometers and
magnetomers, also for determining SmartBall™ location; timing devices for documenting time of
transmission and reception of acoustic signals, and for synchronization with SBR and pulser data; data
storage, and power supply. The SmartBall™ instrumentation is housed within an aluminum case, which
is coated with an elastomer. It is then placed within a foam ball (see Figure 3-6) prior to inserting into the
34
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pipeline. SmartBall™ is free swimming, does not require dewatering of the line or pipe excavation, and
can be operated for up to 15 hr. It is applicable for pipe diameters greater than 10-in., but is most
effective in pipes greater than 24-in. in diameter. The size of the SmartBall™ selected depends on the
various characteristics of the pipe, including diameter, valves, and appurtenances available, but is usually
less than one third of the diameter of the pipe.
SmartBall™ is inserted into the pipeline through a 4-in. diameter tap with a gate valve using an insertion
tube bolted to the valve (see Figure 3-7); this type of connection generally must be added to a water main.
As SmartBall™ is rolled through the pipe by the water flow, the PWA technology records information for
determining the pipe hoop stress at short, consecutive intervals along the pipe, and stores this information
for later analysis. SmartBall™ is then retrieved through another 4- or 6-in. diameter gate valve using an
extraction tube bolted to the valve that contains a specialized net that compresses the foam to capture and
remove it from the pipeline. Information can then be obtained from the SmartBall™ by downloading the
data at the end of the survey. The SmartBall™ software provides the acoustic information relative to the
distance the ball travelled.
The SmartBall™ PWA technology uses low frequency acoustic pulses to evaluate the hoop stiffness of
the pipe wall. The propagation velocity of a transmitted low frequency pulse from the pulser through a
pulsePWA technology utilizes the SmartBall™ acoustic sensor and long range mobility and tracking
capabilities to simultaneously assess the pipe wall condition and detect leaks.
The SmartBall™ PWA technology uses low frequency acoustic pulses to evaluate the hoop stiffness of
the pipe wall, which is indicative of pipe wall condition. The pipe wall condition is assessed by
effectively measuring the propagation velocity of a transmitted low frequency pulse from the pulser, and
then determining the hoop stress of the pipe. PWA technology utilizes the SmartBall™ acoustic sensor
and long range capabilities to simultaneously assess the pipe wall condition and detect leaks.
The low frequency pulses are generated by pulsers mounted onto the insertion and extraction stack (see
Figure 3-8). Pulsers can also be mounted on typical fittings found on pipes, such as valves and can also
be strapped onto the pipe itself. The number of pulsers used is dependent on the length of pipe inspected.
For this field demonstration of a fairly straight, approximately 2,057 ft long pipeline, three pulsers were
required. The propagation velocity is measured based on the arrival time of the acoustic wave from the
upstream and/or downstream pulsers and is compared to the arrival time difference of the pulse(s)
acquired at the previous position. The pipe wall stiffness in the interval traversed by the SmartBall™
between the pulses is correlated based on the propagation velocity of the pulse. As the pipe wall stiffness
decreases and increases, the propagating velocity decreases or increases respectively.
35
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Figure 3-6. Aluminum Case and Foam Housing for SmartBall™ Acoustic Acquisition Device, Data
Storage, and Power Supply
Figure 3-7. SmartBall™ Insertion and Extraction Tubes
36
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(Courtesy of Pure)
Figure 3-8. SmartBall™ PWA Insertion Stack with Pulser
The low frequency pulse generated by the pulser can be obscured by loud noise sources nearby and by
bends and elbows in the pipe. To compensate for the attenuation, three pulsers at nominally 1,000 ft
spacing were used for the field demonstration to ensure that the SmartBall™ would detect at least one
pulse at any given time in the straight pipe. Furthermore, the sensitivity and resolution of the
SmartBall™ PWA technology is also dependent on the velocity of the SmartBall™. The typical spatial
resolution of the SmartBall™ PWA tool is at least one data point every two ft. Since the pipe wall
stiffness is assessed at 2 ft intervals, it is unlikely that individual pits will be detected. However, the tool
is stated to have the capability to highlight areas where a cluster of pits compromises hoop stiffness or
where there is a local thinning of the pipe wall.
ThicknessFinder. ThicknessFinder uses a similar detection methodology as LeakFinderRT; however,
instead of listening for leaks, an acoustic signal is induced in the pipe to determine the acoustic wave
velocity in a section of pipe. For a given distance between the sensors, the acoustic wave velocity can be
calculated by v = d/t, where d is the distance between the sensors, and t is the time taken for the acoustical
signal to propagate between the two sensors. If an accurate measurement of the acoustic wave velocity is
made, it is possible to back-calculate the remaining average thickness of the pipe between the two
sensors. Typically, the length of the pipe section over which the acoustic velocity is measured is 300 ft to
1,000 ft; however this distance can be decreased to anywhere between 100 ft to 300 ft to increase the
resolution.
Echologics proprietary leak noise correlator, LeakfinderRT, was used to determine the acoustic velocity.
An acoustic source outside the section of pipe spanned by the surface mounted sensors (an 'out-of-
bracket' source) was used to induce an acoustic wave in the pipe; the time delay difference was measured
at the sensors; and, the acoustic velocity was calculated from the sensor separation and time delay data.
At each site, the noise source to induce the acoustic wave was either operation of a fire hydrant or
impacting a valve or hydrant.
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The vendor states that the average wall thickness of the pipe section between the acoustic sensors is then
back-calculated from a theoretical model. As the pipe wall thickness decreases over time, the acoustical
wave velocity decreases. The acoustical wave velocity is given in the Wave Velocity Thickness Model
below, which is based on research from NRCC (Hunaidi, 2004). This model does not include secondary
factors that affect the propagation velocity such as water temperature and pipe wall inertia. These factors
are not shown here, but were accounted for in the final results.
where
v: Propagation velocity of leak noise in pipe
v.;. Propagation velocity of sound in an infinite body of water
Ł'•: Internal diameter of pipe
^: Thickness of pipe wall
KWJt,,: Bulk modulus of elasticity of water
Erir,\ Young's modulus of elasticity of pipe material
Wave Velocity - Thickness Model
The acoustic propagation wave (the water hammer mode) propagates as a compression wave in the fluid,
and a dilatational wave in the pipe. There are two key implications of waves traveling in the fluid and
pipe:
1. Only the structural part of the pipe that can carry load will contribute to the structural stiffness of
the pipe, therefore deposits on the pipe wall such as tuberculation or graphite will not be included
in the average wall thickness measurement.
2. The minimum structural thickness of the pipe is measured, as the level of strain of the pipe will
be dependent on the minimum wall thickness at any point around the circumference of the pipe.
Using the above equation, the pipe wall thickness calculated from these measurements represents an
average value for the pipe section over which the acoustic velocity is measured. The technology has been
applied to generally much greater sample lengths of pipe than could be done with random sampling.
Therefore, when surveying long lengths of pipe, the operators begin to look for anomalies in the
measurements that could indicate degraded sections of pipe. When these are seen, the vendor suggests
the distance between the sensors may be decreased and more resolution obtained. Generally, pipes will
have a fairly uniform thickness profile with isolated pockets of corrosion over significant lengths (e.g.,
150 to 300 ft) as soil and bedding conditions are unlikely to change significantly over such distances.
Also, average wall thickness values are suitable to evaluate the residual life of pipes for the purpose of
long-term planning of rehabilitation and replacement needs. The use of techniques such as evaluation of
stray currents, soil corrosivity studies, and main break history may be used in conjunction with this
average wall thickness data to evaluate overall pipe condition.
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3.3.2 Internal Inspection Technology Description. Inline inspection technologies have been
used for years in the oil and gas industry to inspect pipelines for structural integrity issues such as
corrosion and mechanical damage. Inline inspection technologies for water mains can range from
relatively simple CCTV visual tools that assess the ID of the pipe to complex tools that assess the pipe
wall thickness including MFL, ultrasonic, and RFEC (RFT) tools. The more complex technologies have
only recently been used by utilities for inspection of large water mains after a few main breaks that
resulted in extensive service disruptions, significant property damage, and costly repairs. Inline
inspection systems that provide valuable pipeline condition information for critical, non-redundant, in-
service water mains are particularly desirable,
Issues that must be overcome for a wide-spread use of inline inspection technologies (other than CCTV)
for water mains includes the lack of launching and receiving facilities on existing water mains, the variety
of materials used to construct water pipelines, and the expense of conducting such inspections.
Three inline inspection technologies participated in the demonstration at LWC: Sahara® Video,
PipeDiver®' and See Snake® . Each technology is described in more detail below.
Sahara® Video. Sahara® Video provides real-time, in-service CCTV inline inspection of water mains.
During the inspection, the internal condition of the pipe is generally assessed and pipeline features such as
cement liner condition, valve locations, and debris or blockages are documented.
The Sahara® Video system utilizes the same control system and tethered cable as the Sahara® Leak
Detection system, but the hydrophone sensor head is switched to a video camera head that traverses the
pipeline after being inserted through a standard 2 in. tap. Additionally, the drogue (parachute) is attached
just behind the camera rather than in the front to carry the camera and cable down the pipeline without
obstructing the camera's view (see Figure 3-9).
An operator stands by at the controller station to control camera deployment and views the video output
in real-time. A second operator traverses the pipeline above ground using a tool to detect the exact
location of the camera as it travels through the pipe. When an item of interest is seen the second operator
will make a mark on the ground to identify the location and record a global positioning system (GPS)
point for reference.
Like the Sahara® Leak Detection system, the Sahara® video system has a limited survey length based on
the pipeline configuration and available flow rate. One circumstance or factor affecting accuracy is video
clarity. Video images become less clear in larger diameter pipes due to diffuse lighting, reduced field of
view, and unclear water. To calibrate the video system, each video camera is tested and compared to a
standard frequency response. Video is interpreted and analyzed in real-time, but also recorded for future
examination.
Figure 3-9. Sahara® Video System
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PipeDiver®. PipeDiver® is a non-tethered, free swimming platform for inspection of in-service water
mains (see Figure 3-10). The inspection vehicle allows inspection of pipelines from 24-in. in diameter
and larger through two 12-in. diameter taps installed on the pipeline, one at each end of the inspection
region. Large insertion and extraction tubes are installed on the 12-in. taps for launching and receiving
the tool (see Figure 3-10). Alternatively, reservoirs or open channels can be used as insertion and
extraction points.
PipeDiver® is a modular system that includes an electronics module, battery module, and transmitter
module for above ground tracking. PipeDiver® uses RFEC technology to generate magnetic currents in
ferrous pipes for detection of pipe anomalies. Pipe anomalies change the uniformity of the magnetic
current and this change can be measured with sensors. The vendor claims PipeDiver® was designed to
estimate the location, size, and depth of major corrosion anomalies in the pipe wall. A schematic of the
PipeDiver® inspection vehicle is provided in Figure 3-11.
For a standard launch, the insertion tube containing the PipeDiver® vehicle is attached to the 12-in. tap
before being filled with water, pressure equalized, and opened to the pipeline. The internal insertion
piston pushes the PipeDiver® vehicle into the pipe and, once fully in the pipe, the vehicle is released and
begins to travel with the flow (see Figure 3-12). For a standard retrieval, once the PipeDiver® vehicle
reaches the extraction side, a robotic claw and net which blocks the entire pipe diameter grabs the front of
the vehicle and secures it before pulling up out of the pipe and into the retrieval tube (see Figure 3-13).
The PipeDiver® vehicle travels at approximately 90% of the pipeline's flow rate, the neutrally buoyant
inspection vehicle can run for up to 30 hr in a single insertion. Flexible fins are used to center the tool
within the pipe and provide propulsion. Its flexible design also allows PipeDiver® to navigate through
most butterfly valves and bends in the pipeline, while travelling long distances.
RFEC works on the basic theory that when a time harmonic magnetic field is generated inside a metallic
pipe it has two paths from the exciter to detector coils (see Figure 3-14). The direct path remains inside
the pipe and couples the coils directly, while the remote path remains outside of the pipe as long as
possible. When the exciter-detector coil separation exceeds 1.5 pipe diameters, the signal from the
remote field significantly dominates the total signal received at the detector. Since the remote field path
passes twice through the pipe wall, any variation in magnetic wall properties including wall thickness,
conductivity, and magnetic permeability will result in a change in the detector signal. During the
demonstration of this developmental system, exciter coil position, frequency and type, along with sensor
configuration and type were changed and the results combined. Note that the changes in signals appear
twice in an RFEC tool, when the exciter and the detector pass respectively; the data analysis procedures
must match pairs of signals in order to properly locate corrosion defects.
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Figure 3-10. PipeDiver® Inspection Vehicle (left) and Insertion Tube (right)
Inspection
Electronics
Module
Battery
Module
Transmitter
Module
(Courtesy of vendor)
Figure 3-11. Schematic of PipeDiver® Inspection Vehicle
Extraction
Catch Point
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—*
(Courtesy of vendor)
Figure 3-12. The PipeDiver® Inspection System
Figure 3-13. PipeDiver® Extraction Tube and Robotic Claw
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(Courtesy of vendor)
Figure 3-14. RFEC Signal Paths
See Snake®. Russell NDE Systems Inc. custom developed a 24-in. See Snake® remote field testing
(RFT) tool specifically for the field demonstration. The See Snake® technology employs remote field
technology for measuring pipe wall thickness. RFT works by detecting changes in an alternating current
(AC) electromagnetic field generated by the See Snake®. As the electromagnetic field interacts with the
metallic pipe wall, it increases in magnitude at locations where metal loss exists. These changes in the
electromagnetic field can be detected and measured with on-board detectors and processed using analog-
to-digital (A/D) converters and digital signal processors (DSPs). The data is stored on-board for analysis
upon completion of the inspection run and also sent down the wire line for real-time examination.
Dedicated software is used to generate data on pipeline wall thickness and the location of metal loss.
Figure 3-15 schematically shows the magnetic coupling path between the exciter section of the tool and
the detectors.
Exciter Coll
Signal Flow Path
Lead To
Instrument and
Data Acquisition
Computer
(Courtesy of Russell NDE Systems Inc.)
Figure 3-15. Schematic of Magnetic Interaction between RFT Tool and Pipe
The tool is usually a few inches smaller than the pipe diameter and requires about 0.25- to 1-in. clearance
around the tool. The hard diameter of the tool is significantly smaller than the ID of the pipe to allow for
passage around protrusions, lining, and scale within the pipe. Centralizers maintain a uniform annulus
between the tool and the pipe. The recorded RFT signal is sent in real-time to a laptop via a wire line,
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which runs over an odometer sheave to provide an accurate distance reading for the tool. The RFT tool
detects wall thinning caused by corrosion or erosion, as well as line features such as bell and spigot joints,
couplings, branches and elbows. The amount of wire line on the winch limits the range of tethered runs,
and battery power would limit the range for future free-swimming configurations. Ultimately, the See
Snake® is designed to be launched in a live pipeline; however this was not possible for the demonstration
because it was a prototype system. A photo of the third of three modules of the See Snake® is shown in
Figure 3-16. The vendor limited photography of the proprietary, prototype unit.
In the basic RFT probe shown in Figure 3-17, there is one exciter coil and one detector coil. Both coils
are wound co-axial with respect to the examined pipe, and are separated by a distance greater than two (2)
times the pipe diameter. The actual separation depends on the application, but will always be a minimum
of 2 pipe diameters. It is this separation that gives RFT its name - the detector measures the
electromagnetic field remote from the exciter. Although the fields have become very small at this
distance from the exciter, they contain information on the full thickness of the pipe wall.
The detector electronics include high-gain instrumentation amplifiers and steep noise filters. These are
necessary in order to retrieve the remote field signals. The detector electronics output the amplitude and
phase of the remote field signal to an on-board storage device. The data is recalled for display, analysis,
and reporting purposes after the examination process is completed.
Figure 3-16. See Snake® (One of three modules)
Bnergyflaw path
Tnbe
Corrosion
(Courtesy of Russell NDE Systems Inc.)
Figure 3-17. Schematic of Magnetic Interaction between RFT Tool and Pipe
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3.3.3 External Inspection Technology Description. External condition assessment tools provide
detailed condition information for selected locations along the pipeline and then rely on statistical
methods to predict the condition of the entire pipeline segment. Often the detailed external assessments
are supplemented with soil corrosivity and coating condition data to improve confidence in the statistical
predictions. Although these technologies are capable of inspecting the entire pipeline length, that would
require excavation of the full length of the pipeline which is rarely practical.
External inspection of pipelines has been widely used because it allows the pipeline to remain in service
while the localized condition of the pipe is being assessed. Often small areas around the pipe must be
cleared because the sensors on the device need to have contact with the outside pipe surface.
AESL ECAT. The AESL pipeline assessment process identifies existing leakage failure patterns and the
likelihood of structural failure to predict future growth of these failure modes. Inspection is carried out
externally at selected pipeline locations using a range of AESL designed 'high flux' (HF) magnetic flux
leakage inspection tools and commercial ultrasonic instruments.
Typically, AESL conducts an initial assessment of the pipeline route and ground conditions to select the
optimum locations to inspect the pipeline8. Then, the pipeline is inspected to identify and provide
location, sizing, and imaging of internal and external defects, which are differentiated by proximity
sensors. Inspection begins with spot readings of original wall thickness and coating condition in a pre-
defined grid pattern (see Figure 3-18). Wall thickness measurements are taken using conventional
ultrasonic inspection tools, while pipeline coating condition is assessed visually. Wall condition
assessment is then completed using ECAT over 1 m long lengths around the pipe circumference9 (see
Figure 3-19). The ECAT is equipped with GPS and blue tooth technology that is used to transfer the data
in real-time. Once inspections are complete, AESL applies statistical models developed in-house to
predict the condition of long lengths of un-inspected pipe from the results of the few local inspections.
RSG HSK and CAP. The RSG inspection tools use a patented BEM technology to assess localized
pipeline condition in ferrous pipes. These technologies work by inducing a broadband eddy current pulse
in the pipe wall; the decay of the eddy currents are measured with sensors to determine the remaining wall
thickness and fractures (Liu et al., 2012). Sensors can be as small as a 1 in2 and can detect corrosion
pitting as little as 10% of the wall thickness over the entire sensor aperture; corrosion with length and
width smaller than the aperture will produce a proportionally smaller signal. Since the electromagnetic
field can penetrate depths 2.5 times the diameter of the transmitter, it is not necessary for the inspection
system to be in close contact with the pipe; some dirt on the outside of the pipe is acceptable as long as
the system indicates an acceptable signal is attained. This is advantageous for piping systems that are
coated, lined, or insulated. Data can be obtained in real-time or stored for later processing and analysis.
Often, comparisons are made between real-time and processed data to ensure quality of on-site reports.
During the field demonstration, RSG demonstrated two surface scanning systems, one is a fully
commercially available HSK, which externally scans along the length of the pipe as well as around the
pipe circumference (see Figure 3-20); the other is a keyhole inspection system called the CAP, which at
This was not possible during the field demonstration as the inspection locations were predetermined for logistical
reasons.
9 The amount of circumferential coverage depends on the pipeline diameter. For pipe diameters less than or equal to
6-in., full circumferential inspection is provided. For pipe diameters greater than 6-in., inspection is conducted over
105 mm wide increments.
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the time of the demonstration was not commercially available (see Figure 3-21). The HSK is a line of
sensors that is manually moved around the pipe to make a 2 dimensional image. The CAP has a 2-
dimensional array of sensors and records an image with one placement by sequencing through the
sensors. The HSK is an in-the-ditch method designed to examine part or full circumference of the pipe
depending on what is possible to expose. The CAP is capable of scanning the portion of pipe exposed via
the excavation from the street, which in this demonstration was a small excavation exposing only the
crown of the pipe.
Figure 3-18. Grid Pattern Used for Ultrasonic Wall Thickness Measurements and Coating
Assessment
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Figure 3-19. AESL ECAT
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Figure 3-20. RSG Hand Scanning Kit (HSK)
Figure 3-21. RSG Crown Assessment Probe (CAP)
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Advantages of the RSG's HSK and CAP external inspection systems include:
• Scanning is not limited by the diameter of the pipe.
• Capable of surveying through thick coatings (50 mm+) such as paint or tar commonly found on
pipelines.
• The line can remain in service as readings are taken from the external pipe surface.
• Negligible effect of outside stray current fields potentially contaminating resulting data. Where
stray fields are identified (these can be clearly seen in captured data - variations in data capture
parameters are possible since the device is non-frequency dependent).
3.4 Site/Test Preparation. Several activities were necessary prior to, during, and after the
field demonstration to accommodate the various technology vendors/visitors and to verify the
inspection conditions. The following sections detail specific measures taken to make the
demonstration successful for all that participated.
Prior to the actual demonstration, the condition of the test pipe was relatively unknown, aside from basic
pipeline location data and information obtained during previous leak investigations. In June 2009, the
valves at both ends of the 2,057-ft test pipe were closed to evaluate if there was any significant pressure
drop in the system. This assessment showed that the line maintained a nominally constant pressure for a
full day, so it was quite possible that there were no large natural leaks in the test pipe. The leak testing
portion of this demonstration revealed only one large leak at a bell and spigot joint and less than a dozen
smaller leaks. Leaks at the main supply valve may have provided sufficient water to make up for the
leaks from corrosion or at joints. Because of the observations from opportunistic excavations for
maintenance, repair, and tapping; leak testing results; and, the ability to hold pressure, it was not
anticipated that there would be many large wall corrosion defects in the barrel of the pipe.
3.4.1 Access Requirements
Acoustic Pipe Wall Assessment. The internal leak detection/location and inspection technologies
required only the installation of relatively small taps (2 to 4-in. in diameter) for the insertion and
extraction of the inspection tools. However, the in-line, RFEC inspection technology (PipeDiver®)
demonstration required installation of a 12-in. diameter tap and gate valve with a mechanical joint (MJ)
fitting at each end of the test pipe for insertion and retrieval. Therefore, reducers were used for the
demonstration to transition between the access requirements for internal leak detection/location and pipe-
wall screening equipment and the 12-in. MJ fitting for PipeDiver®.
For the Sahara® WTT, a 12-in. MJ to 6-in. MJ reducer and a 6-in. MJ cap with a 2-in. National Pipe
Thread (NPT) tap were used.
SmartBall™ required either a 4-in. or 6-in. American National Standards Institute (ANSI) flange for a
gate valve to launch its equipment. To achieve this set-up, a 12-in. MJ to 6-in. MJ reducer and a 6-in. MJ
to 6-in. ANSI flange were used because this equipment could be easily provided by LWC. LWC supplied
all pipe fittings for the demonstration. Video inspection methods confirmed the pipe did not have any
internal obstructions such as tuberculation, which may have impeded the application of internal inspection
technologies.
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ThicknessFinder required direct access to the pipe exterior for placement of accelerometers at
approximately 300 ft intervals. The intervals were achieved through five large excavation sites and six
smaller excavated holes. In addition, Echologics required the gate valves isolating the test pipe to be in
the open position to prevent reflection of the induced acoustic wave. A summary of all access
requirements is provided in Table 3-2.
Table 3-2. Summary of Test Pipe Access Requirements for LWC Demonstration for Wall
Thickness Screening Technologies
Vendor
PPIC
(now part of
Pure)
Pure
Technologies
Type of
Inspection
Internal;
tethered
Internal
Technology/
Product
Sahara® Wall
Thickness Testing
(WTT)
SmartBall™Pipe
Wall Assessment
(PWA)
Flow Requirements/
Pipeline Constraints
Flow must be >1 ft/s for
single 2-in. diameter tap;
Mule tape is required in
no-flow situations or when
flow is insufficient.
At lower flows, the
parachute is unable to
overcome the drag of the
cable for a given distance.
Requires appurtenances
along pipeline to place
receivers
Flow range reported at
time of demonstration was
> -0.8 ft/s, but < -1.5 ft/s;
Note: Pure reports
inspections as low as 0.5
ft/s and as high as 7 ft/s.
Pipe Access
Requirements
For internal access, One
per inspection interval
(every 2,500 ft for LWC
demonstration; up to 6,000
ft based on Sahara®
maximum cable length).
A 2-in. diameter (or
larger) tap with female
NPT thread reducer
located at upstream to the
section to be inspected;
-10 ft clearance to mount
insertion equipment.
Direct external access to
the top of the pipe for
sound generation every
250 to 400 ft.
Two per inspection
interval (at beginning and
end of inspection).
4-in. or 6-in. diameter
clear bore gate valve.
> 8 ft vertical clearance at
launch tap and > 12 ft
vertical clearance at
retrieval tap.
Both taps at 12 o'clock
position.
Pulsers installed
approximately every 1,000
ft.
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Vendor
Echologics
Engineering
Type of
Inspection
External
Technology/
Product
ThicknessFinder
Flow Requirements/
Pipeline Constraints
Requires appurtenances
and/or pipe access to place
sensors
Requires air to be removed
from the line. Requires
gate valves to be in the
open position to prevent
reflection of induced
acoustic wave.
Pipe Access
Requirements
Two per inspection
interval. Accelerometers
require solid contact with
the pipe exterior.
Pipe access every 200 to
500ft
Internal Inspection. This section summarizes the pipe access and other requirements for deployment of
the internal inspection technologies.
For the PipeDiver® in-line inspection technology demonstration, a 12-in. diameter tap and gate valve with
MJ fitting was installed at each end of the test pipe to install insertion and retrieval tubes. These insertion
and retrieval tubes measure over 20 ft in height and 12 in. in diameter and require a vertical clearance of
over 40 ft at the PipeDiver® launch and retrieval locations.
See Snake® required removal of an 8 ft section from the launch and retrieval points to insert and remove
the equipment from the test pipe during the demonstration. The device was pulled through the drained
and swabbed pipe with a cable. Modifications are planned to enable un-tethered inspection in a full pipe.
The Sahara® Video technology required only the installation of a 2-in. diameter tap for the insertion and
extraction of the tool. Modifications were made to the 12-in. MJ fitting to facilitate launching of the
Sahara® Video equipment. Specifically, a 12-in. MJ to 6-in. MJ reducer and a 6-in. MJ cap with a 2-in.
NPT tap was used. LWC supplied all pipe fittings for the demonstration. The access requirements for all
three technologies are summarized in Table 3-3.
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Table 3-3. Summary of Test Pipe Access Requirements for LWC Demonstration for
Internal Inspection Technologies
Vendor
PPIC
(now part of
Pure)
Russell NDE
Systems Inc.
Type of
Inspection
Internal;
tethered
Internal
Internal
Technology/
Product
Sahara® Video
PipeDiver®
See Snake®
Flow Requirements/
Pipeline Constraints
Flow must be >1 ft/s for
single 2-in. diameter tap;
Mule tape is required in
no-flow situations or
when flow is insufficient.
At lower flows the
parachute is unable to
overcome the drag of the
cable for a given distance.
Butterfly valves > 30-in.
in diameter
Consistent flow rate with
a minimum of 0.7 ft/s and
maximum flow rate ~1.5
ft/s for data collection
Cleaning pig; boom truck
to lower tool; need 8 ft
long tray at open ends of
main; machined, flat
bottom defects to be
spaced 5-in. apart for
calibration
Pipe Access
Requirements
A single 2-in. diameter (or
larger) tap with female
NPT thread reducer located
at upstream end;
~10 ft clearance to mount
insertion equipment.
Two 12-in. diameter taps at
each end of inspection
region with > 40 ft vertical
clearance above taps.
Requires flatbed truck and
crane to move -3,000 Ib
Two excavations with
clearance for 8 ft pipe
removal
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External Inspection. In general, the ECAT and HSK external inspection tools require exposure of a 4 to
6 ft length of pipe with at least 1 ft circumferential clearance every 300 to 2,500 ft along the pipeline. To
accommodate these requirements, three excavation pits were selected by EPA's contractor along the test
pipe based on location constraints and some preliminary condition assessment data. To accommodate
RSG's CAP system, five smaller excavated holes were created and spaced at regular intervals along the
test pipe (approximately every 300 ft). These access requirements for the external inspection
technologies are listed in Table 3-4.
Table 3-4. Summary of Test Pipe Access Requirements for LWC Demonstration for
External Inspection Technologies
Vendor
Advanced
Engineering
Solutions, Ltd.
(AESL)
Rock Solid
Group (RSG)
Type of
Inspection
External
External
External
Technology/
Product
External
Condition
Assessment
Tool (ECAT)
Hand Scanning
Kit (HSK)
Crown
Assessment
Probe (CAP)
Pipeline
Constraints
May require removal of
coating; soil and surface
conditions
Excess soil removed from
the pipe surface; residue
soil , surface corrosion,
and coating can remain
Typical vacuum excavated
holes 8-in. in diameter
Excess soil removed from
the pipe surface; residue
soil , surface corrosion,
and coating can remain
Pipe Access
Requirements
At least three excavations
with 2 ft circumferential
clearance
At least three excavations
with at least 1 ft
circumferential clearance
At least three vacuum
excavated 8-in. diameter
holes
3.4.2
Safety, Logistics, Excavation, and Tapping
Safety and Logistics. During the demonstration, MAC Construction (LWC's contractor) was
responsible for traffic rerouting and control. All technology demonstrations occurred on weekdays during
normal business hours. While the demonstration was ongoing, portions of Westport Road were closed to
through traffic, with some access allowed for local businesses. At the end of each day, MAC
Construction plated all open excavations during the evenings and weekends and reopened both lanes of
traffic on Westport Road.
A construction trailer (see Figure 3-22) equipped with electrical power provided a work space for the
inspection technology vendors, as well as equipment storage during the demonstration. At least one EPA
contractor was on site each day of the demonstration and coordinated the dissemination of safety and
contact information to the technology vendors and visitors. All logistical and operational questions were
handled by the EPA contractor. The EPA contractor also coordinated daily activities with the technology
vendors, MAC Construction foreman, and LWC inspectors to ensure that the demonstration ran
efficiently and effectively.
Several visitors, including representatives of the EPA and utility companies, came to the site during the
demonstration. Visitors were instructed to pre-register via e-mail and sign in with the EPA contractor at
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the construction trailer before going on site. Safety gear including hard hats, steel-toed shoes and safety
vests was required before visitors could gain access to the demonstration site.
Figure 3-22. Construction Trailer for Equipment Storage and Work Space
Excavation. Five large excavations were used for the various technologies during the demonstration;
these included Pits 1 through 5 as shown in Figure 3-23 and described in Table 3-5. These sites were
selected based solely on location along the test pipe. Since the condition of the pipe was initially
unknown, EPA's contractor machined several metal loss defects within Pits 2, 4, 5, and F10 to facilitate
tool calibration and to ensure defects were available to find during inspection. Six small excavations,
identified as Pits A, B, C, D, E, and F in Figure 3-23, were used to demonstrate one leak detection system
and several other condition assessment technologies. Pictures of pre-excavation locations for Pits 1, 2,
and 3 are shown in Figures 3-24 through 3-26.
Three large excavations were used for the external condition assessment technologies during the
demonstration including Pits L, 2, and F as shown in Figure 3-23 and described in Table 3-5. These sites
were selected based on location constraints; Pit L was near an excavation to confirm the largest leak
detected in first few weeks of the demonstration. Since the condition of the pipe was initially unknown,
EPA's contractor machined several metal loss defects within Pit 2 and Pit F to facilitate tool calibration
and to ensure defects were available to find during inspection. Also, small pit-like metal-loss defects
were installed in Pit 4 and 5.
Although calibration defects were machined into Pit F, these were not installed until week three of the
demonstration and therefore were not available during the Sahara® Wall Thickness Assessment and Echologics
initial visit to the demonstration site. Pit F was originally planned to be a keyhole excavation; however a significant
amount of external corrosion was found within the pit and it was decided to make the pit larger for the external
condition assessment technologies discussed in this report.
54
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Pit #2 (1080' from Pit #1; St. Matthews Ave.)
Corp Valve 3 4 5 & 6, machine defects
12 Discharge to
Sanitary Sewer
PitF
(1750' from Pit #1)
Pit #3 (2057' from Pit #1 near Ridgeway Ave.)
Pit #4 (581'from Pit #1)
PitE
(1439'from
One 24 x 12 tee (with adapters to 2 and 6 )
Corp Valve 1 & 2, machine defects
PitD
(1173'from Pit#1)
Pit #1 (near Chenoweth Ln.)
Pit #5 (1580'from Pit #1)
One 24 x 12 tee with adapters to 2 and 6
Corp Valve 7 & 8, machine defects
PitC
(809'from Pit #1)
„ ° Pit B
(510'from Pit#1)
PitL
(338'from Pit #1)
Machine defects
__
WESTPORT RD
— 24 Pipe
— 30" Pipe
I I 10'Wx 16'L Trench Box
• 6' x 6' Sensor Pit
{] Fire Hydrant
Discharge Point
Pressure Gauge
Chenoweth Ln
to
Ridgeway Ave
0 125 250
—
SCALE IN FEET
DATE: 10/22/08
Figure 3-23. Location of Pits for Demonstration
-------
Table 3-5. Summary of Access Pits - Description and Purpose
Pit ID
Pitl
Pit 2
Pit3
Pit 4
Pit5
Pit A
PitB
PitC
PitD
PitE
PitF
PitL
Description
• Near Chenoweth Lane at location of first
24-in. x 12-in. tee
• 8 ft of pipe exposed
• Reference point - 0 ft
• Intersection of Westport Road and St.
Matthews Avenue
• -1,080 ft from first 24-in. x 12-in. tee in Pit
#1
• ~8 ft of pipe exposed; ~2 ft circumferential
clearance
• Near Ridgeway Ave. at location of second
24-in. x 12-in. tee
• -2,057 ft from first 24-in. x 12-in. tee
• 8 ft of pipe exposed
• -581 ft from first 24-in. x 12-in. tee
• 3 ft of pipe exposed; top half only
• -1,580 ft from first 24-in. x 12-in. tee
• 3 ft of pipe exposed; top half only
• -250 ft from first 24-in. x 12-in. tee in Pit
#1
• -3 ft of pipe exposed; top portion only
• -5 10 ft from first 24-in. x 12-in. tee in Pit
#1
• -3 ft of pipe exposed; top portion only
• -809 ft from first 24-in. x 12-in. tee in Pit
#1
• -3 ft of pipe exposed; top portion only
• -1,173 ft from first 24-in. x 12-in. tee in Pit
#1
• -3 ft of pipe exposed; top portion only
• -1,439 ft from first 24-in. x 12-in. tee in Pit
#1
• -3 ft of pipe exposed; top portion only
• -1,750 ft from first 24-in. x 12-in. tee in Pit
#1
• -20 ft of pipe exposed; -2 -ft
circumferential clearance
• 326 ft from first 24-in. x 12-in. tee in Pit 1
• -14 ft of pipe exposed; -2 ft
circumferential clearance
Purpose
• Launch internal inspection technologies
• Install 12-in. service tap; attach 12-in. x 2-in.
and 12-in. x 6-in. reducers to allow access for
internal tools
• Install four 1-in. service taps for leak simulations
• Install two calibration metal loss defects*
• Install nine additional metal loss defects for
condition assessment*
• Retrieve internal inspection technologies
• Install 12-in. service tap; attach 12-in. x 2-in.
and 12-in. x 6-in. reducers to receive internal
tools
• Install 12-in. tee to divert flow to storm/sanitary
sewer
• Install two, 1-in. service taps for leak simulations
• Install pit-like metal-loss defects for condition
assessment*
• Install two, 1-in. service taps for leak simulations
• Install pit-like metal-loss defects for condition
assessment*
• Small excavation for LeakFinderRT, keyhole
condition assessment technologies and soil
sampling*
• Small excavation for LeakFinderRT, keyhole
condition assessment technologies and soil
sampling*
• Small excavation for LeakFinderRT, keyhole
condition assessment technologies and soil
sampling*
• Small excavation for LeakFinderRT, keyhole
condition assessment technologies and soil
sampling*
• Small excavation for LeakFinderRT, keyhole
condition assessment technologies and soil
sampling*
• Small excavation for LeakFinderRT, keyhole
condition assessment technologies and soil
sampling; significant graphitization was found
when excavated*
• Install one large calibration defect (metal-loss
defect - 6 1/8 in. long; 0.28 to 0.45 in. depth)*
• Large leak detected
• A large leak was verified at the bell and spigot
joint.
* These pits were created for demonstration of condition assessment technologies, but were also used to
demonstrate the external leak detection technology (LeakFinderRT).
56
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Figure 3-24. Location of Pit 1 - Near Chenoweth Lane
Figure 3-25. Location of Pit 2 - Near St. Matthews Ave
57
-------
Figure 3-26. Approximate Location of Pit 3 - Near Ridgeway Avenue
Five small excavations were used for external condition assessment. RSG used these locations with their
CAP technology. AESL used these locations for soil sampling. These locations were Pits A, B, C, D,
and E. Soil measurements were also taken by AESL in Pit 1 and Pit 3, which were used for launching the
internal inspection and leak detection tools.
Generating Flow. While some of the inspection
technologies require flow to detect and locate leaks, the test
pipe was no longer supplying water to customers in
anticipation of the pending replacement project. Therefore,
to create flow during the demonstration, water was supplied
to the test pipe through a valve near Chenoweth Lane
connected to a 30-in. diameter line with a pumping station
within a mile. At the end of the test pipe, the flow was
diverted to the sanitary sewer through a 12-in. gate valve and
high density polyethylene (HDPE) line located downstream
of Pit 3 (see Figure 3-27).
There were two drawbacks to this arrangement. First, the
discharge was essentially a very large leak that created noise
during the demonstration and which added to the background
noise recorded by the acoustic sensors: the effects of which
Figure 3-27. Test Pipe Discharge to
Storm Sewer Configuration
became more pronounced as technologies neared the discharge point. Second, because the discharge was
diverted to the combined sewer, it could not be used immediately after heavy rainfall to prevent sewers
from overflowing. Rain delayed several of the demonstrations with a record rainfall of 6.5-in. on August
4, 2009, causing a 2 !/2-day delay.
58
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Internal Inspection Test Pipe Opening/Cut-out. Prior to the inline inspection by Russell NDE Systems
Inc., an 8 ft section of the pipe was removed from Pit 1 and Pit 3 to allow for access to the pipe interior;
this included removal of the 12-in. tee section plus some additional pipe. At the time of the
demonstration, the prototype See Snake® used a winch and cable to pull the tool through the pipeline
rather than being transported by the water flow. The line had to be emptied and a foam pig was used to
remove water that collected in the low spots.
Prior to the See Snake® demonstration, a video inspection of the test pipe was conducted by Pipe Eyes,
LLC to identify any significant pipe restrictions that would prevent a successful demonstration of the See
Snake® technology. Since no restrictions were found, a tether was inserted in the test pipe using the water
flow to eventually thread the pull cable (mule tape) once the line was dewatered. A wooden support
system was provided for launching and receiving the See Snake® technology. Additional equipment
included a backhoe to raise and lower the tool into the pit, as well as the winch and cable system to pull
the tool through the pipeline.
3.4.3 Machined Defects. A milling machine on a magnetic base shown in Figure 3-28 was used to
create several machined metal loss defects that were installed in Pit 2, Pit 4, Pit 5, and Pit F. The intent of
installing machined corrosion defects was: (a) to provide defects for vendors to calibrate their inspection
devices, and (b) to create a set of "hidden" defects whose characteristics were only known by the EPA
contractor, not the inspection vendor. The intent was to produce external defects ranging from simple to
difficult to detect and/or size for in-line and external electromagnetic inspection technologies. In this
way, the demonstration could help to define both the current capability and future challenges for each of
the inspection technologies. Some wall thickness assessment technologies only identify average changes
in wall thickness over a specified pipe length and therefore are not intended to find individual defects
unless the defect is large enough to cause a significant change in the pipe wall hoop stress.
>WSoEM
Figure 3-28. Magnetic Base End Mill Used to Create Machined Defects
59
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The calibration defects were provided to the inspection vendors for system verification and calibration to
facilitate subsequent analysis and post-processing. The manufactured defect sizes ranged from
approximately 1- to 3-in. in length with depths varying between 20% up to 70% wall loss; the Pit F defect
was four closely spaced pits with a 6-in total length. All machined defects (except the calibration defects)
were filled with a non-conductive material to dissuade the vendors from manually measuring the defects
in the ditch. The machined defect configurations for Pit 2, Pit 4, Pit 5 and Pit F are shown in Figures 3-29
to 3-32, while descriptions and photos of each unknown machined defect are provided in Tables 3-7 to 3-
9. During installation of these defects significant areas of natural corrosion were found in the line. As
such, the machined defects were placed as to not disturb the natural corrosion.
Table 3-6. Calibration Defects Provided to Technology Vendors
Calibration
Defect ID
2-0-1 (cal)
2-0-2 (cal)
F-0-1 (cal) - 4
closely spaced
pits
Location
(ft)
1081
1082
1750.7
1750.8
1750.9
1751.0
Degree
Length
(in.)
2.75
1.3125
1.25
1.4375
1.5
1.75
Width
(in.)
1
1.3125
1.25
1.4375
1.5
1.75
Depth
(in.)
0.28
0.44
0.28
0.36
0.40
0.45
Table 3-7. Hidden Defects for Inspection - Pit 2
Defect ID
Location
(ft)
Degree
Length
(in.)
Width
(in.)
Depth
(in.)
Photo
2-45-1
1081.5
45°
2.25
1
0.36
60
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Table 3-7. Hidden Defects for Inspection - Pit 2 (Continued)
Defect ID
Location
(ft)
Degree
Length
(in.)
Width
(in.)
Depth
(in.)
Photo
2-45-2
1082.6
45°
2.9375
1
0.26
2-45-3
2-45-4
2-45-5
1083.7
1084.6
1085.5
45°
1.0
0.53
45°
3.75
0.23
45°
1.25
1.25
0.50
2-90-1
1082.0
90°
2.3125
0.41
2-90-2 - 2
closely spaced
pits
2-90-3
1083.1
1084.1
90°
1.75
1.9375
0.12
0.14
90°
3.0
0.19
61
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Table 3-7. Hidden Defects for Inspection - Pit 2 (Continued)
Defect ID
Location
(ft)
Degree
Length
(in.)
Width
(in.)
Depth
(in.)
Photo
2-90-4
1085.1
90°
2.3125
1
0.35
Table 3-8. Hidden Defects for Inspection - Pit 4
Calibration
Defect ID
Location
(ft)
Degree
Length
(in.)
Width
(in.)
Depth
(in.)
Photo
4-0-1
577.1
0°
1.0625
1.0625
0.32
4-0-2
578.4
1.375
1.375
0.37
4-0-3
579.4
1.25
1.25
0.24
62
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Table 3-9. Hidden Defects for Inspection - Pit 5
Calibration
Defect ID
Location
(ft)
Degree
Length
(in.)
Width
(in.)
Depth
(in.)
5-0-1
5-0-2
5-0-3
1580.5
1581.7
1586.2
0°
1
1
0.23
0.41
0.45
63
-------
•D
Ul <
II
ro
Defect
(Calibr
N
35%-37% rr
1"x2
•c
0Q
iui
ro
Defect 2-90-1 Defect 2-90-2 Defect 2-90-3 Defect 2-904
CD CD-CD CZD CD
55% metal loss 16%-18% metal loss 20%-25% metal loss 47% metal loss
1"x2.3125" 1"x1.75" &1"x 1.9375" 1"x3" 1"x2.3125"
Defect 245-1 Defect 245-2
I I I I
48% metal loss 35% metal loss
1"x2.25" I 1"x2.9375"
2-°-1 Defect 2-0-2
>«on| (Calibrationl (Natl
D 0
etal loss 59% metal loss
75" 1.3125"x 1.3125"
I A
3/4" CV3
3/4" CV
Defect 245-3 Defect 2454
71% metal loss 30% metal loss
1"x1" 1"x3.75"
N1 &N2
ral Corrosion) N3 N4 N5
x [x| x x
•
3/4" CVS
4
Defect 245-5
66% metal loss
1 .25" x 1 .25"
1080
1081
1082
1083
Axial Distance
1084
1085
1086
1087
Figure 3-29. Machined Defect Locations in Pit 2
-------
TJ
C
UJ<
3 W
ra
Defect 4-0-1
42% metal loss
1.0625" diameter
in
T-
n
feet
3/4" CV 1
"g
Im
ra
Defect 4-0-2
O
49% metal loss
1.375" diameter
3/4" CV2
Defect 4-0-3
O
32% metal loss
1.25" diameter
577
578
Axial Distance
579
580
Figure 3-30. Machined Defect Locations in Pit 4
-------
•o
Ł<
n
TO
Defect 5-0-1
31% metal loss
1" diameter
T3
C
Ilil
Defect 5-0-2
O'
55% metal loss
1" diameter
4
34"
... _|.
CV7 j
3/4" CVS
Defect 5-0-3
0% metal loss
1" diameter
1 580
1581
1 552
1583 1584
Axial Distance
1 555
1586
1 557
Figure 3-31. Machined Defect Locations in Pit 5
-------
b
h-
CM
c
UJ <
Defect F-0-1
OOOO
35%-59% metal loss
1.25"-1.75" diameter
•o
c
UJ <
1750
1751 1752
Axial Distance
1753
Figure 3-32. Machined Defect Locations in Pit F
-------
3.5
Test Configuration
3.5.1 Pipe Wall Assessment. Three vendors participated in the water main inspection
demonstration for acoustic wall thickness assessment technologies on the following dates:
• ThicknessFinder - On site from July 6, 2009 through July 8, 2009 then again August 10, 2009
through August 12, 2009'
• Sahara® Wall Thickness Testing - On site from July 13, 2009 through July 17, 2009; wall
thickness assessment on July 16 and July 17.
• SmartBall™ PWA - On site from August 3, 2009 through August 7, 20092
The activities conducted each day are provided in Table 3-10.
Table 3-10. Daily Activities for Each Wall Thickness Assessment Technology Vendor
Date
Daily Activities
ThicknessFinder - One operator
Jul. 6
Jul. 7
Jul. 8
Aug. 10
Aug. 11
Aug. 12
• Checked-in at demonstration site and set-up equipment
• Unable to complete noise test; background levels appeared low
• Installed sensors (accelerometers) in Pits 1 and 3 with receiver in Pit C
• Assessed background noise; added filters
• Reconfigured to 1,000ft
• Pipe pressure at 53 psi
• Suspected that the pipe had air pockets because could not get a clear signal;
tried to swap RF transmitters
• Still unable to get a good signal; prior experience by the vendor suggested that
the cause of the poor signal may have been air in the line.
• Opened fire hydrant to purge air from line; milky water observed.
• Did not get any data; arranged to come back at a later date
• Checked-in at demonstration site and set-up equipment
• Condition assessment for pipe from Pits 1, 2, and 3 using accelerometers
• Found one large leak and one or two smaller leaks
• Hydrophones placed in various pits to conduct leak detection
• Pipe pressure between 52 and 54 psi
• Road traffic near pits caused noise interference. Test repeated.
• Packaged equipment for shipping
1 Because a significant amount of air was in the line during their first visit to the demonstration site, Echologics was
unable to get accurate data from their ThicknessFinder and LeakfmderRT technologies. The test pipe was
dewatered and cut a few weeks prior to the demonstration to install tees at both ends of the test pipe. While the test
pipe was filled and flushed for a few hours upon completion of the tee installation, a video assessment showed that
air pockets remained throughout the pipeline. Attempts were made by LWC to remove air from the line and
Echologics was permitted to return at a later date to complete their demonstration.
2 Heavy rain fall occurred on August 4, 2009, preventing LWC from discharging to the storm sewer for 2-1/2 days.
As such, Pure was unable to access the pipeline for leak assessment until August 6, 2009.
89
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Table 3-10. Daily Activities for Each Wall Thickness Assessment Technology Vendor (Continued)
Date
Daily Activities
Sahara* -2-3 operators
Jul. 13
Jul. 14
Jul. 15
Jul. 16
Jul. 17
• Checked-in at demonstration site and set-up Sahara® Video equipment
• Pipe pressure at 56 psi; flow rate ~ 2.6 ft/s with three valve turns
• Launched Sahara® Video; parachute failed to deploy and was replaced
• Started video inspection; increased flow to keep camera from bouncing (-2-2-
!/2 hours)
• Retrieved Sahara® Video equipment (~45 minutes)
• Launched Sahara® leak detection equipment for calibration survey; natural
leaks and simulated leaks detected during all surveys
• Conducted second leak detection survey
• Pipe pressure at ~58 psi
• Launched Sahara® leak detection equipment for third and fourth simulated leak
surveys
• Installed accelerometers for condition assessment
• Launched Sahara® WTT equipment - hydrophone
• Pipe pressure at ~55 psi
• Finished condition assessment
• Pipe pressure at ~55 psi
• Conducted leak detection survey with new hydrophones
• Prepared for PipeDiver® inspection
• Packaged equipment for shipping
SmartBalFM - Two operators
Aug. 3
Aug. 4
Aug. 5
Aug. 6
Aug. 7
• Check-in at demonstration site and set-up equipment
• Significant rain event; demonstration canceled
• Significant rain event; demonstration canceled
• Installed sensors in Pits 1, C, and 3
• Installed insertion and extraction tubes
• Conducted first SmartBall™ run (~45 minutes)
• Conducted second SmartBall™ run (~50 minutes)
• Dismantled insertion and extraction tubes
• Installed insertion and extraction tubes
• Conducted first SmartBall™ run (-75 minutes)
• Conducted second SmartBall™ run (~53 minutes)
• Conducted third SmartBall™ run (-44 minutes)
• Dismantled insertion and extraction tubes
• Packaged equipment for shipping
13
More were on site for the demonstration. The inspection vendor used the demonstration to train new operators.
69
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Sahara® WTT. Five Sahara® insertions were performed from July 13 to July 17 for three different
inspection technologies (leak detection, video, and condition assessment) that used the same tether,
insertion equipment, and tracking method as the leak detection technology. The equipment arrived by a
custom vehicle on the morning of the inspection. The vehicle contained the sensors, cable deployment
system, support electronics, and electrical power for conducting video, leak, and condition assessment
surveys. Sahara® WTT was performed on July 16 and 17, 2009 in conjunction with Sahara® Leak
Detection activities. The Sahara® sensor head was inserted into Pit 1 and secondary external sensors were
installed at Pits A, C, E, and 3 to conduct the structural integrity survey. Multiple test reference signals
were generated at each of the pits to conduct the wall thickness measurements.
With the proper fittings being installed prior to the inspection, set-up required about 2 hr and tear down
required about 1 hr. Set-up and tear down were faster on subsequent days of the demonstration. All of
the fittings that touched the water were sprayed with a chlorine solution for sterilization. During several
inspections, at the request of the operator, the pipeline flow rate was increased to counteract the
increasing weight of the tether so that the sensor head could be carried the entire length of the test pipe.
Throughout the demonstration observers could watch data being collected on computer screens and speak
with analysts about the real-time results. A preliminary report was provided to EPA's contractor on
August 8, 2009. A final report with the leak detection and structural integrity demonstration results was
submitted to EPA's contractor October 14, 2009.
SmartBall™ PWA. Five SmartBall™ insertions were performed from August 6 to August 7, 2009, for
leak detection and pipe wall thickness assessment. Seven cases of equipment, five suitcase-sized and two
long, thin boxes arrived by common overnight delivery service the week prior to the demonstration.
SmartBall™ PWA was performed by launching the equipment in Pit 1, allowing the SmartBall™ to
travel with the water flow to conduct the inspection, and then extracting the equipment using an
extraction tube in Pit 3. LWC provided a 6-in. ANSI flange on the top of the gate valve in Pit 1 and 3 to
which Pure mounted its 4-in. diameter insertion and extraction tubes. Prior to the insertion, Pure verified
that adequate flow was available to carry the SmartBall™ the full length of the test pipe in a reasonable
amount of time. Flow rates between 1 and 2 ft/s were maintained, resulting in inspection times between
45 minutes and 1 hr.14 The inspection procedure involved first placing the extraction net in the pipeline,
then inserting the SmartBall™. With the proper fittings being installed prior to the inspection, the set-up
and tear down process for SmartBall™ required about an hour each. All fittings that touched the water
were sprayed with a chlorine solution for sterilization.
Knowing the position of the SmartBall™ within the pipeline is critical for accurately assessing the pipe
wall condition and multiple locating methods are used by SmartBall™ to establish the position. Distance
profiles are generated to give a rough estimate of the SmartBall™ position over time. Data obtained from
the accelerometers and magnetometers on board the SmartBall™ are used to obtain a velocity profile for
tracking the tool (see Appendix C for examples of position and velocity data plots). Also, absolute
position reference points from above ground locations were obtained from the SmartBall™ Receivers
(SBR), which use time-stamped data to track the position of the SmartBall™. Individual SBRs tracked
the ball's progress through the pipeline for over 850 ft; the distance and location of the aboveground
points were based on information provided to Pure by EPA's contractor. To establish the position of the
ball as a function of time, the results of the rotation profile, velocity data, and the SBR tracking are
combined to provide a position-versus-time relationship for the entire run of the tool. The exact location
of where each SBR was placed along the test pipe during each run is detailed in Table 3-11.
14 The SmartBall™ typically travels at about 90 percent of the flow rate. The ball was launched a few minutes after
flow was confirmed and stopped after the ball was confirmed to be caught.
70
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Table 3-11. SmartBall™ Receiver (SBR) Locations
Location ID
Insertion
Midpoint
Extraction
Distance from
Launch (ft)
0.0
809.0
2,057.0
Once the ball was launched, observers and technicians waited for the ball to be received at Pit 3. The
vendor verbally reported on pipe condition to EPA's contractor the day after each inspection. There were
no ongoing activities for the operators to perform as the SmartBall™ traveled through the pipeline. A
final report of leak detection and condition assessment results was provided on August 14, 2009.
ThicknessFinder. From July 6 through July 8, 2009, Echologics was on site to demonstrate its
ThicknessFinder and LeakFinderRT technologies. These initial inspections were unsuccessful because
they suspected air in the line.15 Echologics was rescheduled and returned August 10 through 12 to have a
second chance of demonstrating these technologies. The condition assessment was conducted on August
11 and 12. One Echologics technician arrived the day of the inspection with two cases of equipment the
size of a common suitcase in the back of a small rented vehicle.
Echologics used the following survey methodology to conduct their wall thickness assessment:
1. For each location surveyed, sensor locations were chosen and the distance between the locations
were measured. A very accurate measurement of the distance between sensors is required.
Although less important for leak detection measurements, an error in measurement of even 3 ft
over a 300 ft distance can lead to errors of 15% in wall thickness estimation. The margin of error
acceptable is dependent on the pipe type and the distance between sensors. There were some
cases where accurate pipe geometry was not available. For example, elevation changes and
curves in the road may create discrepancies between Echologics' distance measurement along the
surface and the physical distance of the pipe underground. Any locations that presented this
difficulty were noted and discussed in the results.
2. Sensors were placed on the chosen locations, either taps that were previously installed or in
excavations on the surface of the pipe, and a noise source was created by opening an orifice at a
hydrant, typically at a location out-of-bracket (beyond one of the sensors).
3. The temperature of the water was recorded, generally at the time of testing, for each of the test
sites since this can influence wave velocity.
4. The data was stored as a raw wave file for further analysis and later confirmation. To confirm
data quality for future processing, data was reanalyzed and filtered to obtain an optimum
correlation peak.
Wall thickness assessment measurements were performed in pipe section lengths between 250 ft and 360
ft. The assessment lengths were chosen based on typical distances used for commercial leak detection
projects conducted by Echologics.
15 Because a significant amount of air was in the line during their first visit to the demonstration site, Echologics was
unable to get accurate data from their LeakfinderRT technology. The line was dewatered and cut a few weeks prior
to the demonstration to install tees at both ends of the test pipe. While the line was filled and flushed for a few hours
upon completion of the tee installation, a subsequent video assessment showed that air pockets remained throughout
the pipeline.
71
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Additionally, the wave propagation velocity is a function of the total thickness of the pipe wall and the
corresponding material elastic modulus. If a pipe is concrete lined, as is the case with the test pipe, the
structural stiffness of the pipe is increased via the additional strength of the concrete. The wave velocity
then becomes a function of the structural stiffness of the metal and the concrete lining. Therefore,
Echologics reports a thickness that is greater than the thickness of the cast metal. This is referred to as the
equivalent, effective, or structural thickness and generally it is 0.08-in. to 0.12-in. (2 to 3 mm) thicker
than the base metal. For the demonstration, the pipe with an average actual wall thickness of 0.78-in. was
determined to have an effective wall thickness between 0.85 and 0.90 inches.
Echologics stated that the accuracy of the ThicknessFinder method may be affected primarily by the
accuracy of the measured distance between sensors and the presence of water main repairs (pipe
replacement, repair clamps, and collars). Echologics also discussed several other possible sources of
error within their demonstration results documentation (see Appendix D). These sources of error include
manufacturing wall thickness tolerances, variation on Young's Modulus, inaccurate records, and errors
from electronic hardware and digital processing.
3.5.2 Internal Inspection. Three in-line inspection vendors participated in the demonstration on the
following dates:
• Sahara® Video - Vendor was on site from July 13, 2009 through July 17, 2009 for leak and wall
thickness assessment; video assessment on July 13.
• PipeDiver® - On site from July 20, 2009 through July 29, 2009; Testing not conducted on
weekend.
• See Snake® - On site from August 31, 2009 through September 4, 2009; inspections conducted
September 3 and September 4, 2009
The activities conducted each day are provided in Table 3-12.
Table 3-12. Daily Activities for Each Inline Inspection Technology Vendor
Date
Daily Activities
Sahara® Video -2-3 operators16
Jul. 13
• Checked-in at demonstration site and set-up Sahara® Video equipment
• Pipe pressure at 56 psi; flow rate ~ 2.6 ft/s with three valve turns
• Launched Sahara® Video; parachute failed to deploy and was replaced
• Started video inspection; increased flow to keep camera from bouncing
!/2 hours)
• Retrieved Sahara® Video equipment (~45 minutes)
(-2-2-
16 About twice that number were on site for the demonstration. Vendor used the demonstration for training new
operators.
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Table 3-12. Daily Activities for Each Inline Inspection Technology Vendor (Continued)
Date
Jul. 16
Jul. 20
Jul. 21
Jul. 22
Jul. 23
Jul. 24
Jul. 27
Daily Activities
PipeDiver" - 6 operators
PipeDiver equipment delivered to demonstration site and unloaded
Check-in at demonstration site and set-up for PipeDiver® inspection
An above ground tracking system was used. Marked ground every 60 ft
through 600 ft to try to achieve a tool speed of ~ 1 ft/s. If proper speed
achieved, the tool would pass a checkpoint every minute.
Crane did not work properly; made arrangements to have an excavator on site
the next day
Pipe pressure at 52 psig
Excavator arrived before noon
Extraction tube installed (~45 min)
Insertion tube installed (~30 min)
Sanitizing and filling insertion tube with water (~1 hr)
Launched PipeDiver® but the tool got stuck near the tee tie-in to the pipeline
Aborted launch to review Sahara® Video to determine what was causing the
PipeDiver® to get stuck
Removed insertion and extraction tubes (-1-1/2 hr)
Fixed broken paddles and reconfigured the tool to help get it past the ~4" gap
between the tee and original pipe identified in the Sahara® Video
Significant rain event; demonstration canceled
Extraction tube installed (~35 min)
Insertion tube installed (~25 min)
Municipal Sewer Department (MSD) on site to monitor flow to storm sewer
during the demonstration
Sanitizing and filling insertion tube with water plus providing overview of
technology to visitors (-1-1/2 hr)
Pipe pressure at 54 psig as measured by LWC gauge on hydrant; flow rate -0.:
ft/s as measured by vendor
Conducted inspection (~45 min); transmitter located in front module, sensors
in back module to conduct RFEC inspection
Above ground tracker briefly lost contact with PipeDiver®; flow stopped to
relocate
Removed insertion and extraction tubes (-1-1/2 hr)
Extraction tube installed (~30 min)
Insertion tube installed (~30 min)
MSD on site to monitor flow to storm sewer during the demonstration
Sanitizing and filling insertion tube with water (—15 min)
Pipe pressure at 54 psig; flow rate -0.3 ft/s
Conducted inspection (-2 hr); transmitter located in same module as sensors
Removed insertion and extraction tubes (-1 hr)
Extraction tube installed
Insertion tube installed
Sanitizing and filling insertion tube with water
Flow rate -0.5 ft/s
Conducted inspection (-1-1/2 hr); transmitter in same module as sensors
Above ground tracker briefly lost contact with PipeDiver®; flow stopped to
relocate
Removed insertion and extraction tubes
Additional machined defects added
17 A significant rain event occurred on July 22, 2009 that prevented LWC from discharging to the storm sewer for a
full day. As such, the inspection vendor was unable to access the pipeline for condition assessment until July 23,
2009.
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Table 3-12. Daily Activities for Each Inline Inspection Technology Vendor (Continued)
Date
Jul. 28
Jul. 29
Daily Activities
• Extraction tube installed (-20 min)
• Insertion tube installed (-20 min)
• Sanitizing and filling insertion tube with water (-30 min)
• Pipe pressure at 52 psi; flow rate -1 ft/s
• Conducted inspection (-35 min)
• Removed insertion and extraction tubes
• Packaged equipment for shipping
NDE Systems See Snake® - 3 operators
Aug. 31
Sept. 1
Sept. 2
Sept. 3
Sept. 4
• Winch truck arrived
• Check-in at demonstration site
• Retrieved rental winch; steel pull cable installed in line
• Foam cleaning pig pulled through test pipe to dewater line (pulled from receive
pit to launch pit)
• Inspection equipment arrived in the evening
• Check-in at demonstration site and set-up for See Snake® inspection
• Set-up winching truck at extraction end of test pipe
• Test pull to -100 ft; lots of background noise recorded
• Conducted inspection; pull speed was too fast and cable was not pulling
smoothly (-2 l/i hrs); therefore signal/noise ratio on data collected was not
acceptable
• Pull back cable (-1 !/2 hrs)
• Set-up winching truck at extraction end of test pipe
• Conducted inspection; speed -14.5 ft/min (-2-1/2 hrs)
• Pull back cable
• Packaged equipment for shipping
Sahara Video. Five Sahara® insertions were performed from July 13 to July 17 for three different
inspection technologies (leak detection, video, and condition assessment) that used the same tether,
insertion equipment, and tracking method as the leak detection technology. The Sahara® video inspection
was performed first on July 13 to inspect the inside of the pipeline. This inspection identified potential
obstacles for other internal inspections, as well as internal corrosion and air pockets. The Sahara® video
head was inserted into Pit 1 and traversed the line using the pipeline flow. In its initial launch, the
Sahara® video parachute caught during insertion and failed to deploy; it was replaced rather than repaired.
Once re-inserted, the Sahara® video head traveled the length of the test pipe. After reaching Pit 3, the
video head was then retracted and taken out of Pit 1.
PipeDiver®. The PipeDiver® J^FEC demonstration was performed from July 21 to July 29 with four full
runs completed in that timeframe. This demonstration represented a pilot inspection for PipeDiver® using
the J^FEC technique in metallic pipe. Table 3-13 shows the details of the four inspections, specifically
highlighting the survey length, flow speed, and description of the inspection.
Table 3-13. PipeDiver® Insertion Details
Date
July 23
July 24
July 27
July 28
Insertion
Point
Pitl
Pitl
Pitl
Pitl
End
Point
Pit3
Pit3
Pit3
Pit3
Survey
Length (ft)
2,057
2,057
2,057
2,057
Flow Direction
and Speed
East, 1 ft/s
East, 0.5 ft/s
East, 1 ft/s
East, 1 ft/s
Description
PipeDiver® RFEC
PipeDiver® RFEC
PipeDiver® RFEC
PipeDiver® RFEC
74
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Many configurations of PipeDiver® were used for the inspection during the demonstration. One was a
remote field transformer coupling (RFTC) configuration, which is similar to a method used on prestressed
concrete pipe. Another configuration, remote field eddy current, (RFEC) involved moving the exciter
coil forward to the first module, and adding six additional detector coils to petals at the rear of the vehicle.
A schematic of these two PipeDiver® coil locations is provided in Figure 3-33. Only the results of the
tests with the RFEC configuration (bottom illustration in Fig. 3-33) were reported.
Coil Setup for the RFTC Inspection Technique
Coil Setup for the RFEC Inspection Technique
(Courtesy of vendor)
Figure 3-33. PipeDiver® Coil Locations
Common factors that affect the accuracy of the PipeDiver® RFEC system include the pipeline design and
composition (i.e. metallic variations), inspection tool calibration, inspection tool riding quality, and the
type and position of the defect. The future challenges for PipeDiver® RFEC development will be to
increase the number of detectors close to the pipe wall to increase the resolution and accuracy for sizing
individual pits.
During the first insertion attempt on July 21, 2009, the PipeDiver® vehicle became stuck during the
insertion process and therefore the launch had to be aborted. Video data was recorded during the Sahara®
Video (Figure 3-34) inspection to investigate what was causing the PipeDiver® vehicle to become stuck in
the line. The inspection vendor's conclusion was that the front of the PipeDiver® vehicle had become
stuck in a 3- to 4-in. wide, unfilled gap between joints just downstream of the insertion point (see
schematic in Figure 3-35).
Modification of the tool was designed and implemented allowing for the completion of four inspection
runs. PipeDiver® is designed for live inspections using standard accesses including 12-in. diameter hot
75
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taps, tees with minimum joint gaps, or similar features. For certain accesses such as tees with large
unfilled joint gaps or accesses with unknown internal conditions, the vendor recommends using Sahara®
Video prior to the inspection to identify the exact layout of the insertion point. The insertion design and
process can then be modified for a successful insertion if required.
Estimate
Height
= 1"
Estimated
Axial Distance
= 3-4"
(Courtesy of vendor)
Figure 3-34. Sahara® Video of the Joint Gap
Original PipeDiver Design
Using Standard Hot lap
Westport Rd. 24" Cast Iron Pipeline
Using a 24x24x12" Tee
(Courtesy of vendor)
Figure 3-35. PipeDiver® Insertion Schematic
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See Snake®. The water main was available for See Snake® demonstration from August 31 to September
4, the equipment arrived the evening of September 2, and two full runs were completed in that timeframe.
This demonstration represented the first live inspection for the custom designed See Snake® tool for a 24-
in. diameter cast iron water main.
Prior to the arrival, the line was prepared. An 1/8-in. nylon rope was flowed through the line. Then the
isolation valves were closed and 12 ft of pipe was removed from both ends. Since the small nylon line
was not strong enough to pull the steel cable, a stronger MULETAPE® line was threaded in the pipe using
the 1/8-in. line. The first three days of the demonstration were spent preparing the wire line truck,
threading the pipeline with a steel cable to pull the RFT tool back to the launch point, cleaning and
dewatering the line using a foam cleaning pig, and preparing the RFT tool for inspection.
On September 3, a test pull was conducted over a 100 ft length of pipe to verify the detectors and data
processing systems were working properly. This initial test showed a lot of background noise.
Upon completion of the test pull, the inspection vendor adjusted tool settings and prepared for the live
inspection. Unfortunately, because the pulling speed on the cable was too high and the two winches were
not synchronized properly, the RFT tool experienced rapid velocity excursions during most of the
inspection and therefore the data collected was not usable.
On the last half-day of the demonstration, the inspection vendor completed a smooth inspection run of the
entire 2,057 ft length of test pipe at an inspection speed of approximately 14.5 ft/min with the data
recorded being of good quality.
The logged distance data for the test pipe was 2,059 ft, with zero set at the 12-in. launch tee. The data
from the first three pipe segments were not analyzed by the vendor because of velocity excursions at the
start of an inspection .
The complete system used to perform the pipeline inspection included the following equipment:
• 24-in. diameter water pipeline See Snake® RFT tool with data download USB box
• Odometer adaptor box, odometer hydrant adapter, with supporting shoring rod
• Cleaning swab
• Wireline truck with winch fitted with 1 km of wire line
• Laptop running a distance logger
• Proprietary post-analysis software.
Figure 3-36 shows the set-up, with winch truck, hydrant odometer, shoring rod, and spent cleaning swab.
The wire line truck is aligned with the launch point to insure the straightest pull possible from the winch
to the entry point.
Although EPA's contractor provided the specifications for several manufactured metal loss defects
(calibration defects) to allow calibration of the RFT equipment, the inspection vendor was not able to use
the RFT data collected at these locations due to the extremely noisy signals they received. The noise was
present in both the September 3rd and September 4th data, pointing to possible magnetic permeability
noise within the pipe wall, possibly caused by previous inspections made by magnetic external tools such
as ECAT.
77
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Figure 3-36. Wireline Truck and Hydrant Set-up
In general, the magnetic permeability of a pipe section remains fairly constant over its length; however it
is possible for stresses or other external factors to locally change the permeability of the cast iron
material. This is quite unusual, but if present, the RFT tool (which measures magnetic fields far weaker
than the earth's magnetic field) would see these changes in the magnetic properties of the pipe. If the
magnetic permeability variations are very strong, they can become "noise" that masks potential defects.
The inspection vendor identified some possible causes for the permeability noise:
1. If the calibration defects were machined with no or little coolant, this could cause stresses in the
pipe around the defects and locally change the magnetic permeability.
2. If the machining equipment for the defects employed a magnetic base to clamp the equipment to
the pipe, the strong permanent magnets would alter the local permeability significantly.
3. It is also possible that some of the other NDE techniques used permanent magnets for attaching
their external scanning devices which would leave large magnetic "imprints".
4. Finally, some of the other NDE techniques may have tried to magnetically saturate the pipes at
the defect locations. That process would also leave large magnetic imprints on the pipe.
For optimal RFT accuracy, a calibration is performed using pipe with approximately the same pipe
properties (e.g., wall thickness and grade) as the pipe being inspected. However, in this case the data
from the calibration defects was too noisy to be usable. So instead, the calibration was performed by
running the tool through a 24-in. calibration pipe in the inspection vendor's yard after the field
demonstration and comparing the data from the cast iron main to data from the yard calibration. Based on
78
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this procedure, the defect accuracy is expected by the inspection vendor to be +/-20% for short (local)
wall loss, and +/-10% for long (general) wall loss. The above accuracy range is valid for indications
sufficiently removed from major features, such as bell-and-spigot joints. This technology detects bell-and-
spigot joints but cannot inspect them at this time.
3.5.3 External Inspection. Two vendors participated in the water main inspection demonstration
for external condition assessment tools on the following dates:
• AESL - On site from August 17,2009 through August 21,2009
• RSG - On site from August 24, 2009 through August 27, 2009
The activities conducted each day are provided in Table 3-14.
Table 3-14. Daily Activities for Each External Condition Assessment Technology Vendor
Date
Daily Activities
AESL - 2 operators
Aug. 17
Aug. 18
Aug. 19
Aug. 20
Aug. 21
• Check-in at demonstration site and set-up equipment
• Conducted soil analyses and collected samples in Pit F
• Conducted wall thickness and coating assessments in Pit
• Started ECAT scan of Pit F
• Finished ECAT scan of Pit F
• Conducted soil analyses and collected samples in Pit L
• Conducted wall thickness and coating assessments in Pit
• Conducted ECAT scan of Pit L (2-3 hours)
• Additional soil analysis in Pit L
• Conducted soil analyses and collected samples in Pits A,
• Conducted wall thickness and coating assessments in Pit
• Conducted ECAT scan of Pit 2 (2-3 hours)
• Conducted soil analyses and collected samples in Pits D,
• Started cleaning equipment for shipping back to the UK
F
L (2-3 hours)
B, C, I,and2
2 (2-3 hours)
E, and 3
• Finished cleaning equipment and packaged for shipping
RSG - 1 operator
Aug. 24
Aug. 25
Aug. 26
Aug. 27
• Check-in at demonstration site and set-up equipment
• Conducted HSK scan of Pit L (-1-1/2 hour)
• Conducted HSK scan of Pit F (-1-1/2 hour)
• Conducted CAP scans of Pit A, B, C, and D (< 1 hour per keyhole)
• Conducted HSK scan of Pit 2 (-1-1/2 hour)
• Rescanned Pit F
• Conducted CAP scan of Pit E
AESL ECAT. AESL used a detailed process for assessing the pipeline condition within each excavation
location. To start, AESL required the pipe manufacturing specification as input data for their structural
analysis. However, due to the age of the pipeline used in the demonstration, this information was not
readily available. Instead, AESL used the pattern of wall thickness measurements and pipeline
installation date to determine the most appropriate British Standard (BS1211-1945 Class D). The
principal structural details provided by this Standard are given in Table 3-15.
Soil measurements including resistivity, redox, pipe-to-soil potential and pH were taken at every
accessible excavation along the length of the pipeline (Pit 1, Pit L, Pit 2, Pit 3, Pit A, Pit B, Pit C, Pit D,
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Pit E, and Pit F). The soil measurement data were used to evaluate the soil corrosivity according to the
French Standard AFNORA05-250.
Table 3-15. Principal Structural Details for Water Main Based on BS1211-1945 Class D
Parameter
• Nominal Internal Diameter (in.)
• Nominal Wall Thickness (in.)
• Maximum Wall Thickness (in.)
• Minimum Wall Thickness (in.)
• Design Pressure* (psi) from Standard
• Specified Minimum UTS (ksi) from Standard
• Design Stress** (ksi) from Standard
Data
24
0.85
0.89
0.78
175
28
6.7
*Design pressure is calculated as 50% of the specified test pressure
**Design stress is calculated as 25% of the Specified Minimum UTS
The pipe wall thickness was measured using an ultrasonic instrument (Sonatest Sitescan 140), which has
a tolerance of 0.01 mm. The ultrasonic gages were calibrated, then ten ultrasonic measurements were
taken at every 30-degree pipe orientation for a total of 120 measurements taken at each excavation
location (Pit 2, Pit L, and Pit F).
Additionally, a detailed assessment of the pipeline coating and pipe wall was conducted over 1 m long
lengths within each excavation location. To quantify the level of coating failure, a similar grid pattern to
the ultrasonic wall thickness assessment was used to visually report the percentage of coating failure as
depicted in Figure 3-37 with the both sides of the pipe illustrated. The number system shows n
circumferential locations; numbered clockwise with respect to the direction of flow, the first cell
clockwise from the top of the pipe is 1 and the last one is n.
1000
ooo
800 Cell Divisions (mm)
700
600
GOO
400
100
200
too
Cell numbers around the circumference of the pipe
(Courtesy of AESL)
Figure 3-37. Pipe Grid Diagram for Visual Coating Assessment
Pipeline integrity was determined via scans with the ECAT. The ECAT technology is applicable for
ferrous pipes, including cast iron, ductile iron, and steel. The ECAT used in the demonstration was 1.6 m
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long and contained four sensor blocks each with a hall-effect sensor to measure the volume of metal loss
and a proximity sensor to denote if the metal loss is internal or external. Each individual scan took
approximately 3 minutes with a total duration of two to three hours for full circumferential inspection of a
1 m long segment of pipe. The number of sensor blocks and scan rate will change based on the diameter
of the pipeline.
The real-time data that is reported shows a series of peaks from the two types of sensors. If the peak from
the Hall-effect sensor and proximity sensor align, this type of signal indicates that the metal loss is
external. If only one peak from the Hall-effect sensor is registered without a peak from the proximity
sensor, this type of signal indicates that the metal loss is internal. The shape of the peak allows the
analysts to estimate the size of the defect.
Data from the relative soil corrosivity assessment, pipe coating condition assessment, wall thickness
measurements, and full circumference ECAT scans were integrated and analyzed to determine the pipe
condition in the three excavated pits. Subsequent statistical analyses were conducted to predict the
condition of the un-inspected portions of the pipeline based on the detailed findings within the excavated
pits.
RSG HSK. The HSK system used for the demonstration uses electromagnetic energy to produce images
that are used to infer the thickness of the pipe material. The HSK approach involves one operator to place
the antenna on the pipe surface, normally in an excavation pit and ideally with an accurate reference
system. The operator moves the antenna around the circumference of the pipe, and then along the pipe
length to acquire the pipe condition data. Full pipe coverage (100%) is typically achieved using the HSK
method, apart from where obstacles are encountered, such as valves and joints. Where joint scans are
required, these need to be done separately to the pipe sections. The acquired data is typically stored on a
laptop located outside of the excavation pit.
The most preferred procedure is to use pre-plotted grid paper with 2-in. intervals, taking individual
readings around the circumference. The paper is wrapped around the outside of the pipe allowing for
accurate reference points of each individual reading taken. The evaluation grid with survey orientation is
schematically illustrated in Figure 3-38. Scanning is conducted from the outside of the pipe along the
circumference starting and finishing at the crown of the pipe.
I I f
777
.' . .
ill i
j j} i i ji ' j j i
I
(Courtesy of RSG)
Figure 3-38. Typical Survey Grid Along a Pipe Section
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For this demonstration, chalk and tape were used to mark a reference grid on the pipes external surface
rather than the pre-plotted grid paper. All HSK scans for this project started at the crown of the pipe,
moving around the circumference and finishing back at the crown of the pipe (see Figure 3-39).
Southern Springline
Layout of Scanning Grid
X
Crown
Northern Springline
(Courtesy of RSG)
Figure 3-39. Plan View of Specific Referencing for Pipe Section Survey
Interpretation of the BEM HSK data is based on an established relationship between recorded signal and
thickness measurement. With accurate calibration information, a correlation between signal amplitude
and pipe wall thickness can be obtained. However, RSG mentions in their report that microstructures
within ferrous materials make it impossible to determine an absolute thickness conversion. In addition,
the signal is averaged over an area and volume scanned by the sensors (for this demonstration
approximately 2x2-in.), which make absolute measurements of wall thickness difficult. Therefore, only
relative or apparent thickness correlations are provided in the results. Various sensor sizes are available
allowing more detailed assessments or faster surface coverage. The selection of the sensor can be tailored
to suit the required detection and/or budget.
Since the sensors average over a 2x2-in. area, the corrosion within the area is reported as average metal
loss in the scan area, not the deepest depth. For this reason, isolated pits that are small in diameter or
surface scratches (unless significantly large with respect to the scanned area) will not be seen as
significant and may not have enough impact to affect a particular reading. In addition, the HSK system is
not able to discern if the metal loss is internal, external, or both and will indicate a cluster of pits as
general wall thinning.
According to RSG, the BEM plots generated by the HSK are a good representation of the area of each
flaw and flaw trends. However, understanding the nature of the HSK operation and antenna orientation
with respect to the flaw is crucial in determining size of flaws. A common situation is that a low response
from a certain number of sensors does not equate to a flaw of that size (see Figure 3-40). For example, a
low response captured from three 2-in. sensors does not necessarily equate to a flaw 6-in. in size.
Similarly, a flaw small in area (< 2 in2) may be scanned by up to four different sensors, resulting in a
thickness contour plot indicating a larger flaw area of lesser wall thinning than actual.
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Antenna
Sensor 1 j ( Sensor 2 i Sensor 3 ; • Sensor 4
1 Flaw
Steel Pipe * 2
(Courtesy of RSG)
Figure 3-40. Representation of Sensors Responding to Flaw
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RSG CAP. The CAP system uses the same BEM technology as previously discussed for the HSK. The
CAP approach, however, does not require manned entry into the excavation pit. Instead, access to the
pipe is gained through smaller, vacuum excavations near the crown of the pipe. As such, only the area
excavated is available for scanning and assessment. CAP scans do not provide a detailed assessment of
the 'full' circumference of the pipe, but it allows for quicker sampling of many locations along the pipe
length. Full circumference scanning capability is now reported to be available.
The CAP system is ideally suited for situations where corrosion occurs or is suspected to occur along the
crown of a pipe. Trends in pipe crown corrosion will only be identified along the length of the pipeline if
a suitable number of CAP scans are performed. Antennae are lowered into the vacuum excavated hole
(keyhole) on an extension pole and pressed firmly to the crown of the pipe to allow for good contact
between the antenna and pipe. The housing of the antennae is made of flexible material such as cotton to
allow the antenna to conform to the curvature of the pipe as shown in Figure 3-41. Interpretation of the
BEM CAP data is essentially the same as the HSK system except that the area scanned by the sensors is
approximately Ixl-in. rather than 2x2-in. Similar to the HSK, various sensor sizes are available allowing
more detailed assessments or faster surface coverage.
Rigid Housing
Flexible Antenna
(Courtesy of RSG)
Figure 3-41. Typical CAP Scan Set-up and Design
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4.0: MATERIALS AND METHODS FOR POST-DEMONSTRATION CONFIRMATION
STUDY
A post-demonstration confirmation study was conducted in order to select, characterize, and compare the
condition of exhumed pipe samples to the pipe inspection data that was collected by the inspection
technology vendors during the field demonstration in Louisville, KY. The confirmation study included
an assessment of the "as new" wall thickness, inside cement coating thickness, and pipe outer diameter
(OD) measurements for 12 exhumed pipes. The exhumed pipes were also assessed manually and/or with
a laser scanner in order to determine the extent of metal loss. The extent of metal loss was characterized
by total volume loss, number of pits (with loss greater than 50% of depth), maximum pit depth, and
largest corrosion patch dimensions. This section presents the rationale for selection of the exhumed pipe
segments and the methodologies used for the pipe condition assessment during the post-demonstration
confirmation study. Additional information can be found in Appendix A, which includes photo
documentation of the exhumed pipes before and after sandblasting, along with the manual and laser
scanning assessment data.
The section describes data collection, analyses, and project documentation associated with the post-
demonstration confirmation study performed under TO 62 in accordance with EPA NRMRL's Quality
Assurance Project Plan (QAPP) Requirements for Applied Research Projects (EPA, 2008). In performing
the work, Battelle followed the technical and QA/QC procedures specified in the QAPP unless otherwise
stated. Any procedure that was not followed and the rationale for the change is noted in the remaining
sections.
4.1 Selection of Pipe Segments for Removal
After the field demonstration was complete, a CCTV inspection of the entire test pipe length was
performed using PipeEye CCTV. The inspection report indicated that the cement liner was uniform and
no through-wall anomalies were detected in the pipe wall. The joints at the reported natural leak locations
were closely examined, as well as the joints before and after these leak locations, and no significant
differences (such as larger gaps) were observed. Upon completion of the CCTV and joint evaluations, the
24-in. diameter test pipe was removed by LWC to prepare for installation of the 30-in. diameter
replacement line. As the 24-in. line was being removed, EPA's contractor was on site to select over 200
ft of pipe for post-demonstration confirmation of the condition assessment technology results. Pipe
segments were selected using the inspection results reported by each technology vendor and visual
assessment of the pipe condition as it was removed. The selected pipe segments were taken to a holding
area for storage and then transported to the EPA contractor's laboratory.
Selection of the pipe segments used for post-demonstration verification was based on input from each
technology vendor and the EPA contractor's review. Pipes with reported anomalies, as well as those
thought to be in good condition were selected. Approximately 220 ft of pipe were identified as potential
candidates for further assessment based upon inspection results and visual examination during excavation.
This included:
• 17 entire pipe segments with bell and spigot intact
• Two 12-in. tees used for launching and receiving condition assessment equipment
• One 6 ft section with:
o Machined anomalies, and
o Through holes from corp valve taps used to simulate leaks.
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Table 4-1 provides a consolidated list of the pipe segments removed for post-demonstration verification.
The criteria used to select the pipe segments included pipes identified as anomalous by multiple vendors,
pipes identified as 'good' by multiple vendors, and individual vendor interest in specific pipe segments
for evaluation.
Initially, this selection did not include pipe selections from the results of See Snake® as they were the last
vendor to participate in the demonstration and their final report was not available at the time that the pipe
segments were selected and removed. However, Russell NDE Systems Inc. was given the opportunity to
select an additional few pipe segments (No. 61, 65, and 68) for post-demonstration verification based on
their preliminary results.
The pipes were marked for removal by placing a nail and colored washer at the estimated 'middle' of the
selected pipe segments. Then as the pipes were being removed by MAC Construction during installation
of the 30 in. water main, the joints adjacent to the nail were carefully removed, marked with the
sequential pipe number, and saved for shipping to EPA contractor's laboratory.
The excavated pipe segments were in generally good condition and structurally sound. The internal
cement liner was visually examined and no obvious anomalies were detected. The exterior of the pipe
was also examined and appeared to be in its original state with limited, localized graphitization and
corrosion detectable. As each pipe length was removed from the ground, it was sequentially numbered
and the top of the pipe was marked with spray paint.
4.2 Selection of Pipe Segments for Post-Demonstration Wall Thickness Assessment
Twelve pipe lengths were selected, from the over 200 ft of pipe removed, for full wall thickness
assessment. Because the external assessment methods focused their assessments on specific pit locations,
four specific pipe lengths were selected for these technologies. The other eight pipe segments were
selected to demonstrate the assessment capability of the acoustic wall assessment and internal inspection
technologies that assessed the entire pipe segment.
Few obvious signs of significant pipe degradation were found on site. The pipe had a relatively uniform
visual appearance. Tapping with a sharp tool (solid metal sounds bright) did not expose significant
graphitization; this was not uniformly applied as pipe was removed quickly. Therefore, pipe selection
relied upon inspection data from all of the condition assessment vendors and included regions with
suspected anomalies and pipe segments that were thought to be in good condition.
After the pipes were removed, they were sequentially numbered and the top of each pipe was marked.
Table 4-2 provides the pipe length number, approximate location of the bell and spigot joint, and reason
for selection for the twelve exhumed pipes.
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Table 4-1. Consolidated List of Pipe Sections Removed for Post-Demonstration Verification
Est. Start
0
327
339
351
567
651
663
711
723
735
747
759
771
783
795
807
1,078
1,162
1,630
1,726
1,738
1,906
1,978
2,050
Est.
End
8
339
351
363
579
663
675
723
735
747
759
771
783
795
807
819
1,090
1,174
1,642
1,738
1,750
1,918
1,990
2,062
Nail
-
333
345
357
573
657
669
717
729
-
765
801
813
-
1,168
1,636
-
-
1,912
1,984
-
Joint
#
1
29
30
31
49
56
57
61
62
63
64
65
66
67
68
69
91
98
137
145
146
159
166
172
Comment
Pit 1. Tee remove to assess
Pit L. Leaks found by all technologies. Pipe
segment immediately before sewer.
Pipe segment immediately after sewer.
Sahara® and PipeDiver® indicated anomalies
If MAC can't get the joint immediately after
sewer, this is an alternative in the wet area.
Sahara® and PipeDiver® indicated anomalies
Pit 4: 574-580 ft; Valve = 577.4 ft surface, 583
ft Pipe Eyes. Pure low velocity 560 ft to 583 ft
(first choice). See Snake® 5 pits.
Pure requested pipe segment 1. See Snake® 4
pits.
Pure requested pipe segment 2.
See Snake® saw 2 50% pits; Pure low velocity.
Pure low velocity (2nd choice)
Additional pipe selected during site visit; See
Snake® 4 pits. Pure low velocity. Graphitization
& mechanical damage found
Pure low velocity; See Snake® 5 pits.
See Snake® requested pipe 756-768 ft. Pure
low velocity
Tapping sound variation indicated
graphitization may be present. See Snake® 7
pits. Pure low velocity.
Tapping sound variation indicated
graphitization may be present. See Snake® 8
pits.
See Snake® requested pipe. 793 - 805 ft
Pit C: 809-815ft - RSG; corrosion &
graphitization
Pit 2: 1,080-1,090 ft
Pit D: RSG keyhole reference (good pipe). See
Snake® no anomalies.
Internal anomaly at 1,637 ft with Sahara®
Video. PipeDiver® anomalies. Sahara® WTT
3rd choice.
Pit F: RSG and AESL.
Pit F: RSG and AESL. Sahara® WTT and
PipeDiver® anomalies
Leak, Sahara® WTT and PipeDiver®
anomalies.
PipeDiver® reference (good pipe). See Snake®
no anomalies
Pit 3: 2,055 -2,063 ft
Length
(ft)
8.375
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
9.4
5.5
12
12
5.375
Depth
to
Top
(in.)
-
71.5
70.5
68
-
-
N/A
-
N/A
N/A
N/A
N/A
N/A
N/A
-
-
-
-
-
-
-
-
87
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Table 4-2. Pipes Selected for Full Assessment during Post-Demonstration Verification
Pipe
Length
#
30
32
49
56
61
63
64
69
98
137
145/146
166
Bell
location
(Ft)
339
363
567
651
711
735
747
807
1,162
1,438
1,728
1,978
Spigot
Location
(Ft)
351
375
579
663
723
747
759
819
1,178
1,450
1,750
1,990
Reason for Selection
Pit L. Large leak at the spigot of pipe segment 307 bell of pipe segment 3 1 .
PipeDiver® indicated anomalous pipe. Sahara® WTT indicated a medium
change in wall thickness. ECAT and HSK external pipe inspection indicated
anomalous pipe.
Pipe segment 3 1 was the first choice, but could not be extracted intact from
under the sewer line. This area was wet from a large leak and degradation was
expected. Pipe Diver indicated anomalous pipe. Sahara® WTT indicated a
medium change in wall thickness.
SmartBall™ PWA detected low velocity and recommended pipe segment for
excavation.
SmartBall™ PWA indicated normal pipe wall condition and recommended
pipe segment for excavation.
See Snake® inspection reported wall loss anomalies. PWA detected low
velocity and recommended pipe segment for excavation.
See Snake® inspection reported a large number of wall loss anomalies.
See Snake® inspection reported wall loss anomalies. PWA detected low
velocity
Pit C. Corrosion documented by RSG CAP and verified in the field
Pit D. Pipe Diver indicated anomalous pipe. RSG CAP reported as moderate
corrosion at crown of the pipe
Pipe Diver indicated anomalous pipe. Sahara® Video indicated anomalies and
air pocket
AESL ECAT and RSG HSK external pipe inspection.
Good pipe sample requested for verification by PipeDiver® and Sahara®.
4.3
Transportation, Storage, and Surface Preparation
After removal, the selected pipe segments were placed in a holding area at the construction site in
Louisville, KY. In November 2009, the pipe lengths were trucked to the EPA contractor's pipeline
testing facility in West Jefferson, Ohio. Post-demonstration assessment was conducted in the Fall of 2010
when the post-confirmation study scope was funded. All of the pipes were photographed before and after
sandblasting. The pipes were professionally sandblasted by Martin Painting and Coating Company in
Columbus, OH to remove the enamel coating, corrosion products, and graphitization to facilitate
assessment of the pipe degradation.
Three standard levels of blasting, described in Table 4-3, were available and assessed. Initially, the pipe
was blasted to a NACE-3 Commercial Blast Cleaning finish. A visual inspection revealed that not all of
the corrosion and graphitization were removed. A 3-ft-square area with metal loss and un-corroded pipe
wall was blasted to a NACE-2 Near-White Blast Cleaning finish. Nearly all of the corrosion and
graphitization was removed, though sharp features remained at the edges of corrosion pits. A !/2-ft-square
area with sharp pits and small amounts of remaining corrosion and graphitization was blasted to a NACE-
3 White-Metal Blast Cleaning finish. While all of the corrosion and graphitization appeared to be
removed, the sharp features that remained at the edges of corrosion pits were dull and the pit sizes
-------
appeared to be expanded. The NACE-1 blast procedure was considered to be too aggressive and
therefore all pipes were blasted to a NACE-2 Near-White Blast Cleaning finish and lightly primed to
prevent additional corrosion. After blasting and priming, the pipe identification numbers and orientation
markings were transferred back to each pipe segment for identification and orientation.
Table 4-3. Blast Finish Considered for Preparation of Pipe for Assessment
NACEa
1
2
o
5
SSPCb
SP-5
SP-10
SP-6
Method Name
White Metal Blast
Cleaning
Near- White Blast
Cleaning
Commercial Blast
Cleaning
Method Description
The surface shall be free of all visible oil, grease, dust, dirt, mill
scale, rust, coating, oxides, corrosion products and other foreign
matter to the unaided eye.
The surface shall be free of all visible oil, grease, dust, dirt, mill
scale, rust, coating, oxides, corrosion products and other foreign
matter of at least 95% of each unit area
The surface shall be free of all visible oil, grease, dust, dirt, mill
scale, rust, coating, oxides, corrosion products and other foreign
matter over at least two-thirds of each unit area.
a Standard identifier of NACE International, originally known as the National Association of Corrosion
Engineers. A consensus standard with SSPC.
b Standard identifier of the Society for Protective Coatings, originally known as Steel Structures Painting
Council. A consensus standard with NACE.
4.4
General Pipe Parameter Measurements
The original construction records show that cast iron pipe was most likely spun cast using the De Levaud
process. This section reports on the original wall thickness, inside cement coating thickness, and OD
measurements.
Wall Thickness Measurements. The wall thickness of the cast iron pipe is the key parameter that
defines the pressure-carrying capability of the pipe. Two methods are available for assessing wall
thickness of the cast material as follows:
• Caliper for pipe where ID and OD of the cast iron pipe are accessible and can be spanned
• Ultrasonic measurements on areas of the pipe where only one side is accessible.
Caliper Measurements. At the spigot or where the pipe has been cut, the thickness of the cast iron pipe
was measured with a caliper. The caliper was calibrated by EPA contractor's instrumentation services
group. Measurements were taken at four locations around the pipe, as close to 90-degrees as possible
where the spigot was not corroded: top, right, bottom, and left, defined as viewed from the spigot end. In
two cases, measurements were not possible due to localized corrosion. The results were recorded in
tabular format as shown in Table 4-4, where the largest and smallest wall thicknesses are noted. For the
pipes assessed, the average wall thickness at the spigot was 0.795-in. with a standard deviation of 0.021-
in., or 2.5% of the wall thickness. The thickness was uniform around the pipe circumference and most of
the deviations were less than 1% of the wall thickness. Some of the larger deviations could have been due
either to loss of metal or to the pipe manufacturing process. In general, the pipe wall thickness at the
89
-------
spigot was approximately the same around the circumference, indicating that the pipe is spun cast iron,
however, corrosion and damage were observed at many places. Measurements were planned, as detailed
in the QAPP, at four locations on the pipe, 0°, 90°, 180°, and 270°. The QAPP procedure was modified
to collect caliper measurement in full wall thickness pipe as close to the planned location as possible
away from the corrosion and damage at the top, right, bottom and left side of the pipe. The specific
locations are contained in the tables in Appendix A. Corrosion and damage were extensive in some areas
and caliper measurements could not be made in these quadrants; in the tables these areas are marked with
an x.
Table 4-4. Spigot Wall Thickness as Measured by a Caliper at Four Locations
Pipe Number
30
32
49
56
61
63
64
69
98
137 (Min)
145
166 (Max)
Average
Std Dev
Dev in %T
Wall Thickness (in.)
Top
0.781
0.806
0.782
X
0.803
0.813
0.801
0.776
0.814
0.765
0.789
0.829
0.796
0.019
2.4%
Right
0.784
0.803
0.786
0.802
0.779
0.818
0.793
0.774
0.799
X
0.782
0.834
0.796
0.018
2.3%
Bottom
0.79
0.805
0.806
0.794
0.784
0.816
0.7965
0.742
0.812
0.765
0.784
0.833
0.794
0.024
3.0%
Left
0.776
0.796
0.798
0.795
0.789
0.813
0.797
0.742
0.84
0.773
0.787
0.842
0.796
0.028
3.5%
Average
(in.)
0.783
0.803
0.793
0.797
0.789
0.815
0.797
0.759
0.816
0.768
0.786
0.835
0.795
0.021
2.6%
Standard
Deviation
(in.)
0.006
0.005
0.011
0.004
0.010
0.002
0.003
0.019
0.017
0.005
0.003
0.005
0.001
-
-
x indicates an area where reading could not be acquired.
Ultrasonic Measurements. For other areas of the pipe where only the outside was accessible, ultrasonic
methods were used. While reasonably precise for fine-grained steels, ultrasonic thickness methods are
often less accurate for cast iron pipes because of the potentially larger grain structure. The variation is
anecdotally reported to be as much as 20% of the wall thickness (0.150-in.). Spatial averaging methods
were used to estimate wall thickness; nine measurements were averaged over a 3*3-in. grid with each cell
being !/2x!/2-in. The Olympus Model 37DLP ultrasonic thickness gauge was used as a nondestructive
means of measuring pipe wall thickness. The instrument was factory-calibrated at the time of testing.
Table 4-5 shows representative ultrasonic wall thickness measurements for three pipe samples. Appendix
A contains the results for all of the pipe samples. These results show that the pipes did not exhibit the
level of variation often seen in cast iron pipe. The nine readings had a standard deviation between 0.004-
in. and 0.013-in. for all pipes. The pipes tended to be slightly thicker at the bell than at the spigot. A
summary of the ultrasonic thickness measurements are shown in Table 4-6.
90
-------
Table 4-5. Spatial Averaging Methods Were Used to Estimate Wall Thickness
Pipe Number
30
Average
Standard
Deviation
64
Average
Standard
Deviation
137
Average
Standard
Deviation
Wall Thickness (in.)
Spigot
Caliper
0.766
0.766
0.78
0.771
0.008
0.782
0.784
0.788
0.785
0.003
0.764
0.782
0.764
0.770
0.010
UT
0.782
0.771
0.769
0.779
0.771
0.797
0.799
0.768
0.785
0.780
0.012
0.776
0.771
0.762
0.765
0.777
0.759
0.766
0.765
0.766
0.767
0.006
0.749
0.730
0.752
0.741
0.748
0.731
0.73
0.737
0.730
0.739
0.009
Center
UT
0.75
0.73
0.75
0.754
0.743
0.758
0.75
0.752
0.753
0.749
0.008
0.797
0.765
0.775
0.776
0.771
0.766
0.774
0.790
0.771
0.776
0.011
0.738
0.741
0.741
0.736
0.740
0.734
0.74
0.735
0.742
0.739
0.003
Bell
UT
0.805
0.809
0.793
0.831
0.807
0.812
0.807
0.799
0.809
0.808
0.010
0.796
0.810
X
0.815
0.806
X
X
X
0.807
0.807
0.007
0.766
X
X
0.766
0.776
0.785
0.757
0.760
0.786
0.771
0.012
x indicates an area where reading could not be acquired.
Table 4-6. Wall Thickness Measurements of Cast Iron Using an Ultrasonic Thickness Gauge
Pipe Number
30
32
49
56
61
63
64
69
98
137
145
166
Average
Deviation
Dev in %T
Average Wall thickness (in.)
Spigot
Caliper
0.771
0.811
0.789
0.811
0.776
0.818
0.785
0.753
0.831
0.770
0.790
0.833
0.795
0.026
3.2%
Ultrasonic
0.780
0.782
0.795
0.769
0.775
0.786
0.767
0.767
0.825
0.739
0.763
0.817
0.780
0.024
3.0%
Center
Ultrasonic
0.749
0.776
0.784
0.796
0.819
0.766
0.776
0.736
0.790
0.739
0.804
0.829
0.780
0.030
3.7%
Bell
Ultrasonic
0.808
0.817
0.754
0.754
0.787
0.794
0.807
0.785
0.819
0.771
0.763
0.790
0.787
0.023
2.9%
91
-------
Cement Liner Thickness Measurements. For the ends of the pipes where the cement liner was
exposed, such as the spigot or where the pipe was cut, the thickness of the cement liner was measured
with the same caliper as used for the cast iron pipe material. Measurements were taken at four equally
spaced locations around the pipe using a two-step process. First, the thickness of the pipe and the liner
was measured. Second, after a small amount of the liner was removed to expose the pipe internal surface,
the pipe thickness was measured and the liner thickness was determined by subtracting the pipe thickness
from the total thickness. Table 4-7 shows a representative liner thickness calculation for Pipe 30.
Appendix A contains the results for all of the pipe samples that underwent full assessment. The results
show that the pipes did not exhibit the level of variation often seen in cast iron pipe; the nine readings had
a standard deviation between 0.004 and 0.013 in. for all of the pipes. The liner thickness results for all
pipe samples are shown in Table 4-8 with the right and left defined as viewed from the spigot end. The
thickness of the liner was, on average, a quarter inch (0.25-in.) and varied from 0.14- to 0.34-in. The liner
at a few ends was damaged to an extent that prevented measurement. This most likely occurred during
excavation, shipping, or blasting because the video assessment of the pipe interior did not show any
damage.
Table 4-7. Calculation of Thickness of Cement Liner at Spigot with Caliper for Pipe 30
Measurement (in.)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
Top
0.781
1.113
0.332
Right
0.784
0.953
0.169
Bottom
0.790
0.933
0.143
Left
0.776
0.982
0.206
Table 4-8. Thickness Measurements of Cement Liner at Spigot for All Pipe Samples
Pipe
Number
30
32
49
56
61
63
64
69
98
137
145
166
Max
Min
Average
Std Dev
Liner Thickness (in.)
Top
0.33
0.29
0.19
X
0.30
0.27
0.30
0.18
0.29
0.18
0.32
0.32
0.33
0.18
0.27
0.06
Right
0.17
0.25
0.18
0.19
0.31
0.25
0.31
0.21
0.31
X
0.32
0.24
0.32
0.17
0.25
0.06
Bottom
0.14
0.33
0.17
0.20
0.25
0.28
0.16
0.26
0.27
0.15
0.31
0.22
0.33
0.14
0.23
0.06
Left
0.21
0.31
0.17
0.20
0.30
0.34
0.28
0.26
0.24
0.16
0.31
0.17
0.34
0.16
0.24
0.06
92
-------
Pipe Outer Diameter Measurements. The average outer diameter of the pipe was measured using a pi
tape measure (a measuring tape method that accurately measures diameter using the pipe's
circumference). The pi tape manufacturer's procedure was followed.18 Measurements were made
approximately a foot from each end and at the center of the pipe; the results are contained in Table 4-9.
The manufacturer states an accuracy of ±0.001-in. However, this is difficult to achieve on pipe pulled
from service and an accuracy of ±0.010-in. is more practical. The average pipe diameter was 25.82-in.
with a standard deviation of 0.03-in.
Table 4-9. Outer Diameter Measurements Using a Pi Tape
Pipe
Number
30
32
49
56
61
63
64
69
98
137
145
166
Max
Min
Average
Std Dev
Pipe Diameter (in.)
Spigot
25.84
25.83
25.84
25.82
25.85
25.80
25.83
25.88
25.88
25.80
25.83
25.90
25.90
25.80
25.84
0.03
Center
25.81
25.87
25.84
25.79
25.83
25.78
25.88
25.81
25.80
25.80
25.80
25.80
25.88
25.78
25.82
0.03
Bell
25.82
25.83
25.81
25.81
25.84
25.78
25.86
25.86
25.76
25.81
25.80
25.79
25.86
25.76
25.81
0.03
4.5
Assessment of Metal Loss Regions
The amount of remaining metal is a primary measurement for assessing pipe condition. For the pipe
segments selected for verification, corrosion and graphitization occurred in patches and the average metal
loss areas were measured over larger regions. To identify areas on the pipe, anomalous regions were
labeled with a five-part three-digit code, PPP-LLL-AAA-DLL-DAA:
• PPP indicates the pipe number.
• LLL indicates the start location of the defect area along the pipe axis measured from the spigot in
inches (values from 0 to 150).
• AAA indicates the start angle of the defect area around the circumference measured from a
reference mark indicating top of pipe in degrees (values from 0 to 359). The top of the pipe was
marked in the ditch prior to removal.
18
http://www.pitape.eom/specs/Instructions%20O.D.%20Inch%20Tape.pdf
93
-------
• DLL indicates the length of the defect area along the pipe axis in inches (values from 0 to 999).
• DAA indicates the circumferential extent of the defect area around the circumference in degrees
(values from 0 to 359).
For an area to be identified as an anomalous region, the axial length and circumferential extent of its
imperfection had to be greater than one wall thickness (0.75-in.) and the depth of the imperfection had to
be greater than 10% of the wall thickness (0.075-in.). Multiple pits were combined into an anomalous
region until the distance between anomalous regions was greater than one wall thickness. In this study,
standard tape measures were used to locate the anomalous regions. The spigot end of the pipe is defined
as the start zero length. Typically, there were between three and five regions per pipe sample.
Manual Assessment of Wall Loss. For areas with corrosion and graphitization, the remaining metal was
calculated by subtracting the anomaly depth from the local wall thickness. The depth of the pits was
measured with a depth micrometer. The micrometer was calibrated before and checked after use by the
EPA contractor's instrumentation services group. While the specified micrometer has a resolution of
0.001-in., the accuracy is on the order of ±0.010-in. because of the pipe surface roughness, surface
preparation, and other measurement variables. The depth was measured in a grid pattern throughout the
anomalous region. A 1A x !/2-in. grid was established using hardware cloth as seen in Figure 4-1. A
bridging bar, shown in Figure 4-2 was used as a reference position to make measurements. The
micrometer was zeroed on pipe without metal loss at the left of the anomalous region and the height at the
right of the anomalous region was adjusted until pipe without metal loss measured zero. The recorded
data shows these zero readings. The anomalous regions were photographed with a tape measure next to
the region for scaling with zero length starting at the spigot end of the pipe. The micrometer had a digital
output that would transfer the reading to a Microsoft Excel™ spreadsheet. The grids were numbered on
the pipe to ensure that the grid location corresponded to the Excel™ cell numbers. The entire
measurement system is shown in Figure 4-3. This automated process eliminated data recording errors and
improved accuracy. One depth measurement was taken in each !/> x !/2-in. square. A typical anomalous
region had thousands of measurements and, even with automation, this process proved to be labor
intensive. Hence, only the five largest anomalous regions on each pipe were evaluated. In the original
QAPP plan, one out of five measurements was to be repeated. Because of the improved process, this was
considered excessive and 1 or 2 repeat measurements per row were performed to ensure quality.
94
-------
Figure 4-1. Hardware Cloth on Pipe Sample with Corrosion Used to Establish the Vi-xVi-in., Grid
95
-------
Figure 4-2. Bridging Bar Used to Establish a Reference for Measurements
Figure 4-3. Data Recording System for Making Depth Measurements
A typical result of the metal loss evaluation is shown in Figures 4-4 and 4-5. Figure 4-4 shows the
corrosion area on pipe 69 (at 95-in. from the spigot, 129-degrees from the top of the pipe, 27-in. in axial
extent, and 109-degrees in circumferential extent). Figure 4-5 shows a color coded depth area contour
map. Each color change corresponds to a change in depth of 0.05-in. While corrosion is present
throughout the region, the deepest corrosion is more severe on the left side of the anomalous region
shown. The deepest pit is between 0.35- and 0.40-in., or 50% of the pipe wall thickness.
96
-------
Figure 4-4. Corrosion Area on Pipe 69: 95-in. from the spigot, 129-degrees from the top of the pipe,
27-in. in axial extent and 109-degrees in circumferential extent
069-095-129-027-109
0-005 0.05-0,1 01-0,15BO, 15-0,1MO. 2-0.25B0.25-03 0.3-035 035-0,4 0.4-0.45" 0.45-0 5« 0,5-0.55»0.55-0 6m 0,6-0,65» 0.65-0,7
Figure 4-5. Map of Corrosion Area on Pipe 69: 95-in. from the spigot, 129-degrees from the top of
the pipe, 27-in. in axial extent and 109-degrees in circumferential extent
97
-------
Automated Assessment of Wall Loss. A laser based coordinate-measuring machine (CMM) was used
for automated measurement of the four pipes selected for verification and judged to be in the worst
condition. This method uses laser beams that are projected against the surface of the pipe. Many
thousands of points are then taken and used to determine the size and position of corrosion by creating a
three-dimensional (3D) image of the pipe. This point data is then transferred to computer-aided digital
software to create a working 3D model of the pipe. The laser scanner is often used to facilitate the
"reverse engineering" of complex components by taking an existing part, measuring it to determine its
size, and creating engineering drawings from these measurements. The CMM technology used in this
study was supplied by ApplusRTD. For this project, the equipment was supplied from its office in
Houston, TX, which focuses on pipeline applications. Two operators provided a service on site at the
EPA contractor's pipeline test facility.
For pipes, the cylindrical geometry is easily applied to assess corrosion, graphitization, and other
anomalies. One limitation of the accuracy in the process is the quality of the original manufacturing
process. Any natural deviation of the pipe from the assumed cylindrical geometry will produce a
systematic metal loss or gain. While this limitation is not avoidable and systematic metal loss or gain
cannot be separated from loss due to corrosion, the error is less than other methods that could be used to
assess wall thickness over large areas. The method will only assess the external cast iron surface, not the
liner.
Since the CMM technology is equally accurate for metal loss or gain, there is a simple method for
verifying its accuracy. The accuracy of the CMM unit was checked with shim stock of known
thicknesses affixed to the pipe surface in a region without anomalies. Shims of 10%, 25%, and 50% of
wall thickness were attached to the pipe surface and assessed. The accuracy of the unit was within 0.040-
in. , which is 5% of the 0.75-in. nominal wall thickness.
Grid size is a key variable. For example, with the resolution of 2.5-mm, about 100 data points will be
taken for each square inch of pipe, or 1.2 million points for a 12-ft pipe segment. While this was the
resolution that was initially planned, on site analysis indicated that a higher resolution was need to
reconstruct the corrosion and pipe geometry. The number and complexity of anomalies with fine features
dictated the need for a smaller resolution. A final resolution of 2-mm in the axial direction and 1-mm in
the circumferential direction was used, which equates to about 322 data points for each square inch of
pipe, or 3.8 million data points for a 12 ft pipe segment. The data was imported into a Microsoft Excel™
spreadsheet with about 2,000 rows and columns and a file size of over 60 megabytes. The scanning of
each pipe required approximately one day.
Figure 4-6 shows the laser scanning of Pipe 63. The handheld CMM unit is in the upper left hand corner.
The white dots, referred to as targets, are applied to areas of the pipe without metal loss. The coordinates
of these points enables the establishment of a reference cylinder for estimating corrosion depth. A typical
result is seen via laser scan in Figure 4-7 and via normal photography in Figure 4-8.
The CMM laser and manual methods were compared for a region of Pipe 63. The depths of 20 pits are
shown in Table 4-10, and the differences between the two measurements are calculated. The depths
varied about 7% depending on the clock position. Note that the clock position reported by the methods
had about a 9 degree (i.e., 2.5%) variation.
As discussed previously, 12 pipes were sandblasted to expose the corrosion areas. While the corrosion
extent was measured for all 12 pipes, four pipes were CMM laser mapped and eight pipes were assessed
using the manual methods. Selection was based on visual assessment of the extent of the corrosion in the
pipe segment and vendor recommendations. Pipes 56, 63, and 64 had extensive corrosion and were
assessed with the CMM laser. Also assessed by laser were pipe segments 145/146 from Pit F, which
98
-------
were still together at the bell and spigot joint, and were extensively assessed by AESL ECAT and RSG
HSK.
Figure 4-6. CMM Laser Scanning of Pipe 63
Figure 4-7. CMM Laser Scan Image of Pipe 63
99
-------
Figure 4-8. Photograph of Pipe 63
100
-------
Table 4-10. Depth of 20 Pits Measured on Pipe 63 by Laser and Manual Methods
Dist From Bell (in.)
Laser
40.5
43.5
42.5
44
45
42.5
40.5
37.0
42.5
38.5
38.0
45.0
42.0
41.5
38.5
46.5
44.0
46.0
45.0
41.0
Manual
40.0
43
42
43.5
44.5
42
40.0
36.0
42.0
38.0
37.5
44.0
41.5
41.5
38.0
46.0
43.5
45.5
44.5
40.5
Clock (Degrees)
Laser
126
124
129
133
156
160
164
162
171
171
178
202
204
198
202
209
213
218
218
218
Manual
115
115
120
124
146
151
153
151
160
160
168
193
193
186
191
199
204
208
208
208
Maximum Depths
in Defect Area (in.)
Laser
0.282
0.308
0.289
0.332
0.299
0.273
0.334
0.333
0.267
0.400
0.309
0.244
0.214
0.230
0.227
0.264
0.206
0.178
0.237
0.181
Manual
0.225
0.264
0.236
0.289
0.248
0.222
0.282
0.294
0.217
0.352
0.284
0.287
0.284
0.214
0.264
0.265
0.257
0.227
0.288
0.225
Delta
0.057
0.044
0.053
0.043
0.051
0.051
0.051
0.039
0.050
0.048
0.025
-0.043
-0.070
0.016
-0.037
-0.001
-0.051
-0.049
-0.051
-0.044
% Loss
Laser
36%
39%
37%
42%
38%
35%
42%
42%
34%
51%
39%
31%
27%
29%
29%
34%
26%
23%
30%
23%
Manual
29%
34%
30%
37%
32%
28%
36%
37%
28%
45%
36%
37%
36%
27%
34%
34%
33%
29%
37%
29%
Delta
7%
6%
7%
6%
7%
6%
7%
5%
6%
6%
3%
-5%
-9%
2%
-5%
0%
-7%
-6%
-6%
-6%
4.6 Summary of the Extent of Corrosion on Pipes Selected for Post-Demonstration
Verification
The extent of metal loss for each pipe sample is summarized in Table 4-11. Four criteria were used to
rate the 12 pipe samples:
• Total volume loss
• Number of deep pits greater than 50% depth
• Maximum pit depth
• Largest corrosion patch assessment.
While none of the pipe appeared to have significant degradations, the pipes were assigned a relative
severity based on these four criteria with class 1 being the most severe and class 4 being the least severe.
For the most severe, Pipe 49 was chosen because of the large number of deep pits and pipes 63 and 64
were chosen for the large volume loss and some deep pits. For relative class 2, pipes 32, 61 and 69 were
chosen for the moderate volume loss and some deep pits. Pipes 30, 98 and 137 had minimal volume loss
and few if any deep pits and were assigned a relative rating of 4. The rest were a relative rating of 3.
101
-------
Table 4-11. Summary of Metal Loss for Each Destructively Assessed Pipe Sample
Pipe#
30
32
49
56
61
63
64
69
98
137
1457
146
166
Method
Manual
Manual
Manual
Laser
Manual
Laser
Laser
Manual
Manual
Manual
Laser
Manual
Volume Loss
Percent
0.2%
0.7%
1.0%
2.1%
1.4%
2.6%
2.1%
1.6%
0.9%
1.1%
0.8%
0.3%
Relative
Minimal
Small
Small
Largest
Medium
Largest
Largest
Medium
Small
Small
Small
Minimal
Deep Pits
>50%
1
2
13
0
6
6
5
4
1
0
2
0
Relative
Very few
Very few
Most
Very few
Some
Some
Some
Some
Very few
Very few
Very few
Very few
Max. Pit Depth
Max.
Pit
Depth
68%
56%
85%
39%
63%
51%
72%
75%
63%
46%
55%
37%
Rating
Deep
Moderate
Deep
Not deep
Moderate
Moderate
Deep
Deep
Moderate
Moderate
Moderate
Not deep
Largest Patch
Length
(in.)
5
22.5
25.2
60
26.5
40
60
14.5
9.5
20
28.4
20
Ave
Depth
26%
35%
48%
22%
28%
32%
29%
33%
30%
22%
24%
15%
Visual Assessment
Generally light corrosion with one deep
pit
A long corrosion area with a moderately
deep pit in the center. Generally light
corrosion elsewhere.
A ~2 ft long corrosion area with many
deep pits, one close to being through wall.
Generally moderate corrosion elsewhere
Large area of corrosion, however none of
the corrosion areas were very deep
A few deep areas of corrosion.
Significant amount of pipe with full wall
thickness.
Large areas of corrosion with moderate
depth. Some pipe with full wall thickness.
Areas of corrosion with moderate depth
and a few deep pits. Significant amount
of pipe with full wall thickness.
Moderate and a few deep corrosion pits,
mostly in clusters.
Moderate corrosion pits, often in clusters.
Generally light corrosion. Clusters of
shallow corrosion pits and large areas of
pipe with full wall thickness.
Areas of shallow corrosion and areas of
pipe with full wall thickness. Neither was
a full length of pipe.
Light corrosion and areas of pipe with full
wall thickness.
Relative
4
2
1
3
2
1
1
2
3
4
3
4
o
to
-------
5.0: RESULTS AND DISCUSSION
Each vendor was able to deploy their technology through mobilizing crews on site, setting up the
equipment, operating the technology, collecting data, and providing the requested inspection reports.
Detailed results for all of the pipe wall thickness assessment technologies are discussed in this section.
The individual inspection reports provided by each vendor are included in Appendix B (Sahara® Video,
Sahara®WTT, and PipeDiver®), Appendix C (SmartBall™ PWA), Appendix D (ThicknessFinder),
Appendix E (See Snake®), Appendix F (ECAT), and Appendix G (HSK and CAP).
Because this demonstration was a snapshot in time, new developments may have taken place since
completion of the demonstration. Therefore, the findings in this report may not be wholly representative
of the current operational capabilities of the demonstrated technologies. For this reason, the vendors were
asked to provide formal comments on the acoustic pipe wall thickness assessment report to highlight
advancements since completion of the demonstration and/or clarification on what was reported. These
comment letters are contained in Appendix H. For current status of these technologies, see vendor
websites, which are listed in the Executive Summary and Section 2 (Summary and Conclusions) to this
report.
5.1 Acoustic Pipe Wall Thickness Assessment
The Sahara® WTT, SmartBall™ PWA, and ThicknessFinder acoustic pipe wall thickness assessment
technologies were demonstrated on a 76-year-old, 2,057-ft-long portion of a cement-lined, 24-in. diameter
cast iron water main in Louisville, KY. While each technology used some form of acoustic device, the
implementations were quite different:
• Sahara® WTT uses a hydrophone sensor at the end of a cable tether. The hydrophone was
inserted and pulled through the pipeline using the water flow. The sound energy used for the
acoustic velocity measurement was generated by contacting the pipe at selected locations.
• The SmartBall™ PWA sensor and data-recording device were placed within a foam ball. The
sensor and ball were inserted in the pipeline and propelled by the water through the pipeline to a
downstream extraction point where a net inserted into the pipe caught and removed the unit. The
sound energy was generated by a speaker in contact with the water placed at the ends and the
middle of the test pipe.
• ThicknessFinder used pairs of accelerometers mounted on the outside of the pipe at discrete
locations to measure sound velocity in the pipe to determine average pipe wall thickness. The
sound was generated by an orifice.
5.1.1 Sahara® WTT.
The results of the wall thickness assessment are presented as an average wall thickness loss ratio (in 15%
increments) over a 33 ft interval. EPA's contractor performed a detailed assessment of seven exhumed,
12-ft pipe segments that fell within the 3 3-ft spans of pipe where average wall thickness loss was
determined by Sahara®WTT. The two sets of results are compared.
Summary of Results. Sahara® WTT assessment was performed in conjunction with their leak detection
assessment. Analysis of the Sahara® WTT results uncovered specific intervals of the pipeline with higher
wall thickness loss than other pipeline intervals. Details of the wall thickness loss are presented in Table
5-1 and specify the pipeline interval (-33 ft) and average wall thickness loss over that interval.
103
-------
Table 5-1. Sahara® Wall Thickness Results
Distance from
Start (ft)
0-17
17-33
33-66
66-98
98-131
131-164
164-197
197-230
230-295
295-328
328-361
361-394
394-426
426-459
459-492
492-525
525-558
558-590
590-623
Average Wall Thickness
Loss Ratio (%)19
Results not available
< 15%
Nominal
< 15%
Nominal
Nominal
Nominal
15-30%
Results not available
> 30%
> 30%
> 30%
Nominal
< 15%
15-30%
< 15%
< 15%
< 15%
Nominal
Distance from
Start (ft)
590-623
623-656
656-689
689-722
722-754
754-787
787-1640
1640-1673
1673-1706
1706-1738
1738-1771
1771-1804
1804-1837
1837-1870
1870-1902
1902-1935
1935-2057
-
-
Average Wall Thickness
Loss Ratio (%)
Nominal
< 15%
Nominal
15-30%
15-30%
Nominal
Results not available
Nominal
Nominal
< 15%
< 15%
< 15%
< 15%
Nominal
Nominal
15-30%
Results not available
-
-
The vendor defined nominal loss of pipe wall thickness as less than 2%. Three pipe sections ([295 to 328
ft], [328 to 361 ft], and [361 to 394 ft]), showed the highest wall thickness loss (i.e., >30%). Five sections
showed 15% to 30% of wall thickness loss. Eleven pipe sections showed <15% of wall thickness loss.
The remaining sections showed nominal wall loss. However, a wall thickness ratio could not be
calculated for several pipe sections comprising about 1040 ft of the 2057 ft test pipe, (i.e., [230 to 295 ft],
[787 to 1,640 ft], and [1,935 to 2,057 ft]), due to reasons such as the close proximity of the internal and
external sensors, presence of large air pockets, or noise from the pipeline discharge, which masked
acoustic activity after 1,935 ft.
Comparison to Assessed Pipe Samples. Sahara® WTT provided average wall loss results for 32
intervals that were typically 33-ft in length. For seven of these 33-ft intervals, each one had a 12-ft
length of pipe characterized in detail by EPA's contractor. The data from the 33-ft interval and the
corresponding 12-ft pipe length were compared to determine whether they appeared to be in rough
agreement. The results are given in Table 5-2. The data from the seven pipe lengths were compiled in
several ways to facilitate several types of comparisons: (1) volume loss, (2) number of pits deeper than
50% wall thickness, (3) maximum pit depth, and (4) largest patch (i.e., a combination of depth and
length). A summary visual assessment and the numerical results of the 4-level, relative condition ranking
are also included in Table 5-2. For the seven pipe sections that included a length of pipe that was
exhumed and characterized by EPA's contractor, Sahara® WTT predicted two pipe sections with average
wall loss >30%, three pipe sections with average wall loss between 15%-30%, and two pipe sections
<15% wall loss. However, the exhumed pipes that were fully assessed within those sections had limited
variation with an average wall loss of no more than 2.6 % .. Therefore, predicted values for five of the
seven 33-ft pipe sections reported by Sahara® WTT did not correlate with condition of the included,
exhumed pipe. Furthermore, the average wall loss measurements did not correlate with the number of
deep pits, the maximum pit depth, the severity of the largest patch, the visual assessment, or the 4-level
relative ranking system.
19 Pipeline intervals with an average wall thickness loss of less than 2% are listed as nominal. The average wall
thickness loss ratio is in relation to the nominal mean value.
104
-------
Table 5-2. Results for Sahara® WTT and Seven Included, Destructively Assessed Pipes
Pipe#
30
32
49
56
61
63
64
Method
Manual
Manual
Manual
Laser
Manual
Laser
Laser
Wall
Thickness
Loss
Ratio
>30%
>30%
<15%
<15%
15-30%
15-30%
15-30%
Volume Loss
Percent
0.2%
0.7%
1.0%
2.1%
1.4%
2.6%
2.1%
Relative
Minimal
Small
Small
Largest
Medium
Largest
Largest
Deep
Pits
>50%
1
2
13
0
6
6
5
Rating
Very
few
Verv
Most
None
Some
Some
Some
Max.
Pit
Depth
68%
56%
85%
39%
63%
51%
72%
Rating
Deep
Moderate
Deep
Not deep
Moderate
Moderate
Deep
Largest Patch
Length
(in.)
5
22.5
25.2
60
26.5
40
60
Depth
26%
35%
48%
22%
28%
32%
29%
Visual Assessment
Generally light corrosion
with one deep pit.
A long corrosion area
with a moderately deep
corrosion pit in the center.
Generally light corrosion
elsewhere.
A 2 ft long corrosion area
with many deep pits, one
near through wall.
Generally moderate
corrosion elsewhere
Large area of corrosion,
however none very deep.
A few deep areas of
corrosion. Significant
amount of pipe with full
wall thickness.
Large areas of corrosion
with moderate depth.
Some pipe with full wall
thickness.
Areas of corrosion with
moderate depth and a few
deep corrosion pits.
Significant amount of
pipe with full wall
thickness.
Relative
4
2
1
3
2
1
1
-------
Discussion. Sahara® WTT provided results that indicated that a wide range of conditions were present in
the pipe. However, the pipe was found to have minimal wall loss degradation based upon the post-
demonstration confirmation study. It is possible the vendor conservatively estimated average wall
thickness by assigning the largest velocity changes to a significant loss. The results of the post-
confirmation study suggest that additional vendor experience with excavation information is needed to
improve calibration of the tool and reduce the amount of over calls. Also, since the test pipe appeared to
have minimal overall wall loss (e.g., < 2.6 % wall loss in the 12 exhumed sections), the capability of this
and other wall thickness screening technologies to successfully identify severely corroded pipe could not
be assessed, so that remains a topic for future evaluation.
By utilizing the tethered Sahara® system and being able to stop the hydrophone at precise locations, the
Sahara® WTT technique allows more flexible distance and selectable intervals for calculating average
wall thickness loss; finer intervals (better resolution) can be selected at the cost of longer inspection
times. Knowledge of average wall thickness in a pipe section does not identify specific defects, but it
could be used for focusing subsequent, more detailed and expensive structural inspections on the most
problematic areas.
5.1.2 SmartBall™ Pipe Wall Assessment.
SmartBall™ PWA reported the wall thickness assessment results as general intervals of interest with
reduced wall stiffness for the first 1,050 ft of the test pipe. It had difficulties assessing the second half of
the test pipe potentially due to SmartBall™ PWA being unable to detect the signal from the third pulser,
which was nearest the large amount of noise produced by discharge of water from the test pipe. The
signals from the first and second pulsers were detectable and those results are summarized below.
EPA's contractor performed a detailed assessment of 12 pipe segments to compare the metal loss data
from the pipes selected for verification with the area of suspected wall loss reported by SmartBall™
PWA. The same four point rating system was used to describe the metal loss defect's impact on the
pipeline condition. Similarly, because SmartBall™ PWA presented results over intervals longer than one
pipe segment the results could not be completely verified due to the limited number of exhumed pipe
segments.
Summary of Results. Upon retrieval of the tool, the acoustic, time, and position data recorded by the
SmartBall™ PWA were analyzed and cross-referenced with the acoustic, time, and position data from the
fixed SBRs and the pulsers to determine the acoustic velocity for consecutive, short intervals of the pipe
during the inspection.
The graphs in Figure 5-1 through Figure 5-7 show the condition of the pipe as detected by the
SmartBall™ PWA with respect to its distance along the pipeline. Since the pipe wall thickness is directly
proportional to the velocity of the signal as it propagates through a water filled pipe, these graphs indicate
that there is some evidence of pipe wall stiffness changes within the highlighted areas. However,
although the data suggests that several interesting variations exist in the pulse velocity at different points
along the pipeline, it was unclear whether the data revealed actual changes in the hoop stiffness of the
pipe wall, or if the data had been affected by the presence or condition of the mortar lining or other pipe
stiffness enhancements (such as previous repairs on the pipe). This is a common issue for acoustic-based
technologies.
106
-------
Table 5-3 provides a summary of the locations with evidence of pipe wall weakness up to the second
pulser location. In addition, the SmartBall™ PWA was able, in some portions of the pipeline, to detect
features such as valves and joints based on increased acoustic velocity. For example, the acoustic profile
showed increased acoustic velocities at, or in the vicinity of, the 12-ft intervals of the joints (see Figure 5-
8) and at a drain valve approximately 260 ft from the insertion location (see Figure 5-9). The spatial
resolution of the tool factored in the flow velocity and was at least one data point every two ft along the
line. This technique is not designed to detect individual pits, but may reveal areas where clusters of
pitting or thinning produce weakening over several feet along the pipe.
107
-------
4500 -i
4300
Pulse Velocity vs. Distance
12.0
24.0
36.0
48.0
60.0
72.0 84.0
Distance [ft]
96.0 108.0 120.0 132.0 144.0
(Courtesy of Pure)
Figure 5-1. Acoustic Profiles from 0 ft to 150 ft
Pulse Velocity vs. Distance
2900
2700
2500
130.0 142.0 154.0 166.0 178.0 190.0 202.0 214.0 226.0 238.0 250.0 262.0 274.0 286.0 298.0
Distance [ft]
(Courtesy of Pure)
Figure 5-2. Acoustic Profiles from 130 ft to 300 ft
108
-------
Pulse Velocity vs. Distance
5100
4900
2900
300.0 312.0 324.0 336.0 348.0 360.0 372.0 384.0 396.0 408.0 420.0 432.0 444.0 456.0
Distance [ft]
(Courtesy of Pure)
Figure 5-3. Acoustic Profiles from 300 ft to 465 ft
Pulse Velocity vs. Distance
5400
5200
5000
3800
3600
3400
480.0 492.0 504.0 516.0 528.0 540.0 552.0 564.0 576.0 588.0 600.0 612.0 624.0
Distance [ft]
(Courtesy of Pure)
Figure 5-4. Acoustic Profiles from 480 ft to 630 ft
109
-------
Pulse Velocity vs. Distance
3400
630.0 642.0 654.0 666.0 678.0 690.0 702.0 714.0 726.0 738.0 750.0 762.0 774.0
Distance [ft]
(Courtesy of Pure)
Figure 5-5. Acoustic Profiles from 630 ft to 775 ft
Pulse Velocity vs. Distance
2500
780.0 792.0 804.0 816.0 828.0 840.0 852.0 864.0 876.0 888.0 900.0
Distance [ft]
(Courtesy of Pure)
Figure 5-6. Acoustic Profiles from 780 ft to 900 ft
110
-------
Pulse Velocity v.s Distance
5500
5000
-4500
Ł
~ 4000
u
o
01
> 3500
3000
2500
90
J
TV
V
U
*5
v H
.
I/
IT
d
V*
**
W*
-------
4500 -,
4300
4100
3900
Ł 3700
a) 3500
3300
3100
Pulse Velocity vs. Distance
Pipe Joints
2900
822.0 834.0 846.0 858.0 870.0 882.0
Distance [ft]
894.0
906.0
(Courtesy of Pure)
Figure 5-8. Joint Locations
Pulse Velocity vs. Distance
2700
2500
200.0 212.0 224.0 236.0 248.0 260.0
Distance [ft]
272.0
284.0
296.0
(Courtesy of Pure)
Figure 5-9. Drain Valve Location as Seen by Acoustic Pulses
Comparison to Assessed Pipe Samples. SmartBall PWA provided results for approximately the first
half of the test section, which corresponds to 7 of the 12 pipes that were fully assessed by EPA's
contractor. The results are given in Table 5-4. For the other 5 pipes, pipeline and inspection variables
adversely affected data collection and therefore SmartBall™ PWA was unable to provide results. Pure
identified four areas of reduced stiffness and three areas where the pipe was normal. The three relatively
worse pipes were identified as having reduced wall thickness. These pipes had either a larger volume of
metal loss or a larger area of corrosion with deep pits. One of the pipes identified as being potentially
damaged had a low volume loss and relatively moderate pitting. Two of the pipes identified as normal
had minimal volume loss and only a few deep pits. One of the pipes identified as normal had metal loss
pitting over a large area, but none of the pit depths exceeded 40%.
112
-------
Table 5-4. Results for Pure SmartBall™ Pipe Wall Assessment (PWA) and Seven Included, Destructively Assessed Pipes
Pipe
#
30
32
49
56
61
63
64
Method
Manual
Manual
Manual
Laser
Manual
Laser
Laser
SmartBall™
Condition
Rating for
Span with
included Pipe
Normal
Normal
Reduced
stiffness
Normal
Reduced
stiffness
Reduced
stiffness
Reduced
stiffness
Volume Loss
Percent
0.2%
0.7%
1.0%
2.1%
1.4%
2.6%
2.1%
Relative
Minimal
Small
Small
Largest
Medium
Largest
Largest
Deep
Pits
>50%
1
2
13
0
6
6
5
Rating
Very
few
Very
few
Most
None
Some
Some
Some
Max
Pit
Depth
68%
56%
85%
39%
63%
51%
72%
Rating
Deep
Moderate
Deep
Not deep
Moderate
Moderate
Deep
Largest Patch
Length
(in.)
5
22.5
25.2
60
26.5
40
60
Depth
26%
35%
48%
22%
28%
32%
29%
Visual Assessment
Generally light
corrosion with one
deep pit
A long corrosion area
with a moderately deep
corrosion pit in the
center. Generally light
corrosion elsewhere.
A 2 ft long corrosion
area with many deep
corrosion pits, one near
through wall.
Generally moderate
corrosion elsewhere
Large area of
corrosion, however
none very deep
A few deep areas of
corrosion. Significant
amount of pipe with
full wall thickness
Large areas of
corrosion with
moderate depth. Some
pipe with full wall
thickness
Areas of corrosion
with moderate depth
and a few deep
corrosion pits.
Significant pipe with
full wall thickness
Relative
4
2
1
3
2
1
1
-------
Discussion. Pipes with significant degradation, though desired for this demonstration, were not part of
this water main. Nonetheless, within the level of degradation that was available, SmartBall™ PWA
provided wall thickness estimates for spans of pipe that were usually consistent with the relative
condition, as determined by EPA's contractor, of the exhumed 12-ft pipe contained in the span. From the
results of the post-confirmation study, it may also be inferred that some segments of the pipe were
improperly assessed and that additional vendor experience with excavated, characterized pipe information
is needed, especially to better calibrate results for pipes with minimal wall thickness loss. Given the
overall good condition of the pipe in this demonstration, there is also a need for further evaluation for
pipes with severe wall loss due to corrosion or other causes. Some capability to detect the extra wall
thickness at bell and spigot joints and a drain valve was demonstrated.
The high density of the measurements provided by SmartBall™ PWA could prove useful for average wall
thickness measurements on a segment by segment basis. Analysis methods continue to be improved for
this emerging inspection methodology.
5.1.3 ThicknessFinder. ThicknessFinder reported the condition assessment results as the remaining
equivalent thickness of the pipe. The equivalent thickness of a cement-lined metallic pipe is the thickness
of an un-lined metallic pipe that would be required to match the structural stiffness of the cement-lined
pipe. Since the cement lining enhances the structural stiffness of the pipe, the equivalent thickness of a
cement-lined metallic pipe is generally thicker than the actual metal pipe. The 2,057-ft long test pipe was
divided into seven sections. Each section was bracketed by access pits where acoustic sensors were
attached; the sections ranged in length from approximately 250 to 360 ft (averaging 293 ft).
Summary of Results. Based on current and previous analyses using ThicknessFinder, Echologics
recommended the guidelines presented in Table 5-5 for interpreting their wall thickness data.
Table 5-5. Guidelines for Interpreting ThicknessFinder Wall Thickness Data
Wall Loss (%)
0-10
10-20
20-35
>35
Description of Pipe Condition
The pipe is in very good condition, but may still have
minor levels of uniform corrosion. Some localized areas of
pitting corrosion may exist but it is expected that the areas
are isolated.
Pipe is in good condition, there may be some moderate
uniform surface or internal corrosion, or more localized
areas of pitting corrosion.
Pipe may have significant localized areas of pitting
corrosion, or moderate uniform corrosion throughout.
Pipe is in poor condition and may have numerous areas of
pitting corrosion, including significant uniform thinning of
the pipe.
The results of the condition assessment measurements are presented in Table 5-6. Six sections in a row
presented remaining equivalent thickness greater than 0.70-in. with the seventh section .01-in. below, at
0.69-in. Echologics concluded that there may be some deterioration in these sections and that the pipe is
in good structural condition, which they define in Table 5-5 as having wall loss in the 10%-20% range.
They more specifically estimated the effective wall thickness loss to be approximately 14%-20%.
114
-------
Table 5-6. Echologics ThicknessFinder Condition Assessment Results
File#
la
2c
3c
4b
5d
6c
7b
Location
Pit 1 to Pit A
Pit A to Pit B
Pit B to Pit C
Pit C to Pit 2
Pit 2 to Pit E
Pit E to Pit F
Pit F to Pit 3
Sensor-to-
Sensor
Spacing (ft)
250.7
260.5
298.6
271
360.9
294.6
312.7
Measured
Average
Thickness (in.)
0.73
0.74
0.75
0.71
0.71
0.72
0.69
Condition
Good
Good
Good
Good
Good
Good
Good
Comparison to Assessed Pipe Samples. Echologics provided results for the entire pipe length used in
the demonstration. ThicknessFinder was operated with the pipe full, but not flowing, and in this
operating mode there is no need for a noisy discharge to the sewer, as was required for transporting
Sahara® WTT and SmartBall™ PWA through the pipe. The results are given in Table 5-7.
Discussion. ThicknessFinder provided average wall thickness values over 250 ft to 360 ft intervals. The
reported results showed that all pipes were in "good" condition per Echologics' definition of the term, and
loss from the effective wall thickness was in the 14%-20% range. Thus ThicknessFinder reported wall
loss that was about 11% to 17% more severe than the maximum average wall loss (i.e., 2.6 %) determined
by the destructive assessment results and other findings that indicated that pipes with significant
degradation were not part of this water main. The reported inspection results contained a slight variation
(~7%) from Pit F to Pit 3, which may have indicated an area with slightly more metal loss. Because of
the large inspection interval and the small number of pipes that were exhumed and characterized in detail,
this reported variation could not be confirmed ThicknessFinder was not designed to, nor did it appear to
be able to, discriminate between slight variations in the condition of locally degraded pipe.
5.2 Internal Inspection
The Sahara Video®, PipeDiver® RFEC, and See Snake® RFT internal inspection technologies were
demonstrated on the same cast iron water main in Louisville, KY as described above. Sahara Video®
used CCTV to conduct an internal inspection of the pipeline, while PipeDiver® and See Snake® used a
form of RFEC technology. The inspections were conducted as follows:
• Sahara Video® uses a video camera at the end of a cable tether. The camera, which was inserted
and pulled through the pipeline using the water flow, provided real-time, in-service CCTV
inspection of the test pipe. The camera was also tracked by an operator from ground level to
mark items of interest on the pavement.
• PipeDiver® RFEC is a non-tethered, free swimming platform for inspection of in-service water
mains and includes an electronics module, battery module, and transmitter module for above
ground tracking. PipeDiver® is inserted and extracted from the water pipe via large, vertical
tubes designed to launch or receive the tool at pipeline pressures.
• See Snake® RFT was pulled though the main, which was emptied and swabbed. The hard
diameter of the tool is smaller than the ID of the pipe to allow for passage around protrusions,
lining, and scale within the pipe. Centralizers maintain a uniform annulus between the tool and
the pipe. The vendor indicates that future versions can be made for in-service mains.
115
-------
Table 5-7. Echologics ThicknessFinder Condition Assessment Results for Eleven Destructively Assessed Pipes
20
Pipe
#
30
32
49
56
61
Method
Manual
Manual
Manual
Laser
Manual
ThicknessFinder
Equivalent
Thickness
(Includes Coating)
0.74-in.
0.74-in.
0.75-in.
0.75-in.
0.75-in.
Volume Loss
Percent
0.2%
0.7%
1.0%
2.1%
1.4%
Relative
Minimal
Small
Small
Largest
Medium
Deep
Pits
>50%
1
2
13
0
6
Rating
Very
few
Very
few
Most
Very
few
Some
Max.
Pit
Depth
68%
56%
85%
39%
63%
Rating
Deep
Moderate
Deep
Not deep
Moderate
Largest Patch
Length
(in.)
5
22.5
25.2
60
26.5
Depth
26%
35%
48%
22%
28%
Visual
Assessment
Generally light
corrosion with
one deep
corrosion pit
A long corrosion
area with a
moderately deep
corrosion pit in
the center.
Generally light
corrosion
elsewhere.
A 2 ft long
corrosion area
with many deep
corrosion pits,
one near through
wall. Generally
moderate
corrosion
elsewhere
Large area of
corrosion,
however none
very deep
A few deep areas
of corrosion.
Significant
amount of pipe
with full wall
thickness
-. »
^ 2.
" a
4
2
1
3
2
1 Not including Pipe 145/146, which was an incomplete pipe segment exhumed for comparison to external inspection results.
-------
Table 5-7. Echologics ThicknessFinder Condition Assessment Results for Eleven Destructively Assessed Pipes (Continued)
Pipe
#
63
64
69
98
137
166
Method
Laser
Laser
Manual
Manual
Manual
Manual
ThicknessFinder
Equivalent
Thickness
(Includes Coating)
0.75-in.
0.75-in.
0.75.
0.71-in.
0.72
0.69-in.
Volume Loss
Percent
2.6%
2.1%
1.6%
0.9%
1.1%
0.3%
Relative
Largest
Largest
Medium
Small
Small
Minimal
Deep
Pits
>50%
6
5
4
1
0
0
Rating
Some
Some
Some
Very
few
Very
few
Very
few
Max.
Pit
Depth
51%
72%
75%
63%
46%
37%
Rating
Moderate
Deep
Deep
Moderate
Moderate
Not deep
Largest Patch
Length
(in.)
40
60
14.5
9.5
20
20
Depth
32%
29%
33%
30%
22%
15%
Visual
Assessment
Large areas of
corrosion with
moderate depth.
Some pipe with
full wall
thickness
Areas of
corrosion with
moderate depth
and a few deep
corrosion pits.
Significant
amount of pipe
with full wall
thickness.
Moderate and a
few deep pits,
mostly in
clusters.
Moderate pits,
often in clusters.
Generally light
corrosion.
Clusters of
shallow pits and
large amount of
pipe with full
wall thickness.
Light corrosion
and areas of pipe
with full wall
thickness.
*B
" a
i
i
2
3
4
4
-------
5.2.1 Sahara® Video. Sahara Video® presented the results of the video inspection as a sequence of
observations. Three types of observations were reported: outlets (branch connections, hydrants, etc.), air
pockets, and corrosion. EPA's contractor had no means to verify the presence of air pockets. However,
one week prior, one of the leak detection systems noted that air pockets were present.
Summary of Results. The Sahara® Video inspection identified several visible features over the length of
the test pipe. Two fairly large areas of internal corrosion were found at 1,565 ft and 1,637 ft. Additional
air pockets, ranging from small to large in size, were also discovered during the video inspection. Details
of these observations are presented in Table 5-8 with specific information on the direction and distance
the observation was found from the insertion point (Pit 1).
Table 5-8. Sahara Video Observation Details
No.
1
2
3
4
5
6
7
8
9
10
11
12
Description
Outlet
Outlet
Air pocket
Large air pocket
Outlet
Large air pocket
Outlet
Corrosion
Outlet
Large area of corrosion
Outlet
Outlet
Estimated
Distance
from Pit 1 (ft)
154
677
886
,024
,061
,237
,552
,565
,628
,637
,755
,946
Direction from
Insertion
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Potential Correlated
Pipe Feature
-
-
-
-
Pit 2 (1,080 ft)
-
Pit 5 (1,580 ft)
-
-
-
Pit F (1,750 ft)
-
Comparison to Assessed Pipe Samples. Sahara Video® provided results for the entire pipe length used
in the demonstration. EPA's contractor examined the cement lining using a CCTV crawler in the pipe
after it was dewatered prior to excavation. In general, the CCTV revealed that the lining in the pipe was
continuous without any missing areas, which compares well with what Sahara Video® reported. Due to a
miscommunication with the excavation company, the two pipes with internal coating defects were
scrapped before confirmation could be performed.
Discussion. Sahara Video® examined a segment of the interior circumference for the full length of the
test pipe. Sahara Video® provided results that confirmed that the pipe lining was in generally good
condition and had minimal degradation or delamination. Also, no debris or tuberculation was found in
the pipe. This inspection was a valuable part of the demonstration as it was the first assessment of the ID
of the pipe and provided some assurance that subsequent internal condition assessment methods could be
successfully applied since an unobstructed path was available from one end of the pipe to the other.
5.2.2 PipeDiver®. PipeDiver® testing was conducted as early implementation of this technology.
Data was analyzed and characterized based on basic pattern recognition from simple models of wall
thickness variations. PipeDiver® could detect the start and end locations of pipe joints where anomalies
were identified. Specific anomalies with metal loss or pitting were not identified.
118
-------
Summary of Results. The PipeDiver® RFEC results showed joint signals, known features and
anomalous signals, which were reportedly due to wall thickness loss. Table 5-9 lists the location of pipe
sections that PipeDiver® data characterized as anomalous and their distance from the launch location in
Pit 1. Forty-one of a total of 170 pipe segments showed anomalous signals; this was a detection
methodology and sizing of the extent of degradation based on the signal was not performed. Of the
anomalous pipe segments, 14 were identified in the first half of the test pipe, while 27 were identified in
the second half of the test pipe. Further verification and calibration are needed by the inspection vendor
to confirm the nature of these anomalous signals.
Table 5-9. PipeDiver® Anomalous Pipes
Start
216
264
276
324
360
384
444
504
516
576
612
864
936
948
,044
,056
,176
,212
,284
308
332
Distance from Pit 1 (ft)
End
228
276
288
336
372
396
456
516
528
588
624
876
948
960
1,056
1,068
1,188
1,224
1,296
1,320
1,344
Start
,356
,368
,416
,452
,512
,584
,608
,620
,644
,656
,704
,740
,752
,788
,812
,860
,872
,908
,956
,992
End
1,368
1,380
1,428
1,464
1,524
1,596
1,620
1,632
1,656
1,668
1,716
1,752
1,764
1,800
1,824
1,872
1,884
1,920
1,968
2,004
Figure 5-10 shows an example of several pipes classified as anomalous from their RFEC signal. The
proprietary processing routine produced two separate outputs, signal amplitude (red curve) and signal
phase (green curve). When assessing the red signal, the two hump pattern with the first higher than the
second is considered normal. The entire signal in pipe 81 is larger and different from the normal pipe
signal and could be due to wall thickness loss or from an unidentified pipe feature. Pipe 80 is missing the
pattern altogether, which could be due to a wall thickness loss. For pipe 79, the dip is missing, but this
may be due to degradation in pipe 80. The green signal was not useful in characterizing pipe.
Four manufactured defects were machined into Pit F on July 28th (see Figure 5-11). By comparing the
RFEC signals from the data before and after the defects were created gave PipeDiver® data analysts the
119
-------
best possible chance of seeing the relatively small amount of wall thickness loss in the data (see Figure 5-
12).
The PipeDiver® RFEC results showed good repeatability between multiple scans using the same
configuration. The RFEC data showed joint signals, known features and anomalous signals that were
attributed to wall thickness loss, but the results of this demonstration suggest that further calibration is
needed to confirm the nature of these anomalous signals.
The detection and sizing sensitivity of PipeDiver® is limited by the number of sensor channels. As such,
the inspection vendor reported that the future developments will focus on improving the detectors and
their placement (including increasing the number of available detectors). In addition, the analysis process
will be reviewed for new techniques and improved software. Specifications and implementations of the
size and installation of hot taps for tool access will also be reviewed to prevent future insertion and
retrieval issues.
Signal amplitude (red)
Signal phase (green)
V
/' '•--.
A
V"
1400
1520
15BO
Ul'fl IJ4D 1460 Uan 15DD
Elapsed Inspection Time (Seconds)
(Courtesy of vendor)
Figure 5-10. PipeDiver RFEC Anomalous Pipes (for Reference Elapsed Inspection Time (sec) and
Pipe Length Number are Given)
120
-------
jjj I I.
Figure 5-11. Calibration Defects in Pit F
121
-------
0)
73
:fc!
Q.
c
O)
CO -|
Potential
Pit F Signals
1 Pnfnrn Pit F Hnf
Aftnr Pit F Hofflr
40 2950
ects \
ts
1 1 '
2960
1
i 1 i i i I
2970 2980
Time (seconds), July 23rd
(Courtesy of vendor)
Figure 5-12. Comparing RFEC Data Before and After Defects
Comparison to Assessed Pipe Samples. Forty-one of the 169 pipe lengths (24%) were identified by
PipeDiver® as being anomalous. Twelve, 12-ft pipe lengths were characterized by EPA's contractor, and
ranked on a 4 point scale with "1" being relatively more degraded and "4" being relatively least degraded.
The results of the evaluations for 11 of these pipe lengths, for both PipeDiver® and for EPA's contractor,
are in Table 5-10. PipeDiver® reported two of the 11 pipe lengths as anomalous. One pipe rated by
EPA's contractors as being in the relatively most degraded category (i.e., "1"), with the most pits > 50%
(13), the deepest pit (85% wall thickness), and the largest corrosion patch (25.2-in. long and 48% deep)
was identified as anomalous by PipeDiver®. Two other pipes rated "1" were not determined anomalous
by PipeDiver®. One of those pipes had large areas of corrosion with moderate depth and some pipe with
full wall thickness; the other had areas of corrosion with moderate depth, a few deep corrosion pits, and a
significant amount of pipe with full wall thickness. A second anomalous pipe identified by PipeDiver®
was rated "2" by EPA's contractor, and it had a long corrosion area (22.5-in long; 35% depth) with a
moderately deep (56%) corrosion pit in the center, and generally light corrosion elsewhere. Two other
pipes rated "2" were not found anomalous by PipeDiver®. The remaining five pipes that showed minimal
degradation, were rated "3" or "4", and were correctly identified as not degraded by PipeDiver®.
122
-------
Discussion. The demonstration showed that a large in-line inspection tool could be launched and
retrieved from an operating pipeline. This was the initial use of this technology on an operational cast
iron water main. PipeDiver® provided results for the entire pipe length used in the demonstration. It
successfully identified pipes independently determined to be in good condition. Due to the lack of test
pipe sections with large areas of severe metal loss, its capability for identifying these types of pipes could
not be demonstrated or evaluated. PipeDiver® results were mixed compared to the EPA contractor's
assessment when attempting to discriminate between levels of degradation in pipe that was in overall
good condition (i.e., < 2.6 % overall wall loss). In those pipes, some substantial corrosion patches, deep
corrosion pits, and up to 6 pits > 50% did not cause pipes to be reported as anomalous. This may or may
not be a concern, depending on inspection goals and criteria. The technology capability could be
evaluated and potentially improved with further calibration to a wider range of pipe excavation
information from the field. This vehicle may prove to be a good platform for mounting sensors for
condition assessment of cast iron and other pipes.
123
-------
Table 5-10. PPIC PipeDiver® Results for Eleven Destructively Assessed Pipes21
Pin A
-T 1JJC
#
30
32
49
56
61
63
Method
Manual
Manual
Manual
Laser
Manual
Laser
PipeDiver®
Anomalous
Signals
no
yes
yes
no
no
no
Volume Loss
Percent
0.2%
0.7%
1.0%
2.1%
1.4%
2.6%
Relative
Minimal
Small
Small
Largest
Medium
Largest
Deep
Pits
>50%
1
2
13
0
6
6
Rating
\7(*r\T
v ci y
few
Verv
V ^flj
fpw
i^f VV
Most
Verv
V ^lj
few
Some
Some
Max.
Pit
Depth
68%
56%
85%
39%
63%
51%
Rating
Deep
Moderate
Deep
Not deep
Moderate
Moderate
Largest Patch
Length
(in.)
5
22.5
25.2
60
26.5
40
Depth
26%
35%
48%
22%
28%
32%
Visual Assessment
Generally light
corrosion with one
deep pit
A long corrosion
area with a
moderately deep
corrosion pit in the
center. Generally
light corrosion
elsewhere.
A 2 ft long corrosion
area with many deep
corrosion pits, one
near through wall.
Generally moderate
corrosion elsewhere
Large area of
corrosion, however
none very deep
A few deep areas of
corrosion.
Significant amount
of pipe with full wall
thickness
Large areas of
corrosion with
moderate depth.
Some pipe with full
wall thickness
$
1
^'
n
4
2
1
o
6
2
1
Not including Pipe 145/146, which was an incomplete pipe segment exhumed for comparison to external inspection results.
-------
to
Pin A
#
64
69
98
137
166
Method
Laser
Manual
Manual
Manual
Manual
PipeDiver®
Anomalous
Signals
no
no
no
no
no
Volume Loss
Percent
2.1%
1.6%
0.9%
1.1%
0.3%
Relative
Largest
Medium
Small
Small
Minimal
Deep
Pits
>50%
5
4
1
0
0
Rating
Some
Some
Very
few
Very
few
Verv
Max.
Pit
Depth
72%
75%
63%
46%
37%
Rating
Deep
Deep
Moderate
Moderate
Not deep
Largest Patch
Length
(in.)
60
14.5
9.5
20
20
Depth
29%
33%
30%
22%
15%
Visual Assessment
Areas of corrosion
with moderate depth
and a few deep
corrosion pits.
Significant amount
of pipe with full
wall thickness
Moderate and a few
deep pits, mostly in
clusters.
Moderate pits, often
in clusters.
Generally light
corrosion. Clusters
of shallow pits and
large amount of pipe
with full wall
thickness.
Light corrosion and
areas of pipe with
full wall thickness.
ff
-
^4-
n
1
2
o
J
4
4
-------
5.2.3 See Snake®. See Snake® collected data over the entire pipe length and reported bell and
spigot joints, pipeline features such as tees, and metal loss anomalies. For the metal loss anomalies, the
maximum extent, axial distance, and clock position was provided. For many pipe segments, no metal loss
anomalies were reported, while other pipe segments had multiple anomalies. The report also provided a
summary of the results, which gave a quick overview of the condition of the pipe.
Summary of Results. The tabulated results provided by the vendor indicated all verified ball and socket
joints were detected. Some other large signals were also observed, but they could not always be
correlated back to observable or known features such as hydrants and tees, and were assumed to be metal
loss anomalies. Valves and tee branches were accurately located by See Snake®. The following was
noted:
• 12.2 ft pipe lengths were common throughout the line.
• A number of major line features were noticed in the data, which are believed to be two valves and
two branches.
The inspection of the water line resulted in 367 wall loss indications. A histogram of the results shows
that a majority of the defects were less than or equal to 50% deep, with a much smaller group in the 60-
80% range, and only a few defects 90% or deeper. More importantly, the results from the See Snake®
tool show that the deep defects are concentrated within the first half of the line, leaving about half the line
in relatively good shape. A histogram of the number of defects by wall loss percentage is provided in
Figure 5-13, while the defect depth as a function of distance along the pipeline is provided in Figure 5-14.
The vendor reported that due to magnetic permeability noise, See Snake® was not able to characterize
any of the machined calibration pits or test pits. Four potential causes of the noise were identified by the
vendor: (1) insufficient coolant when drilling the pits may have caused heating and stresses that changed
magnetic permeability; (2) a magnetic base on the drilling machine may have affected magnetic
permeability; (3) use of other inspection devices with permanent magnets for attaching to the pipe; and,
(4) use of technologies that saturated the pipe with a magnetic field. Therefore, the vendor calibrated
their device with their own test samples.
Comparison to Assessed Pipe Samples. See Snake® provided detailed results for the entire pipe length
examined in the demonstration. The comparison of results is provided in Table 5-11. Of the eleven pipes
that underwent detailed examinations, the pipes with the largest number of metal loss indications were
also reported by See Snake® to have a large number of pits. The number of pits may not be an exact
measure because deciding whether a corrosion area is two pits or one larger pit is not always possible.
Additionally, the pipes that showed minimal degradation in the detailed examinations were also correctly
identified by See Snake® as having few or small anomalies.
Discussion. Of all of the condition assessment technologies demonstrated, See Snake® provided the most
detailed results for the entire pipe length and correlated the best with the post-demonstration assessment
of the exhumed pipe segments. The total number of corrosion pits, as well as corrosion pit location with
respect to the pipe joint and clock position, were clearly reported and correlate well. This was the initial
use of this tool and the last technology demonstrated. Since replacement of the line was scheduled to
begin immediately following the demonstration, there was not time for additional tests or slips in the
schedule. There was trouble controlling the winch that caused velocity excursions, jerking and surging.
On the final day, all equipment worked well and an acceptable data set was acquired. The
implementation was intrusive for the demonstration as the pipe had to be drained and cut, and a pull cable
had to be threaded for this inspection. The potential for magnetic interference and its potential effects on
See Snake® performance should be considered during future testing and/or application of the technology.
126
-------
120
<20 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100
Defect Depth [in % of wall thickness]
(Adapted from vendor report)
Figure 5-13. See Snake® Defect Histogram
Defect Depth as a function of distance along the length of the pipe.
"
12
^ 80 -
u
IE
o
"o
1 ^°
tj 40 -
I "
30 -
*
*
„** - V
** V. ^*-
» * • i • »
- » »* » »
» »
**»*••»»»•« •* *» •*
X. . t^v,; ^;\
*v * * •• n<*»* • ******* ** * V ** *
*• %**•/ v ?*»^*:** * ^ ?.*.** * »\ /** »*
0.00 200.00 400.00 600.00 800.00 1000.00 1200.00 1400.00 1600.00 1800.00 2000.00
Distance [Ft]
(Courtesy of vendor report)
Figure 5-14. See Snake® Defect Scatter Graph
127
-------
Table 5-11. See Snake® Results for Eleven Destructively Assessed Pipes1
Pipe
#
30
32
49
56
61
63
64
Method
Manual
Manual
Manual
Laser
Manual
Laser
Laser
See Snake® Pit
Assessment
[% of wall
thickness]
1 pit [at about
60%]
0
7 reported, [2
greater than
40%]
4 reported, [all
less than 20%]
3 reported, [2
greater than
40%]
7 reported, [4
greater than
40%]
6 reported, [2
greater than
40%]
Volume Loss
Percent
0.2%
0.7%
1.0%
2.1%
1.4%
2.6%
2.1%
Relative
Minimal
Small
Small
Largest
Medium
Largest
Largest
Deep
Pits
>50
%
1
2
13
0
6
6
5
Rating
Very
few
Very
few
Most
Very
few
Some
Some
Some
Max
Pit
Depth
68%
56%
85%
39%
63%
51%
72%
Rating
Deep
Moderate
Deep
Not deep
Moderate
Moderate
Deep
Largest Patch
Length
(in.)
5
22.5
25.2
60
26.5
40
60
Depth
26%
35%
48%
22%
28%
32%
29%
Visual Assessment
Generally light corrosion
with one deep pit.
A long corrosion area
with a moderately deep
corrosion pit in the center.
Generally light corrosion
elsewhere.
A 2 ft long corrosion area
with many deep corrosion
pits, one near through
wall. Generally moderate
corrosion elsewhere
Large area of corrosion,
however none very deep.
A few deep areas of
corrosion. Significant
amount of pipe with full
wall thickness.
Large areas of corrosion
with moderate depth.
Some pipe with full wall
thickness.
Areas of corrosion with
moderate depth and a few
deep corrosion pits.
Relative
4
2
1
3
2
1
1
to
oo
:Not including Pipe 145/146, which was an incomplete pipe segment exhumed for comparison to external inspection results.
-------
to
VO
Pipe
#
69
98
137
166
Method
Manual
Manual
Manual
Manual
See Snake® Pit
Assessment
[% of wall
thickness]
2 reported on
the order of
30%
1 pit at about
35%
1 pit at about
35%
1 small pit
Volume Loss
Percent
1.6%
0.9%
1 1%
0.3%
Relative
Medium
Small
Small
Minimal
Deep
Pits
>50
%
4
1
0
0
Rating
Some
Very
few
Very
few
Very
few
]Max
Pit
Depth
75%
63%
46%
37%
Rating
Deep
Moderate
Moderate
Not deep
Largest Patch
Length
(in.)
14.5
9.5
20
20
Depth
33%
30%
22%
15%
Visual Assessment
Significant amount of
pipe with full wall
thickness.
Moderate and a few deep
pits, mostly in clusters.
Moderate pits, often in
clusters
Generally light corrosion.
Clusters of shallow pits
and large amount of pipe
with full wall thickness
Light corrosion and areas
of pipe with full wall
thickness
w
—
S"
rt-
"
re
2
3
\
4
-------
5.3. External Assessment
The AESL ECAT, RSG HSK and RSG CAP external inspection technologies were demonstrated on the
same cast iron water main in Louisville, KY as described above.
• AESL attaches the ECAT system to the exterior of the pipe using high strength magnets. The
ECAT is manually operated at a small number of excavations along the pipeline, and uses MFL
technology to locate and size defects. ECAT only scans a portion of the exposed pipe at one time
and then must be repositioned. This process continues until the entire circumference and length
of the exposed pipe has been scanned. The data from the ECAT system is used in combination
with data from commercial ultrasonic instruments, visual inspection of coating condition, soil
properties, and traffic loads to statistically predict the condition of long lengths of un-inspected
pipe.
• RSG HSK is a handheld device that uses a patented BEM technology to assess the localized
pipeline condition in select excavations. The HSK is manually moved around the exposed pipe in
a grid pattern to collect pipe defect data (remaining wall thickness, areas of metal loss, and
fractures). The HSK system is designed to scan along the length and diameter of the pipe.
• RSG CAP also uses the BEM technology, but is for keyhole inspections. The device operates
with a down-hole, clamp-on device to affix the sensors to the pipe. The CAP system is only
designed to scan the top portion of the pipe exposed via the keyhole excavation. Capability for
full circumference scans via a keyhole is now reportedly available .
Each external condition assessment tool found a large number of anomalies in the excavated pipeline
sections that underwent inspection. Verification of all anomalies is not practical; however some
comparisons were attempted using the location and size of the machined defects with the results provided
by each inspection vendor.
In particular, the corrosion sizing results for AESL ECAT were plotted in a manner commonly used by
pipeline inspection vendors to demonstrate commercial inspection technology capabilities. For these
graphs, benchmark data is plotted against the values reported by the technology developers. Care must be
taken in interpreting these graphs since:
• Error in the destructive measurements is not zero.
• Grit blasting can remove good metal when attempting to remove deep graphitization. Also, the
blasting process may not remove all of the corrosion or graphitization products.
• Only the maximum depth is compared, while the corrosion pit depth varied throughout the defect;
many corrosion areas had more than one area of local thinning.
• Length and width were measured at the surface; however other measures can also be used that
still accurately describes the anomaly such as volume divided by maximum depth.
Overall these graphs show the results predicted by AESL correlated well with the machined defect
benchmark data. The same comparison charts could not be used to verify the results provided by RSG.
As discussed previously, RSG only provides relative wall thinning data averaged over the sensor area
(Ixl-in. for CAP and 2x2-in. for HSK) and therefore does not offer the sensitivity needed to make a direct
comparison with the machined defect data. Only general comments can be made based on the CAP and
RSK devices regarding possible increased wall thinning in the location of the machined defects.
130
-------
In addition, AESL provided soil and wall thickness analyses that were integrated with the condition
assessment results to perform a statistical analysis of the condition of the uninspected portion of the
pipeline.
5.3.1
AESL ECAT
Summary of Results. AESL took soil measurements including resistivity, redox, pipe-to-soil potential,
and pH at 10 accessible locations along the pipeline (Pits A-F, Pits 1-3, and Pit L). Results from the soil
survey were used to calculate a soil corrosivity score according to the French Standard AFNOR A05-250.
These results are presented in Table 5-12.
Table 5-12. Soil Corrosivity Results
Excavation
Pit
Pitl
Pit A
PitL
PitB
PitC
Pit 2
PitD
PitE
PitF
Pit3
AFNOR
Score
6
6
7
5
8
5
6
6
9
7
Soil Corrosivity
Fairly Corrosive
Fairly Corrosive
Fairly Corrosive
Fairly Corrosive
Highly Corrosive
Fairly Corrosive
Fairly Corrosive
Fairly Corrosive
Highly Corrosive
Fairly Corrosive
AESL also conducted, at pits F, 2, and L, visual inspections of the bitumen paint coating on the external
surface of the pipeline. The general condition of the coating for each excavation as reported by AESL is
provided in Figure 5-15 through Figure 5-17 as the percentage of failed coating per 0.1 m (3.9 in.) at
regular intervals (16-degree) around the pipe circumference. Pit F and Pit L showed the least amount of
coating failure with overall failure percentages of 11-percent and 6-percent, respectively. An area of
coating at Pit F was in poor condition between 170-degrees and 280-degrees. Pit 2 exhibited the most
failed coating with an overall failure percentage of 70-percent and several specific locations showing 100-
percent coating failure.
AESL conducted a detailed pipe wall condition assessment using the ECAT for Pit F, Pit 2, and Pit L over
aim length and full pipe circumference. Table 5-13 summarizes the condition assessment results for the
three excavation pits. The vast majority of the defects were external (~ 800), but ~ 23 internal defects
were identified. The internal and external defects were differentiated with a proximity sensor. Some
mechanical damage was also identified in Pits F and L. Figure 5-18 through Figure 5-21 graphically
depict the size and location of specific metal loss defects. Because of the sheer number of defects
identified in each excavation location only the 20 largest defects are presented in the figures. AESL also
determined wall thickness with an ultrasonic device. The wall thickness for all three excavation locations
ranged from a minimum of 17.6 mm (0.69 in.) to a maximum of 20.8 mm (0.82 in.).
131
-------
Table 5-13. Summarized Condition Assessment Results for Pit F, Pit 2, and Pit L
Excavation
Pit
PitF
Pit 2
PitL
Summarized Condition Assessment Results
*
*
*
*
*
*
*
*
-240 external defects (largest was 0.43-in. depth)
~9 internal defects (largest was 0.39-in. depth)
Mechanical damage between 180° and 270°; likely not
to have occurred recently
-225 external defects (largest was 0.59-in. depth)
~11 internal defects (largest was 0.41-in. depth)
-330 external defects (largest was 0.57-in. depth)
-3 internal defects (largest was 0.41-in. depth)
Mechanical damage at -90° and between 180° and 280°
132
-------
TABLE 41- VWOAL OOATIMQ FAILURE DI8TH1BUTIO*! - PERCENTAGE COAT1MQ F/ULURE AT till F
( y
V^/'
I
I
a
i
W
33
4B
65
82
88
115
131
14?
184
180
196
213
229
245
282
27S
295
31t
327
344
% Coaling failure
per axial location
Axial Distance from Datum Point («m|
3-1 M
a
5
5
5
a
25
to
a
10
a
a
0
0
a
25
25
25
0
25
a
a
a
7
loo-
no
0
j;
0
0
0
j:
0
o
IS
8
0
0
20
•C,
25
50
25
10
25
0
0
0
a
200-
300
0
0
Q
Q
0
Q
a
a
IB
a
0
Q
2C
25
30
50
0
2^-
20
Q
0
3
1C
300-
400
g
Q
C
0
C
C
8
a
5
5
0
0
0
20
ao
25
8
C
Ł
C
C
Ft
6
400-
500
Q
Q
Q
a
5
0
a
0
0
a
0
10
Q
2C1
78
30
Q
0
0
Q
0
a
8
500-
600
0
0
0
Q
0
3
0
0
0
Q
10
50
50
20
50
0
0
10
26
0
0
0
10
SW-
7iQ
D
a
D
Q
0
D
D
D
0
25
3C
Ł0
K
54)
25
5
2E
50
75
0
Q
0
10
TiO-
sao
G
'3
C1
0
0
C
Q
0
5
25
20
25
50
60
10
25
20
25
50
0
C
Q
14
000-
HO
Q
18
0
D
0
5
D
0
0
10
25
25
20
25
28
18
10
26
75
0
0
0
12
s*e-
1000
C
10
Q
0
0
C
10
0
0
15
50
70
75
40
Q
0
0
25
25
0
0
Q
15
Overall area of coat n-q failure f%|
Total Cells Analysed
% Coating failure per
circumferential
location
Q
3
r
4
2
3
4
S
14
23
29
28
39
22
11
17
33
0
C
5
11
22ft
(Courtesy of AESL)
Figure 5-15. Visual Coating Failure Distribution - Pit F
133
-------
TABLE A2_1 VISUAL COATING FAILURE DtSTRIBtmOH - PERCENTAGE COATING FAILURE 8TTE 2
/
\\
%
!
-c
1
1
!
I
u
"*\
i •
p ,
/'
0
18
33
48
63
B2
sa
115
131
147
164.
1iO
198
213
223
245
262
271
295
311
327
344
% Coating failure
per axial location
Axial Distance from Datum Pont (mm)
MOC
50
fO
40
50
25
5
T=s
100
100
TOO
SO
100
too
100
IDE)
100
40
50
10
5
20
fO
Ł6
no-
am
40
15
25
20
25
j:
20
60
100
80
90
1QC
100
100
100
100
70
70
10
10
10
10
54
2Qi-
300
23
10
3C
40
15
20
20
SB
90
100
80
100
100
100
100
100
75
20
20
5
5
15
62
SW-
AM
10
20
50
20
+0
50
50
80
BO
100
90
100
100
100
100
100
75
70
25
20
5
20
5fl
400-
500
20
25
50
75
70
75
100
100
m
100
60
100
100
100
100
100
30
so
40
25
10
2f
70
58i-
600
40
75
75
eo
80
75
100
&D
SO
100
BO
9D
100
100
100
100
50
75
50
40
20
25
74
SM-
700
30
90
ac
100
too
90
too
«00
too
100
too
100
100
SOD
too
too
70
8C
100
8C
25
80
86
700-
100
30
100
100
100
100
100
100
1QO
100
100
100
100
100
100
100
100
1DO
80
100
7D
25
eo
91
wo-
rn
20
50
30
75
100
100
100
100
1DO
100
100
too
100
100
180
100
100
50
7*:
70
75
70
83
9m-
f'WO
10
20
25
20
70
75
eo
100
100
100
100
100
100
100
100
1QO
100
70
75
70
75
20
73
Overall area of coating failure \%}
Tata! Celts Analysed
% Coating failure per
circumferential
location
30
42
51
58
64
60
70
92
93
es
81
•ge
1DO
100
100
100
78
67
51
40
27
36
70
220
(Courtesy of AESL)
Figure 5-16. Visual Coating Failure Distribution - Pit 2
134
-------
TABlŁ AZJ VISUAL COAT1MG FAILURE WSTKIBtmON- PERCENTAGE COATING FAILURE STTE L
j?
|':'
""^
8
I
I
-jg
1
I
u
\\
i
?
_,^J""
a
is
33
43
65
S2
si
115
131
14?
164
110
1S6
213
22S
245
262
2?i
2S5
311
327
344
% Coaling failure
per axial location
Axial Distance front Datum Pom'. I mm)
1-101
20
5
0
0
0
0
5
0
0
0
0
0
0
a
0
2,5
53
15
0
53
0
Pj
6
100-
zm
20
.C
K
0
10
9
20
0
10
0
0
a
0
0
0
15
25
15
Bi
B
G
0
6
200-
30fl
10
0
5
0
D
10
5
D
D
D
0
0
0
D
10
29
4C
•If",
0
0
0
5
6
SW-
IM
Fs
0
0
Q
10
0
Q
0
0
c
S
Q
0
0
20
1Q
50
20
D
0
u
5
Ł
400-
5W
1 F
0
0
0
5
1 1=
5
D
5
0
10
10
5
IS
"B
to
•?*,
25
0
0
5
0
e
500-
600
5
0
Q
0
5
S
Q
Q
0
a
a
a
a
ID
Q
a
25
40
Q
Q
a
a
4
680-
700
25
5
10
^
Q
5
5
D
D
0
5
a
0
D
D
10
15
40
1C
5
5
5
7
700-
iOi
40
0
s~
5
0
10
D
0
0
D
D
0
0
Q
0
D
20
60
20
0
5
0
a
MO-
MO
15
0
5
0
0
20
0
10
0
0
0
0
0
0
0
5
15
5§
0
15
10
a
T
906-
fOOO
10
Q
0
5
0
5
10
0
0
10
10
20
0
0
a
Q
0
25
0
20
0
0
5
Overall -area c-f coating failure (%)
Total Cells Analysed
% Coating failure per
ciccu inferential
location
17
2
3
2
3
7
5
1
2
1
3
3
1
2
8
10
27
31
4
5
3
-1
e
220
(Courtesy of AESL)
Figure 5-17. Visual Coating Failure Distribution - Pit L
135
-------
Axial Location
0
16
33
49
65
82
98
115
. . «1
(O
-------
Axial Location
0
16
33
49
65
82
98
115
«•—. 131
(0
O) 147
O)
GO 164
O 180
196
.2 213
S 22s
5 245
"to 262
"ji 278
S! »
s 3"
3 327
^- 344
G
123456789 10
•
-wJ
•
•
•
0 qrrim.'Tl
•
fO 2mm(l)
•
•
•
•
•
•
•
fl 1mm(F]
E = external
I = internal
71%
(Courtesy of AESL)
Figure 5-19. Defect Plot for Pit 2 (20 Largest Defect Depths)
137
-------
Axial Location
4 5
6 7
Courtesy of AESL
Figure 5-20. Machined Defect Plot for Pit 2
9 10
Circumferential Location (Degrees)
o
K^^^roKScoo^^oS-^^cn
4 8n~iin{E'>
•
io.5tniT!(E}
<<•»
*•*
•
7 6. 5mm fir,1
J7 y^m/PI
•
6.4mnnE)
•
Td.5mmf^
4^
9. 7mm(E)
E = external
I = internal
71%
14%
138
-------
Axial Location
(O
CU
CU
Q^
c
g
is
CU
u
o
16
33
49
65
82
98
115
131
147
164
180
196
213
229
245
262
278
295
311
327
344
10
-i-4:4mm(E)-
•
Q g^rnf1^
•
Ifs Qrnm/Q
•
•
-J}-QfF>fŁ)(E)
•
10 3mmif)
•
•
1
10 Imrn(E)
•
-3-Srom(-S.
•
•
71%
E = external
I = internal
(courtesy of AESL)
Figure 5-21. Defect Plot for Pit L (20 Largest Defect Depths)
139
-------
AESL also conducted a pipeline stress analysis assuming various loading regimes (soil overburden and
traffic), membrane and bending stress, structural significance of the corrosion and fracture mechanics
models to predict critical defect sizes for the risk of structural pipeline failure. The failure assessment
diagrams (FADs) are provided in the AESL report and Table 5-14 summarizes the critical defect depth at
the location of maximum stress for each of the excavated pits.
Table 5-14. Defect Depth to Cause Fracture
Pit
F
2
L
Load Case
Minor Road
Minor Road
Minor Road
Critical Defect Depth at Location of
Maximum Stress (in.)
0.62
0.57
0.67
AESL's analysis of external defects indicated >65(23) through-wall defects and >63(23) critical defects.
The 2/3 of the pipeline representative of Pits 2 and F likely has 15 through-wall defects, while the 1/3 of
the pipeline representative of Pit L likely has >50 through-wall defects. With regard to critical defects,
for the 2/3 of pipeline representative of Pit 2 and Pit F, there are potentially 13 critical defects ( >0.57-in.)
and for the 1/3 of pipeline representative of Pit L, there are potentially >50 critical defects (>0.67-in.)
along the pipeline. Based on the estimated maximum stresses, defect distribution models, and assumed
pipe material properties, AESL concluded that defects of sufficient depth to cause structural failure of the
pipe may be present.
Because detailed pipeline material property data could not be provided to AESL due to the age of the
pipeline system, there are uncertainties in the stress analysis and critical defect depth predictions. The
identification of a historic American pipe standard for cast iron pipe would allow AESL to reduce the
uncertainty in their assessment of original dimensions, material properties, and test pressures.
AESL also notes that there may be variations in the soil properties and hence corrosion drivers along the
pipeline length, which may affect the validity of the statistical predictions.
Lastly, the fracture mechanics modeling conducted by AESL is based on a singular defect being present
at a point of maximum stress to determine critical defects. Defects found in close proximity to each other
are likely to give rise to higher stress concentration and therefore a further increase in the risk of structural
failure.
Comparison to Assessed Pipe Samples. AESL took nondestructive measurements on the pipe and
coating from 1-m wide sections around the pipe at Pits 2, F, and L, and also made soil measurements at
ten accessible pit locations along the pipeline. AESL reported coating loss, wall thickness, and metal loss
location and depth. AESL also used a systematic approach to extrapolate the data collected into a
! These numbers are based on 2500-ft, which AESL was incorrectly given as the test pipe length instead of 2057-ft.
140
-------
condition assessment for the entire pipe length. Specifically, AESL projected the number of potential
through-wall defects and critical defects for the test pipe.
The machined defects in Pit 2 were distributed over a length of pipe greater than the 1 m that AESL
scanned, so the verification had to be limited to those machined defects that AESL was able to scan in Pit
2. The AESL ECAT detection rate for the machined defects in Pit 2 was 100%, detecting six of six of the
machined defects within their scan range. On average, AESL located anomalies within a small distance
(2.6 inches) of the recorded defect location, but this apparent error may be attributed to differences
between AESL's and EPA contractor's coordinate reference systems. ECAT's sizing accuracy is
depicted in Figure 5-22 and Figure 5-23 in which the predicted and measured anomaly depths and lengths
are presented. Ideally, the ECAT predicted values and the measured value should fall on the 45° line.
The ±10 percent error is representative for MFL systems, and long skinny defects such as the ones in this
pipe are difficult to accurately assess. The other 12 machined defects were not assessed by ECAT.
Under the demonstration program requirements, the ECAT MFL method used by AESL reported, in one
case (Pit L; Pipe 30), a substantially larger number of corrosion pits greater than the size measured
manually after grit blasting; and for Pit F, a similar number (5 vs. 3) of corrosion pits greater than 50%
deep. For Pit L, AESL reported that for the 20 deepest pits, 18 of these were greater than 50% deep. The
post assessment by EPA's contractor found one deep pit, at 68%, two pits near 50% (i.e., 46% and 47%),
and many smaller pits. AESL may or may not remove the corrosion product within natural defects.
While done for the first pipe assessed, AESL was asked not to do it for this pipe because this could
possibly influence results for subsequent tests in the demonstration. Per AESL, removal or non-removal
of corrosion does not affect AESL's calibration or sizing of defects, since the MFL inspection tools are
calibrated prior to arrival on site and sizing models are based on a database of defects at AESL. The
pipes in Pit 2 were not subjected to detailed assessment after the demonstration, so there is no data for
direct comparison with AESL pit depth data.
The wall thickness data from ultrasonic devices were in good agreement from both AESL and EPA's
contractor.
Fifteen internal defects were noted in the data. The concrete liner was in good condition and internal
metal loss anomalies identified by AESL could not be found.
The project is focused on the innovative pipe wall integrity measuring devices, so EPA's contractor did
not do an assessment comparable to AESL's assessment of soil characteristics or coating condition; nor
did they perform modeling, statistical, or structural analyses to integrate and extrapolate indirect and
direct data into a condition assessment for the full length of the test pipe.
AESL used a systematic and detailed approach to predict that there would be > 65 potential through-wall
holes along a 2500-ft test pipe. While there are indications that this may be a significant overestimate,
there are also mitigating factors that prevent a definite conclusion about the accuracy of the estimate.
Indicators that an estimate of > 65 potential through-wall holes is high are: (a) no through-wall defects
were found in the 144-ft (i.e., 7% of actual test pipe length) that was sandblasted and evaluated in detail;
and (b) the leak detection phase of the study (Nestleroth et al, 2012), reported approximately 8 possible
through-wall leaks/1000 ft, which, assuming a uniform leak density across the pipe, projects to 20
through-wall leaks over 2500-ft. However, there are insufficient data to eliminate the possibility that a
substantial number of through-wall holes, or near- through-wall holes, do exist. For example: (a) only 12
of 171 (7%) of pipe lengths were measured in detail for wall loss and corrosion pits, so the actual number
of through-wall holes in the remaining 93% of the test pipe is not known; (b) AESL collected metal loss
data on only 0.5% of the test pipe, but they augmented their direct measurements with other relevant data,
and then subjected the data to a logical and systematic analysis in order to generate their predictions of
141
-------
potential through-wall defects in the remainder of the pipe, and a comparable assessment was not within
the EPA contractors' scope of work; (c) some through-wall holes may be present, but not leak due to
plugging; and (d) AESL was given 2500-ft as the length of the test pipe, instead of 2057-ft, so this
elevated their extrapolated number of potential through-wall holes; the EPA contractor's numbers were
extrapolated to 2500-ft for the comparisons above.
AESL also used a systematic approach to determine the depth of a critical defect, and the number of
critical defects. The project scope did not include a similar level of analysis by EPA's contractor, so no
comparison of the number of critical defects was possible. AESL's analysis indicated that the first 1/3 of
the pipe (i.e., nearest to Pit #1) had a substantially higher defect density than the remaining 2/3 of the
pipe.
Discussion. The AESL ECAT MFL device successfully detected six of six machined defects. The
measured defect depths ranged from 0.13-in. to 0.53-in. with the ECAT device reporting -47% to + 96%
of the measured depths. The measured defect lengths ranged from 1-in. to 3.7-in. with the ECAT device
reporting -45% to +210% of the measured lengths.
AESL's ECAT MFL device was operated successfully on three, 1-meter circumferential bands of pipe,
representing about 0.5% of the full test pipe. AESL has a systematic, multi-step approach to collecting
and analyzing direct and indirect pipe data that produces estimates of wall loss, number of through-wall
defects, and size and number of critical defects that could potentially result in fracture failure. The ECAT
device plays a critical role in the method by providing detailed data on the circumferential bands of pipe
to the modeling and statistical processes that are used to analyze and extrapolate the data to the full length
of pipe. AESL successfully demonstrated that they could implement their approach and produce the
aforementioned estimates.
AESL's estimated numbers of through-wall defects and critical defects could not be rigorously evaluated
for the reasons cited in the previous section.
Other factors in addition to those cited in the previous section may also have influenced AESL's findings.
One excavated pipe location used by AESL was near a large leak, which may have contributed to higher
corrosion rates that may have biased the extrapolations towards larger defects. Some procedural
differences occurred in the selection of the assessment points, and assessment of detect, which could have
influenced the results. For example, AESL would normally select the assessment points, but the selection
was influenced by the test program requirements. Additionally, the sizing software used by AESL is
based on calibration scans of flat-bottomed corrosion defects from different pipes of different wall
thicknesses and potentially different magnetic properties. As such, this demonstration provides a unique
opportunity for AESL to improve their sizing algorithms based on the more complex geometry of natural
defects found in the test pipe.
AESL's approach has the advantages of not requiring entry into the pipe or disrupting flow. Also, only
selected locations along the pipe require excavation. The ECAT is equipped with GPS and blue tooth
technology that is used to enable data transfer in real-time.
142
-------
U.DUUU •
at
.c
u
_c
Ł
§• 0.3000 •
Q
•o
5
.2
•D
Ł 0.2000 •
n nnnn •
X
x"
...**
x/
s'
.,-•••"
...•
x
./
./
^^^
...-••""
..•••'"'
,.-••
^
X
,..••
^x
X
X
..••
x
» .X"
_^r
/
...••'
x
x--
*
x
X
/
^^
X
..-••
s
;T
jr
/
+
Measured Depth (inches)
Figure 5-22. Measured Depth vs. Predicted Depth for
the AESL ECAT for Machined Defects in Pit 2
4.5
3.5
S 2.5
1
a.
,.
..•
X"
0.5
0.5
1.5 2 2.5 3 3.5 4 4.5 5
Measured Length (inches)
Figure 5-23. Measured Length vs. Predicted Length for the AESL ECAT for
Machined Defects in Pit 2
143
-------
5.3.2
RSG HSK and CAP
Summary of Results. In general, the RSG results indicate that there is notable metal loss in the sections
of pipe scanned during the demonstration. RSG did not find a common wall thinning trend for the entire
pipeline length and indicated that the trends appear to be section specific. The minimum wall thickness
recorded was in Pit C at 0.627 in. Detailed plots for each excavation location are provided in Figure 5-24
through Figure 5-32 with a summary of the results provided in Table 5-15.
Comparison to Assessed Pipe Samples. The method provided local wall thickness values at nominally
250 ft intervals on the top of the pipe and full pipe circumference measurements in three locations. These
readings did not discover significant metal loss that would indicate that the condition of the pipe was
poor. RSG only provided relative wall thinning data averaged over the sensor area. The sensors are on a
1-in. spacing in both the axial and circumferential direction for CAP and a 2-in. spacing in both the axial
and circumferential direction for HSK. A single reading is provided for each sensor, averaging over the
sensor aperture. CAP and HSK did not offer the sensitivity needed for direct comparison with the
machined defect data. Only general comments can be made regarding possible increased wall thinning in
the location of the machined defects. The HSK scan of Pit F, which contained fairly large machined
defects (35% to 59% wall loss over a 6-in. length), did indicate areas of reduced wall thickness over a 6-
in. length near the crown of the pipe; however, since the results were averaged there is not sufficient
granularity to directly compare the scans with the actual depths of the machined defects in Pit F (RSG
reported minimum wall thickness of 0.678-in. , but the measured minimum of the machined defects is
approximately 0.3-in.).
Discussion. The RSG HSK and CAP results did not detect any large corrosion areas, which compared
well with the general condition of the pipe. Due to the manner in which the HSK and CAP technologies
report data (e.g., wall thinning data averaged over the sensor aperture area), it is not possible to do a one-
for-one comparison with the measurements recorded for the machined defects in Pits 2 and F.
Table 5-15. Summarized RSG Condition Assessment Results for Pit A to F, Pit 2, and Pit L
Location
[ft]
250
(Pit A)
338
(PitL)
510
(PitB)
809
(PitC)
1,080
(Pit 2)
1,173
(PitD)
1,439
(PitE)
Type
of
Scan
CAP
HSK
CAP
CAP
HSK
CAP
CAP
Minimum
Wall
Thickness
[in.]
0.662
0.654
0.680
0.627
0.688
0.666
0.704
Average
Wall
Thickness
[in.]
0.737
0.735
0.719
0.703
0.735
0.689
0.709
Summarized Condition Assessment Results
* Moderate corrosion near the pipe crown (Fig. 5-26)
* Higher degree of wall thinning near the pipe crown
* Moderate degree of wall thinning at the pipe sides
* One section could not be scanned due to access
restrictions; BEM data could not be analyzed for two
sections due to noise interference (Fig. 5-24)
* Moderate corrosion near the pipe crown (Fig 5-27)
* Most severe corrosion near the pipe crown (Fig. 5-28)
* Moderate to severe corrosion on the southern side of the
pipe
* Moderate corrosion at the bottom of the pipe (Fig. 5-30)
* Moderate corrosion near the pipe crown (Fig. 5-29)
* Negligible wall thickness variation (Fig. 5-32)
144
-------
Location
[ft]
1,750
(PitF)
TVIIA
1 j|Jc
of
Scun
HSK
Minimum
Wall
Thickness
fin.l
0.678 to
0.711
Average
Wall
Thickness
fin.l
0.745 to
0.748
Summarized Condition Assessment Results
* Higher degree of wall thinning near pipe crown
* Moderate degree of wall thinning at the pipe sides; more
prevalent on northern side
* Thinning in isolated areas; therefore likely due to pitting
clusters or graphitization
* (Fig 5-25 and 5-31; two different lengths of pipe in the
same pit, separated by b/s joint).
145
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Battelle - Site 1 - Pit L
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
Crown
1 'V1 >
^+\4
<§ + \s+ i.
4 4"~K"4 W -P 4
ty44-(-4ft4t -tjf-
4444jt.4ji4444 ^V-* 4- V- •
H H 4 4 N-fc' 4 •
4 4 ,^4
4 44 4 4 / 4 H-
4 1.4 44-4
+ 4 + 4 4(±_J__4
Northern
Springline
Invert
Apparent Wall
Thickness
(Inches)
079
163$
lo.7T
'0,74-
•0.7J
• 0.72
0,71
0.7
6.89
-0.6S
•0,67
1 0.66
0.6.
0.64
06J
'o,62
Crown
30"
40"
50"
Along Length of Pipeline-
(Courtesy of RSG)
Figure 5-24. HSK Data Plot - Pit L
146
-------
Battelle - Site 2 - Pit F
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast iron Pipe
Crown-
80-
Southern 7(r
Sprlngline
etr
Invert
SOT
40"
3D"
Northern
Springline
1Q-
Crown—>o"
. . .
,^^ . , ,n,7s ., . . . .
. I h -T i + + 4 •Ł> 4 • - - -I ^ ( •
_
-> » - » • * +jb 4 *N^* + + 4*+-+* +
4 ... TT +* J+ * * ^* «• + +4r~+*'* *+
(&** * •+ +•
^^I^5~"+ •>»^fi 4
rJLjUs^*'^ * v* *3*' "^ ++•»•••
> -T< t4^*»*« n ,\ I li *" -
* * —^ -1-
+7t^»- * -I- -+ + + -f
r>?i,>iq i A
0"
20" 30 40" 50"
<— Along Length of Pipeline—>
Thickness
(inches)
0.79
0,78
0.77
0.76
0.75
074
0.73
0.72
0.71
0.7
0,69
0.68
0.67
0.66
065
0.64
0.63
0.62
(Courtesy of RSG)
Figure 5-25. HSK Data Plot - Pit F
147
-------
Battelle - Site 3 - Pit A
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast iron Pipe
(CAP Scan Only)
Northern
Haunch
e
12' 13"
Southern
Haunch
15
16" 17' 18* 19" 20"
Along Length of Pipeline — »
Apparent Wall
Thickness
(Inchest
os
079
0.78
0.77
0.76
075
074
073
0.72
0.71
0.7
0.69
o.sa
067
056
D.65
o.64
063
21" 22" 23"
(Courtesy of RSG)
Figure 5-26. CAP Data Plot - Pit A
148
-------
Battelle - Site 4 - Pit B
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
(CAP Scan Only)
Northern
Haunch
Apparent Wall
Thickness
(inchest
0.76
Crow— *B
ie- iap 2cr
Southern
Haundi
Along Length of Pipeline
0.82
(Courtesy of RSG)
Figure 5-27. CAP Data Plot - Pit B
149
-------
Battelle-Site5-PitC
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast iron Pipe
(CAP Scan Only)
Apparent Wall
Thickness
(Indwa)
Northern
Haunch
'"
Southern
Haunch
10" 15" 2fT
-Along Length of Pipeline—>
(Courtesy of RSG)
Figure 5-28. CAP Data Plot - Pit C
150
-------
Battelle - Site 6 - Pit D
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iran Pipe
(CAP Scan Only)
Apparent Wall
Thidute*!
(Inches)
-11 tfetoek-
ir-
Southern
Haunch
2" 3" 4" 6" B"
*-—Along L»ny!h of PipaliiM- —*
(Courtesy of RSG)
Figure 5-29. CAP Data Plot - Pit D
151
-------
Battelle - Site 7 - Pit 2
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast iron Pipe
Crown
70"
60"
Northern
Springline
Invert
50"
40"
30"
Southern
Spring line
2(T
10"
Crown
1 * L 1 > • 1—H H
t-•+1t A-*-y+ o+/^
*• •+/* + + *" + * + + 4/i.J
Thickness
(Inches)
sa-
079
076
077
076
075
074
071
072
071
0.7
0.69«
069
067
066
065
064
065
032
Along
of Pipeline
(Courtesy of RSG)
Figure 5-30. HSK Data Plot - Pit 2
152
-------
Battelle - Site 8 - Pit F
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
Apparent Wall
{Inches)
Norltvern
n-n « *» i
>tfc«.«>»fi
i i i •'••>-*-•
,!!..«*. .....I.
[*tr
t r ~*- > - - - JJ-T
, s ,.» .,.»(, nii+Aj.44+^»(.,ir*^,
•^fc*-''** *»•* <-»! **-t t f- 4.*+l!+*+-»»» + Vf *4 + t. -
.--., , ^ + ,-1-n - T-J^ V» 1 *1-1-i3>U+ir-r-i »**J*"-t-f |- •
- , - ^ s. ^'4^-h.4-'-« 4 - r-tr - ~ *4 4- 4- -t T ^- - -™*^T'4 -1^ •
**"**** +"4 T*-f- - -T*"
I. < I . , . , . ,.ll I . . l>, ...
50" Sff1 7CT SO" 90" nOT 1TO"
Length of Pipeline—*•
(Courtesy of RSG)
Figure 5-31. HSK Data Plot - Pit F
153
-------
Battelle - Site 9 - Pit E
EPA Demonstration of Condition Assessment Technologies
24* Diameter Cast Iron Pipe
(CAP Scan Only)
Crown
Apparent Wall
Thickness
{Inchest
9 p'cfwfc——*
(Southern Hsunchlo" r
!
2" 3T
4"
er
•Along Length of Pipeline'
10"
(Courtesy of RSG)
Figure 5-32. CAP Data Plot - Pit E
5.4
Cost of Technologies
The cost of an inspection has two main components: (1) the cost of the service provided by the inspection
vendor; and (2) the cost for the water company to prepare the line and conduct the inspection, which is
often more difficult to quantify. The costs are described below for the acoustic pipe wall surveys, internal
inspection technologies, and external inspection technologies for a specific case and time (i.e., 2009).
5.4.1 Acoustic Pipe Wall Survey Costs. The cost to conduct an average wall thickness survey is
dependent on a number of variables including the length and diameter of pipe to be inspected, pipe
accessibility, and types of services requested (some vendors offer volume discounts for leak detection and
condition assessment services). Costs usually include mobilization/demobilization, inspection (per ft or
mile), tap installation (if required), travel, and data analysis and reporting.
154
-------
To supplement the cost information gathered for the demonstration, EPA's contractor also requested that
the vendors provide a cost estimate for inspecting 10,000 ft of 24-in. cast iron pipe along the same route
as the demonstration in Louisville, KY. They were asked to include in their cost estimates:
The cost of conducting a leak survey alone
The cost of conducting a pipe wall thickness assessment alone
The cost of conducting both (leak and pipe wall thickness survey) at the same time.
Each vendor was given drawings of the 30-in. diameter pipeline that replaced the test pipe used for the
demonstration. The vendors were instructed that the pipeline for the cost estimate would follow the route
of the 30-in. line, but to assume that the line is 24-in. diameter and 10,000 ft in length.
To the extent possible, the vendors were asked to supply with their cost estimates:
• Mobilization/demobilization costs
• Inspection costs (including data analysis and reporting)
• Factors that can affect pricing, such as diameter, length, risers, valves, bends, tees, insertions, etc.
and how these factors might impact the cost
• Costs for line modifications to perform the inspection are typically the responsibility of the utility
and are provided in Section 5.4.2.
Since some details regarding the pipeline and its location were not well defined, the vendors were
informed that a range of costs was acceptable.
PPIC Sahara®. For a 24-in. diameter, 10,000 ft long cast iron pipe, the cost estimates for a Sahara® leak
and/or pipe wall thickness inspection are provided in Table 5-16. Costs were not broken out by
individual activity (e.g., data acquisition, data analysis, reporting, etc.). Charges for mobilization/
demobilization are $4,000, while data analysis and reporting are included in the price of the survey.
As reported by PPIC, each site inspection has different factors that may result in modification costs for
either the client or inspection vendor. Pipeline and operational parameters, such as pipeline length, access
preparation, features, flow condition, etc. can affect pricing. Proper pre-inspection preparation (drawings,
access preparation, flow rate control, etc.) by the client can significantly increase productivity, while
reducing the overall cost of the inspection. Inspecting longer lengths of pipe at the same time can benefit
from long-term program pricing discounts.
Table 5-16. PPIC Sahara* Cost Estimates for Inspection of a 24-in. Diameter, 10,000 ft Long Cast
Iron Pipeline
Leak and gas pocket survey (includes data acquisition, data
155
$22,000
-------
analysis, and final report)
Pipe wall thickness survey (includes data acquisition, data
analysis, and final report)
Leak and gas pocket AND pipe wall thickness survey
(includes data acquisition, data analysis, and final report)
$33,000
$44,000
Pure SmartBall™. Pure provided a range of costs to conduct three types of surveys: (1) aleak and gas
pocket survey, (2) a pipe wall thickness survey, and (3) both leak and pipe wall thickness surveys on one
mobilization. Line modifications would be required of the client to install two 4-in. taps, one at the
beginning and one at the end of the survey length. Pipeline flow would also need to be maintained
between 1.5 and 2 ft/s and pipeline pressure above 10 psi. Pure stated that it was possible to conduct a
leak survey at lower pipeline pressures, but the accuracy of the results could sometimes be compromised.
Pure also stated that these prices were to be used as a guideline and not as fact for inspection projects of
this size.
For a 24-in. diameter, 10,000 ft long cast iron pipe, the cost estimates for a SmartBall™ inspection are
provided in Table 5-17. Costs were not broken out by individual activity (e.g., mobilization, data
acquisition, reporting, etc.). Charges for mobilization, demobilization, data acquisition, data analysis, and
final report run between $25,000 and $40,000 per inspection depending on which technology is used.
This type of survey would require two days on site, one to do a site review with the client and an actual
day of work with the tool in the pipeline. Pure can produce an on-site interim report and the final report
within two weeks of completing the survey. The interim report generated just after the survey, while the
field crew is still on site would cost an additional $3,000 to $5,000.
Table 5-17. Pure SmartBall Cost Estimates for Inspection of a 24-in. Diameter, 10,000 ft Long
Cast Iron Pipeline
Type of Survey
Leak and gas pocket survey (includes mob/demob, data
acquisition, data analysis, technology charges, and final
report)
Pipe wall thickness survey (includes mob/demob, data
acquisition, data analysis, technology charges, and final
report)
Leak and gas pocket AND pipe wall thickness survey
(includes mob/demob, data acquisition, data analysis,
technology charges, and final report)
Cost Estimate
$40,000 to $50,000
$55,000 to $65,000
$80,000 to $90,000
Echologics LeakfinderRT. Echologics provided a fairly detailed cost proposal describing the work to be
done for executing leak and condition assessment surveys for a 24-in. diameter, 10,000 ft long cast iron
pipeline. Preparation work would be required by the client before the arrival of Echologics field
technicians and includes:
• Assess traffic management requirements and prepare a traffic management plan.
• Identify confined space entry locations and provide a confined space entry plan and necessary
equipment.
156
-------
• Identify all fittings to be used for the inspection and mark with blue spray paint or the equivalent.
• All fittings should be in working order with no leaking seals or joints when under pressure. Any
leaking fittings must be repaired before the inspection. Failure to do so prevents accurate data
from being acquired in this location.
• Any valves installed on the pipe to be surveyed should be operated, if possible, to make sure they
are fully open. Any boundary/closed valves should be acoustic sounded to make sure the valve is
not passing water.
• Valve boxes, chambers, and vaults are to be cleared of debris prior to the inspection. Failure to
meet this requirement will prompt the need for an on-call VAC truck for the duration of the
project.
• Provide detailed maps, plans, and as-built drawings, if possible, showing all pipe fittings and any
other essential distribution information to establish a data acquisition plan.
• Provide all repairs and rehabilitation history, if possible, on the section of pipe to be surveyed.
• Air must not be present in the main and all air relief valves must be in good working order and
inspected prior to the start of the survey. If air is present, flushing must be undertaken to
eliminate any trapped air.
• Pipe pressure must be maintained at a minimum working pressure of 25 psi with a maximum
pressure of 150 psi. Anything outside of these limits will require special consideration.
Echologics also requires the provision of an experienced water operator with a fully equipped truck for
the duration of the project. These requirements are necessary to accomplish the project within the
proposed timeline and budget.
For the condition assessment survey, Echologics requires access to the pipe every 300 to 400 ft through
the use of vacuum excavated potholes. The potholes should measure 6 to 8-in. in diameter and provide
access to the top of the pipe. Data acquisition will be performed using magnetic surface mounted sensors
attached to available fittings or the pipe surface. Fire hydrants will need to be flushed to take the water
temperature at each measurement site. Pipeline installation date and site-specific pipe manufacturer data
must be provided prior to field work.
Echologics provided cost estimates for mobilization, data acquisition, data analysis, and final reporting.
Mobilization includes all of the preparation work required by Echologics field technicians along with
travel and shipping expenses. Data acquisition will take approximately three to five days with two field
technicians. Generally, it is possible to cover between 2,500 ft and 5,000 ft of pipe per day. If any leaks
are discovered during the data acquisition process, it will be the decision of the client as to whether or not
a detailed investigation will be performed to pinpoint the location of the leak. Data analysis includes the
time required to analyze the acoustic recordings upon completion of data acquisition using proprietary
processes. The analysis time will depend on the pipe size and total length of pipe surveyed. The final
report will summarize all of the results and include background, methodology, sources of error, data
interpretation methods, analysis, results, and final recommendations. A draft report will be submitted to
the client prior to its finalization. For a 24-in. diameter, 10,000 ft long cast iron pipe, the cost estimates
for a LeakfinderRT inspection are provided in Table 5-18.
For a condition assessment and leak detection survey, Echologics estimated a total of four to five days on
site and an additional 22 hours of data analysis and final report preparation.
157
-------
Table 5-18. Echologics LeakfinderRT Cost Estimates for Inspection of a 24-in. Diameter, 10,000 ft
Long Cast Iron Pipeline
Type of Survey
Leak detection survey
Mobilization
Data Acquisition
Data Analysis
Reporting
Total
Condition assessment and leak detection
Mobilization
Data Acquisition
Data Analysis
Reporting
Total
Cost Estimate
$3,000
$12,500
$2,500
$2,310
$20,310
$3,500
$15,000
$5,000
$3,630
$27,130
5.4.2
Internal Inspection Technology Costs
PPIC PipeDiver™. Since the PipeDiver™ system is currently in the development stage, commercial
pricing was not available. The cost elements would be expected to include: mobilization of the inspection
crew; inspection and data acquisition on the 10,000 ft of 24-in. pipe, which is expected to take one day to
inspect; use of a crane or backhoe and operator for tube placement (included in site preparation cost
below); and data analysis and reporting, which would take up to eight weeks after the inspection.
PPIC Sahara* Video. Since the PPIC Sahara® Video was in development at the time the demonstration
report was submitted, PPIC and then Pure declined to give a cost estimate. The cost elements would be
expected to include: mobilization of the inspection crew; inspection and data acquisition on the 10,000 ft
of 24-in. pipe; and data analysis and reporting.
Russell NDE Systems Inc. See Snake®. Russell NDE Systems Inc. provided a detailed cost proposal
describing the work to be done for executing the condition assessment survey for a 24-in. diameter,
10,000 ft long cast iron pipeline using the free swimming operation. The free swimming operation was
recommended over the tethered operation, which is typically applicable for lengths less than 3,000 ft with
no more than three elbows. Site preparation work that would be required by the client before the arrival
of the NDE Systems Inc. team includes:
• Assess traffic management requirements and prepare a traffic management plan.
• Isolation of the line to be inspected and preparation of two access pits with trench boxes for tool
launching and receiving.
• Removal of 10 ft of pipe in each access pit for tool launching and receiving.
• Cleaning of the line before inspection.
Russell NDE Systems Inc. also requires an experienced water operator to operate valves and control water
flow during inspection and an equipment operator to assist with launching and removal of the tool form
the access pits. These requirements are necessary to accomplish the project within the proposed timeline
and budget.
158
-------
Russell NDE Systems Inc. provided cost estimates for mobilization/demobilization, bore proofing (i.e.,
ensuring the bore diameter is sufficient along the length of the pipe), launch and receive barrel rental,
inspection, and data analysis and reporting. Mobilization includes travel to and from the site and shipping
expenses. Inspection and data acquisition is estimated to take two days, covering about 5,000 ft of pipe
per day. For a 24-in. diameter, 10,000 ft long cast iron pipe, the cost estimates for a See Snake inspection
are provided in Table 5-19.
Table 5-19. Russell NDE Systems Inc. See Snake® Cost Estimates for Inspection of a 24-in.
Diameter, 10,000 ft Long Cast Iron Pipeline
Type of Survey
Free swimming operation (barrel rental included)
Mobilization/Demobilization
Bore Proofing
Launch & Receive Barrel Rental
Inspection Fee
Analysis and Reporting Fee
Total
Free swimming operation (barrel rental not included)
Mobilization/Demobilization
Bore Proofing
Inspection Fee
Analysis and Reporting Fee
Total
Cost Estimate
$20,000
$10,000
$40,000
$60,000
$60,000
$190,000
$20,000
$10,000
$60,000
$60,000
$150,000
5.4.3
External Inspection Technology Costs
AESL ECAT. AESL provided a lump sum cost proposal for executing the condition assessment survey
for a 24-in. diameter, 10,000 ft long cast iron pipeline. The costs provided by AESL include mobilization
and demobilization from Northumberland, UK and have been broken down into inspection only and
inspection with condition assessment. Site preparation work that would be required prior to the
inspection would include excavations with trench boxes roughly every 1,200 ft, which would require
roughly nine excavations. The costs for inspecting a 24-in. diameter, 10,000 ft long cast iron pipe by
AESL are provided in Table 5-20.
Table 5-20. AESL ECAT Cost Estimates for Inspection of a 24-in. Diameter, 10,000 ft Long Cast
Iron Pipeline
Type of Survey
Inspection Only
Inspection with Condition Assessment
Cost Estimate
$27,414
$35,963
RSG HSK. RSG provided a lump sum cost proposal for executing the condition assessment survey with
HSK for a 24-in. diameter, 10,000 ft long cast iron pipe. Costs associated with the use of CAP were not
included. The proposed survey included 13 locations evenly distributed along the pipe length (except
where the pipe ran below a railroad track where additional scans were proposed on both sides of the
track). The scanning would cover the full pipe circumference, with 100% pipe surface coverage, for a
pipe length of 5 ft at each location. It was estimated that between four to five sites could be scanned per
day and 3 days of pipe scanning were accounted for in the cost estimate. Real-time results would be
159
-------
made available on site following the completion of each scan and preliminary processed plots within one
week. Post-survey processing, plotting, analysis, and reporting would be submitted within 4 weeks of
field work completion.
The costs for inspecting a 24-in. diameter, 10,000 ft long cast iron pipe by RSG HSK are provided in
Table 5-21. The cost elements would include: mobilization to the site; establishment at the site; 3 days of
field work; provision of scanning equipment; provision of results on site; and demobilization from site.
The water utility would be responsible for all excavation work, reinstatement of soils at each location,
surface restoration, traffic control and safety of excavations, permitting, and other site preparation work.
Table 5-21. Rock Solid HSK Cost Estimates for Inspection of a 24-in Diameter, 10,000 ft Long Cast
Iron Pipeline
Type of Survey
External Inspection at 13 Locations
Cost Estimate
$29,460
5.4.4 Site Preparation Costs. The inspection costs presented above do not include the cost for the
water utilities to prepare the pipe and provide traffic control and other logistical support.
The site preparation costs for line modification and field support are highly site-specific and for this
reason the estimates provided are order of magnitude estimates based upon typical construction costs
(RSMeans, 2011). The actual site preparation costs for a given site will depend upon regional costs for
construction labor, along with factors such as the access requirements, availability and condition of
existing hydrants/valves, length of deployment, days on site, and more.
It is estimated that the site preparation costs to conduct a wall thickness survey of 10,000 ft of 24-in.
diameter cast iron pipe may range in magnitude from $0.48/ft to $0.69/ft (including traffic control,
pit/pothole excavation, tapping, backfill, and restoration). It is estimated that site preparation costs for an
internal inspection of 10,000 ft of 24-in. diameter cast iron pipe may be approximately $0.58/ft (including
traffic control, pit excavation, tapping, backfill, and restoration). It is estimated that site preparation costs
for an external inspection of 10,000 ft of 24-in. diameter cast iron pipe may range in magnitude from
$0.94/ft to $1.63/ft (with 9 to 13 excavated locations, respectively).
Acoustic Pipe Wall Assessment Technologies. During a Sahara® WTT inspection, a 1-in. diameter
hydrophone is inserted into a live main through a 2-in. tap. The maximum length of inspection is 6,000 ft
based on the umbilical cable length. For purposes of this cost estimate, it is assumed that two required
access points must be installed for a 10,000 ft pipe inspection (e.g., no existing taps are used). Another
24 potholes to position a sensor on top of the pipe (i.e., one every 400 ft) would also be required. Table
5-22 estimates the site preparation costs based upon the required excavations and the installation of two 2-
in. taps for a Sahara® WTT inspection.
During an inspection, SmartBall™ can be inserted into the pipeline through existing hydrants or any
valve configuration with greater than 4-in. diameter clearance. SmartBall™ is then retrieved through
another 4-in. or greater valve. For purposes of this cost estimate, it is assumed that the two required
access points must be installed for a 10,000 ft pipe inspection (e.g., no existing hydrants or valves are
used). Another nine smaller pits to position a sensor on top of the pipe (i.e., one every 1,000 ft) would
also be required. Table 5-23 estimates the site preparation costs based upon the required excavations and
installation of two 4-in. taps for a SmartBall™ inspection (with pits located at 0 ft and 10,000 ft).
160
-------
Echologics mounts accelerometers directly on the pipe surface (using magnetic surface mounted sensors
attached to available fittings or the pipe surface). For purposes of this cost estimate, it is assumed that 26
pothole excavations (i.e., one every 400 ft), 8-in. in diameter would be needed for a 10,000 ft pipe
inspection. Table 5-24 estimates the site preparation costs based upon the required pothole excavations.
Table 5-22. Estimated Site Preparation Costs for Sahara® WTT Pipe Wall Survey of 10,000 ft pipe
Cost
Item
1
2
3
4
5
6
7
Set-up Costs
2 - Rented 6 ft x 8 ft trench boxes
2-in. taps w/ valve and 150 Ib standard
flange with extension tube
2 CY of stone backfill around the pipe
Traffic control
3 Persons - Labor (excavate*, install taps,
backfill, restoration)
1 Person - Equipment Operator
(excavate*, remove plates, backfill)
1 - 5/8 CY wheel mounted backhoe rental
Quantity
2 boxes x 3 days
= 6 days
2 taps
2CY
1 person x 3 daysA x
8 hrs/day = 24 hrs
3 persons x 2 days x
8 hrs/day = 48 hrs
1 person x 2 days x
8 hrs/day = 16 hrs
2 days
Unit
Cost
$93.00
$346.23
$46.50
$50.00
$52.70
$67.75
$215.00
Unit
6
2
2
24
48
16
2
Total
Total
Cost
$558.00
$692.46
$93.00
$1,200.00
$2,529.60
$1,084.00
$430.00
$6,587.06
A Traffic control required during 2 days of site preparation and on the day of inspection.
* Excavation of 2 access pits 8 ft x 10 ft x 8 ft with trench boxes and 26 potholes (one every 400
position the sensor on top of the pipe would require 2 days.
ft) to
Table 5-23. Estimated Site Preparation Costs for SmartBall1M Pipe Wall Survey of 10,000 ft pipe
Cost
Item
1
2
3
4
5
6
7
Set-up Costs
2 - Rented 6 ft x 8 ft trench boxes
4-in. taps w/ valve and 150 Ib standard
flange with extension tube
2 CY of stone backfill around the pipe
Traffic control
3 Persons - Labor (excavate*, install
taps, backfill, restoration)
1 Person - Equipment Operator
(excavate*, remove plates, backfill)
1 - 5/8 CY Wheel Mounted Backhoe
Quantity
2 boxes x 3 days
= 6 days
2 taps
2CY
1 person x 3 daysA x
8 hrs/day = 24 hrs
3 persons x 2 days x
8 hrs/day = 48 hrs
1 person x 2 days x
8 hrs/day =16 hrs
2 days
Unit
Cost
$93.00
$525.00
$46.50
$50.00
$52.70
$67.75
$215.00
Unit
6
2
2
24
48
16
2
Total
Total
Cost
$558.00
$1,050.00
$93.00
$1,200.00
$2,529.60
$1,084.00
$430.00
$6,944.60
A Traffic control required during 2 days of site preparation; and on the day of inspection.
* Excavation of 2 access pits 8 ft x 10 ft x 8 ft with trench boxes and 9 pits (one every 1,000 ft) to position
the sensor on top of the pipe would require 2 days of work.
161
-------
Table 5-24. Estimated Site Preparation Costs for ThicknessFinder Pipe Wall Survey of 10,000 ft pipe
Cost
Item
1
2
3
4
Set-up Costs
Traffic control
1 Person - Labor (excavate*, backfill,
restoration)
1 Person - Equipment Operator
(excavate*, remove plates, backfill)
1 - 5/8 CY Wheel Mounted Backhoe
Quantity
1 person x 6 daysA x
8 hrs/day = 48 hrs
1 person x 2 days x
8 hrs/day =16 hrs
1 person x 2 days x
8 hrs/day =16 hrs
2 days
Unit
Cost
$50.00
$52.70
$67.75
$215.00
Unit
48
16
16
2
Total
Total
Cost
$2,400.00
$843.20
$1084.00
$430.00
$4,757.20
A Traffic control required during 2 days of site preparation and 4 days of inspection.
* Excavation of 26 potholes that are 8-in. in diameter (one every 400 ft) to position the sensor on top of the
pipe would require 2 days (assuming 13 potholes/day).
Internal Inspection Technologies. Inspection costs were not provided for PipeDiver®, so site
preparation costs are not estimated in this report.
For a See Snake® inspection, two 10 ft sections of pipe must be removed to allow for access and
inspection. For purposes of this cost estimate, it is assumed that two required access points must be
installed for a 10,000 ft pipe inspection. Table 5-25 estimates the site preparation costs based upon the
required excavations for access for a See Snake® inspection.
Table 5-25. Estimated Site Preparation Costs for See Snake® Pipe Wall Survey of 10,000 ft pipe
Cost
Item
1
2
3
4
5
6
Set-up Costs
2 - Rented 8 ft x 16 ft trench boxes
3 CY of stone backfill around the pipe
Traffic control
3 Persons - Labor (excavate, backfill,
restoration)
1 Person - Equipment Operator (excavate,
remove plates, backfill, inspection)
1 - 5/8 CY wheel mounted backhoe rental
Quantity
2 boxes x 3 days
= 6 days
3 CY
1 person x 3 daysA x
8 hrs/day = 24 hrs
3 persons x 1 day x
8 hrs/day = 24 hrs
1 person x 3 days* x
8 hrs/day = 24 hrs
3 days
Unit
Cost
$158.00
$46.50
$50.00
$52.70
$67.75
$215.00
Unit
6
o
6
24
24
24
o
J
Total
Total
Cost
$948.00
$139.50
$1,200.00
$1,264.80
$1,626.00
$645.00
$5,823.30
A Traffic control required during 1 day of site preparation; and on 2 days of inspection.
* Operator required during 1 day of site preparation; and on 2 days of inspection.
External Inspection Technologies. For an AESL ECAT inspection, excavations with trench boxes are
needed every 1,200 ft to access the pipe inspection. For purposes of this cost estimate, it is assumed that
nine required access points must be installed for a 10,000 ft pipe inspection. Table 5-26 estimates the site
preparation costs based upon the required excavations for an ECAT inspection.
162
-------
Table 5-26. Estimated Site Preparation Costs for ECAT Pipe Wall Survey of 10,000 ft pipe
Cost
Item
1
2
3
4
5
6
Set-up Costs
9 - Rented 6 ft x 8 ft trench boxes
9 CY of stone backfill around the pipe
Traffic control
3 Persons - Labor (excavate*, backfill,
restoration)
1 Person - Equipment Operator
(excavate*, remove plates, backfill)
1 - 5/8 CY wheel mounted backhoe rental
Quantity
9 boxes x 4 days
= 36 days
9CY
1 person x 4 daysA x
8 hrs/day = 32 hrs
3 persons x 2 days x
8 hrs/day = 48 hrs
1 person x 2 days x
8 hrs/day = 16 hrs
2 days
Unit
Cost
$93.00
$46.50
$50.00
$52.70
$67.75
$215.00
Unit
36
9
32
48
16
2
Total
Total
Cost
$3,348.00
$418.50
$1,600.00
$2,529.60
$1,084.00
$430.00
$9,410.10
A Traffic control required during 2 days of site preparation; and on 2 days of inspection, assuming 4 to 6
scans per day.
* Excavation of 9 access pits 8 ft x 8 ft x 8 ft with trench boxes (one every 1,200 ft) would require 2 days of
work assuming 4 to 5 pits/day.
For an RSG HSK inspection, excavations with trench boxes are needed every 900 ft to access the pipe
inspection. For purposes of this cost estimate, it is assumed that 13 required access points must be
installed for a 10,000 ft pipe inspection (11 locations, plus 2 on either side of the railroad track as listed
above). Table 5-27 estimates the site preparation costs based upon the required excavations for an HSK
inspection. The site preparation costs for a CAP inspection are not provided as the vendor did not provide
corresponding inspection costs.
Table 5-27. Estimated Site Preparation Costs for HSK Pipe Wall Survey of 10,000 ft pipe
Cost
Item
1
2
3
4
5
6
Set-up Costs
13 - Rented 6 ft x 8 ft trench boxes
13 CY of stone backfill around the pipe
Traffic control
3 Persons - Labor (excavate*, backfill,
restoration)
1 Person - Equipment Operator
(excavate*, remove plates, backfill)
1 - 5/8 CY wheel mounted backhoe rental
Quantity
13 boxes x6 days
= 78 days
13 CY
1 person x 6 daysA x
8 hrs/day = 48 hrs
3 persons x 3 days x
8 hrs/day = 72 hrs
1 person x 3 days x
8 hrs/day = 24 hrs
3 days
Unit
Cost
$93.00
$46.50
$50.00
$52.70
$67.75
$215.00
Unit
78
13
48
72
24
3
Total
Total
Cost
$7,254.00
$604.50
$2,400.00
$3,794.40
$1,626.00
$645.00
$16,323.90
A Traffic control required during 3 days of site preparation; and on 3 days of inspection, assuming 4 to 5
scans per day.
* Excavation of 13 access pits 8 ft x 8 ft x 8 ft with trench boxes (one every 900 ft) would require 3 days of
work assuming 4 to 5 pits/day.
163
-------
6.0: REFERENCES
Hunaidi, O. 2006. Condition Assessment of Water Pipes. NRCC-50306, Workshop on Innovation and
Research for Water Infrastructure in the 21st Century, sponsored by EPA, 20-21 March
2006, Arlington, VA. Available at http://nparc.cisti-icist.nrc-
cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=5751187&article=7.
Hunaidi, O., A. Wang, M. Bracken, T. Gambino, and C. Fricke. 2004. Acoustic Methods for Locating
Leaks in Municipal Water Pipe Networks. International Conference on Water Demand
Management, Dead Sea, Jordan, 1-14.
Liu, Z., Y. Kleiner, B. Rajani, L. Wang, and W. Condit. 2012. Condition Assessment Technologies for
Water Transmission and Distribution Systems. EPA/600/R-12/017, prepared for U.S. EPA,
Office of Research and Development, National Risk Management Research Laboratory.
Available at http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100E3Y5.txt
NACE Standard ASME B31G, Remaining Strength of Corroded Pipe, Standard available for ASME
International, 3 Park Avenue, New York, NY 10016
Nestleroth, B., S. Flamberg,W. Condit, J.Matthews, L. Wang, and A. Chen. 2012. Field
Demonstration of Innovative Condition Assessment Technologies for Water Mains: Leak
Detection and Location. EPA/600/R-12/018, prepared for U.S. EPA, Office of Research and
Development, National Risk Management Research Laboratory. Cincinnati, OH. Available
athttp://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100EK7Q.txt
RSMeans. 2011. CostWorks® Cost Books Online, http://meanscostworks.com/. Norcross, GA: Reed
Construction Data.
Thomson, J. and Wang, L. 2009. Condition Assessment of Ferrous Water Transmission and Distribution
Systems: State of the Technology Review Report. EPA/600/R-09/055, prepared for U.S. EPA,
Office of Research and Development, National Risk Management Research Laboratory.
Available at http://www.epa.gov/nrmrl/pubs/600r09055/600r09055.pdf
164
-------
FINAL REPORT
FIELD DEMONSTRATION OF INNOVATIVE CONDITION ASSESSMENT TECHNOLOGIES
FOR WATER MAINS: ACOUSTIC PIPE WALL ASSESSMENT, INTERNAL INSPECTION,
AND EXTERNAL INSPECTION
VOLUME 2: APPENDICES (A-H)
by
Bruce Nestleroth, Stephanie Flamberg, Vivek Lai, Wendy Condit, and John Matthews
Battelle
Abraham Chen and Lili Wang
Alsa Tech, LLC
Contract No. EP-C-05-057
Task Order No. 0062
for
Michael Royer
Task Order Manager
Water Supply and Water Resources Division
National Risk Management Research Laboratory
2890 Woodbridge Avenue (MS-104)
Edison, NJ 08837
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
July 2013
-------
VOLUME 2
CONTENTS
APPENDICES
APPENDIX A: Assessment Data for Excavated Pipe (160 pp.) A-l
APPENDIX B: Sahara® Report (39 pp.) B-l
APPENDIX C: Pure SmartBall™ Report (12 pp.) C-l
APPENDIX D: Echologics ThicknessFinder Report (37 pp.) D-l
APPENDIX E: Russell Report (37 pp.) E-l
APPENDIX F: AESL Report (58 pp.) F-l
APPENDIX G: RSG Report (22 pp.) G-l
APPENDIX H: Technology Vendor Letters (8 pp.) H-l
-------
APPENDIX A
Assessment Data for Excavated Pipe
A-l
-------
CONTENTS
Pipe 30 A-3
Pipe 32 A-8
Pipe 49 A-14
Pipe 56 A-25
Pipe 61 A-46
Pipe 63 A-56
Pipe 64 A-78
Pipe 69 A-99
Pipe 98 A-lll
Pipe 137 A-118
Pipe 145 A-129
Pipe 146 A-146
Pipe 166 A-156
A-2
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
>
90°
180°
270°
Figure A-30(l). Pipe 30 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
—— ;,s* _T
Mi-*'1
^ •.
270°
Figure A-30(2). Pipe 30 after Sandblasting
-------
Table A-30(1). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
30
Wall Thickness (inches)
0°
0.781
180°
0.784
220°
0.790
240°
0.776
Table A-30(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
30
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.766
0.766
0.780
0.771
0.008
0.766
0.780
-
UT
0.782
0.771
0.769
0.779
0.771
0.797
0.799
0.768
0.785
0.780
0.012
0.768
0.799
0.785
Center
UT
0.750
0.730
0.750
0.754
0.743
0.758
0.750
0.752
0.753
0.749
0.008
0.730
0.758
0.745
Bell
UT
0.805 0.831 0.807
0.809 0.807 0.799
0.793 0.812 0.809
0.808
0.010
0.793
0.831
0.788
Table A-30(3). Outer Diameter Measurement
Using a pi Tape
Pipe
Number
30
Outer Diameter
Spigot
25.835
Center
25.812
Bell
25.817
Table A-30(4). Wall Thickness of Cement
Liner at Spigot with Caliper
Measurement
(Inches)
Cast Iron
Cast Iron &
Cement Liner
Cement Liner
0°
0.781
1.113
0.332
180°
0.784
0.953
0.169
220°
0.790
0.933
0.143
240°
0.776
0.982
0.206
Table A-30(5). Pipe 30 Summary Table
Defect Area
030-114-336-010-040
030-104-328-010-041
030-087-308-011-047
030-045-340-007-042
Total
Volume
Loss
(in.3)
3.5
7.3
5.9
3.9
Dist
From
Bell
(in.)
32.0
34.5
31.0
32.0
42.0
40.5
60.0
58.5
54.5
102.0
Maximum
Depths In
Defect Area
(in.)
0.279
0.217
0.198
0.173
0.531
0.276
0.367
0.257
0.185
0.362
%
Loss
36%
28%
25%
22%
68%
35%
47%
33%
24%
46%
Remaining
(in.)
0.50
0.56
0.58
0.61
0.25
0.50
0.41
0.52
0.60
0.42
%
Remaining
64%
72%
75%
78%
32%
65%
53%
67%
76%
54%
Clock
(Degrees)
2
2
13
355
10
16
30
36
39
353
Clock
(12hr)
0:04
0:04
0:26
11:50
0:20
0:32
1:00
1:12
1:18
11:46
20.7
A-5
-------
030-114-336-010-040
0005 00101 "01015 "01502 «07025 "02505 "05055
V ^ » 1 fc
030-104-328-010-041
0-G.flS 00*1-0 1 0 1-0 IS BO tVO.J • D J-4I./S BD JS-0 1 «0 ]•».}«!
0350.4 0.4045 "04^05 "0505S "055 06 "06005 BO.OS 07
Figure A-30(l). Pipe 30, area 030-114-336-010-040 Figure A-30(2). Pipe 30, area 030-104-328-010-041
A-6
-------
030-087-308-011-047
(HIVII 1 II 1-U 1', • II 1MM •() 7
0 \ « 0 l-O IV
030-045-340-007-042
Figure A-30(3). Pipe 30, area 030-087-308-011-047 Figure A-30(4). Pipe 30, area 030-045-340-007-042
A-7
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
Figure A-32(l). Pipe 32 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
>
90°
180°
270°
Figure A-32(2). Pipe 32 after Sandblasting
-------
Table A-32(1). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
32
Wall Thickness (inches)
140°
0.806
190°
0.803
270°
0.805
310°
0.796
Table A-32(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
| Pipe Number
32
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.817
0.818
0.797
0.811
0.012
0.797
0.818
-
UT
0.777
0.784
0.777
0.781
0.788
0.785
0.783
0.780
0.784
0.782
0.004
0.777
0.788
0.786
Center
UT
0.772
0.771
0.773
0.782
0.777
0.775
0.775
0.782
0.780
0.776
0.004
0.771
0.782
0.777
Bell
UT
0.815 0.813
0.809 0.831
0.815 0.821
0.817
0.811
0.817
X
0.007
0.809
0.831
0.818
Table A-32(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
32
Outer Diameter |
Spigot
25.830
Center
25.870
Bell 1
25.834 |
Tab
e A-32(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
140°
0.806
1.091
0.285
190°
0.803
1.053
0.250
270°
0.805
1.137
0.332
310°
0.796
1.102
0.306
A-10
-------
Table A-32(5). Pipe 32 Summary Table
Defect Area
032-082-145-039-050
032-017-118-032-119
Total
Volume
Loss
(in.3)
32.3
34.3
Dist
From
Bell
(in.)
51.5
51.0
43.5
65.5
46.0
48.5
61.5
60.5
36.5
67.0
59.0
40.5
45.0
62.5
66.0
58.0
61.5
39.0
33.5
128.5
129.5
129.5
125.5
130.0
115.5
117.0
111.5
Maximum
Depths In
Defect
Area (in.)
0.620
0.474
0.434
0.379
0.366
0.355
0.353
0.341
0.288
0.269
0.269
0.263
0.260
0.253
0.249
0.246
0.243
0.220
0.208
0.333
0.276
0.250
0.237
0.228
0.225
0.221
0.216
%
Loss
79%
61%
56%
49%
47%
46%
45%
44%
37%
34%
34%
34%
33%
32%
32%
31%
31%
28%
27%
43%
35%
32%
30%
29%
29%
28%
28%
Remaining
(in.)
0.16
0.31
0.35
0.40
0.41
0.43
0.43
0.44
0.49
0.51
0.51
0.52
0.52
0.53
0.53
0.53
0.54
0.56
0.57
0.45
0.50
0.53
0.54
0.55
0.56
0.56
0.56
%
Remaining
21%
39%
44%
51%
53%
54%
55%
56%
63%
66%
66%
66%
67%
68%
68%
69%
69%
72%
73%
57%
65%
68%
70%
71%
71%
72%
72%
Clock
(Degrees)
180
188
182
202
180
184
180
186
186
195
180
180
191
197
191
182
195
188
184
187
184
189
182
178
149
142
215
Clock
(12hr)
6:00
6:16
6:04
6:44
6:00
6:08
6:00
6:12
6:12
6:30
6:00
6:00
6:22
6:34
6:22
6:04
6:30
6:16
6:08
6:14
6:08
6:18
6:04
5:56
4:58
4:44
7:10
A-ll
-------
032-082-145-039-050
0-0.05 0.05-0.1 0.1-0.15 • 0.15-0.2 • 0.2-0.25 • 0,25-03 03-035 035-0.4 0.4-0.45 • 0.45-0.5 • 0.5-0.55 • 0.55-0.6 • 0.6-0.65 • 0.65-0.7
t^r^
« V T, •>> t. s> 4> -\ % <» %o vs %a ^ vt« ^ %to ^ ^, ^t ao
Inches
Figure A-32(l). Pipe 32, area 032-082-145-039-050
A-12
-------
032-017-118-032-119
0-0.05 0,05-0.1 0.1-0.15»0.15-0.2»0.2-0.25« 0.25-03 0.3-0.35 0.35-0.4 0.4-0.45" 0.45-0.5« 0.5-0.55B0.55-0.6B0.6-0.65B0.65-0.7
0
1
2
3
4
5
6
1
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
•c •»"• •? •? -f
inches
Figure A-32(2). Pipe 32, area 032-017-118-032-119
A-13
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
-,
90°
180°
270°
Figure A-49(l). Pipe 49 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
i
--»-• . '.'•>- . - ... «':-UL- . i
*v&
•#; '
.
Figure A-49(2). Pipe 49 after Sandblasting
-------
Table A-49(l). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
49
Wall Thickness (inches)
125°
0.782
145°
0.786
155°
0.806
200°
0.798
Table A-49(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
49
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.789
0.794
0.785
0.789
0.005
0.785
0.794
-
UT
0.779
0.802
0.789
0.804
0.804
0.785
0.802
0.807
0.786
0.795
0.010
0.779
0.807
0.810
Center
UT
0.776
0.778
0.795
0.788
0.786
0.798
0.776
0.776
0.780
0.784
0.009
0.776
0.798
0.785
Bell
UT
0.783 0.782
0.746 0.743
0.758 0.747
0.754
0.737
0.753
0.740
0.017
0.737
0.783
0.740
Table A-49(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
49
Outer Diameter |
Spigot
25.840
Center
25.835
Bell 1
25.805 |
Tab
e A-49(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
125°
0.782
0.974
0.192
145°
0.786
0.966
0.180
155°
0.806
0.979
0.173
200°
0.798
0.969
0.171
A-16
-------
Table 49-5. Pipe 49 Summary Table
Defect Area
049-095-151-020-056
049-047-145-031-053
049-014-059-020-062
049-074-355-010-065
049-113-336-012-043
049-100-260-018-051
049-011-299-011-035
Total
Volume
Loss
(in.3)
21.5
32.5
11.1
8.8
8.8
8.5
4.7
Dist
From
Bell
(in.)
39.5
43.5
44.5
41.0
50.5
51.0
52.5
47.0
45.0
48.0
42.0
94.5
90.0
83.0
78.0
77.0
79.0
98.5
99.5
77.5
93.0
74.5
82.0
121.5
119.5
134.0
124.5
134.0
70.5
68.0
72.5
71.5
67.5
28.0
34.0
31.5
34.5
36.0
47.5
46.5
44.0
130.5
134.0
131.0
138.0
Maximum
Depths In
Defect
Area (in.)
0.563
0.418
0.417
0.412
0.394
0.387
0.364
0.361
0.340
0.294
0.265
0.664
0.596
0.592
0.592
0.561
0.523
0.510
0.508
0.443
0.410
0.401
0.365
0.362
0.325
0.228
0.213
0.200
0.261
0.233
0.227
0.217
0.211
0.546
0.409
0.341
0.217
0.466
0.432
0.249
0.191
0.310
0.276
0.260
0.173
%
Loss
72%
54%
53%
53%
50%
50%
47%
46%
44%
38%
34%
85%
76%
76%
76%
72%
67%
65%
65%
57%
53%
51%
47%
46%
42%
29%
27%
26%
33%
30%
29%
28%
27%
70%
52%
44%
28%
60%
55%
32%
24%
40%
35%
33%
22%
Remaining
(in.)
0.22
0.36
0.36
0.37
0.39
0.39
0.42
0.42
0.44
0.49
0.52
0.12
0.18
0.19
0.19
0.22
0.26
0.27
0.27
0.34
0.37
0.38
0.42
0.42
0.46
0.55
0.57
0.58
0.52
0.55
0.55
0.56
0.57
0.23
0.37
0.44
0.56
0.31
0.35
0.53
0.59
0.47
0.50
0.52
0.61
%
Remaining
28%
46%
47%
47%
50%
50%
53%
54%
56%
62%
66%
15%
24%
24%
24%
28%
33%
35%
35%
43%
47%
49%
53%
54%
58%
71%
73%
74%
67%
70%
71%
72%
73%
30%
48%
56%
72%
40%
45%
68%
76%
60%
65%
67%
78%
Clock
(Degrees)
182
182
185
165
191
174
185
191
191
191
185
186
186
180
173
197
175
188
185
188
199
197
188
243
288
266
283
285
343
341
336
345
332
2
11
6
22
87
93
58
80
52
34
48
50
Clock
(12hr)
6:04
6:04
6:10
5:30
6:22
5:48
6:10
6:22
6:22
6:22
6:10
6:12
6:12
6:00
5:46
6:34
5:50
6:16
6:10
6:16
6:38
6:34
6:16
8:06
9:36
8:52
9:26
9:30
11:26
11:22
11:12
11:30
11:04
0:04
0:22
0:12
0:44
2:54
3:06
1:56
2:40
1:44
1:08
1:36
1:40
95.9
A-17
-------
049-095-151-020-056
0-0.05 0.05-0.1 0.10.15 • 0.15-0.2 BO.2-0.25 «0,25-0.3 0.3-0.35 035-0.4 0.4-0.45 • 0.45-0.5 • 0.5-0.55 • 0.55-0.6 • 0.6-0.65 • 0.65-0.7
5
6
7
8
9
10
11
12
13
Inches
Figure A-49(l). Pipe 49, area 049-095-151-020-056
A-18
-------
049-047-145-031-053
0-0.05 0.05-0.1 0.1-0.15B0.15-0.2B0.2-0.25B0.25-O.J 0.3-035 0.35-0.4 0.4-0.45* 0.45-0.5« 0.5-0.55B 0.55-0.6B 0.6-0.65« 0.65-0.7
0
1
2
3
4
5
6 •
7
8
9
10
11
12
o *» 'V % fc ^ fe A N>\>O->'^'vtoO
•? n? -\>
^ %> ip- 9 ^ -^ ^ 9 SP s^ T v
Inches
•V* -P
Figure A-49(2). Pipe 49, area 049-047-145-031-053
A-19
-------
/
?^,1 -=••!- oj—l-^i^-afcis.
4
'^
/«
t
t
r-
t
I
i
,,,,11
01
o
a
i
• «
e
•
K
0
* «
Oo
Oc
O o
a t
I", , 5 u « ii n .1 w it n '« K a. M » *t a « J« r> /« *l 7. « u M i< w it
tt
049-014-059-020-062
0-0.05 0.05-0.1* 0.1-0.15 • 0.15-0.2B 0.2-0.25B 0.25-0.3» 0.3-0.35 0.35-0.4 0.4-0.45» 0.45-0.5 • 0.5-0.55 • 0.55-0. 6 • 0.6-0. 65 • 0.65-0.7
K
• ^ \
%^^
A
-^%
^^ tt
10 **
^
^y
u
1
2
3
4
5
6
7
8 8
u
Ł
9
10
11
12
13
14
0 -, ^ -, * «, to A % 0 V0
-------
049-074-355-010-065
•CMJjQS QjOS'fU sO.10.J5 1515 0.2 110.2 0.25 «0.2S O.i * O.i & i5
035-0.4 , 04-0 45 • 0.«-&S • 0 S-0.55 • 0 SI-iKV • O.iJ-O.fiS. • D 6^-0 7
Figure A-49(4). Pipe 49, area 049-074-355-010-065
A-21
-------
049-113-336-012-043
0-0.05 0.05-0,1 0,1-0.15 • 0.15-0.2 • 0.2-0.25 • 0.25-0.3 0.3-035 0.35-0.4 0.4-0.45 • 0.45-0.5 • 0.5-0.55 • 0.55-0.6 • 0.6-0.65 • 0.65-0,7
Inches
Figure A-49(5). Pipe 49, area 049-113-336-012-043
A-22
-------
049-100-260-018-051
0-0.05 0.05-0.1 0.1-0.15 B0.15-0.2B0.2-0.25B 0.25-0.3 -0.3-035 035-0.4 04-0.45B 0.45-0. 5B 0.5-0.55B 0.55-0.6B 0.6-0. 65B 0.65-0.7
0 o
•
' 1 ^
Inches
0
1
2
3
4
5
6 i
7
8
9
10
Figure A-49(6). Pipe 49, area 049-100-260-018-051
A-23
-------
049-011-299-011-035
0-0.05 0.05-0.1 0.1-0.15 BO.15-0.2BO.2-0.25d 0.25-0.3 u 0.3-035 0,35-0.4 0.4-0.45B 0.45-0.5 • 0.5-0,55 • 0.55-0.6 • 0.6-0.65 • 0.65-0.7
0
Inches
Figure A-49(7). Pipe 49, area049-011-299-011-035
A-24
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
,
90°
>
180°
270°
Figure A-56(l). Pipe 56 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
to
90°
180°
270°
Figure A-56(2). Pipe 56 after Sandblasting
-------
Table A-56(1). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
56
Wall Thickness (inches)
x°
X
130
0.802
155°
0.794
180°
0.795
Table A-56(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
56
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.804
0.813
0.816
0.811
0.006
0.804
0.816
-
UT
0.781
0.759
0.773
0.772
0.762
0.769
0.759
0.781
0.768
0.769
0.008
0.759
0.781
0.776
Center
UT
0.797 0.789 0.792
0.796 0.798 0.802
0.800 0.795 0.794
0.796
0.004
0.789
0.802
0.798
Bell
UT
0.762 0.757
0.750 0.741
0.780 0.747
0.754
0.749
0.740
0.762
0.013
0.740
0.780
0.760
Table A-56(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
56
Outer Diameter
Spigot
25.823
Center
25.785
Bell
25.810
Tabl
e A-56(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
x°
X
X
X
130
0.802
0.995
0.193
155°
0.794
0.998
0.204
180°
0.795
0.990
0.195
A-27
-------
Table A-56(5). Scanned Pipe 56 Summary Table
Defect
Area
Hll
H12
H13
H14
H21
H22
H23
H24
H31
H32
Total
Volume
Loss
(in3)
-2.0
-6.4
8.9
-5.1
-1.5
20.6
0.7
30.9
-17.9
45.6
Dist
From
Spigot
(in.)
24.0
28.0
28.0
30.5
39.0
32.5
13.5
22.0
37.5
27.0
14.0
19.5
39.0
50.0
46.0
72.0
39.5
41.5
56.0
58.5
66.0
37.5
41.5
45.0
48.5
40.0
42.0
43.0
45.0
46.5
72.5
72.0
96.5
98.5
105.9
107.0
74.4
88.5
Maximum
Depths In
Defect
Area (in.)
0.1870
0.1677
0.2890
0.2291
0.2291
0.2043
0.3039
0.3012
0.2106
0.2012
0.2028
0.1957
0.2028
0.2130
0.1890
0.1587
0.2291
0.2272
0.2248
0.2217
0.2894
0.2106
0.2079
0.2799
0.2346
0.2354
0.2354
0.2299
0.2780
0.2193
0.2315
0.3043
0.1693
0.2465
0.2862
0.3126
0.2051
0.3398
% Loss
24%
22%
38%
30%
30%
27%
40%
39%
27%
26%
26%
25%
26%
27%
24%
20%
29%
29%
28%
28%
36%
26%
26%
35%
29%
30%
30%
29%
35%
28%
29%
38%
21%
31%
36%
39%
26%
43%
Remaining
(in.)
0.5820
0.6013
0.4800
0.5399
0.5399
0.5647
0.4651
0.4678
0.5584
0.5678
0.5662
0.5733
0.5662
0.5830
0.6070
0.6373
0.5669
0.5688
0.5712
0.5743
0.5066
0.5854
0.5881
0.5161
0.5614
0.5606
0.5606
0.5661
0.5180
0.5767
0.5645
0.4917
0.6267
0.5495
0.5098
0.4834
0.5909
0.4562
%
Remaining
76%
78%
62%
70%
70%
73%
60%
61%
73%
74%
74%
75%
74%
73%
76%
80%
71%
71%
72%
72%
64%
74%
74%
65%
71%
70%
70%
71%
65%
72%
71%
62%
79%
69%
64%
61%
74%
57%
Clock
(Degrees)
22
65
98
93
127
120
253
244
255
253
273
275
291
89
51
0
127
127
129
120
102
255
217
266
224
286
286
271
266
111
329
355
5
122
118
169
115
122
Clock
(12hr)
0:44
2:09
3:15
3:06
4:13
3:59
8:26
8:08
8:30
8:26
9:06
9:10
9:42
2:57
1:42
0:00
4:13
4:13
4:17
3:59
3:24
8:30
7:14
8:52
7:28
9:32
9:32
9:02
8:52
9:14
10:58
11:50
0:09
4:04
3:55
5:37
3:50
4:04
A-28
-------
Defect
Area
H33
H34
H41
H42
H43
H44
Total
Volume
Loss
(in3)
-9.9
39.9
9.5
72.0
21.0
46.1
Dist
From
Spigot
(in.)
88.0
92.0
94.0
95.5
97.4
97.4
107.0
72.5
72.5
66.0
73.0
133.5
119.0
107.0
109.0
111.1
113.0
113.0
114.5
115.0
119.0
119.6
123.5
129.0
126.0
129.6
132.0
132.6
125.0
107.0
133.5
117.5
112.6
114.1
120.5
121.1
Maximum
Depths In
Defect
Area (in.)
0.2713
0.2709
0.2563
0.2437
0.3823
0.2673
0.2138
0.2956
0.2315
0.2283
0.2138
0.2083
0.1929
0.3126
0.2634
0.3386
0.3406
0.2508
0.2516
0.2504
0.2272
0.2264
0.2508
0.2709
0.2984
0.2453
0.2854
0.2366
0.2382
0.2134
0.1980
0.2378
0.2343
0.2354
0.2638
0.2362
% Loss
34%
34%
32%
31%
48%
34%
27%
37%
29%
29%
27%
28%
26%
41%
35%
45%
45%
33%
33%
33%
30%
30%
33%
36%
40%
33%
38%
31%
32%
28%
26%
32%
31%
31%
35%
31%
Remaining
(in.)
0.5247
0.5251
0.5397
0.5523
0.4137
0.5287
0.5822
0.5004
0.5645
0.5677
0.5822
0.5457
0.5611
0.4414
0.4906
0.4154
0.4134
0.5032
0.5024
0.5036
0.5268
0.5276
0.5032
0.4831
0.4556
0.5087
0.4686
0.5174
0.5158
0.5406
0.5560
0.5162
0.5197
0.5186
0.4902
0.5178
%
Remaining
66%
66%
68%
69%
52%
66%
73%
63%
71%
71%
73%
72%
74%
59%
65%
55%
55%
67%
67%
67%
70%
70%
67%
64%
60%
67%
62%
69%
68%
72%
74%
68%
69%
69%
65%
69%
Clock
(Degrees)
118
118
120
133
173
178
178
355
329
309
324
76
69
169
173
173
146
135
127
138
138
109
118
131
164
146
122
113
224
178
257
320
320
309
318
304
Clock
(12hr)
3:55
3:55
3:59
4:26
5:46
5:55
5:55
11:50
10:58
10:18
10:48
2:31
2:17
5:38
5:46
5:46
4:52
4:30
4:13
4:36
4:36
3:38
3:55
4:22
5:28
4:52
4:04
3:46
7:28
5:56
8:34
10:40
10:40
10:18
10:36
10:08
A-29
-------
0.00-0.05 0,05-0.10 0.10-0,15 • 0.15 -0.20 BO.20-0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 »0.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
t •
i
f
f
^^^r ^
1.0
2.0
3.0
4.0
50
6.0
7.0
8.0 |
9.0 -
10.0
11.0
12.0
13.0
14.0
15,0
160
170
18,0
19.0
Inches
Figure A-56(l). Pipe from 0-3 feet and 0-90 degrees
A-30
-------
H(12)
0.00-005 0.05-0.10 0.10-0.15 BO.15-0.20 »0.20-0.25 BO.25-0.30 0.30-035
0.35-0,40 0.40-0.45 «0.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0,70
^ ^^^^^
20.0
21 0
^^P^S 1 f
22.0
22.9
^™
>• 1 24.0
. 4 ~ '^
^ M .^KV **
25,0
26.0
27.0
27.9 |
29.0 =
30.0
31.0
32.0
32.9
34,0
35.0
36.0
37.0
37.9
39.0
Inches
Figure A-56(2). Pipe from 0-3 feet and 90-180 degrees
A-31
-------
0.00-0.05
0.35-040
0.05-0.10
0.40-0.45
0.10-0,15
BO.45-0.50
H(13)
O.15-0.20
il 50-055
BO.20-0.25
BO.55-0.60
0.25 -O.JO
O.60-0,65
BO.30-0.35
B065-0.70
40.0
40.9
41.9
42.9
43.9
44,9
45.9
46.9
47.9 „
48.9-5
E
49.9
50.9
51.9
52.9
53.9
54.9
55.9
56.9
57.9
58.9
Inchec-
Figure A-56(3). Pipe from 0-3 feet and 180-270 degrees
A-32
-------
H(14)
0.00-0.05 005-0.10 0.10-0.15 BO. 15-0.20 BO.20-0.25 BO.25-030 0.30-0.35
0,35-0,40 0,40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0.60 B 0.60-0.65 B065-0.70
-- *
• ^^
^ * ^^ •>> •*
^Ł
« t
•
^B
\
\>\j.\j
60.9
61.9
62.9
63.9
64.9
65.9
66.9
67.9 |
68.9 "§
69.9
70.9
71.9
72.9
73,9
74.9
75.9
76.9
77.9
78.9
Inches
Figure A-56(4). Pipe from 0-3 feet and 270-300 degrees
A-33
-------
H(21)
0.00-0.05 005-0.10 «0.10-015 «0.15-0.20 BO.20-0.25 BO.25-030 «0.30-0.35
0.35-0,40 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0,65 BO, 65-0.70
"
L »
T.I IJ
1.0
2.0
30
4.0
50
6.0
7.0
8.0 |
9.0 =
10.0
11.0
12.0
13.0
14.0
15.0
16.0
170
18.0
19.0
^ # # # ^ „•> t.-v & t? t> fr vta # ix* t? «,•> ^ 4> # •} fcto # # i? <• ^ ^
Inches
Figure A-56(5). Pipe 3-6 feet and 0-90 degrees
A-34
-------
H(22)
0.00-0.05 0.05-0.10 «0.10-0.15 BO. 15-0.20 BO.20-0.25 BO.25-030 "0.30-0.35
0.35-0,40 0.40-0.45 BO.45-0,50 BO.50-0.55 BO.55-0.60 BO.60-0,65 BO.65-0.70
v *
^ 4
•^ Ł ^B^l
•r -•*.««'•» T> •
••• ^BB! -4 L •
§ ^^^^
^
r^
*
•VWiW
21.0
22.0
22.9
24.0
25.0
26.0
27.0
27.9 1
29.0-
30.0
31.0
32.0
32.9
34.0
35.0
36.0
37.0
37.9
39.0
Inches
Figure A-56(6). Pipe from 3-6 feet and 90-180 degrees
A-35
-------
- -0.1
0.4-0.4
0.1-0.1
0.4-0.5
• 0.1-0.2
• 0.5-0.5
H(23)
I 0.2-0.2
I 0.5-0.6
I 0.2-0.3
I 0.6-0.6
I 0.1-0.3
I 0.6-0.7
0.3-0.4
I 0.7-0.7
K.
4
40.0
40.9
41.9
42.9
43.9
44.9
45.9
46.9
47.9 ji
48.9 Ł-
49.9
50.9
51.9
52.9
53.9
54.9
55.9
56.9
57.9
58.9
Figure A-56(7). Pipe from 3-6 feet to 180-270 degrees
A-36
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
O.45-0.50
H(24)
BO.15-0.20
BO.50-0.55
BO.20-0.25
BO.55-0.60
O.25-0.30
0.60 -0.65
,0.30-0.35
10.65-0.70
.#
.
(? •(• V>
-------
H(31)
0.00-005 0.05-0.10 0.10-0.15 »0.15-0.20 BO.20-0.25 »0.25-0.30 0.30-0.35
0.35-0,40 0.40-0,45 »0.45-0,50 HO.50-0,55 BO.55-0.60 mO.60-0.65 BO. 65-0.70
f
_rf*
^1 •
^
-
U.IT
1.0
2.0
3.0
4.0
50
6.0
7.0
8.0 |
9.0 1
10.0
11.0
12.0
13.0
14.0
15.0
16.0
170
18,0
19.0
Inches
Figure A-56(9). Pipe from 6-9 feet and 0-90 degrees
A-38
-------
0,00-0.05
0.35-0.40
0.05-0,10
0.40-0.45
0.10-0.15
O.45-0.50
H(32)
BO.15-0.20
BO.50-0.55
0.20-0.25
O.55-0.60
•0.25-0.30
BO.60-0.65
0.30-0.35
O.65-0.70
Inches
Figure A-56(10). Pipe from 6-9 feet and 90-180 degrees
A-39
-------
H(33)
0.00-0,05 0.05-0.10 0.10-0.15 «0.15-0.20 BO.20-0.25 »0.25-0.30 0.10-0.35
0.35-0,40 0.40-0.45 BO.45-0,50 BO.50-0,55 HO.SS-O.eO »0.60-0.65 BO.65-0.70
-\s
- r-
'..
^ta
Inches
40.0
40.9
41.9
42.9
43.9
44.9
45.9
46.9
47.9 x
48.9 -
49.9
50.9
51.9
52.9
53.9
54.9
55.9
56.9
57.9
58.9
Figure A-56(ll). Pipe from 6-9 feet and 180-270 degrees
A-40
-------
0.00-0,05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
• 0.45-0.50
H{34)
10.15-0.20
I 0.50-0.55
10.20-0.25
10.55-0.60
• 0.25-0.30
• 0.60-0.65
0.30-0.35
• 0.65-0.70
60.0
60.9
61.9
62.9
63.9
64.9
65.9
66.9
67 9 J
68.9 -
69.9
70.9
71.9
72.9
73.9
74.9
75.9
76.9
77.9
78.9
Inches
Figure A-56(12). Pipe from 6-9 feet and 270-300 degrees
A-41
-------
H(41)
0.00-0.05 0.05-0,10 0.10-0.15 BO.15-0.20 BO.20-0.25 BO.25-0.30 030-0.35
0.35-0.40 0.40-0,45 BO.45-0.50 BO.50-0,55 BO.55-0.60 BO.60-0.65 BO.65-0.70
*»
1 !
-
4fl
^
U - t
"~ ^B^ A
,? ^0 A as ^ %, ^. ^ ^ TA ^ ^ ,Q ^ ,-V ^ ^ ^ ^ ,A ,,
Inches
00
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 Ł
9.0 -Ł
100
11,0
120
13.0
14.0
15,0
16.0
17.0
18.0
19.0
Figure A-56(13). Pipe from 9-12 feet and 0-90 degrees
A-42
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
• 0.45-0.50
H(42)
• 0.15-0.20
• 0.50-0.55
• 0.20-025
• 0.55-0.60
10.25-0.30
10.60-0.65
0.30-0.35
10.65-0.70
Inches
Figure A-56(14). Pipe from 9-12 feet and 90-180 degrees
A-43
-------
H(43)
0.00-0.05 0.05-0,10 0.10-0.15 BO.15-0,20 BO.20-0.25 BO.25-0.30 030-0.35
0.35-0,40 0.40-0.45 BO.45-0.50 BO.50-0,55 BO.55-0.60 BO.60-0.65 BO.65-0.70
^ ^ 1
1 * ^1**^
/ *
4>flk
_
•>•
^
^
^
.^^
— •
4 ^^^H|
i
V v ^ ^^
40.0
40.9
41.9
42.9
43.9
44.9
45.9
46.9
47.9 Ł
•5
48.9 Ł
49.9
50.9
51.9
52.9
53.9
54.9
55.9
56.9
57.9
58.9
Figure A-56(15). Pipe from 9-12 feet and 180-270 degrees
A-44
-------
- -0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
I 0.45-0.50
H(44)
I 0.15-0.20
I 0.50-0.55
I 0.20-0.25
I 0.55-0.60
I 0.25-0.30
I 0.60-0.65
0.30-0.35
I 0.65-0.70
•v ^ •- *s
,J*&r • *
2tek'-
****;•• '
!
59,yb
60.94
61.92
62.90
63.93
64.91
65.94
66.92
67.90
68.93
69.91
70.94
71.92
72.90
73.93
74.91
75.94
76.92
77,90
78.93
fO C$S -51 C* N\ ^ «^ "i> "Ł -^ "5> "3 -^ l"* l"*- 1^> -^ ^*> -^ -1^ -%* -^ 1? T^ 1^ "?> T? T^>
•? •? S> SV N" S1 %* VV %" %• ~> S> N1 •?• N1- %> ~? •?• S1 •?• ^ V1 -f V" •? V>
]nrhac
Figure A-56(16). Pipe from 9-12 feet and 270-300 degrees
A-45
-------
90°
180°
270°
Figure A-61(l). Pipe 61 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
Figure A-61(2). Pipe 61 after Sandblasting
-------
Table A-61(l). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
61
Wall Thickness (inches)
0°
0.803
90°
0.779
205°
0.784
280°
0.789
Table A-61(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
61
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.773
0.780
0.776
0.776
0.004
0.773
0.780
-
UT
0.794
0.777
0.777
0.765
0.783
0.762
0.773
0.768
0.773
0.775
0.010
0.762
0.794
0.769
Center
UT
0.813
0.827
0.816
0.798
0.821
0.836
0.835
0.820
0.808
0.819
0.012
0.798
0.836
0.808
Bell
UT
0.781 0.792
0.780 0.777
0.793 0.793
0.787
0.798
0.773
0.797
0.009
0.773
0.798
0.792
Table A-61(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
61
Outer Diameter |
Spigot
25.850
Center
25.830
Bell 1
25.835 |
Tab
e A-61(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
0°
0.803
1.103
0.300
90°
0.779
1.090
0.311
205°
0.784
1.038
0.254
280°
0.789
1.085
0.296
A-48
-------
Table A-61(5). Pipe 61 Summary Table
Defect Area
061-099-097-020-051
061-119-100-017-114
061-082-150-013-072
061-058-182-025-060
061-007-102-029-103
061-056-108-021-052
Total
Volume
Loss
(in.3)
12.8
21.2
11.9
23.6
40.6
15.6
Dist
From
Bell
(in.)
38.5
43.5
37.0
40.0
40.0
40.0
23.5
23.0
23.0
26.0
21.5
60.5
60.5
58.5
60.0
65.0
72.0
84.5
71.0
75.0
88.0
116.5
118.0
116.5
116.5
119.5
90.0
91.0
87.0
85.0
84.0
84.0
Maximum
Depths In
Defect
Area (in.)
0.396
0.268
0.258
0.247
0.211
0.210
0.492
0.436
0.425
0.318
0.308
0.488
0.409
0.374
0.367
0.254
0.319
0.314
0.279
0.247
0.239
0.374
0.346
0.335
0.311
0.304
0.399
0.385
0.355
0.346
0.338
0.318
%
Loss
51%
34%
33%
32%
27%
27%
63%
56%
54%
41%
39%
63%
52%
48%
47%
33%
41%
40%
36%
32%
31%
48%
44%
43%
40%
39%
51%
49%
45%
44%
43%
41%
Remaining
(in.)
0.38
0.51
0.52
0.53
0.57
0.57
0.29
0.34
0.36
0.46
0.47
0.29
0.37
0.41
0.41
0.53
0.46
0.47
0.50
0.53
0.54
0.41
0.43
0.45
0.47
0.48
0.38
0.40
0.43
0.43
0.44
0.46
%
Remaining
49%
66%
67%
68%
73%
73%
37%
44%
46%
59%
61%
38%
48%
52%
53%
68%
59%
60%
64%
68%
69%
52%
56%
57%
60%
61%
49%
51%
55%
56%
57%
59%
Clock
(Degrees)
216
252
214
232
223
250
200
193
185
207
180
175
168
203
186
150
171
171
167
158
167
200
209
216
185
207
210
228
234
219
223
239
Clock
(12hr)
7:12
8:24
7:08
7:44
7:26
8:20
6:40
6:26
6:10
6:54
6:00
5:50
5:36
6:46
6:12
5:00
5:42
5:42
5:34
5:16
5:34
6:40
6:58
7:12
6:10
6:54
7:00
7:36
7:48
7:18
7:26
7:58
A-49
-------
061-007-102-029-103
0-0.05 0.05-0.1 0.1-0.15 BO.15-0.2 • 0.2-0.25 • 0.25-0.3 0.3-0.35 0.35-0.4 0.4-0.45 • 0.45-0.5 • 0.5-0.55 • 0.55-0.6 • 0.6-0.65 • 0.65-0.7
Inches
Figure A-61(l). Pipe 61, area 061-007-102-029-103
A-50
-------
061-056-108-021-052
0-0.05 0.05-0.1 0.1-0.15 • 0.15-0.2 • 0.2-0.25 BO. 25-0.3 0.3-0.35 0.35-0.4 0.4-0.45 • 0.45-0.5 • 0.5-0.55 • 0,55-0.6 • 0.6-0.65 • 0.65-0.7
10
12
N'V'b
Inches
Figure A-61(2). .Pipe 61, area 061-056-108-021-052
A-51
-------
061-099-097-020-051
0-0.05 0.05-0.1 0.1-0.15B 0.15-0.2" 0.2-0.25B0.25-0.3 0.3-035 0.35-0.4 0.4-0.45" 0.45-0.5B 0.5-0.55" 0.55-0.6m 0.6-0.65" 0,65-0.7
8
9
10
11
12
Inches
Figure A-61(3). Pipe 61, area 061-099-097-020-051
A-52
-------
061-119-100-017-114
00.05
D.li-0.4
110101
» 0.1-0,45
01015
«0.4i-0.i
"0150Z millOft
•05054 • 055-00
"0250!
• O.t 0 (>b
-IUU»
BO .61-0 ./
061-082-150-013-072
0005 005-0] 101015 •0)502 filial',
0>504 "0.4045 "04505 •05UH •nS'/oC, .in.in.':
Figure A-61(4). Pipe 61, area 061-119-100-017-114 Figure A-61(5). Pipe 61, area 061-082-150-013-072
A-53
-------
061-058-182-025-060
0-0.05 0.05-0.1 0.1-0.15" 0.15-0.2" 0.2-0.25" 0.25-03 0.3-035 035-0.4 0.4-0.45" 0.45-0.5" 0.5-0.55" 0.55-0.6" 0.6-0.65" 0.65-0.7
0
1
2
3
4
5
6
7 1
8
9
10
11
12
13
O V -V
Inches
Figure A-61(6). Pipe 61, area 061-058-182-025-060
A-54
-------
061-007-102-029-103
0-0.05 0.05-0.1H 0.1-0.151 0.15-0.2I 0.2-0.25B 0.25-0.3 r. 0.3-035 0.35-0.4 0.4-0.45B 0.45-0.51 0.5-0.551 0.55-0.(>• 0.6-0.65B 0.65-0.7
0 V •V •> «. <,
Inches
Figure A-61(7). Pipe 61, area 061-007-102-029-103
A-55
-------
90°
180°
270°
Figure A-63(l). Pipe 63 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
Figure A-63(2). Pipe 63 after Sandblasting
-------
Table A-63(l). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
63
Wall Thickness (inches)
45°
0.813
140°
0.818
230°
0.816
240°
0.813
Table A-63(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
63
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.820
0.817
0.816
0.818
0.002
0.816
0.820
-
UT
0.795 0.788
0.783 0.788
0.801 0.775
0.786
0.775
0.791
0.774
0.010
0.774
0.801
0.785
Center
UT
0.766 0.762
0.764 0.760
0.793 0.768
0.766
0.759
0.755
0.764
0.011
0.755
0.793
0.770
Bell
UT
0.790 0.796
0.787 0.817
0.781 0.797
0.794
0.789
X
X
0.012
0.781
0.817
0.805
Table A-63(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
63
Outer Diameter
Spigot
25.800
Center
25.775
Bell
25.775
Tab
e A-63(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
45°
0.813
1.087
0.274
140°
0.818
1.067
0.249
230°
0.816
1.099
0.283
240°
0.813
1.154
0.341
A-58
-------
Table A-63(5). Scanned Pipe 63 Summary Table
I
Defect Area
H22/H23 Comparison
Hll
H12
H13
H14
H21
Total
Volume
Loss
(in.3)
43.35
28.9
32.1
17.4
4.3
10.7
Dist
From
Spigot
(in.)
38.5
47.0
40.5
37.0
44.0
38.0
43.5
45.0
42.5
40.5
42.5
42.5
46.5
45.0
45.0
41.5
38.5
42.0
44.0
41.0
46.0
13.7
18.2
20.2
40.7
37.2
41.7
36.7
38.2
40.7
40.7
32.7
34.7
38.7
38.7
41.7
38.2
39.7
5.7
28.7
41.7
37.0
Maximum
Depths In
Defect
Area (in.)
0.4004
0.3957
0.3339
0.3327
0.3323
0.3087
0.3075
0.2992
0.2894
0.2819
0.2728
0.2673
0.2642
0.2441
0.2370
0.2299
0.2268
0.2142
0.2063
0.1811
0.1780
0.2035
0.2299
0.2465
0.2579
0.2803
0.3024
0.3327
0.4004
0.3339
0.2819
0.2472
0.2488
0.2764
0.2268
0.2299
0.3205
0.2795
0.2358
0.2921
0.2835
0.2803
%
Loss
51%
50%
42%
42%
42%
39%
39%
38%
37%
36%
35%
34%
34%
31%
30%
29%
29%
27%
26%
23%
23%
26%
29%
31%
33%
36%
38%
42%
51%
42%
36%
31%
32%
35%
29%
29%
41%
36%
30%
37%
36%
36%
Remaining
(in.)
0.3856
0.3903
0.4521
0.4533
0.4537
0.4773
0.4785
0.4868
0.4966
0.5041
0.5132
0.5187
0.5218
0.5419
0.5490
0.5561
0.5592
0.5718
0.5797
0.6049
0.6080
0.5825
0.5561
0.5395
0.5281
0.5057
0.4836
0.4533
0.3856
0.4521
0.5041
0.5388
0.5372
0.5096
0.5592
0.5561
0.4655
0.5065
0.5502
0.4939
0.5025
0.5057
%
Remaining
49%
50%
58%
58%
58%
61%
61%
62%
63%
64%
65%
66%
66%
69%
70%
71%
71%
73%
74%
77%
77%
74%
71%
69%
67%
64%
62%
58%
49%
58%
64%
69%
68%
65%
71%
71%
59%
64%
70%
63%
64%
64%
Clock
(Degrees)
171
180
164
162
133
178
124
156
129
126
160
171
209
202
218
198
202
204
213
218
218
49
67
53
58
16
2
162
171
164
126
240
242
227
202
198
178
178
269
291
351
16
Clock
(12hr)
5:42
6:00
5:28
5:24
4:26
5:56
4:08
5:12
4:18
4:12
5:20
5:42
6:58
6:44
7:16
6:36
6:44
6:48
7:06
7:16
7:16
1:37
2:13
1:46
1:55
0:31
0:04
5:23
5:42
5:28
4:12
7:59
8:04
7:33
6:44
6:35
5:55
5:55
8:57
9:41
11:41
0:31
A-59
-------
Defect Area
H22
H23
H24
H31
Total
Volume
Loss
(in.3)
50.1
40.3
7.2
9.2
Dist
From
Spigot
(in.)
42.0
43.5
39.5
40.5
43.5
42.5
44
45
42.5
40.5
37.0
42.5
38.5
46.0
51.5
54.5
66.0
58.5
47.0
38.0
45.0
42.0
41.5
38.5
46.5
44.0
46.0
45.0
41.0
38.5
54.5
56.5
57.0
65.0
70.5
69.0
63.5
61.5
59.0
57.0
42.0
95.0
Maximum
Depths In
Defect
Area (in.)
0.3024
0.2236
0.2642
0.2819
0.3075
0.2894
0.3323
0.2992
0.2728
0.3339
0.3327
0.2673
0.4004
0.2713
0.2602
0.2464
0.5626
0.2575
0.3957
0.3087
0.2441
0.2142
0.2299
0.2268
0.2642
0.2063
0.1780
0.2370
0.1811
0.2677
0.3000
0.2835
0.2941
0.4413
0.2780
0.2760
0.2831
0.3185
0.2961
0.2614
0.2846
0.2209
%
Loss
38%
28%
34%
36%
39%
37%
42%
38%
35%
42%
42%
34%
51%
35%
33%
31%
72%
33%
50%
39%
31%
27%
29%
29%
34%
26%
23%
30%
23%
34%
38%
36%
37%
56%
35%
35%
36%
41%
38%
33%
36%
28%
Remaining
(in.)
0.4836
0.5624
0.5218
0.5041
0.4785
0.4966
0.4537
0.4868
0.5132
0.4521
0.4533
0.5187
0.3856
0.5147
0.5258
0.5396
0.2234
0.5285
0.3903
0.4773
0.5419
0.5718
0.5561
0.5592
0.5218
0.5797
0.6080
0.5490
0.6049
0.5183
0.4860
0.5025
0.4919
0.3447
0.5080
0.5100
0.5029
0.4675
0.4899
0.5246
0.5014
0.5651
%
Remaining
62%
72%
66%
64%
61%
63%
58%
62%
65%
58%
58%
66%
49%
65%
67%
69%
28%
67%
50%
61%
69%
73%
71%
71%
66%
74%
77%
70%
77%
66%
62%
64%
63%
44%
65%
65%
64%
59%
62%
67%
64%
72%
Clock
(Degrees)
2
9
62
126
124
129
133
156
160
164
162
171
171
166
171
173
171
173
180
178
202
204
198
202
209
213
218
218
218
229
186
191
180
178
211
209
218
215
224
204
351
42
Clock
(12hr)
0:04
0:17
2:04
4:12
4:08
4:18
4:26
5:12
5:20
5:28
5:24
5:42
5:42
5:32
5:42
5:46
5:41
5:46
6:00
5:56
6:44
6:48
6:36
6:44
6:58
7:06
7:16
7:16
7:16
7:37
6:12
6:21
5:59
5:55
7:01
6:57
7:16
7:10
7:28
6:48
11:41
1:24
A-60
-------
Defect Area
H32
H33
H34
H41
H42
H43
H44
Total
Volume
Loss
(in.3)
11.2
22.8
28.5
10.5
44.1
27
14.4
Dist
From
Spigot
(in.)
100.5
101.5
108.0
74.0
74.0
75.5
95.9
104.0
73.0
95.9
98.0
104.0
104.4
93.5
97.4
95.5
95.9
107.0
110.0
113.0
114.1
119.0
125.0
114.1
115.6
121.1
126.6
110.5
Maximum
Depths In
Defect
Area (in.)
0.2130
0.2634
0.2110
0.4626
0.2791
0.2209
0.3811
0.3654
0.3665
0.4260
0.3319
0.3799
0.4327
0.2528
0.2693
0.3815
0.3303
0.2071
0.2031
0.3488
0.3287
0.3780
0.4213
0.3311
0.5173
0.3063
0.3673
0.1693
%
Loss
27%
34%
27%
59%
36%
28%
48%
46%
47%
54%
42%
48%
55%
32%
34%
49%
42%
26%
26%
44%
42%
48%
54%
42%
66%
39%
47%
22%
Remaining
(in.)
0.5730
0.5226
0.5750
0.3234
0.5069
0.5651
0.4049
0.4206
0.4195
0.3600
0.4541
0.4061
0.3533
0.5332
0.5167
0.4045
0.4557
0.5789
0.5829
0.4372
0.4573
0.4080
0.3647
0.4549
0.2687
0.4797
0.4187
0.6167
%
Remaining
73%
66%
73%
41%
64%
72%
52%
54%
53%
46%
58%
52%
45%
68%
66%
51%
58%
74%
74%
56%
58%
52%
46%
58%
34%
61%
53%
78%
Clock
(Degrees)
40
67
53
138
149
171
178
178
218
180
180
178
193
295
309
311
318
51
44
160
178
169
169
178
191
189
198
326
Clock
(12hr)
1:20
2:13
1:46
4:35
4:57
5:42
5:55
5:55
7:16
6:00
6:00
5:56
6:26
9:50
10:18
10:22
10:35
1:42
1:28
5:19
5:55
5:38
5:38
5:56
6:21
6:18
6:36
10:52
A-61
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
I 0.45-0.50
10.15-0.20
10.50-0.55
10.20-0.2 5
10.55-0.60
10.25-0.30
10.60-0.65
0.30-0.35
10.65-0.70
I
Figure A-63(l). Pipe 63, 0-3 feet and 0-90 degrees
A-62
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
a 0.45-0.50
H(12)
• 0.15-0.20
• 0.50-0.55
• 0.20-0.25
• 0.55-0.60
• 0.25-0.30
• 0.60-0.65
0.30-0.35
10.65-0.70
Figure A-63(2). Pipe 63, 0-3 feet and 90-180 degrees
A-63
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
BO.45-0.50
H(13)
BO. IS -0.20
BO.50-0.55
BO.20-0.25
BO.55-0.60
BO.25-0.30
BO.60-0.65
0.30-0.35
BO.65-0.70
40.0
41.0
41.9
42.9
44.0
44.9
46.0
46.9
47.9
49.0 -
49.9
51.0
51.9
52.9
54.0
54.9
56.0
56.9
57.9
59.0
Figure A-63(3). Pipe 63, 0-3 feet and 180-270 degrees
A-64
-------
H(14)
0.00-0.05 0.05-0.10 0.10-0.15 •0.15-0.20 BO.20-0.25 •0.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO. 45 -0.50 BO.SO-O.SS BO.55-0.60 BO.60-0.65 BO.65-0.70
I
•
ou.u
61.0
61.9
62.9
64.0
64.9
66.0
66.9
67.9 |
69.0-
69.9
71.0
71 9
72.9
74.0
74.9
76.0
^ _ fllj 76.9
^-^^J 77.9
1 79'°
v> »•> <» *> ,•> ,c? ^ f ^ t> ^ 4? ^ ^ ^ ^ 4> *> i> •
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
• 0.45-0.50
H(21)
• 0.15-0.20
• 0.50-0.55
• 0.20-0.25
• 0.55-0.60
• 0.25-0.30
• 0.60-0.65
0.30-0.35
0.65-0.70
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 .g
9.0 ^
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
Figure A-63(5). Pipe 63,3-6 feet and 0-90 degrees
A-66
-------
0.000-0.050
0.350-0.400
0.050-0.100
0.400-0.450
0.100-0.150
BO. 450-0.500
H(22)
UO.KOO.200
• 0.500-0.550
• 0.200-0.250
• 0.550-0.600
• 0.250-0.300
• 0.600-0.650
0.300-0.350
10.650-0.700
Figure A-63(8). Pipe 63,3-6 feet and 90-180 degrees
A-67
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
• 0.45-0.50
H(23)
• 0.15-Q.20
• 0.50-0.55
• 0.20-0.25
• 0.55-0.60
• 0.25-0.30
• 0.60-0.65
0.30-0.35
10.65-0.70
Figure A-63(9). Pipe 63, 3-6 feet and 180-270 degrees
A-68
-------
H(24)
0.00-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 •0.20-0.25 BO^S-O.SO 0.30-0.35
0.35-0.40 0.40-0.45 BO.45-0.50 BO.50-0.55 • 0.55-0.60 «0.60-0.65 BO.65-0.70
*
*
^^~^^m
^^••^•^
^B —
61.0
61.9
62.9
64.0
64.9
66.0
66.9
67 .9 Jj
69.0 -
69.9
71.0
71.9
72.9
74.0
74.9
76.0
76.9
77.9
79.0
•$ -f •*> •? «• i- i> f if> f> * N* # i? <,-• «,•> ^ ^ •*• 41 •? i? •> <="• (?• J- * *S° «? *
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
• 0.45-0.50
H(31)
• 0.15-0.20
• 0.50-0.55
• 0.20-0.25
• 0.55-0.60
• 0.25-0.30
• 0.60-0.65
0.30-0.35
• 0.65-0.70
-f -f" A*
^"> 0,-V o> o> A Jf X?
if ^ oi° if
-------
0.00-0.05
0.35-0.40
0.05 -0.10
0.40-0.45
0.10-0.15
10.45-0.50
H(32)
10.15-0.20
10.50-0.55
I 0.20 -0.25
I 0.55-0.60
• 0.25-0.30
BO.60-0.65
0.30-0.35
10.65-0.70
Inches
Figure A-63(12). Pipe 63,6-9 feet and 90-180 degrees
A-71
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
10.45-0.50
H(33)
10.15-0.20
10.50-0.55
I 0.20 -0.25
I 0.55-0.60
10.25-0.30
10.60-0.65
0.30-0.35
10.65-0.70
•C- ^ -v* •f' -f> •*> "0 1* A"
Inches
Figure A-63(13). Pipe 63, 6-9 feet and 180-270 degrees
A-72
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
iO.45-0.50
H(34)
BO.15-0.20
BO.50-0.55
mO.2D-0.Z5
BO.55-0.60
BO.25-0.30
O.60-0.65
«0.30-0.35
BO.65-0.70
60.0
61.0
61.9
62.9
64.0
64.9
66.0
66.9
67.9 |
69.0-
69.9
71.0
71.9
72.9
74.0
74.9
76.0
76.9
77.9
79.0
Inches
Figure A-63(14). Pipe 63, 6-9 feet and 270-300 degrees
A-73
-------
H(41)
0.00-0.05 0.05-0.10 0.10-0.15 • 0.15 -0.20 BO.20-0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO. 45 -0.50 • 0.50 -0.55 B 0.55 -0.60 B 0.60 -0.65 B 0.65 -0.70
0
It
# f s s j s j s S j f # ? f f j # # # f f f j f # j f j j f
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 3
-5
9.0 B
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
Inches
Figure A-63(15). Pipe 63, 9-12 feet and 0-90 degrees
A-74
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
• 0.45-0.50
H(42)
10.15-0.20
10.50-0.55
10.20-0.25
I 0.55-0.60
10.25-0.30
I 0.60-0.65
0.30-0.35
10.65-0.70
Inches
Figure A-63(16). Pipe 63, 9-12 feet and 90-180 degrees
A-75
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
• 0.45-0.50
H(43)
10.15-0.20
10.50-0.55
• 0.20-0.25
• 0.55-0.60
• 0.25-0.30
• 0.60-0.65
0.30-0.35
• 0.65-0.70
\
40.0
41.0
41.9
42.9
44.0
44.9
46.0
46.9
47.9
49.0 J!
u
49.9 -
51.0
51.9
52.9
54.0
54.9
56.0
56.9
57.9
59.0
Figure A-63(17). Pipe 63,9-12 feet and 180-270 degrees
A-76
-------
H{44)
0.00-0.05 0.05-0.10 0.10-0.15 • 0.15 -0.20 BO.20-0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO.45-0.50 «0.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
\ r
r %
*
J
">>SSNvSv*yv%vSvNvSvS>Sy\l'Sl'S^Sl'pO'SV"'^Sl''^'\l'-v>1yJV''v'V>-?'V'v'
60.0
61.0
61.9
62.9
64.0
64.9
66.0
66.9
67.9
69.0 g
69.9 Ł
71.0
71.9
72.9
74.0
74.9
76.0
76.9
77.9
79.0
Inches
Figure A-63(18). Pipe 63,9-12 feet and 270-300 degrees
A-77
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
^i
00
180°
270°
Figure A-64(l). Pipe 64 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
m
Figure A-64(2). Pipe 64 after Sandblasting
s
*
-------
Table A-64(l). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
64
Wall Thickness (inches)
10°
0.801
130°
0.793
290°
0.7965
330°
0.797
Table A-64(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
64
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.782
0.784
0.788
0.785
0.003
0.782
0.788
-
UT
0.776 0.765 0.766
0.771 0.777 0.765
0.762 0.759 0.766
0.767
0.006
0.759
0.777
0.770
Center
UT
0.797 0.776
0.765 0.771
0.775 0.766
0.774
0.790
0.771
0.776
0.011
0.765
0.797
0.760
Bell
UT
0.796 0.815
0.810 0.806
X X
0.807
X
X
0.807
0.007
0.796
0.815
0.810
Table A-64(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
64
Outer Diameter
Spigot
25.830
Center
25.875
Bell
25.860
T;
ible A-64(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
10°
0.801
1.096
0.295
130°
0.793
1.098
0.305
290°
0.7965
0.952
0.1555
330°
0.797
1.078
0.281
A-80
-------
Table A-64(5). Scanned Pipe 64 Summary Table
Defect
Area
Hll-64
H 12-64
H 13-64
H 14-64
H21-64
H22-64
H23-64
H 24-64
H31-64
H32-64
H33-64
Total
Volume
Loss (in.3)
-7.0
12.2
24.6
8.8
8.8
20.1
-11.9
9.6
1.8
30.4
-1.9
Dist
From
Spigot
(in.)
128.0
119.1
113.1
135.5
133.1
112.5
127.0
135.0
142.5
117.0
103.3
100.9
81.5
78.5
78.5
89.0
82.4
93.5
82.0
90.5
79.0
119.0
78.0
112.4
90.0
86.5
120.5
47.0
42.5
49.0
78.8
78.8
75.5
50.0
78.9
125.0
47.5
78.8
51.0
Maximum
Depths In
Defect Area
(in.)
0.2878
0.2429
0.2280
0.2264
0.1689
0.2689
0.2484
0.2122
0.3287
0.1358
0.2685
0.1697
0.3772
0.3130
0.3004
0.2866
0.2866
0.2803
0.2689
0.2598
0.2476
0.2280
0.4138
0.2681
0.2331
0.2173
-
0.2118
0.1555
0.5642
0.3524
0.3130
0.3004
0.2760
0.2646
0.2476
0.2472
0.4346
0.3902
0.3409
%
Loss
37%
31%
29%
29%
22%
34%
32%
27%
42%
17%
34%
22%
48%
40%
39%
37%
37%
36%
34%
33%
32%
29%
53%
34%
30%
28%
-
27%
20%
72%
45%
40%
39%
35%
34%
32%
32%
56%
50%
44%
Remaining
(in.)
0.4922
0.5371
0.5520
0.5536
0.6111
0.5111
0.5316
0.5678
0.4513
0.6442
0.5115
0.6103
0.4028
0.4670
0.4796
0.4934
0.4934
0.4997
0.5111
0.5202
0.5324
0.5520
0.3662
0.5119
0.5469
0.5627
-
0.5682
0.6245
0.2158
0.4276
0.4670
0.4796
0.5040
0.5154
0.5324
0.5328
0.3454
0.3898
0.4391
%
Remaining
63%
69%
71%
71%
78%
66%
68%
73%
58%
83%
66%
78%
52%
60%
61%
63%
63%
64%
66%
67%
68%
71%
47%
66%
70%
72%
-
73%
80%
28%
55%
60%
61%
65%
66%
68%
68%
44%
50%
56%
Clock
(Degrees)
265
256
260
238
271
127
109
145
18
34
276
347
245
189
247
240
265
247
236
245
265
260
176
127
129
134
287
291
254
265
189
247
251
258
265
258
182
178
169
Clock
(12hr)
8:49
8:31
8:40
7:56
9:02
4:14
3:38
4:50
0:36
1:07
9:11
11:33
8:09
6:18
8:13
8:00
8:49
8:13
7:51
8:09
8:49
8:40
5:51
4:14
4:18
4:27
-
9:33
9:42
8:27
8:49
6:18
8:13
8:22
8:36
8:49
8:36
6:04
5:56
5:38
A-81
-------
Defect
Area
H34-64
H41-64
H42-64
H43-64
H44-64
Total
Volume
Loss (in.3)
15.8
-7.9
51.8
27.3
25.5
Dist
From
Spigot
(in.)
42.0
44.0
48.5
71.0
42.8
42.8
37.5
39.0
27.0
39.5
34.5
36.0
28.0
32.5
37.5
29.0
33.0
30.5
42.8
39.0
33.0
Maximum
Depths In
Defect Area
(in.)
0.3193
0.3134
0.2354
0.1197
0.1520
0.5642
0.4142
0.3508
0.3220
0.3035
0.2929
0.2909
0.2567
0.2535
0.4390
0.3902
0.3028
0.3008
0.2980
0.2811
0.1508
%
Loss
41%
40%
30%
15%
19%
72%
53%
45%
41%
39%
38%
37%
33%
33%
56%
50%
39%
39%
38%
36%
19%
Remaining
(in.)
0.4607
0.4666
0.5446
0.6603
0.6280
0.2158
0.3658
0.4292
0.4580
0.4765
0.4871
0.4891
0.5233
0.5265
0.3410
0.3898
0.4772
0.4792
0.4820
0.4989
0.6292
%
Remaining
59%
60%
70%
85%
81%
28%
47%
55%
59%
61%
62%
63%
67%
68%
44%
50%
61%
61%
62%
64%
81%
Clock
(Degrees)
167
180
171
31
278
254
187
198
189
187
245
249
183
240
182
178
165
171
165
176
45
Clock
(12hr)
5:34
6:00
5:42
1:02
9:15
8:27
6:13
6:36
6:18
6:13
8:09
8:18
6:06
8:00
6:04
5:56
5:29
5:42
5:29
5:51
1:29
A-82
-------
0.00-0.05 0.05-0.10 0.10-0.15 BO. 15 -0.20 «0.20-0.25 »0.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 HO.45-0.50 «0.50-0.55 «0.55-0.60 BO.60-0.65 BO.65-0.70
_
^ • •
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 JS
9.0 -
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
Inches
Figure A-64(l). Pipe 64, 0-3 feet and 0-90 degrees
A-83
-------
H(12)
0.00-0.05 0.05-0.10 0.10-0.15 •0.15-0.20 «0.20-0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
» • . ^^
r"^ v**^ ^
^^^^i ^•V^H
r A
JP
i ^
20.0
21.0
22.0
22.9
24.0
25.0
26.0
27.0
VI
27.9 |
29.0 -
30.0
31.0
32.0
32.9
34.0
35.0
36.0
37.0
37.9
39.0
»-»»*«4*4*+**+ + + 4 * * -f « « •? * * * * * * * * * * + * * * * *
Inches
Figure A-64(2). Pipe 64,0-3 feet and 90-180 degrees
A-84
-------
H{13)
0.00-0.05 0.05-0.10 0.10-0.15 BO. 15 -0.20 mO.20-0.2S BO.25-0.30 10.30-0.35
0.35^.40 0.40-0.45 BO.45-0.50 BO.50-0.55 •0.55-0.60 •0.60-0.65 BO.65-0.70
4
1 <• »
I % -*i x
J + + v
r^. * <
•• K . •• ,
R^ • *> '*
A*
•b 1 «, «. 1 «>^4><$l C S* •? -!> T> -0 -P T? ^ T,fc <- « ^^ * ^ •* •*> ^ «f> * -b1 ^* ^
40.0
41.0
42.0
42.9
44.0
45.0
46.0
47.0
47-9s
49.0 -g
50.0 ~
51.0
52.0
52.9
54.0
55.0
56.0
57.0
57.9
59.0
Inches
Figure A-64(3). Pipe 64, 0-3 feet and 180-270 degrees
A-85
-------
H{14)
0.00-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 «0.20-0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
-V
'4
fl^k^B
-
* .'.-
A
j*
°
•I
*k* + ***4 * s» s- * * * * -v- * * 4 * * * * * * * * + ^ * *
60.0
61.0
62.0
62.9
64.0
65.0
66.0
67.0
67.9J!
u
69.0 Ł
70.0
71.0
72.0
72.9
74.0
75.0
76.0
77.0
77.9
79.0
Inches
Figure A-64(4). Pipe 64,0-3 feet and 270-300 degrees
A-86
-------
H(21)
0.00-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 BO.20-0.25 BO.25-0.30 «0.30-0.35
0.35-0.40 0.40-0.45 «0.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
•
1
^1
u.u
1.0
2.0
3.0
4,0
5.0
6.0
7.0
8.0 J8
9.0 1
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
Inches
Figure A-64(5). Pipe 64, 3-6 feet and 0-90 degrees
A-87
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
BO.45-0.50
H{22)
BO.15-0.20
BO.50-0.55
O.20-0.25
O.55-0.60
BO.25-0.30
BO.60-0.65
0.30-0.35
BO.65-0.70
Figure A-64(6). Pipe 64,3-6 feet and 90-180 degrees
A-8
-------
H(23)
0.00-0.05 0.05-0.10 0.10-0.15 • 0.15 -0.20 • 0.20 -0.25 • 0.25 -0.30 0.30-0.35
0.35 -0.40 0,40 -0.45 • 0.45 -0.50 • 0.50 -0.55 • 0.55 -0.60 • 0.60-0.65 • 0.65 -0.70
O
•
^_^fc
^^ *A
,-x 1 ^A
U ^
A W ^ »
• ^^l "^^^. ^^
•
40.0
41.0
42.0
42.9
44.0
45.0
46.0
47.0
47.9 J!
|
49.0 -
50.0
51.0
52.0
52.9
54.0
55.0
56.0
57.0
57.9
59.0
Inches
Figure A-64(7). Pipe 64,3-6 feet and 180-270 degrees
A-89
-------
H(24)
0.00-0.05 0.05-0.10 '0.10-0.15 •0.15-0.20 •0.20-0.25 »0.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0.60 •0.60-0.65 BO.65-0.70
•*•
f •# «? tP & t- f> if fr & 0 & # h° «,"• O- (? * * & $ & & •? <• -\~ •f
60.0
41.0
42.0
42.9
44.0
45.0
46.0
47.0
47.9 |
49.0 -
50.0
51.0
52.0
52.9
54.0
55.0
56.0
57.0
57.9
59.0
Inches
Figure A-64(8). Pipe 64, 3-6 feet and 270-300 degrees
A-90
-------
H(31)
0.00-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 B 0.20 -0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 «0.45-0.50 BO.50-0.55 BO.55-0.60 B0.60-O.65 BO.65-0.70
•jfe
| y
•» ^H
^ll fltt KB^
^^L
•flH^P^
» 1- --.
• .9
u.u
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 |
9.0 -
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
Inches
Figure A-64(9). Pipe 64,6-9 feet and 0-90 degrees
A-91
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
• 0.45-0.50
H{32)
• 0.15-0.20
• 0.50-0.55
• 0.20-0.25
• 0.55-0.60
• 0.25-0.30
• 0.60-0.65
0.30-0.35
10.65-0.70
Inches
Figure A-64(10). Pipe 64,6-9 feet and 90-180 degrees
A-92
-------
H(33)
0.00-0.05 0.05-0.10 0.10-0.15 BO. 15 -0.20 «0.20-0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
5 >• 1
o' «
^k
«T* *• '• ' * *
P
^^
^^^
• • • t
Inches
40.0
41.0
42.0
142.9
44.0
45.0
46.0
47.0
47.9 1
49.0-
50.0
51.0
52.0
52.9
54.0
55.0
56.0
57.0
57.9
59.0
Figure A-64(ll). Pipe 64, 6-9 feet and 180-270 degrees
A-93
-------
H{34)
0.00-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 BO.20-0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 «0.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
*
-
.
Inches
60.0
61.0
62.0
62.9
64.0
65.0
66.0
67.0
67.9 Ł
-=
69.0 Ł
70.0
71.0
72.0
72.9
74.0
75.0
76.0
77.0
77.9
79.0
Figure A-64(12). Pipe 64,6-9 feet and 270-300 degrees
A-94
-------
H(41)
0.00-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 »0.20-0.25 «0.25-D.30 0.30-0.35
0.35-0.40 0.40-0.45 •0.45-0.50 BO.SO-O.SS «0.5S-0.60 BO.50-0.65 «0.65-0.70
L J
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 a
1
9.0 S.
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
Inches
Figure A-64(13). Pipe 64,9-12 feet and 0-90 degrees
A-95
-------
0.00-0.05
0.35-0.40
0.05 -0.10
0.40-0.45
0.10-0.15
10.45-0.50
H(42)
• 0.15-0.20
• 0.50-0.55
10.20-0.25
10.55-0.60
10.25-0.30
10.60-0.65
0.30-0.35
• 0.65-O.7Q
b &
•*
/
20.0
20.5
21.0
21.4
22.0
22.5
22.9
23.5
24.0
24.5
25.0
25.5
26.0
26.4
27.0
27.5
27.9
28.5
29.0
29.5
30.0
30.5
31.0
31.4
32.0
32.5
32.9
33.5
34.0
34.5
35.0
35.5
36.0
36.4
37.0
37.5
37.9
38.5
39.0
40.0
Inches
Figure A-64(14). Pipe 64,9-12 feet and 90-180 degrees
A-96
-------
0.00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0.15
10.45-0.50
H(43)
10.15-0.20
10.50-0.55
10.20-0.25
10.55-0.60
• 0.25-0.30
• 0.60-0.65
0.30-0.35
• 0.65-0.70
40.0
41.0
42.0
42.9
44.0
45.0
46.0
47.0
47.9
49.0
50.0
51.0
52.0
52.9
54.0
55.0
56.0
57.0
57.9
59.0
Inches
Figure A-64(15). Pipe 64, 9-12 feet and 180-270 degrees
A-97
-------
H(44)
0.00-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 BO.20-0.25 BO.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
*
r
«^MJ
^^P
*m »
-
1 •
^
g^^M
60.0
61.0
62.0
62.9
64.0
65.0
66.0
67.0
67.9 S
€
69.0 Ł
70.0
71.0
72.0
72.9
74.0
75.0
76.0
77.0
77.9
79.0
# ^ f s* ,? * j + f # f
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
0°
90°
180°
270°
Figure A-69(l). Pipe 69 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
Figure A-69(2). Pipe 69 after Sandblasting
-------
Table A-69(l). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
69
Wall Thickness (inches)
70°
0.776
110°
0.774
200°
0.742
315°
0.742
Table A-69(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
1
Pipe Number
69
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.756
0.752
0.750
0.753
0.003
0.750
0.756
-
UT
0.792 0.768
0.767 0.755
0.796 0.760
0.767
0.758
0.744
0.760
0.017
0.744
0.796
0.759
Center
UT
0.730 0.736
0.730 0.755
0.728 0.739
0.736
0.739
0.730
0.734
0.008
0.728
0.755
0.740
Bell
UT
0.783 0.780
0.778 0.788
0.814 0.784
0.785
0.786
0.776
0.776
0.012
0.776
0.814
0.808
Table A-69(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
69
Outer Diameter
Spigot
25.880
Center
25.810
Bell
25.860
Ta
ble A-69(4). Wall Thickness of Cement Liner at Spigot with Cali
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
70°
0.776
0.958
0.182
110°
0.774
0.980
0.206
200°
0.742
0.998
0.256
315°
0.742
0.998
0.256
Der
A-101
-------
Table A-69(5). Pipe 69 Summary Table
Defect Area
069-095-129-027-109
069-083-030-014-078
069-106-040-032-089
069-069-315-010-023
069-048-297-006-037
069-024-274-014-277
069-115-275-014-098
069-006-141-015-148
Total
Volume
Loss
(in.3)
38.1
11.4
39.5
1.3
1.8
17.2
11.4
30.0
Dist
From
Bell
(in.)
48.5
47.0
44.0
61.0
63.0
63.0
65.0
62.0
22.0
17.5
33.0
30.5
80.0
76.0
100.5
98.0
123.0
123.5
120.0
123.5
118.0
26.0
29.0
131.0
141.0
135.0
138.0
138.0
132.0
Maximum
Depths In
Defect
Area (in.)
0.362
0.351
0.320
0.391
0.239
0.238
0.233
0.219
0.584
0.354
0.307
0.272
0.294
0.251
0.362
0.173
0.420
0.365
0.353
0.269
0.239
0.392
0.241
0.368
0.367
0.338
0.332
0.327
0.319
%
Loss
46%
45%
41%
50%
31%
30%
30%
28%
75%
45%
39%
35%
38%
32%
46%
22%
54%
47%
45%
34%
31%
50%
31%
47%
47%
43%
43%
42%
41%
Remaining
(in.)
0.42
0.43
0.46
0.39
0.54
0.54
0.55
0.56
0.20
0.43
0.47
0.51
0.49
0.53
0.42
0.61
0.36
0.42
0.43
0.51
0.54
0.39
0.54
0.41
0.41
0.44
0.45
0.45
0.46
%
Remaining
54%
55%
59%
50%
69%
70%
70%
72%
25%
55%
61%
65%
62%
68%
54%
78%
46%
53%
55%
66%
69%
50%
69%
53%
53%
57%
58%
58%
59%
Clock
(Degrees)
200
207
202
321
317
272
308
303
307
284
231
291
34
38
36
59
46
68
24
26
82
43
358
115
117
99
135
84
137
Clock
(12hr)
6:40
6:54
6:44
10:42
10:34
9:04
10:16
10:06
10:14
9:28
7:42
9:42
:08
:16
:12
:58
:32
2:16
0:48
0:52
2:44
1:26
11:56
3:50
3:54
3:18
4:30
2:48
4:34
A-102
-------
069-095-129-027-109
0-0.05 0,05-0.1 0,1-0.15 • 0.15-0.2* 0.2-0.25B 0.25-0.3 O.J-0,?,5 0.?,5-0.4 0.4-0,45 . 0.45-0.5B 0.5-0,55« 0.55-0.6B 0.6-0,65» 0.65-0.7
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Inches
Figure A-69(l). Pipe 69, area 069-095-129-027-109
A-103
-------
069-083-030-014-078
0-0.0% D 01-0.1 * 0.14 IS • 0.1VQ.J • O.J-O.J'* BD.j^.l B O.i-O 15
0.35 0.4 '0,40.4s • 0,4^ 0.5 «O.S O.iS •D.&^O.fr •(>,<> Ofrb Bljfeb 0 /
t>
Figure A-69(2). Pipe 69, area 069-083-030-014-078
A-104
-------
069-106-040-032-089
0-0.05 0.05-0.1 0.1-0.15 • 0.15-0.2 » 0.2-0.25 BO.25-03 0.3-0.?,5 035-0.4 0.4-0.45 B 0.45-0.5 • 0.5-0.55 • 0.55-0.6 • 0.6-0.65 • 0.65-0.7
>
: r ^.-
12 -
Inches
Figure A-69(3). Pipe 69, area 069-106-040-032-089
A-105
-------
069-069-315-010-023
0-0.05 0.05-0.1 0.1-0.15 • 0.15-0.2 • 0.2-0.25 BO.25-03 0.i-0.?.5 035-0.4 0.4-0.45 • 0.45-0.5 • 0.5-0.55 • 0.55-0.6 • 0.6-0.65 • 0.65-0.7
0
O •> T. ^ k <3 fe
Inches
Figure A-69(4). Pipe 69, area 069-069-315-010-023
A-106
-------
069-048-297-006-037
OQ.Oi O.Oi-U.I sO.10.lS 10.1^0.2 "0.20,2} l0.25Qi -iO.iO.il
OJS0.4 010JS «04505 "05055 "1)5506 "06065 "06507
Figure A-69(5). Pipe 69, area 069-048-297-006-037
A-107
-------
069-024-274-014-277
0 0.0& Q.OS 0.1 B010.15 BO.1)0,2 »020,25 •0.2^-0,3 "O.JO.iS
0.550.4 0.4045 «CH505 "05055 •05506 '060.65 I0650?
Figure A-69(6). Pipe 69, area 069-024-274-014-277
A-108
-------
069-115-275-014-098
oo.oi
0,1 id 4
0.050.1
0,4 (Mi
" 0,1 O.li
*0,4iO,i
• 0.2-0.3*
« ••
1.S
J
25
3
S5
4
4.S
S
S.S
ts
7
7.5
a
B,5
9
9.S
10
105
11
115
125
1}
15.5
16
17
1J.5
195
20
20!
Figure A-69(7). Pipe 69, area 069-115-275-014-098
A-109
-------
0-0.05
055-04
069-OQ6-141-Q15-14S
"01-015
• 015-0.2
• 05-055
OJ-OiS
055-06
• OJ5-0!
• OG-0.6')
10 i (155
• 065-0.7
Figure A-69(8). Pipe 69, area 069-006-141-015-148
A-110
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
Figure A-98(l). Pipe 98 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
to
90°
180°
270°
Figure A-98(2). Pipe 98 after Sandblasting
-------
Table A-98(1). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
98
Wall Thickness (inches)
90°
0.814
180°
0.799
270°
0.812
345°
0.840
Table A-98(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
98
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.831
0.832
0.830
0.831
0.001
0.830
0.832
-
UT
0.832
0.822
0.827
0.828
0.826
0.825
0.829
0.822
0.818
0.825
0.004
0.818
0.832
0.820
Center
UT
0.789
0.790
0.778
0.783
0.793
0.793
0.801
0.797
0.789
0.790
0.007
0.778
0.801
0.796
Bell
UT
0.814 0.817
0.815 0.816
0.815 0.822
0.819
0.829
0.815
0.826
0.006
0.814
0.829
0.817
Table A-98(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
98
Outer Diameter
Spigot
25.875
Center
25.800
Bell
25.760
Tab
le A-98(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
90°
0.814
1.102
0.288
180°
0.799
1.11
0.311
270°
0.812
1.085
0.273
345°
0.840
1.078
0.238
Table A-98(5). Pipe 98 Summary Table
Defect Area
098-047-271-012-047
098-066-282-024-066
098-109-337-010-121
098-103-168-029-039
Total
Volume
Loss
(in.3)
5.0
13.4
39.5
24.4
Dist
From
Bell
(in.)
96.5
62.0
81.0
36.5
39.5
38.5
21.0
25.0
23.0
36.0
44.0
32.0
Maximum
Depths In
Defect
Area (in.)
0.493
0.379
0.339
0.299
0.252
0.236
0.328
0.314
0.298
0.295
0.251
0.224
%
Loss
63%
49%
43%
38%
32%
30%
42%
40%
38%
38%
32%
29%
Remaining
(in.)
0.29
0.40
0.44
0.48
0.53
0.54
0.45
0.47
0.48
0.49
0.53
0.56
%
Remaining
37%
51%
57%
62%
68%
70%
58%
60%
62%
62%
68%
71%
Clock
(Degrees)
69
23
54
1
288
310
174
163
172
163
176
161
Clock
(12hr)
2:18
0:46
1:48
0:02
9:36
10:20
5:48
5:26
5:44
5:26
5:52
5:22
A-113
-------
098-047-271-012-047
0-0.05 005-0.1 0.1-015 • 0.15-0.2 • 0.2-0.25 • 0.25-0.3 0.3-0.35
0.35-0.4 0.4-0,45 «0,45-0.5 "0.5-0.55 "0.55-0.6 "0.6-0.65 "0.65-0.7
-
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
Inches
Figure A-98(l). Pipe 98, area 098-047-271-012-047
A-114
-------
098-066-282-024-066
0-005 0.05-0.1 0.1-0.15 • 0.15-0.2 • 0.2-0.25 • 0.25-03 •- 03-035 035-0.4 0.4-0.45 • 0.45-0.5 • 0.5-0.55 • 0.55-0.6 • 0.6-0.65 • 0.65-0.7
V
0
0.5
1
1.5
2
2.5
3
J.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9.5
10
10.5
11
11.5
12
12 5
li
13.5
14
14.5
15
15.5
16
16.5
V N V S S S o ^ S
Inches
Figure A-98(2). Pipe 98, area 098-066-282-024-066
A-115
-------
098-109-E37-010-121
0-005 0.05-01 101-015
0.1MH .0.1.045 • oil-OS
• 02-025
• OVl-Ob
• 025-OJ
• Ob-oel
f
-A
"^
1 5
2
2-S
3
J.J
5
55
I
65
7
7.S
8
a •,
9
10
105
U
115
JZ
19
US
14
145
15
1S.S
16
161
17
If.4
18
185
19
195
20
?0i
21
215
11
2S
2i5
24
24.5
25
J55
Figure A-98(3). Pipe 98, area 098-109-337-010-121
A-116
-------
098-103-168-029-039
0-0,05 0.05-0.1 0.1-0.15 • 0.15-0.2 10.2-0.25 10.25-03 03-035 035-0.4 0.4-0.45 a 0,45-0.5 • 0.5-0.55 • 0.55-0.6 BO.6-0,65 • 0.65-0.7
0
1
2
3
4 OT
6
7
8
9
Inches
Figure A-98(4). Pipe 98, area 098-103-168-029-039
A-117
-------
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
Figure A-137(l). Pipe 137 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
«' •• - ft
i, -i'-. _L. ' 4 . * * "^^J" ' - — ''-
Figure A-137(2). Pipe 137 after Sandblasting
-------
Table A-137(l). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
137
Wall Thickness (inches)
80°
0.765
x°
X
190°
0.765
290°
0.773
Table A-137(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
137
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.764
0.782
0.764
0.770
0.010
0.764
0.782
-
UT
0.749 0.741
0.730 0.748
0.752 0.731
0.730
0.737
0.730
0.739
0.009
0.730
0.752
0.734
Center
UT
0.738 0.736
0.741 0.740
0.741 0.734
0.740
0.735
0.742
0.739
0.003
0.734
0.742
0.738
Bell
UT
0.766 0.766
x 0.776
x 0.785
0.771
0.757
0.760
0.786
0.012
0.757
0.786
0.763
Table A-137(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
137
Outer Diameter
Spigot
25.800
Center
25.803
Bell
25.810
Table A-137(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
80°
0.765
0.940
0.175
x°
X
X
X
190°
0.765
0.911
0.146
290°
0.773
0.930
0.157
A-120
-------
Table A-137(5). Pipe 137 Summary Table
Defect Area
137-025-136-025-046
137-017-182-033-059
137-010-299-040-094
137-000-000-010-360
Total
Volume
Loss
(in.3)
10.7
16.9
18.8
52.7
Dist
From
Bell
(in.)
111.5
109.5
120.0
103.5
122.0
113.0
113.0
109.5
124.0
146.5
146.0
146.0
146.5
146.5
Maximum
Depths In
Defect
Area (in.)
0.243
0.239
0.231
0.238
0.206
0.202
0.207
0.189
0.181
0.361
0.328
0.324
0.321
0.320
%
Loss
31%
31%
30%
31%
26%
26%
27%
24%
23%
46%
42%
42%
41%
41%
Remaining
(in.)
0.54
0.54
0.55
0.54
0.57
0.58
0.57
0.59
0.60
0.42
0.45
0.46
0.46
0.46
%
Remaining
69%
69%
70%
69%
74%
74%
73%
76%
77%
54%
58%
58%
59%
59%
Clock
(Degrees)
195
193
197
160
145
165
357
5
34
253
213
200
160
260
Clock
(12hr)
6:30
6:26
6:34
5:20
4:50
5:30
11:54
0:10
1:08
8:26
7:06
6:40
5:20
8:40
A-121
-------
137-025-136-025-046
0-0.05 0.05-0.1 0.1-0.151 0.15-0.2BO. 2-0.25* 0.25-0.3 0.3-035 0.35-0.4 0.4-0.451 0.45-0.5B 0.5-0.55B 0.55-0.61 0.6-0.65B 0.65-0.7
0
1
2
3
4
5 j
i
6
7
8
9
10
Inches
Figure A-137(l). Pipe 137, area 137-025-136-025-046
A-122
-------
137-017-182-033-059
0-0.05 0.05-0.1 0.1-0. 15B G.I 5-0.2»G.2-0.25« 0.25-03 0.3-035 035-0.4 0. 4-0.45 • 0.45-0.5 • 0.5-0. 55 • 0.55-0.61 0.6-0.651 0.65-0.7
'•-
11
12
13
OV'V">Vcjlo'\
Inches
Figure A-137(2). Pipe 137, area 137-017-182-033-059
A-123
-------
137-010-299-040-094
0-0.05 0.05-0.1B0.1-0.15B0.15-0.2B0.2-0.25B0.25-03 03-035 035-0.4 0.4-0.45B 0.45-0.5 • 0.5-0.55B 0,55-0 ,6m 0.6-0.65BO .65-0.7
*w
/
P
_ ~*
*^ -.
c
^^ "•^r ^BM.
A
^ '
»***• + *******•*> + **,&* 3 ^ ^ ^ ^ ^. ^ afe ^ ^, ^ ^ ^> ^ ^ ^ ^ ^ ^ ^
0
1
2
3
4
5
6
7
8
9 Ł
10 g
11
12
13
14
15
16
17
18
19
20
Inches
Figure A-137(3). Pipe 137, area 137-010-299-040-094
A-124
-------
137-000-000-010-160
00 05
0 35 04
0 OS 01
04 045
11 0.1 015
• 0 45 0 f.
• O.lS 02
• 0505S
• 02 025 • 025 03
• 0 Vi nil • iii> 0 65
»0 10J5
• • ' •• 7
Figure A-137(4). Pipe 137, area 137-000-000-010-160
A-125
-------
137-000-160-010-160
0.1 015
• 0.45-0.5
iO 15 &2
• ft 5 0 55
• 02 0.25
• 0.550.6
• 0.250.1
• 0.60.65
20
21
25
2$
i
Figure A-137(5). Pipe 137, area 137-000-160-010-160
A-126
-------
137-000-320-010-40
0 005 005 0.1
0 .35-01
mn, .<>*•> m 0650 7
Figure A-137(6). Pipe 137, area 137-000-320-010-40
A-127
-------
137-000-000-010-360
0-fl05 005-01 -010 IS BIUS-OJ «OJ-OJ5 BO 25-01 '03-015
0.35-0.4 04-045 •0.15-O.S • O.S-O.SS 10.55-0.6 «06-0&5 BO.65-0.7
18
»
a
Zi
74
75
Figure A-137(7). All depths at the spigot for Pipe 137 from 0° to 360° combined into one image,
area 137-000-000-010-360
A-128
-------
0-3 ft
3-6 ft
6-9 ft
90°
180°
270°
Figure A-145(l). Pipe 145 as Removed from Site
A-129
-------
0-3 ft
3-6 ft
6-9 ft
90°
180°
270°
Figure A-145(2). Pipe 145 after Sandblasting
A-130
-------
Table A-145(l). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
145
Wall Thickness (inches)
5°
0.789
335°
0.782
345°
0.784
355°
0.787
Table A-145(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
145
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.791
0.794
0.785
0.790
0.005
0.785
0.794
-
UT
0.765
0.771
0.765
0.766
0.770
0.759
0.761
0.763
0.749
0.763
0.007
0.749
0.771
0.751
Center
UT
0.808
0.815
0.817
0.804
0.814
0.782
0.788
0.790
0.807
0.811
0.013
0.782
0.817
0.780
Bell
UT
0.764
0.757
0.760
0.763
0.767
0.783
0.747
0.759
0.768
0.762
0.010
0.747
0.783
0.765
Table A-145(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
145
Outer Diameter
Spigot
25.825
Center
25.803
Bell
25.803
Table A
L-145(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
5°
0.789
1.106
0.317
335°
0.782
1.105
0.323
345°
0.784
1.091
0.307
355°
0.787
1.098
0.311
A-131
-------
Table A-145(5). Scanned Pipe 145 Summary Table
Defect
Area
Hll
H12
H13
H14
H21
H22
H23
Total
Volume
Loss
(in.3)
29.7
33.9
20.4
-3.6
12.9
-1.1
35.4
Dist
From
Spigot
(in.)
12.9
4.8
4.4
4.8
2.0
6.3
10.4
8.9
7.8
13.3
15.3
18.9
18.3
17.8
19.8
19.8
27.8
28.9
24.4
26.3
28.9
37.4
35.3
64.9
63.4
60.4
55.9
54.0
_
60.4
Maximum
Depths In
Defect Area
(in.)
0.3343
0.2216
0.2441
0.2118
0.2677
0.2142
0.2535
0.2370
0.2528
0.2272
0.2673
0.3740
0.3173
0.2559
0.2760
0.3083
0.2449
0.2362
0.1898
0.1850
0.1898
0.1906
0.1835
0.2102
0.1890
0.1858
0.1890
0.1902
_
0.3319
%
Loss
44%
29%
32%
28%
35%
28%
33%
31%
33%
30%
35%
49%
42%
34%
36%
40%
32%
31%
25%
24%
25%
25%
24%
26%
24%
23%
24%
24%
_
41%
Remaining
(in.)
0.4287
0.5414
0.5189
0.5512
0.4953
0.5488
0.5095
0.5260
0.5102
0.5358
0.4957
0.3890
0.4457
0.5071
0.4870
0.4547
0.5181
0.5268
0.5732
0.5780
0.5732
0.5724
0.5795
0.5938
0.6150
0.6182
0.6150
0.6138
_
0.4721
%
Remaining
56%
71%
68%
72%
65%
72%
67%
69%
67%
70%
65%
51%
58%
66%
64%
60%
68%
69%
75%
76%
75%
75%
76%
74%
76%
77%
76%
76%
_
59%
Clock
(Degrees)
80
13
38
71
151
122
113
106
100
97
100
100
122
113
111
64
193
198
202
217
213
286
288
7
20
9
7
9
_
255
Clock
(12hr)
2:39
0:26
1:15
2:22
5:02
4:03
3:46
3:32
3:19
3:14
3:19
3:19
4:03
3:46
3:41
2:08
6:25
6:35
6:43
7:14
7:05
9:32
9:36
0:13
0:40
0:17
0:13
0:17
_
8:30
A-132
-------
Defect
Area
H24
H31
H32
H33
H34
Total
Volume
Loss
(in.3)
21.7
1.8
4.5
23
1.6
Dist
From
Spigot
(in.)
50.4
55.9
58.5
48.9
42.5
54.0
57.0
75.0
88.9
74.4
75.9
98.0
100.0
Maximum
Depths In
Defect Area
(in.)
0.2236
0.2157
0.2535
0.2154
0.2465
0.3272
0.2578
0.1433
0.2000
0.2106
0.2012
0.3161
0.2012
%
Loss
28%
27%
32%
27%
31%
41%
32%
19%
26%
28%
26%
41%
26%
Remaining
(in.)
0.5804
0.5883
0.5505
0.5886
0.5575
0.4768
0.5462
0.6197
0.5630
0.5524
0.5618
0.4469
0.5618
%
Remaining
72%
73%
68%
73%
69%
59%
68%
81%
74%
72%
74%
59%
74%
Clock
(Degrees)
242
251
244
242
293
311
297
27
171
195
206
304
304
Clock
(12hr)
8:04
8:21
8:08
8:03
9:46
10:21
9:54
0:53
5:41
6:30
6:52
10:08
10:08
A-133
-------
0,00-0,05
0.35-0.40
0.05-0,10
0.40-0.45
0.10-0.15
"0.45-0.50
• 0.15 -0.20
BO.50-0.55
0.20-0.25
O.55-0.60
O.25-0,30
O.60-0.65
0.30-0,35
B065-070
A
f
-^
i
*$>&«Ł>&<»&'$
»*. A Jo .A A J>>
Inches
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
.
-------
0.00-0.05
0.35-0.40
0.05-0,10
0.40-0.45
0.10-0.15
10.45-0.50
H(12)
IO.15-0.ZO
10.50-0.55
• 0.20-0.25
• 0.55-0.60
• 0.25-0.30
• 0.60-0.65
030-0.35
• 0.65-0.70
nchas
Figure A-145(2). 0-3 feet and 90-180 degrees
A-135
-------
'
0,00-0.05
0.35-0.40
0.05-0,10
0.40-0.45
0.10-0.15
O.45-0.50
H(13)
O.15-0.20
BO.50-055
BO.20-0.25
BO.55-0.60
BO.25-0.30
BO.60-0.65
0.30-0,35
BO.65-0.70
1
! 40.0
41.0
41.9
42.9
43.9
44.9
46.0
46.9
48.9-
49.9
51.0
51.9
529
53,9
54.9
56.0
56.9
57.9
58.9
Inches
Figure A-145(3). 0-3 feet and 180-270 degrees
A-136
-------
H(14)
0.00-0.05 0.05-0,10 0.10-0.15 • 0.15 -0,20 • 0.20 -025 • 0.25 -0.30 030-0.35
0.35-0.40 0.40-0.45 10.45 -0.50 • 0.50 -0.55 • 0.55 -0.60 • 0.60 -065 • 0.65 -0.70
61.0
61.9
62.9
63.9
^ ^^«A^0 64.9
66.0
66.9
67.9 1
68.9-
69.9
71.0
71.9
72.9
73.9
74.9
76.0
76.9
77.9
78,9
Inches
Figure A-145(4). 0-3 feet and 270-300 degrees
A-137
-------
H(21)
0,00-0.05 0.05-0,10 0.10-0,15 BO.15-0,20 BO.20-025 BO.25-0,30 0.30-0,35
O.J5-0.40 0.40-0.45 • 0.45 -0.50 • 0.50 -0.55 • 0.55 -0.60 • 0.60 -0.65 • 0.65 -0.70
•f
*+» ,+**
w ^\^ *
1
•$ •? tP Ł• ^ 1* t.8- * * Ł # ^> ^ •>* "o8- <*> 1? b* t? A0 *• -?• -H- -f
Inches
0.0
1.0
2,0
3.0
4.0
5.0
6.0
7.0
8.0 1
9.0 -5
100
11,0
12.0
13.0
14,0
15.0
160
170
18.0
19.0
Figure A-145(5). 3-6 feet and 0-90 degrees
A-138
-------
0.00-0.05
035-0.40
0.05-0.10
0.40-0.45
0.10-0.15
10.45-0.50
H(22)
• 0.15-020
BO 50-0.55
B 0.20-0.25
BO.55-0.60
10.25-0.30
10.60-065
0.30-0,35
BO 65-0.70
20.0
21,0
21.9
22.9
23.9
24.9
26.0
26.9
27.9^
28.9-
29.9
31.0
31.9
32.9
33.9
34.9
36.0
36.9
37.9
389
Figure A-145(6). 3-6 feet and 90-180 degrees
A-139
-------
0,00-0.05
0.35-0.40
0.05-0.10
0.40-0.45
0.10-0,15
I 0.45-0.50
H(23)
10.15 -0.20
10.50-0.55
10.20-0.25
10.55-0.60
I 0.25-O.JO
I 0.60-0.65
0.30-0.35
• 0.65-0.70
Inches
Figure A-145(7). 3-6 feet and 180-270 degrees
A-140
-------
H(24)
0.00-0.05 0.05-0,10 0.10-0.15 BO.15-0.20 BO.20-0.25 BO.25-0.30 0.30-0,35
O.J5-0.40 0.40-0.45 «0.45-0.50 BO.50-0,55 BO.55-0.60 BO.GO-0.65 BO.65-0.70
HP
1 »
t * « * *
^
X.-7 •• •
m A
•
1^*
O*
mr
u/
xSj
- •• •
DU.U
61.0
61.9
62.9
63.9
64.9
66.0
66.9
67.9 i
68.9-
69.9
71.0
71.9
72.9
73.9
74.9
76.0
76.9
77.9
78.9
Inches
Figure A-145(8). 3-6 feet and 270-300 degrees
A-141
-------
H(31)
0.00 -0.05 0.05 -0,10 0,10 -0.15 • 0.15 -0,20 • 0.20 -025 • 0.25 -0.30 0.30 -035
035 -0.40 0.40 -0.45 • 0.45 -0.50 • 0.50 -0,55 • 0.55 -0.60 • 0.60 -0.65 • 0.65 -0.70
1
4
0.0
0.5
1.0
1.5
2.0
2.5
3.0
J.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0 a!
8.5 "6
9.0 -
9.S
10.0
10.5
11.0
11.5
12.0
12.5
13.0
13.5
14.0
14.5
15.0
15.5
16.0
16.5
17.0
17.5
18.0
18.5
19.0
in n
Inches
Figure A-145(9). 6-9 feet and 0-90 degrees
A-142
-------
H(32)
000-0.05 0.05-0,10 0.10-0.15 • 0.15 -0.20 «0.20-025 BO.25-030 030-035
035-0.40 0.40-0.45 • 0.45 -0.50 • 0.50 -0.55 • 0.55 -0.60 • 0.60 -0.65 • 0.65 -0.70
^b =
^
. A
20. tl
20.4
21.0
21 4
21.9
22.5
22.9
23.4
23.9
24.5
24.9
25.4
26.0
26.4
26.9
27.5
27.9 ;;
28.4 -5
28.9 -
29.5
29.9
J0.4
31.0
31.4
31.9
32.5
32.9
33.4
33.9
34.5
34.9
35.4
36.0
36^4
36.9
J7.5
37.9
38.4
38.9
an n
-f- & *!• * -f> A*> "0 •f- -f & & & »» ^ * * Ł # 1? °>N k <#• * *
-------
H(33)
0,00-0.05 0.05-0,10 0.10-0,15 BO.15-0.20 BO.20-0.25 BO.25-0.30 0.30-0,35
0.35-0.40 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0,60 BO.60-0.65 BO.65-0.70
4
ft^BkOB *
|
* A ^
•1 *fc ^V
t
^| •
-
C^^
"• ' /
ww
1
p
H
40. U
41.0
41.9
42.9
43.9
44.9
46.0
46.9
47.9 Ł
M
48.9 Ł
49.9
51.0
51.9
52.9
53.9
54.9
56.0
56.9
57.9
58.9
Inches
Figure A-145(ll). 6-9 feet and 180-270 degrees
A-144
-------
H(34)
0.00 -0.05 0.05 -0,10 0.10 -0.15 • 0.15 -0,20 • 0.20 -0.25 • 0.25 -0.30 0.30 -035
035-0.40 0.40-0.45 • 0.45 -0.50 • 0.50 -0,55 • 0.55 -0.60 • 0.60 -0,65 • 0.65 -0.70
(
^^^
**
tiU.O
61.0
619
62.9
6J.9
64.9
66.0
66.9
67.9 «
.c
68.9 Ł
69.9
71,0
71.9
72,9
7J.9
74.9
76.0
76.9
77,9
789
Inches
Figure A-145(12). 6-9 feet and 270-300 degrees
A-145
-------
Figure A-146(l). Pipe 146 as
Removed from Site
Figure A-146(2). Pipe 146 after Sandblasting
A-146
-------
Note that Pipe 146 was a cutout and not a complete pipe. Therefore, only partial measurements were
made and are presented next.
Table A-146(l). Scanned Pipe 146 Summary Table
Defect
Area
Hll
H12
H13
H14
H21
H22
H23
H24
Total
Volume
Loss
(in.3)
4.3
17.3
9.1
20.3
1.9
16.0
12.5
7.2
Dist
From
Spigot
(in.)
19.4
24.4
29.8
28.9
2.0
9.8
17.4
18.9
10.9
18.9
25.9
30.4
55.5
49.0
51.0
50.0
47.5
56.0
55.0
38.5
37.1
Maximum
Depths In
Defect Area
(in.)
0.1185
0.1732
0.2367
0.1618
0.4024
0.4185
0.2858
0.4126
0.2394
0.2429
0.2244
0.2591
0.1713
0.2681
0.2984
0.2539
0.2173
0.2236
0.1461
0.1902
0.1878
%
Loss
16%
23%
31%
21%
53%
55%
37%
54%
31%
32%
29%
34%
21%
33%
37%
32%
27%
28%
18%
24%
23%
Remaining
(in.)
0.6445
0.5898
0.5263
0.6012
0.3606
0.3445
0.4772
0.3504
0.5236
0.5201
0.5386
0.5039
0.6327
0.5359
0.5056
0.5501
0.5867
0.5804
0.6579
0.6138
0.6162
%
Remaining
84%
77%
69%
79%
47%
45%
63%
46%
69%
68%
71%
66%
79%
67%
63%
68%
73%
72%
82%
76%
77%
Clock
(Degrees)
84
149
191
180
273
271
269
269
311
326
331
328
89
155
155
144
138
157
206
313
335
Clock
(12hr)
2:48
4:57
6:22
5:59
9:05
9:01
8:57
8:57
10:21
10:52
11:01
10:56
2:57
5:10
5:10
4:48
4:35
5:14
6:52
10:26
11:10
A-147
-------
000-0.05 0.05-0,10 0.10-0.15 • 0.15 -020 • 0.20 -0.25 • 0.25 -0.30 0.30-0,35
0,35-0.40 0.40-0.45 BO.45-0,50 BO.50-0,55 BO.55-0.60 BO.60-0.65 BO.65-0.70
-
A
~r' m ' r"
^&^L
^
Inches
0.0
1,0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 |
9.0 -
10.0
11.0
12.0
130
14.0
15.0
16,0
17.0
18.0
19.0
Figure A-146(l). 0-3 feet and 0-90 degrees
A-148
-------
H(12)
0.00-0.05 0.05-010 0.10-0,15 BO.15-0.10 BO.20-0.15 BO.15-0.30 0.30-0.35
0,35-0.40 0.40-0,45 BO.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
-
k
.^
v
^_
4aW
11.0
11.9
22.9
23.9
24.9
26,0
269
27.9 JS
28.9-
29.9
31.0
31.9
31.9
33.9
34.9
360
36.9
37.9
38.9
*»*.H%, **,****«*»» »*,>»*^«**»***^** 4 «*
Inches
Figure A-146(2). 0-3 feet and 90-180 degrees
A-149
-------
H(13)
0.00-0.05 0.05-0,10 0.10-0.15 BO.15-0.20 BO.20-0.25 BO.25-0.30 »0.30-0,35
0.35-0.40 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
-\
•
*
hk-
k
«*-*ft**-t4,$<$^*64i o %* $ # T> ^ ^ ^ ^ ^ T> ^ ^ ^> ^ ^ # ^ # # $ # #
Inches
40.0
41.0
41.9
42.9
439
44.9
46.0
46.9
47, gj
48.9-
49.9
51.0
51.9
52.9
53.9
54.9
56.0
56.9
57.9
58,9
Figure A-146(3). 0-3 feet and 180-270 degrees
A-150
-------
0,00-0.05
0,35-0.40
0.05-0.10
0.40-0.45
0.10-0,15
O.45-0.50
H(14)
O.15-0.20
BO.50-0.55
0.20-0.25
O.SS-0.60
O.25-0.30
O.60-0.65
0.30-055
BO.65-0.70
Figure A-146(4). 0-3 feet and 270-300 degrees
A-151
-------
H(21)
000-0.05 0.05-0.10 0.10-0,15 «0.15-0.20 «0.20-0.25 BO^S-O.SO «0.30-0.35
035-0.40 0.40-0,45 BO.45-0.50 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
^|
I
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 S
.E
9.0 -
100
11.0
12.0
130
140
150
160
17.0
18.0
190
W#**++^+*»»*+M^tt+t9+f++&i>+4+*#+it+
Inches
Figure A-146(5). 3-6 feet and 0-90 degrees
A-152
-------
H(22)
000-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 BO.20-0.25 10.25-0.30 «0.30-0.35
0.35-040 0.40-0.45 BO.45-0.50 BO.50-0.55 BO.55-060 10.60-0.65 10.65-0.70
$
BE 20.0
• 21.0
1 21.9
• 22.9
—
'I*
« T
^k
^feMBBBJ _|^B^
ft ' 1 /I
23.9
24.9
26.0
26.9
27.9 Ł
.c
28.9 -Ł
29.9
31.0
31.9
32.9
33.9
J M.9
*
Inches
36.0
36.9
37.9
38.9
Figure A-146(6). 3-6 feet and 90-180 degrees
A-153
-------
H(23)
000-0.05 0.05-0.10 0.10-0,15 BO.15-0.20 BO.20-0.25 BO.25-0.30 '0.30-0.35
0.35-040 0.40-0.45 BO.45-050 BO.50-0.55 BO.55-0.60 BO.60-0.65 BO.65-0.70
/
—
A ^
W
1
•'• f
*-w i V-*
* u*
40.0
41.0
41.9
42.9
43.9
449
460
46.9
479 -j
48.9 -
49.9
51.0
51.9
52.9
53.9
549
56.0
569
57.9
58.9
Inches
Figure A-146(7). 3-6 feet and 180-270 degrees
A-154
-------
H(24)
000-0.05 0.05-0.10 0.10-0.15 BO.15-0.20 BO.20-0.25 »0.25-0.30 0.30-0.35
0.35-0.40 0.40-0.45 BO.45-0,50 BO.50-0.55 BO.55-0.60 10.60-0.65 10.65-0.70
^b
^HH
^k ^^^^^^^* ^ ^^L
%^m 1^^
•••
^*
*
"->.
>
f
60.0
61.0
61.9
62.9
63.9
64.9
66.0
66.9
or
67.9 |
68.9
69.9
71.0
71.9
72.9
73.9
74.9
76.0
76.9
~i~i n
Inches
Figure A-146(8). 3-6 feet and 270-300 degrees
A-155
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
Figure A-166(l). Pipe 166 as Removed from Site
-------
0-3 ft
3-6 ft
6-9 ft
9-12 ft
90°
180°
270°
Figure A-166(2). Pipe 166 after Sandblasting
-------
Table A-166(l). Wall Thickness of Cast Iron at Spigot with Caliper
Pipe Number
166
Wall Thickness (inches)
75°
0.829
150°
0.834
180°
0.833
270°
0.842
Table A-166(2). Wall Thickness Cast Iron Using an Ultrasonic Gauge (inches)
Pipe Number
166
Average
Standard Deviation
Minimum
Maximum
Repeat Center Cell
Wall Thickness
Spigot
Caliper
0.832
0.830
0.836
0.833
0.003
0.830
0.836
-
UT
0.814
0.822
0.808
0.817
0.815
0.819
0.819
0.819
0.816
0.820
0.004
0.808
0.822
0.814
Center
UT
0.830
0.832
0.827
0.829
0.834
0.822
0.829
0.831
0.828
0.831
0.003
0.822
0.834
0.828
Bell
UT
0.781
0.776
0.791
0.790
0.769
0.793
0.804
0.788
0.812
0.798
0.014
0.769
0.812
0.790
Table A-166(3). Outer Diameter Measurement Using a pi Tape
Pipe Number
166
Outer Diameter
Spigot
25.900
Center
25.800
Bell
25.792
Table
A-166(4). Wall Thickness of Cement Liner at Spigot with Caliper
Measurement (Inches)
Cast Iron
Cast Iron & Cement Liner
Cement Liner
75°
0.829
1.152
0.323
150°
0.834
1.078
0.244
180°
0.833
1.056
0.223
270°
0.842
1.015
0.173
Table A-166(5). Pipe 166 Summary Table
Defect Area
166-095-113-015-043
166-080-156-026-055
166-026-092-038-058
Total
Volume
Loss
(in.3)
5.5
12.6
9.5
Dist
From
Bell
(in.)
45.0
43.0
67.5
68.5
65.0
111.0
101.5
101.5
113.0
Maximum
Depths In
Defect
Area (in.)
0.260
0.223
0.291
0.246
0.206
0.256
0.196
0.189
0.166
%
Loss
33%
29%
37%
31%
26%
33%
25%
24%
21%
Remaining
(in.)
0.52
0.56
0.49
0.53
0.57
0.52
0.58
0.59
0.61
%
Remaining
67%
71%
63%
69%
74%
67%
75%
76%
79%
Clock
(Degrees)
211
216
162
155
151
228
230
248
237
Clock
(12hr)
7:02
7:12
5:24
5:10
5:02
7:36
7:40
8:16
7:54
A-158
-------
166-095-113-015-043
0-0.05 0.05-0.1 0.1-0.15 • 0.15-0.2 • 0.2-0.25 • 0.25-0.?, 03-0.35 0.35-0.4 0.4-0.45 • 0.45-0.5 • 0.5-0.55 • 0.55-0.6 • 0.6-0.65 • 0.65-0.7
•JP ^
JM *•
^^^^^^^^^L
4
Inches
0
1
2
B
4
5
HI
X
c
6
7
8
9
10
Figure A-166(l). Pipe 166, area 166-095-113-015-043
A-159
-------
n
n
*
V
a
p
»«
*
„
*
1 fco*° C"(j(?'|So" Oit-OSr
i % ^ ^ j7_\\% i » * nnn*'tn itfiuttttitNtf .tnM tt»ti«*iwi*iis»**ii»i«*fifiifi»'r»
-------
Appendix B
the Pressure Pipe
Inspection Company
FIELD DEMONSTRATION OF NONDESTRUCTIVE
PIPELINE CONDITION ASSESSMENT
OF METALLIC WATER PIPE USING
SAHARA™ LEAK DETECTION/ VIDEO/ WALL THICKNESS TESTING
& PIPEDIVER™ RFEC TESTING
JULY 2009
-------
TABLE OF CONTENTS
1. EXECUTIVE SUMMARY 1
2. PROJECT BACKGROUND 2
2.1 Project Background 2
2.2 Purpose of Inspection 4
2.3 Test Pipe Line Description 4
3. SAHARA TECHNOLOGY 5
3.1 Background and Theory 5
3.2 Sahara Tests 10
3.3 Sahara Results 11
4. PIPEDIVER TECHNOLOGY 1 7
4.1 PipeDiver Background and Theory 1 7
4.2 PipeDiver Testing 20
4.3 PipeDiver Results 22
5. SUMMARY 29
5.1 Combined Test Results 29
5.2 Inspection Conclusions 31
5.3 Advantages and Limitations 32
5.4 Future Developments 33
6. PHOTOGRAPHS 34
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1. EXECUTIVE SUMMARY
Over the course of July 1 3th to 29th, 2009, the Pressure Pipe Inspection Company (PPIC)
performed non-destructive condition assessment of a cast iron main using two non-
disruptive inspection platforms, Sahara and PipeDiver. The assessment was conducted
on a 2057 foot long, 24 inch diameter, cast iron section of the Westport Rd.
Transmission Main between Pit 1 (Launch/Insertion Pit) and Pit 3 (Receive/Extraction
Pit).
PPIC used its patented Sahara Technology, including Sahara Leak Detection, Sahara
Video, and Sahara Wall Thickness Testing. In addition, PPIC conducted a Remote Field
Eddy Current (RFEC) pilot test for metallic pipe wall condition assessment using the
PipeDiver inspection platform. Both technologies are non-disruptive and allow the
pipeline to remain in service during the inspection. PPIC's inspections are part of a
study conducted by the U.S. Environment Protection Agency (EPA).
Sahara Leak Detection identified six natural leaks and an air pocket within the inspected
area and detected all simulated leaks. Sahara Video identified several corrosion spots,
outlets, and air pockets within the pipeline. Analysis of the Sahara Wall Thickness
Testing data revealed several areas of suspected wall thickness loss. PipeDiver RFEC
testing was performed over the full scope (2057 ft) under live conditions and identified
41 pipe sections with anomalous data signals. Verification and further calibration are
recommended to confirm the exact nature of these anomalies and help in further
refinement of the PipeDiver analysis procedures. Each individual technology provides a
particular service but their combined results provide a complete overall condition
assessment of the pipeline.
2.1 Project Background
The U.S. Environmental Protection Agency (EPA) contracted the Battelle Memorial
Institute (BMI) to demonstrate selected innovative leak detection/location and
structural condition assessment technologies. This study emphasizes the need for non-
invasive, non-destructive, "inexpensive" techniques to help utilities assess the
condition of their lines to allow them to make good decisions regarding capital
replacements, rehabilitation or monitoring of their pipe infrastructure.
The Pressure Pipe Inspection Company (PPIC) is one of the several companies
contracted by BMI to demonstrate their non-destructive condition assessment
techniques of metallic pipes. These include PPIC's patented Sahara Leak Detection,
Sahara Video, Sahara Wall Thickness Testing and PipeDiver RFEC Testing. All these
technologies are invasive, requiring internal pipe access, but are non-disruptive in
nature and are performed while the pipeline is in service. Each technology has its own
set of advantages and limitations which allows utilities an option on which inspection
technique best fits their needs and expectations. Additionally, multiple techniques can
be applied to a single pipeline to provide successive levels of detail about the pipe
condition.
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The condition assessment technologies deployed by PPIC are at various stages of
commercial deployment. The Sahara leak detection system, for example, has been
successfully used commercially worldwide for over 1 0 years. While PipeDiver has been
successfully used in PCCP for live condition assessment, PipeDiver RFEC for metallic
pipes is still undergoing development and in the process of becoming a commercially
available service.
The Westport Rd. Transmission Main is a 24 inch diameter cast iron pipe that has been
taken out of service. EPA has acquired this pipeline for a non-destructive condition
assessment study, which PPIC is a part of. A map showing the approximate location of
the inspected pipeline is shown in Figure 2.1.
Westport Road
Transmission Main
Additional features were created along the inspection scope for various test
procedures. These features are listed in Table 2.1 (distances provided by the Battelle
Memorial Institute).
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Table 2.1 Feature List
Feature
Pit 1 (Launch/Insertion Pit)
Pit A
Pit B
Pit 4
PitC
Pit 2
Pit D
Pit E
Pit 5
Pit F
Pit 3 (Receive/Extraction Pit)
Distance from Pit 1 (ft)
0
250
510
581
809
1080
1173
1439
1580
1750
2057
STA
160+55
163+05
165+65
166+36
168+64
171+35
172+28
1 74+94
176+35
178+05*
181+12
*STAs are in relation to fire hydrant STA of 178+05 and distances from Pit 1 (hydrant listed in
same location as Pit F from Battelle chart).
2.2 Purpose of Inspection
The purpose of this inspection is to demonstrate PPIC's various non-destructive
condition assessment services on metallic pipe which, together, provide an overall
condition assessment of the pipeline. These services include:
• A visual inspection of the inside of the pipeline
• Identifying and quantifying the presence of leaks
• A pipe wall assessment including wall thickness loss and irregularities
All services are performed using PPIC's patented Sahara technology platform and the
PipeDiver platform, both of which are live inspection platforms that operate while the
pipeline is in service.
2.3 Test Pipe Line Description
The non-destructive condition assessment inspections of the Westport Rd.
Transmission Main were conducted from July 1 3th to 29th, 2009. The test details are
summarized in Table 2.2.
Table 2.2 Test Summary
Pipeline
Inspection Dates
Total Distance
Westport Rd. Transmission Main
July 13th to 29th, 2009
2057 feet
In order to produce sufficient flow in the pipeline for inspection purposes a 1 2 inch tee
past the extraction point was used to temporarily create flow by diverting water into a
nearby storm drain.
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Figure 2.2 Pipeline Flow Setup
Insertion
Point
^~ \
Flow—fr- )
Extraction
Point
24" Cast Iron
Storm Sewer
Diversion
_Siflirn Sewer
The flow amount and duration was limited by the capacity of the storm sewer. In the
event of rain, the storm sewer's capacity would be reduced or eliminated entirely
which, in turn, would likewise affect the flow available in the 24 inch cast iron line.
3. SAHARA TECHNOLOGY
3.1 Background and Theory
3.1.1 Sahara Platform
The first tool designed for live inspection of large diameter water mains, the Sahara
Pipeline Inspection System, is capable of detecting leaks, pockets of trapped gas, and
structural defects in large mains. Sahara is a critical component of condition
assessment and water loss management programs for utilities around the world. The
unique Sahara platform allows adaption of multiple technologies such as leak
detection, video inspection, and wall thickness assessment.
Advantages to the Sahara inspection system include:
• No disruption to pipeline service
• Use existing 2 inch (50 mm) taps
• A tethered system allows complete control of the sensor's position along the
pipe and ensures no lost sensors
• Accurate surface tracking to map pipelines and leak locations
• Usable in mains of all material types, as small as 4 inches in diameter, and with
pressures up to 200 PSI
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3.1.2 Sahara Leak Detection
The Sahara system is a non-destructive condition assessment technology that pinpoints
the location and estimates the magnitude of leaks in large diameter, 1 2 inch and
above, water transmission mains of all construction types. With over 1,000 miles
(1,600 km) of inspections Sahara Leak Detection has proven sensitive to leaks as small
as 0.005 gal/min (located in 72" PCCP at 87 psi). Leaks are located above ground in
real-time and marked to within 1 foot of accuracy.
In operation, the system is inserted into a live pipeline through any tap that is at least
2 inches in diameter. Carried by the flow of water, the tethered sensor head can then
travel through the pipe for distances up to 6,000 feet per survey detecting each leak as
it is found. The leak's position is then located and marked on the above ground
surface facilitating subsequent repairs.
An electronics processing unit with audio and visual output is used for data analysis. A
leak produces a distinctive acoustic signal which is recorded by the sensor and
processed into a visual signal. The visual signal is then analyzed along with the audio
signal to quantify the leak.
In no flow situations a second tethering line (mule tape) can be used to pull the
hydrophone through a pipeline.
Figure 3.1 Sahara Inspection System
CibVt Drum
(In O«tnf*ct»m Bath)
Locating Tool Signalt
Processing Unrt
(Video / Audio)
Tip
One Chut*
An operator stands by at the controller station to control hydrophone deployment
and listen to the hydrophone signal for leaks in real time. Once a leak is detected
the hydrophone can pass over the leak multiple times to classify and pinpoint the
leak. A second operator travels the pipeline above ground using a tool to detect the
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exact location of the sensor. When a leak is detected this operator will make a
mark on the ground identifying the location and record a GPS point for reference.
The capable survey length of the Sahara system is limited not only by the amount
of available cable, usually 1.2 miles (2 km), but also by the pipeline geometry
(horizontal/vertical elbows and bends), the pipeline flow rate, and the internal pipe
conditions.
Sahara Leak Detection is a proven technique in identifying the smallest leaks in
pipelines. Figure 3.2 below depicts some verified leaks and the corresponding
pressures the leaks were detected at.
Figure 3.2 Sahara Verified Leaks
Sahara Verified Sensitivity to Small Leaks
-Estimated Seepage Threshold
Sahara Verified Small Leaks
10 20 30 40 50 60 70
90 100 110 120 130 140 150 160 170
Pressure (PSI)
Calibration is performed by testing each hydrophone and comparing it to a
standard frequency response. The Sahara hydrophone has sensitivity to leaks as
small as 0.005 gal/min (detected on 48" PCCP pipeline at 87 psi).
Data is interpreted and analyzed in real time by on screen spectrogram and audio
listening. Using dual analysis methods provides high accuracy and can clearly
distinguish leaks from ambient noise.
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Factors such as low water pressure, electrical noise, air pockets, and external
ambient noise can all affect the real time analysis of the sensor signal. During the
inspection, some leaks were masked by external factors and required post analysis
to detect the leaks.
3.1.3 Sahara Video Description
Sahara Video provides real time, in-service CCTV inspection through a 2 inch or larger
tap. Real-time video inspection enables visual inspection of features including:
• Cement and other liners
• Internal corrosion and tuberculation assessments
• Valve location and inspection _^^^^^^^^^^^^^^^^^^^^^^^1_
• Debris and blockages
The Sahara video system utilizes the same
control system and tethered cable as the
Sahara Leak Detection system but the
hydrophone sensor head is switched to a
video camera head that traverses a pipeline
after begin inserted through a standard 2
inch tap. A drogue (parachute) is attached
just behind the camera which captures
water flow and carries the camera and cable
down the pipeline.
An operator stands by at the controller
station to control camera deployment and
views the video output in real time. A second operator traverses the pipeline above
ground using a tool to detect the exact location of the camera. When an item of
interest is seen the second operator will make a mark on the ground identifying the
location and record a GPS point for reference.
Like the Sahara leak detection, the Sahara video system has a limited survey length
from the pipeline configuration and available flow rate. One circumstance or factor
affecting accuracy is video clarity. Video image becomes less clear in larger
diameter pipes, due to diffuse lighting and reduced field of view, and unclear
water. To calibrate the video system, each video camera is tested and compared to
a standard frequency response. Video is interpreted and analyzed in real time, but
also recorded for future examination.
3.1.4 Sahara Wall Thickness Testing
Sahara Wall Thickness Testing can be performed in conjunction with a Sahara Leak
Detection inspection. Testing requires a secondary acoustic sensor, either an
external accelerometer attached to the pipe surface or an additional internal
hydrophone. Reference signals (e.g., test strikes at access points or sounds
produced by a speaker) are generated within the pipe for testing.
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The sound waves propagate through the pipeline in a specific manner bouncing
repeatedly off of the pipe walls. As the sound wave travels in this manner they
gather information about the pipe wall. By measuring the speed of sound multiple
times in a section of pipe the average wall thickness can be deduced. By using
multiple acoustic sensors separated by a known distance time of arrival data from
the reference signal can be used to calculate the speed of sound within the pipe
and thus the average wall thickness.
Accelerometer
and Acoustic Unit
for Reference
Reference
Signal
Sahara^
Hydrophone"
Time Delay
The tethered control of the Sahara system allows the hydrophone to stop at precise
locations for each interval. Time of arrival data is then used to calculate the
average wall thickness over each interval. Since the wall thickness average intervals
are defined by hydrophone location there are infinite interval possibilities limited
only by the amount of time and resources available for the inspection.
Sahara wall thickness has the same limitations on survey as the leak detection
system. Also like the leak detection, air pockets can significantly interfere with the
wall thickness measurements as they affect the acoustic signal propagation. It is
important to note that the wall thickness measurements resulting from this
technique are only an average thickness over a range of pipes
Average wall thickness results need detailed pipe information and fluid parameters for
calculations. Current testing procedure requires an access (i.e. hydrant, flange, or
exposed pipe surface) a minimum of every 400 feet to generate reference acoustic
signals.
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Some factors affecting wall thickness accuracy include:
• Distance of a given section (the shorter, the more uncertain)
• Distance readings of the sections
• Accuracy of the pipeline and fluid parameters
• Unknown pipe features
• Rehabilitation, or large stationary air pockets
However, many pipeline related factors can be eliminated through a repeat inspection.
Before each Sahara Wall Thickness test adequate calibration and preparation is performed
to ensure high quality. This includes:
• Calibration of Sahara sensor's sensitivity and distance reading
• Calibration of reference acoustic sensor for synchronization with Sahara
• Repeatability tests
A relative result is obtained based on all calculated results in every 30 foot interval. A
nominal pipe wall thickness would be calculated from a group of intervals that shows
similar wall thickness results (< 2% difference from the mean), and the result of other
portions would show the wall thickness change ratio to this nominal value. This relative
result is provided instead of calculated wall thickness to eliminate and minimize possible
uncertainties introduced by composite pipe material and alterable fluid parameters.
3.2 Sahara Tests
3.2.1 Sahara Test Schedule
A total of five Sahara insertions were performed from July 1 3th to July 1 7th for all the
different inspection technologies. The Sahara video inspection was performed first, on July
1 3th, to inspect the inside of the pipeline. This inspection identifies potential obstacles for
other internal inspections as well as internal corrosion and air pockets. The Sahara video
head was inserted into Pit 1 and traversed the line using the pipeline flow. After reaching
Pit 3 the video head was then retracted and taken out of Pit 1.
Sahara Leak Detection was performed on July 14th, 1 5th, and 1 7th. Three full surveys of the
pipeline were performed to test different arrangements of simulated leaks and perform a
repeatability survey under varying conditions. Like the Sahara video head, the Sahara
sensor head was inserted and retracted out of Pit 1. The leak detection survey was
conducted during the deployment and retrieval of the sensor through the pipeline. On July
1 5th a thunderstorm required that flow in the pipeline be stopped due to reduced storm
sewer capacity and the survey ended before completion.
Sahara Wall Thickness Testing was performed on July 1 5th and 16th in conjunction with
Sahara Leak Detection. The Sahara sensor head was inserted into Pit 1 and secondary
external sensors were installed at Pits A, C, E, and 3. Multiple test reference signals were
generated at each of the pits to conduct the wall thickness measurements.
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Table 3.1 Insertion Details
Date
July 13th
July 14th
July 15th
July 16th
July 17th
Insertion
Point
Pit 1
Pit 1
Pit 1
Pit 1
Pit 1
End Point
Pit 3
Pit 3
After Pit F
Before Pit 3
Pit 3
Survey
Length (ft)
2057
2050
1797
1984
2050
Flow
Direction
East
East
East
East
East
Description
Video
Leak Detection & Leak
Simulations
Leak Simulations
Wall Thickness
Repeat Leak Detection,
Simulations & Wall
Thickness
3.3 Sahara Results
3.3.1 Sahara Video Survey Results
The Sahara Video inspection of Westport Rd. Transmission Main successfully identified
several significant observations. Details of the observations are presented in Table 3.2,
specifically the direction and distance the observation was found from the insertion point
(Pit 1).
Table 3.2 Observation Details
#
1
2
3
4
5
6
7
8
9
10
11
12
Description
Outlet
Outlet
Air pocket
Large air pocket
Outlet
Large air pocket
Outlet
Corrosion
Outlet
Large area of corrosion
Outlet
Outlet
Estimated Distance
from
Pit 1 (ft)
154
677
886
1024
1061
1237
1552
1565
1628
1637
1755
1946
Direction from
Insertion
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Potential
Correlated Pipe
Feature
Pit 2 (1080ft)
Pit 5 (1 580 ft)
Pit F (1750ft)
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Many additional air pockets, ranging from small to large in size, were discovered
during the video inspection. Both air pockets and wall corrosion could be clearly
distinguished in the video inspection.
Figure 3.5 Sahara Video Examples
Close-Up of a Joint Gap at the Insertion
Example of an cutlet
Extraction Point 24x24x1 2" Tee
Example of Large Air Pocket
3.3.2 Sahara Leak Detection Results
The Sahara Leak Detection of Westport Rd. Transmission Main successfully identified 6
natural leaks and 14 simulated leaks. Details of the natural leaks are presented in
Table 3.3, specifically the direction and distance the leak was found from the insertion
point. The most accurate method to locate a leak is from the mark created above
ground by the inspection team during the survey.
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Table 3.3 Natural Leak and Air Pocket Details
Leak*
1
2
3
4
5
-
6
7
Feature
Very Small Leak
Very Small Leak
Large Leak
Very Small
Small Leak
Large Air Pocket
Very Small Leak
Small Leak
~Distance from Pit 1
(ft)
50
194
338
558
638
900
1696
1906
Direction from
Insertion Point
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Downstream
Simulated leaks were rearranged several times. Each simulated leak was a combination
of one to three consecutive leaks, from orifices of different sizes, arranged one to two
feet apart. When individual leaks are at close proximity, the leak signatures combine
and do not necessarily differentiate. Details of the detected simulated leaks are
presented in Table 3.4, specifically the arrangement number, direction, and location.
The following screen capture is from the simulated leak recording located at pit 4,
from 541 ft to 607 ft. A small peak around 558ft shows a very small natural leak.
Signatures of both leaks are combined and are difficult to report in real-time.
Peak of
simulated
leak (578 ft)
Very small
leak (558 ft)
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Table 3.4 Simulated Leak Details
Arrangement #
1*
1
2
2
2*
3
3
3
4
4
4*
5
6
7
Date
July 14th
July 14th
July 14th
July 14th
July 14th
July 1 5th
July 1 5th
July 15th
July 15th
July 15th
July 1 5th
July 1 7th
July 17th
July 1 7th
Leak Classification
Very small
Small
Large
Very small
Very small
Small
Small
Medium
Medium
Small
Very small
Small
Very small
Very small
Location
Pit 4
Pit 2
Pit 5
Pit 2
Pit 4
Pit 4
Pit 2
Pit 5
Pit 5
Pit 2
Pit 4
Pit 4
Pit 4
Pit 4
These leaks required post analysis. Leak signal could be masked by air pockets, water discharge,
and/or electrical issues.
After recording signals from inspections, PPIC used post analysis to filter noise and
improve leak detection. The signals were filtered and show that post analysis can
make leak signals more distinguishable.
Figure 3.7 Post Processed Leak
After initial inspection, the Sahara hydrophone was tested on-site and found to have
technical problems. Subsequently, that particular hydrophone was replaced with an
alternate hydrophone confirmed to pass quality control/assurance tests. Two of the
very small leaks were re-simulated and were detected on-site using the new
hydrophone. As a precaution, all Sahara hydrophones are tested onsite following
standard QC/QA procedures prior to inspection.
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Leak classification is mainly based on the distance away from a leak that the leak can
be detected. In pipes of diameter 24" to 60", leak classification is believed to represent
leak sizes shown in Table 3.5.
Table 3.5 Leak Classification
Classification
Very small
Small
Medium
Large
Very Large
Distance
detected
0-2 m
2 - 5 m
5 - 15 m
15 - 50 m
50+ m
Approx. Measured Size
Min m3/hr
0
0.4
4
17
29
Max m3/hr
0.4
4
17
29
42
Median m3/hr
0.2
2
10
23
35
Median gpm
0.88
8.8
44
101
154
Figure 3.8 Sahara Video Examples
Signal Genetated by a Small Leak
Signal Generated by a Medium Leak
Signal Generated by a Large Leak
Signal Generated by the Discharge Line
3.3.3 Sahara Wall Thickness Results
The Sahara Wall Thickness Assessment of Westport Rd. Transmission Main successfully
identified specific areas of wall thickness loss. Details of the wall thickness loss are
presented in Table 3.6, specifically the pipeline interval and average result over that
interval.
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Table 3.6 Thickness Details
Distance from Pit 1 (ft)
0-17
17-33
33-66
66-98
98-131
131-164
164-197
197-230
230-295
295-328
328-361
361-394
394-426
426-459
459-492
492-525
525-558
558-590
590-623
623-656
656-689
689-722
722-754
754-787
787-1640
1640-1673
1673-1706
1706-1738
1738-1771
1771-1804
1804-1837
1837-1870
1870-1902
1902-1935
1935-2057
Average Wall Thickness Loss Ratio (%)
N/A
< 15%
Nominal
< 15%
Nominal
Nominal
Nominal
1 5 - 30%
N/A
> 30%
>30%
>30%
Nominal
< 15%
1 5 - 30%
< 15%
< 15%
< 15%
Nominal
< 15%
Nominal
1 5 - 30%
1 5 - 30%
Nominal
N/A
Nominal
Nominal
< 15%
< 15%
< 15%
< 15%
Nominal
Nominal
1 5 - 30%
N/A
Pipeline intervals with an average wall thickness loss of less than 2% are listed as
nominal. The average wall thickness loss ratio is in relation to the nominal mean value.
The section from 295 to 328 feet shows the highest wall thickness loss. Increased
error margin in the section from 230 to 295 feet is due to the close proximity of
internal and external sensors. Subsequently, a wall thickness loss ratio cannot be
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calculated for this interval. From 787 to 1 640 feet a wall thickness ratio cannot be
calculated due to presence of large air pockets and/or the proximity of sensors. The
pipeline discharge masked acoustic activity after 1 935 feet.
4. PIPEDIVERTECHNOLOGY
4.1 PipeDiver Background and Theory
4.1.1 PipeDiver Platform
The PipeDiver system has been specifically designed for use in pipelines that are live or
can not be taken out of service due to lack of redundancy or operational constraints.
PipeDiver provides accurate condition assessment of critical infrastructure, specifically
detecting prestressing wire breaks in Prestressed Concrete Cylinder Pipe (PCCP). This
solution offers significant cost savings as the pipeline remains in service eliminating
the need for service shutdown and dewatering. The system has been proven effective
for the inspection of live PCCP lines from the verification of its pilot inspection of 30
inch diameter pipe in Halifax in 2007.
PipeDiver is a non-tethered, free swimming inspection platform for in-service water
mains. The inspection vehicle allows inspection of pipelines from 24 inch in diameter
and larger through two 1 2 inch diameter taps installed on the pipeline, one at each
end of the inspection region. Alternatively, reservoirs or open channels can be used as
insertion and extraction points.
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Figure 4.2 PipeDiver Retrieval Arm
For a standard launch the insertion tube containing the PipeDiver vehicle is attached to
the 1 2 inch tap before being filled with water, pressure equalized, and opened to the
pipeline. The internal insertion piston pushes the PipeDiver vehicle into the pipe and,
once fully in the pipe, the vehicle is released and begins to travel with the flow. For a
standard retrieval, once the PipeDiver vehicle reaches the extraction side, a robotic
claw and net which blocks the entire pipe
diameter grabs the front of the vehicle and
secures it before pulling up out of the pipe
and into the retrieval tube.
The PipeDiver vehicle travels at
approximately 90% of the pipeline's flow
rate, the neutrally buoyant inspection
vehicle can run for up to 30 hours in a
single insertion. Flexible fins are used to
center the tool within the pipe and provide
propulsion. Its flexible design ensures that
PipeDiver can navigate through most
butterfly valves and bends in the pipeline
while travelling long distances.
inspection
Extraction
Catch Point
Catch Point BU :
Electronics
Module
Battery
Module
Transmitter
Module
The PipeDiver inspection tool is inserted into a live main through a 1 2" tap directly on
top of the main, then retrieved using a robotic arm inside a similar chamber at the end
of each inspection run. The modular system includes an electronics module, battery
module, and transmitter module for above ground tracking.
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4.1.2 PipeDiver RFEC Testing Description
The Remote Field Eddy Current (RFEC) is a proven technique for non-destructive
inspection of metallic pipelines. The PipeDiver is similarly a proven platform for
insertion into live pipelines and inspection using the RFTC technique. While the RFTC
and RFEC techniques are similar in nature there are several challenges involved in
modifying the PipeDiver platform to support RFEC technology:
• Detectors have to be closer to the wall
• More detectors are required
• Signal levels are significantly lower than RFTC
• Exciter to detector axial separation is much larger
To modify the PipeDiver for a RFEC inspection the exciter coil was moved from the rear
body near the center detector into the first body to achieve the minimum 1.5-2 pipe
diameters required for the RFEC technique. Six additional detector coils were added to
petals at the rear of the vehicle to provide increased sensitivity to wall thickness loss
while still permitting the the vehicle to be inserted and extracted through a 1 2 inch
diameter opening.
Figure 4.4 PipeDiver Coil Locations
Coil Setup for the RFTC Inspection Technique
Coil Setup for the RFEC Inspection Technique
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The future challenges for PipeDiver RFEC development will be to increase the number
of detectors close to the pipe wall, especially for larger diameter pipes, to increase the
resolution and accuracy of the wall thickness measurements.
Common factors affecting accuracy for any RFEC system include the pipeline
design and composition (i.e. metallic variations), inspection tool calibration,
inspection tool riding quality, the type and position of the defect. Calibration
details include running standard RFEC tests (with various coil separation/frequency
setups) on pipes with a set of defects (size and shape) to achieve the best detection
and sensitivity.
4.2 PipeDiver Testing
4.2.1 PipeDiver Inspections
PipeDiver RFEC Testing and trials were performed from July 21st to July 29th and four
successful runs were completed. This was a pilot inspection using the RFEC technique
in metallic pipe to obtain additional field data for analysis.
Table 4.1 shows the details of actual inspections, specifically the survey length and
description of the inspection.
Table 4.1 Insertion Details
Date
July 23rd
July 24th
July 27th
July 28th
Insertion
Point
Pit 1
Pit 1
Pit 1
Pit 1
End Point
Pit 3
Pit 3
Pit 3
Pit 3
Survey
Length
(ft)
2057
2057
2057
2057
Flow Direction
and Speed
East, 1 ft/sec
East, 0.5 ft/sec
East, 1 ft/sec
East, 1 ft/sec
Description
PipeDiver RFEC
PipeDiver RFEC
PipeDiver RFEC
PipeDiver RFEC
4.2.2 PipeDiver Insertion Issue
On July 21st, the first insertion attempt, the PipeDiver vehicle became stuck during the
insertion process and that day's inspection had to be stopped and the vehicle retrieved
from the pipe. An investigation of the issue with the help of Sahara video (Figure 4.5
and 4.6) led to the conclusion that the front of the PipeDiver has become stuck in a
large, unfilled gap estimated to be 3 to 4 inches in width between joints just
downstream of the insertion point.
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Figure 4.5 Sahara Video of the Joint Gap
Estimate
Height
= 1"
Estimated
Axial Distance
= 3-4"
An alternate insertion process was designed and implemented and the following four
insertions were successful.
Figure 4.6 PipeDiver Insertion Schematic
PipeDiver
Insertion Tube
12" Ho: Tap
Original PipeDiver Design
Using Standard Hot Tap
24x24x12" Tee
24" Cast Iror*
Westport Rd. 24" Cast Iron Pipeline
Using a 24x24x12" Tee
PipeDiver is designed for live inspections using standard accesses including 1 2 inch
diameter hot taps, tees with minimum joint gaps, or similar features. For certain
accesses such as tees with large unfilled joint gaps or accesses with unknown internal
conditions Sahara Video is recommended to identify the exact layout of the insertion
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point. The insertion design and process can then be modified for a successful insertion
if required.
4.3 PipeDiver Results
4.3.1 PipeDiver RFEC Result Description
PipeDiver RFEC Testing was conducted as a pilot project to obtain field data for
analysis. Data was analyzed and characterized based on basic pattern recognition
from simple models of wall thickness variations.
Remote Field Eddy Current works on the basic theory that when a time harmonic
magnetic field is generated inside a metallic pipe it has two paths from the exciter to
detector coils (see Figure 4.7).
Figure 4.7 RFEC Signal Paths
The direct path remains inside the pipe and couples the coils directly while the remote
path remains outside of the pipe as long as possible. When the exciter-detector coil
separation exceeds 1.5 pipe diameters the signal from the remote field significantly
dominates the total signal received at the detector. Since the remote field path has
passed twice through the pipe wall any variation in magnetic wall properties including
wall thickness, conductivity, and magnetic permeability will result in a change in the
detector signal.
4.3.2 PipeDiver RFEC Results Overview
Table 4.2 lists the location of pipe sections PipeDiver data characterized as anomalous
and their distance from Pit 1.
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Table 4.2 PipeDiver Anomalous Pipes
Distance from Pit 1 (ft)
Start
216
264
276
324
360
384
444
504
516
576
612
864
936
948
1044
1056
1176
1212
1284
1308
1332
1356
1368
1416
1452
1512
1584
1608
1620
1644
1656
1704
1740
1752
1788
1812
1860
1872
1908
1956
1992
End
228
276
288
336
372
396
456
516
528
588
624
876
948
960
1056
1068
1188
1224
1296
1320
1344
1368
1380
1428
1464
1524
1596
1620
1632
1656
1668
1716
1752
1764
1800
1824
1872
1884
1920
1968
2004
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4.3.3 PipeDiver RFEC Pipe Signals
Figure 4.8 below shows the center detector signal amplitude (red) and phase (green)
from the July 23rd inspection of a section of pipeline which is classified as containing
normal pipes.
Figure 4.8 PipeDiver RFEC Nominal Pipes
240
3BO
m
• i
320
340
360
380
400
Each joint is composed of a double signal due to the remote field effect. One signal is
from the exciter passing the joint and one from the detector passing. The first signal in
a joint is generally higher and longer due to the relative lengths of the pipe and axial
exciter-detector coil separation, 1 2 and 5.5 ft respectively (Figure 4.9).
Figure 4.9 PipeDiver RFEC Joint Detection
Pipe 136
1120
114O 116O
Time (seconds). July 23rd
118O
120G
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Figure 4.10 below shows an example of several pipes classified as anomalous from
their RFEC signal. The second half of pipe 79 and the first half of pipe 80 show an
anomalous signal which could be due to a wall thickness loss from pipe 80. The entire
signal in pipe 81 differs largely from the nominal pipe signal and could be due to wall
thickness loss or from an unidentified pipe feature.
Figure 4.10 PipeDiver RFEC Anomalous Pipes
1400 1420
1440
1460 HBO
I5DO
1520 1540
I5EO
The PipeDiver configuration used on the July 23rd and 28th inspections were almost
identical which allows a direct comparison of the signals. Figure 4.11 below shows a
comparison for a section of four pipes from the center detector. One of the objectives
of this inspection was to verify the validity of the PipeDiver RFEC technology by
performing such repeatability tests. The results from the multiple PipeDiver scans
show good repeatability.
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A known feature from the pipeline that is readily seen in the PipeDiver RFEC data is the
hydrant outlet that is located near Pit F (Figure 4.1 2). While the signal is relatively small
as compared to the joint signal it can be distinguished by having a double signal
occurring the exact distance as the PipeDiver's detector-exciter coil separation
distance.
Figure 4.11 RFEC Repeatability
0)
gi
CO
Pipe 133
Pi pel 36
1060
1070
1080
1090
1100
1110
Time (seconds), July 23rd
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Figure 4.12 PipeDiver RFEC Hydrant Signal
Q.
<
"ro
c
O>
CO
2960
2980 3000
Time (seconds), July 23rd
3020
Four new defects were machined into Pit F on July 28th (Figure 4.13). By
comparing the RFEC signals from the data before and after the defects were
created we have the best possible chance of seeing this relatively small amount of
wall thickness loss in the data (Figure 4.14).
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Figure 4.13 New Pit F Defects
Figure 4.14 Comparing RFEC Data Before and After Defects
Befci
Aft.
fore Pit F Defects \
er Pit F Defects
2940
2950 2960
Time (seconds). July 23rd
2970
29SO
The PipeDiver RFEC results show good repeatability between multiple scans using the
same configuration which validate it as a non-destructive inspection technique. The
RFEC data clearly shows joint signals, known features and anomalous signals which
may be potentially due to wall thickness loss. Further verification and calibration is
needed to confirm the nature of these anomalous signals.
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5. SUMMARY
5.1 Combined Test Results
The following figure 5.1 combines all results including Sahara Leak Detection, Sahara
Video, Sahara Wall Thickness, and PipeDiver RFEC, showing their relative locations
along the pipeline.
^^^^^H Figure 5.1 Combined Results ^^^^^H
Nominal Wall Thickness A Leak Positions
-- 15% Wall Loss + Video Features
^•••i 16-30% Wall Loss X PipeDiver Anomalies
1 « tj » ^ W
Is " ST
0 100 ZOO 300 400
X XX X X =,
1
500 BOO TOO 800
+ + *
X 1 XX | X>f XX
s I
900 1000 1100 1200
• •• +4K
1 xxx xx xx x 11 x xxl i
g. 0 E 0 2
i- 00
^ U 0
1300 1400 1500 1600
i * Ir
x |x )l x * Ix x
5 ° I °
A A|
1700 1800 1900 2000
Distance (ft)
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The combined results make it easier to identify potential areas of interest within the
pipe. For example, the section between 300 to 400 ft contains a large leak, several
PipeDiver RFEC anomalies and has a high average wall thickness loss and is one of the
areas recommended for further verification and calibration. Similarly, the area between
1 560 to 1 640 ft contains several identified corrosion spots and PipeDiver RFEC
anomalies.
5.2 Inspection Conclusions
PPIC's evaluation of the Westport Rd. Transmission Main between Pit 1 and Pit 3 (2057
foot section) provided an overall condition assessment of the metallic pipeline.
The Sahara platform was used to provide three critical non-destructive condition
assessment services, including:
• Internal video inspection
• Leak detection
• Sahara and PipeDiver wall thickness assessment
All Sahara services were successfully inserted using a 2 inch tap in live conditions not
requiring the line to be shut down. The tethered system allowed the sensor to be
stopped at precise locations which enabled operators to make accurate and repeatable
identifications regarding pipeline condition discoveries.
Sahara Leak Detection detected six unidentified leaks and one air pocket, recorded and
marked their above ground position, and estimated the leak size all in real time.
Several simulated leaks were also detected in real time, and post analysis was able to
identify all leaks that had been masked by external noise factors such as the pipeline
discharge.
Sahara Video's tethered CCTV inspection was also successfully deployed using a 2 inch
tap. Real time analysis of the video provided insight into the internal condition of the
pipeline and clearly distinguished two areas of corrosion. Air pockets and outlets were
also clearly identifiable from the real time inspection. The second purpose of a video
inspection, to discover possible obstacles for a PipeDiver inspection, showed that
PipeDiver could be used with no risk from unidentified obstacles. Video recordings
were used for post analysis and helped identify a previously unknown risk: a joint gap
just downstream of the insertion point. These video results can now be used to
improve and change aspects of the PipeDiver system.
Sahara Wall Thickness was performed in conjunction with leak detection thus
minimizing extra resources and time. Analysis of the results uncovered specific
intervals of the pipeline showing higher wall thickness loss than others. By utilizing the
tethered Sahara system and being able to stop the hydrophone at precise locations,
consistent and multiple pipe intervals could be set to calculate average wall thickness
readings.
The PipeDiver platform is poised to becoming the industry standard for in-service
pipeline inspections. The technology can be modified for different services and
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eliminates the need to take pipelines out of service during inspections. PipeDiver was
successfully inserted and retrieved via two 1 2 inch Tees installed into the live main.
Results obtained form the Westport Rd. Transmission main inspection have identified
anomalous signals and processes that will allow PPIC to further improve the PipeDiver
system, specifically RFEC Testing.
5.3 Advantages and Limitations
The significant advantage to the overall Sahara inspection technologies is that its
tethered cable design brings the sensor as close as possible to the leak and allows
unlimited control of the sensor position. For Sahara Leak Detection this means that the
farthest the hydrophone sensor will be from a leak is the pipe diameter, or more
realistically the pipe radius, which permits very small leaks to be detected. Leaks are
detected in real time and immediately accurately located and marked above ground.
The primary limitation of the Sahara system is the same as its main advantage: its
tethered cable design. The inspection length possible from an insertion point is limited
by the amount of available cable as well as the amount of flow in the pipe line and how
far this flow can carry the hydrophone and cable through the pipe before friction stops
it.
Sahara Video permits a real time video inspection of a live pipeline and only requires a
2 inch access although it has the same cable and inspection limitation and the video
quality is reduced in larger diameter pipes.
The Sahara Wall Thickness technique allows flexible distance and better interval
resolution from the cable control but can only indicate the average wall thickness in a
section and not specific defects.
PipeDiver is a proven platform designed for live inspection of PCCP using the RFTC
technology but has been adapted to use the RFEC technique to provide wall thickness
loss in metallic pipelines. The detection sensitivity is limited by the number of sensor
channels but since the significant challenge of non-disruptive inspection has been
overcome future development can focus on increasing the number of available
detectors.
The Sahara and PipeDiver techniques are complementary technologies that offer a
spectrum of solutions to utilities. By detecting very small leaks and accurately
pinpointing the leak position, Sahara leak can provide pinhole corrosion in pipe wall
and joint problems, which are a good indication of pipe condition. For wall thickness
issues, including graphite, wall thinning, but not yet leaking, Sahara Wall Thickness can
provide average sectional wall thickness info during the same time with Sahara leak
and PipeDiver RFEC will be able to provide more detailed information. Also, Sahara
Video provides internal line condition and visual corrosion information. All are live
inspections that take place while the pipeline remains in service.
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5.4 Future Developments
Sahara Leak Detection is a mature technology used successfully for many years and
future development of the technique will focus on making it even easier to use. The
main challenge with Sahara Video is to improve its video and lighting quality in larger
diameter pipes and to possibly combine the video and leak techniques into a single
sensor head which would reduce the amount of insertions required and make the
overall inspection more efficient. The Sahara Wall Thickness technique will continue to
fine tune its field and analysis procedure in addition to more verification and
calibration.
PipeDiver is a proven platform for entering a pipe through a standard access in live
conditions and for inspection of PCCP. Using the data and experience obtained from
this first PipeDiver RFEC inspection pilot PPIC will be able to further improve the
PipeDiver system for metallic pipeline inspections. Technical components will be
reviewed for possible advancements including improved detectors and detector
placement. As well, the analysis process will be reviewed for new analysis techniques
and improved software. Specifications and implementations of standard accesses will
be reviewed to prevent future insertion and retrieval issues. Results need to be
compared to actual pipe calibration and verification from the Westport Rd.
Transmission Main in order to review and improve the current analysis techniques.
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6. PHOTOGRAPHS
Sahara insertion site with valve and tap
in Pit 1.
Sahara control center (truck) and Sahara
insertion setup at Pit 1.
Valve creating a simulated leak in Pit 4.
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Pits were constantly flooded due to
ground water and rain storms.
PipeSpy locating a simulated leak at Pit 4
Orifice used to create simulated leaks
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The Sahara Video sensor head and
drogue.
Technicians inserting the Sahara
hydrophone into the pipe in live
conditions.
The Sahara insertion tube setup in Pit
1.
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Acoustic unit recording reference
sound signals at the insertion point.
Accelerometer acoustic sensor attached
to the Sahara insertion tube.
Carrying the PipeDiver tool ready to be
installed into the insertion tube.
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Preparing the PipeDiver insertion and
retrieval tubes.
PipeDiver insertion tube setup at the
launch site.
Attaching the PipeDiver extraction tube
on the gate valve.
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Setting up the PipeDiver extraction
tube.
Technicians locating the PipeDiver vehicle
from above ground.
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APPENDIX C
SmartBall® Pipe Wall Assessment Survey
24" Cast Iron Pipeline with Mortar Lining
Louisville, Kentucky
Prepared For:
Battelle Memorial Institute
505 King Avenue
Columbus, Ohio 43201
TECHNOLOGIES LTD.
Prepared By Vinh Nguyen
Pure Technologies Ltd
705-11th Ave. SW
Calgary, Alberta
Canada
T2R-OE3
January 5, 2009
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1.0 Executive Summary
In partnership with the Environmental Protection Agency and Battelle Memorial Institute, Pure Technologies was given the
opportunity to conduct leak detection and pipe wall assessment on a waterline in Louisville Kentucky. The pipeline
assessed was a 24 inch steel water pipeline with mortar lining. The inspection was done using Pure Technologies'
proprietary leak detection technology SmartBall and Pipe Wall Assessment technology.
The SmartBall was deployed to assess the pipe wall condition of 2057 ft of 24 inch cast iron pipeline in Louisville
Kentucky on Thursday August 6th and Friday August 7th, 2009. Each combination of pipe wall assessment and leak
detection survey took approximately one hour to perform. The SmartBall was able to detect a total of 15 non-simulated
leaks as presented in the SmartBall Leak Detection Survey report. This report details the results from the pipe wall
assessment portion of the inspection.
2.0 Summary of Technology
Maintaining and monitoring of municipal water and waste water pipelines is extremely important because leakage of water
pipeline can lead to financial loss and loss of service. More importantly, leakage in waste water pipelines poses a threat
to the environment and the general population. As such, utilities owner require a method of assessing the pipe wall
thickness of the pipelines to efficiently manage and maintain their infrastructure.
The preferred method of assessing the condition of the pipe wall thickness would be a method that does not involve de-
watering the pipelines or does not require the excavation of the pipes. Therefore, a non-destructive method of assessing
the pipeline is most preferred as it is the most cost effective and it does not disrupt services.
Pure Technologies' pipe wall assessment (PWA) technology is a non-disruptive technology that uses low frequency
pulses to evaluate the hoop stiffness of the pipe. The pipe wall condition is assessed by effectively measuring the
propagation velocity of the transmitted pulse. By calculating the velocity of the
wave as it propagates in the pipe, one can essentially determine the hoop stress
of the pipe and in effect the pipe wall condition. Pure's PWA technology utilizes
the SmartBall™ acoustic sensor and long range capabilities to assess the pipe
wall condition and detect leaks simultaneously.
The low frequency pulses are generated by pulsers mounted onto the
SmartBall™ insertion stack, extraction stack, and intermediate locations along
the pipeline. The pulser can also be mounted to typical fittings found on Fjgure 2/|. |nsertjon stack with pulser
pipes, such as valves, and can also be strapped onto the pipe itself. The
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number of pulsers used is dependent on the length of the inspection. The Louisville Kentucky inspection required the use
of three pulsers. The propagation velocity of the pulse is measured based on the arrival time of each pulse as compared
to the previous pulse. The pipe wall stiffness in the interval traversed by the Smartball™ between the pulses is calculated
based on the propagation velocity of the pulse. As the pipe wall stiffness decreases and increases, the propagating
velocity of a low frequency acoustic wave moving through the water also decreases or increases respectively.
The low frequency pulse generated by the pulser can be obscured by loud noise sources nearby and propagation of the
wave generated can be diminished by bends and elbows in the pipe. In order to compensate for the attenuation, three
pulsers were used to ensure that the SmartBall would detect at least one pulse at any given time. Furthermore, the
spatial resolution of the SmartBall™ PWA technology is also dependent on the velocity of the SmartBall™. The spatial
resolution of the SmartBall™ PWA tool for the subject run was approximately 1 data point every 2 ft. As stated, the pipe
wall stiffness was assessed at 2 ft. intervals and is unlikely to detect individual pits. However, it is an effective tool to
highlight areas where a cluster of pits compromises hoop stiffness, or where there is a general deterioration of the pipe
wall.
3.0 Pipeline Summary
Project Date
Service
Material
Diameter
Pressure
Length
Flow
August 6tn and T 2009
SmartBall/Pipe Wall Assessment
Cast Iron with Mortar Linings
24 inch
50 psi
2057ft
1.0ft/s
Table 3.1: Summary of Inspection Details
The approximate layout of the 24 inch cast iron water pipeline inspected started at the intersection of Chenoweth Lane
and Westport Road, to the intersection of Ridgeway Avenue and Westport Road in Louisville, Kentucky. The approximate
line location is displayed on the aerial photograph below in Figure 3.1.
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Figure 3.1: General layout of the pipeline inspected.
As shown in Figure 3.1, the inspection required the use of three different pulsers positioned at the same locations as the
surface sensors. Multiple pulsers were used to ensure that the SmartBall™ will always pick up the signals at any given
time along the pipeline. Similar to the SmartBall™ and the SmartBall™ Receiver (SBR), the pulsers are synchronized.
Furthermore, the use of multiple pulsers will compensate for the attenuation of the pulses by bends and elevation
changes.
4.0 Tracking the Position of the SmartBall™
Knowing the position of the SmartBall™ within the pipeline is critical to accurately assess the pipe wall conditions. The
methodology used to track the SmartBall™ involves obtaining a velocity profile using data obtained from the
accelerometers and magnetometers on board the SmartBall™. Absolute position reference points obtained from the
SmartBall™ Receiver (SBR) are applied to time stamped data. The three sensors used were able to track the SmartBall™
throughout the whole inspection without any blind spots. The result of the rotation profile and SBR tracking is a position
versus time relationship for the entire inspection. The exact location of where each SBR was placed along the pipeline
during the run is detailed in Appendix A.
An example of the data collected during the first of five inspections is shown below. Figure 4.1 shows the position data for
the run. The position of the SmartBall™ indicated by the red line was fixed by fitting the position profile to known locations
along the pipeline. The slope of the red line indicates the instantaneous velocity of the tool. The velocity of the
SmartBall™ as it travelled through the pipeline for the first run is shown in Figure 4.2. Figure 4.3 displays the position of
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the ball as it was tracked in real time on site by the SBRs.
1969 - -
0 --
13:43:18 13:51:38 13:59:58 14:08:18
Timed Day(hh:mrn:ss)
14:16:38
th.
Figure 4.1: SmartBall™ Position vs. Time for Run 1 (August 6 )
14:24:58
1-3 •-
* VY^r/^V%^^WH^^^^
15:59:58 14:08:18
Time of Day(hh:mrri:ss)
th.
Figure 4.2: Velocity Profile vs. Time of Day for Run 1 (August 6 )
820 -F
0 -I
th.
Figure 4.3: SBR Tracking Point vs. Time of Day for Run 1 (August 6 )
The SmartBall position profile, velocity profile and SBR tracking point data are shown above.
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5.0 Results
Upon retrieval of the tool, the acoustic data recorded by the SmartBall™ PWA tool was analyzed and cross-referenced
with the position data from the SBR to determine the location of the SmartBall™ during the inspection. The location
accuracy of the anomalies is dependant on the accuracy of the pipe distance and lay information provided to Pure.
The signals transmitted from the pulser at the extraction site were obscured by the large amount of noise generated by
the pressure control apparatus at the discharge line just past the extraction site. However, the signals from the first and
second pulsers were detectable and those results are summarized below.
The graphs below show the condition of the pipe as detected by the SmartBall™ with respect to the position of the
SmartBall™ along the pipeline. Since the pipe wall thickness affects the velocity of the signal as it propagates through a
water filled pipe, it is therefore concluded that there is some evidence of pipe wall weakness at highlighted areas.
Pulse Velocity v.s Distance
4500 -i
4300
2700
2500
0.0 12.0 24.0 36.0 48.0 60.0 72.0 84.0
Distance [ft]
96.0
108.0 120.0 132.0 144.0
Figure 5.1: Acoustic Profiles from Oft - 150ft
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Pulse Velocity v.s Distance
4900
4700
2900
2700
2500
130.0 142.0 154.0 166.0 178.0 190.0 202.0 214.0 226.0 238.0 250.0 262.0 274.0 286.0 298.0
Distance [ft]
Figure 5.2: Acoustic Profiles from 130ft-300ft
Pulse Velocity v.s Distance
5100
4900
2900
300.0 312.0 324.0 336.0 348.0 360.0 372.0 384.0 396.0 408.0 420.0 432.0 444.0 456.0
Distance [ft]
Figure 5.3: Acoustic Profiles from 300ft-465ft
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Pulse Velocity v.s Distance
5400
5200
3800
3600
3400
480.0 492.0 504.0 516.0 528.0 540.0 552.0 564.0 576.0 588.0 600.0 612.0 624.0
Distance [ft]
Figure 5.4: Acoustic Profiles from 480ft-630ft
Pulse Velocity v.s Distance
5400
5200
3600
3400
630.0 642.0 654.0 666.0 678.0
690.0 702.0 714.0
Distance [ft]
726.0 738.0 750.0 762.0 774.0
Figure 5.5: Acoustic Profiles from 630ft to 775ft
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Pulse Velocity v.s Distance
5500 -i
2500
780.0 792.0 804.0 816.0 828.0 840.0 852.0 864.0 876.0 888.0 900.0
Distance [ft]
Figure 5.6: Acoustic Profile from 780ft to 900ft
Pulse Velocity v.s Distance
5500 -i
2500
900.0 912.0 924.0 936.0 948.0 960.0 972.0 984.0 996.0 1008.0 1020.0 1032.0 1044.0
Distance [ft]
Figure 5.7: Acoustic Profile from 900ft to 1050ft
The data obtained by the SmartBall™ PWA pipe wall assessment tool suggest that there exist several interesting
variations in the apparent pulse velocity at different points along the pipeline. It is not known whether or not the data
reveal actual changes in the hoop stiffness of the pipe wall, or if the data has been affected by the existence or condition
of the mortar lining or other pipe stiffness enhancements (such as previous repairs along the pipeline).
The data obtain from the SmartBall PWA tool also suggests that it is capable of detecting features on the pipeline such as
valves and joints. The peaks presented in Figure 5.8 illustrate the location of the joints. As shown, a typical joint section
for this pipeline is approximately 12ft.
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4500 -i
4300
4100
3900
s 3700
3500
3300
3100
Pulse Velocity v.s Distance
Pipe Joints
2900
822.0 834.0 846.0 858.0 870.0 882.0 894.0 906.0
Distance [ft]
Figure 5.8: Joint Locations
The anomaly shown in Figure 5.9 illustrates the acoustic representation of the drain valve found at approximately 260 ft
from the insertion location.
Pulse Velocity v.s Distance
5100
4900
2700
2500
200.0 212.0 224.0 236.0 248.0 260.0 272.0 284.0 296.0
Distance [ft]
Figure 5.9: Drain Valve Location as Seen By Acoustic Pulses
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The SmartBall™ PWA tool is capable of revealing variance and trends that can be later assessed by other means. The
spatial resolution of the tool was approximately 1 data point every 2 feet which was unlikely to reveal individual pits, but
may reveal areas where clusters of pitting or thinning produce weakening reaching over several feet along the pipe.
Confirmation of the areas of weakness will await excavation and inspection data, which in the case of this Louisville
survey, are expected later this year.
6.0 Summary
Pure Technologies Ltd. is in the process of testing equipment and methods to do pipe wall assessment simultaneously
with the operation of its SmartBall™ leak detection technology. In partnership with the Environmental Protection Agency
and Battelle Memorial Institute, Pure Technologies was given the opportunity to conduct leak detection and pipe wall
assessment on a waterline in Louisville Kentucky. Results indicate variances in the propagation velocity of low frequency
acoustic pulses that may have resulted from variances in the hoop stiffness of the pipe. The simultaneous detection of 15
leaks including all three simulated leaks with the same instrument at the same time as the SmartBall™ PWA was
functioning demonstrates the practical nature of the device and method.
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Appendix A: Ball Tracking Sensor and Pulser Locations
Sensor and Pulser Locations for August 6th and 7th, 2009 Inspections
Distance from Launch
Distance from Launch
AGM Location ID
Latitude
Longitude
Distance from Launch
Extraction
38.2566
-85.6489
2057.0 ft
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echo^logics
Summary
Echologics Engineering Inc.
50 Ronson Drive, Unit 155
Toronto, Canada M9W 1B3
T:+1[416]249.6124
F:+l[416]249.3613
www.echologics.com
The purpose of this study is to assess the performance of Echologics proprietary non-
destructive acoustic condition assessment technology for leak detection and condition
assessment on cast iron pipes. Data acquisition was performed on a 24-inch cast iron
pipe that runs beneath Westport Rd in Louisville Kentucky on August 11th and 12th
2009. This report summarizes the results of the data acquisition and the corresponding
analysis.
Acknowledgements
Battelle
Abraham Chen - Program Manager
Bruce Nestleroth - Research Leader
Lili Wang - Program Assistant
Louisville Water Company
Keith Coombs - Program Manager
Revisions
0.1 Sept 7, 2009
0.2 Sept 18, 2009
0.3 Sept 25, 2009
0.4 Sept 30, 2009
1.0 Nov4, 2009
1.1 Nov13, 2009
Dave Johnston - Draft Report
Ellen Turner - Draft Report Revision
Marc Bracken - Draft Review
Dave Johnston - Draft Submittal to Client
Dave Johnston - Final Revision
Dave Johnston - Update
1.2 August 2, 2012 Dave Johnston - Results Update (for spun cast iron)
1.3 Nov22, 2012
Dave Johnston - Error Correction
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echo^logics
Echologics Engineering Inc.
50 Ronson Drive, Unit 155
Toronto, Canada M9W 183
T:+1[416]249.6124
F:+l[416]249.3613
www.echologics.com
Contents
1. Introduction 1
2. Background 2
2.1. Signal Processing 2
2.2. Leak Detection 3
2.3. Non-Destructive Condition Assessment 3
2.4. Metallic Pipe 5
2.5. Concrete Lining 6
2.6. Nominal Data 7
2.7. Sensitivity Analysis 7
Distance Measurement 7
Pipe Manufacturing Tolerances 8
Repair Clamps on Previous Leaks 8
Variation on Young's Modulus 8
Replacement of short Pipe Sections for Leak Repairs 9
Inaccurate Records 9
2.8. Sources of Error 10
2.9. Negative Correlation Signals 10
2.10. Condition Assessment Data Interpretation 11
2.11. Results of Pipe with 5% degradation 11
2.12. Results of Pipe with 9% degradation 12
2.13. Results of Pipe with 47% degradation 12
Guidelines for Interpretation of Results 15
3. Methodology 16
3.1. Leak Detection 16
3.2. Condition Assessment 17
3.3. Instrumentation 18
4. Results and Discussion 20
4.1. Demonstration Results 22
Section 1: PMl to PM2, Demonstration in Pit#4 22
Section 2: PM2 to PM3, Demonstration in Pit #5 23
Section 3: Pit#4 to Pit#5, Demonstration in Pit#2 23
General Comments 24
4.2. Leak Detection Results 25
File #2a- Pit A to Pit B 25
File#7c-PitFtoPit3 25
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echo^logics
Echologics Engineering Inc.
50 Ronson Drive, Unit 155
Toronto, Canada M9W 183
T:+1[416]249.6124
F:+l[416]249.3613
www.echologics.com
4.3. Condition Assessment Results 27
5. Concluding Remarks 28
6. Appendix 29
Figures
Figure 1: Photos of pipe with 4.2% measured loss 13
Figure 2: Photos of pipe with 8.9% measured loss 13
Figure 3: Photos of pipe with 47.3% measured loss 14
Figure 4: Correlation result for File #2 25
Figure 5: Correlation Result for File #7 26
Figure 6: Pipe Wall Cross-Section i
Figure 7: Site Layout ii
Figure 8: Correlation Report for File #2a -PitAto PitB iii
Figure 9: Correlation Report for File #7c - PitF to Pit3 iv
Tables
Table 1: Nominal Dimensions 7
Table 2: Excavation Locations 21
Table 3: Sensor-to-Sensor Distances 21
Table 4: Demonstration Results 22
Table 5: Condition Assessment Results 27
IV
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Cast Iron Pipe Pilot Study
1. Introduction
Echologics Engineering was invited to conduct a pilot study on selected cast iron pipes
in Louisville, Kentucky. The intent of the study is to test the feasibility of Echologics
proprietary non-destructive condition assessment technology both for condition
assessment and leak detection on a 24-inch spun cast iron pipe along Westport Rd.
Data acquisition was performed on several sections of the 24-inch main. There are
three sets of results presented in this report. First, the results of the background leak
detection results will be discussed. Locations of any already existing leaks will be
presented in this section. Second, the results of the leak detection demonstration will be
presented. This will include whether or not the demonstration leak was discovered and
what the estimated flow rate is. Finally, the results of the condition assessment will be
presented.
Background measurements were performed in section lengths between 250-feet and
360-feet in length. The background measurements were performed with the purpose of
finding any already existing leaks and performing the condition assessment
measurements. Typically, the same methods are used when Echologics is performing
commercial assessment services.
The demonstration measurements were performed using different sensors
(hydrophones) and longer section lengths, approximately 1000-feet. Again, this
arrangement was chosen because it would be typical for commercial leak detection
projects.
As a warning to the reader, it should be noted at the outset that for completeness, we
have included fairly extensive technical information, some of which will be beyond the
technical knowledge base of some of the readers of this report. It is not our intent to
educate readers in signal processing theory, although we have provided some layman's
explanation of the background theory.
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Cast Iron Pipe Pilot Study
2. Background
2.1. Signal Processing
Time differences are measured using fast Fourier transforms (FFTs) and advanced
cross-correlation algorithms. There are also a number of other acoustic tools that aid in
data analysis processes. For the purposes of understanding this report, there are
several signal processing functions that should be understood:
Coherence Function: The coherence function is a measure of how similar the vibration
signals are on a frequency basis. When two signals are perfectly similar at a given
frequency (for example, two sine waves), the coherence function value is 1 at that
frequency. Good coherence would be considered anything at 0.5 and above.
Transfer function: The transfer function is a frequency based plot of the relative strength
of the two measurement channels. This function shows the relative vibration level of the
blue and white stations, and can be given in log or linear format. Many vibration
engineers prefer to see both formats, as a log plot is easier on initial read, however a
linear plot will show more detail.
Frequency plot (FFT): The frequency plots given in this report are fast Fourier
transforms of the raw level vs. time signals. Very simply, these plots show the frequency
content of the vibration signals measured. It is often possible to pick out leak noise on
the frequency plots, and these can be used to analyze the leak detection signals. For
example an FFT from the blue station may show a spectrum consistent with leak noise
with significant higher frequency vibration, while the white station signal may show no
high frequency content indicating a possible PVC repair (the PVC repair may filter out
high frequency content).
Correlation Function: The correlation function is the level vs. time function that will
indicate a leak, and in the case of condition assessment measurements will show the
out-of-bracket peak or time difference. Ideally a good correlation peak should be very
sharp, and very prominent. The LeakfinderRT software will present a warning for an out-
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Cast Iron Pipe Pilot Study
of-bracket signal when the time delay of the signal approaches the total time delay of
the entire measurement distance (i.e when t=>d/v).
2.2. Leak Detection
The leak detection methodology used is the cross correlation method. A correlator
listens passively for noise created by a leak. Two sensors are mounted on fire hydrants,
exposed pipe, or valves in such a way that the leak lies between them, or is 'bracketed'
by the sensors. A leak that lies outside the area spanned by the sensors is known as an
'out-of-bracket' leak. Any active leaks or draws or other sources of noise on the pipe will
vibrate the pipe and detected by the sensors.
The signals will be recorded and the cross-correlation plot will be analyzed. Any
potential leaks will appear as a spike in the cross-correlation plot. The position of the
spoke on the x-axis corresponds to the time difference it takes for the signal to arrive at
the Blue and White stations. The wave velocity is known and therefore the position
relative to either of the stations can be computed.
2.3. Non-Destructive Condition Assessment
An acoustic signal induced in the pipe may be used to determine the acoustic wave
velocity in a section of pipe, which can in turn be used to back calculate the average
wall thickness of the pipe. Knowing the distance between two sensors mounted some
distance apart on valves or fire hydrants, the acoustic wave velocity will be given by v =
d/t, where d is the distance between the sensors, and t is the time taken for the
acoustical signal to propagate between the two sensors. If an accurate measurement of
the acoustic wave velocity is made, it is possible to back-calculate the remaining
average thickness of the pipe between the two sensors.
The wall thickness measured represents an average between the two sensors. Typically
the length of the pipe section over which the acoustic velocity is measured 100 to 300
metres (300'-1000!), however this distance can be decreased to anywhere between 30-
100 m to increase the resolution.
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Cast Iron Pipe Pilot Study
Echologics proprietary leak noise correlator, LeakfindeRT was used to determine the
acoustic velocity. An acoustic source outside the area spanned by the sensors (an 'out-
of-bracket' source) was used to induce an acoustic wave in the pipe, and the time delay
difference was measured. At each site the noise source to induce the acoustic wave;
was either operation of a fire hydrant, or a valve or hydrant was impacted.
The average wall thickness of the pipe section between the acoustic sensors is then back calculated from
a theoretical model. As the pipe wall thickness decreases over time, the acoustical wave velocity
decreases. From an intuitive perspective, this is akin to trying to run on a trampoline versus solid ground;
as the bounding layer becomes more flexible the propagation velocity decreases. The acoustical wave
velocity is given in Equation 1: Wave Velocity - Thickness Model below. It should be noted that
there are other factors that affect the propagation velocity such as water temperature and pipe
wall inertia. These factors are not shown here but have been accounted for in the final results.
where
v: Propagation velocity of leak noise in pipe
v.: Propagation velocity of sound in an infinite body of water
L: Internal diameter of pipe
;-: Thickness of pipe wall
KKMr: Bulk modulus of elasticity of water
Efif;. Young's modulus of elasticity of pipe material
Equation 1: Wave Velocity - Thickness Model
The acoustic propagation wave (the water hammer mode) propagates as a
compression wave in the fluid, and a dilatational wave in the pipe. Therefore the pipe
will breathe on a microscopic level, and therefore the pipe will go into stress. There are
two key implications to this:
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Cast Iron Pipe Pilot Study
1. Only the structural part of the pipe that can carry load will contribute to the
structural stiffness of the pipe, therefore deposits on the pipe wall such as
tuberculation or graphite will not be included in the average wall thickness
measurement.
2. We will measure the minimum structural thickness of the pipe, as the level of
strain of the pipe will be dependent on the minimum wall thickness at any point
around the circumference the pipe.
As noted, the pipe wall thickness calculated from these measurements represents an
average value for the pipe section over which the acoustic velocity is measured. At first
glance, this may appear to be a limitation of the technology, as the question could be
reasonably asked as to whether the method can find pockets of corrosion. In practice
this has not been the case. The technology has been applied to generally much greater
sample lengths of pipe than could be done with random sampling or electro-magnetic
technologies. Therefore when surveying long lengths of pipe, the operators begin to
look for anomalies in the measurements that could indicate degraded sections of pipe.
When these are seen, the distance between the sensors may be decreased and more
resolution obtained. Generally, pipes will have a more-or-less uniform thickness profile
with isolated pockets of corrosion over significant lengths, say 50 to 100 meters, as soil
and bedding conditions are unlikely to change significantly over such distances. Also,
average wall thickness values are suitable to evaluate the residual life of pipes for the
purpose of long-term planning of rehab and replacement needs. The use of techniques
such as evaluation of stray currents, and soil corrosivity studies and main break history
may be used in conjunction with our data to evaluate overall pipe condition.
2.4. Metallic Pipe
The primary degradation mechanism in buried metallic pipes is corrosion. Corrosion
occurs in many different forms and can be accelerated or inhibited based on soil
properties, water properties and characteristics of the pipes surroundings.
Two main forms of corrosion occur in buried pipelines: uniform corrosion and pitting
corrosion. Uniform corrosion occurs when general, constant corrosion occurs on all
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Cast Iron Pipe Pilot Study
surfaces of the pipeline. This can occur from the inside out and is caused by the
properties of the water that the pipe is carrying. Or it can occur from the outside in if the
pipe is in submerged or semi-submerged conditions.
Pitting corrosion occurs on the inside and outside surfaces of the pipe. This is when
small areas corrode preferentially leading to cavities or pits, and the bulk of the surface
remains unaffected. Pitting corrosion can be accelerated under stagnant conditions,
which is why it is generally more severe on the outside surface of the pipe.
Other forms of corrosion can occur including: galvanic (dissimilar metals), De-Alloying
(graphite), inter-granular and erosion corrosion. All of these can contribute to the overall
degradation of the pipe but they are considered to be relatively insignificant compared
to the impact of uniform and pitting corrosion.
2.5. Concrete Lining
The wave propagation velocity is a function of the thickness of the pipe wall and the
corresponding material elastic modulus. Therefore, if a pipe is concrete lined the
structural stiffness of the pipe is increased via the addition strength of the concrete. The
wave velocity then becomes a function of the structural stiffness of the metal and the
concrete lining.
In order to account for this, it is necessary to calculate the nominal thickness of the pipe
as if it was not lined with concrete i.e. the equivalent structural thickness of a metallic
pipe without the concrete lining. This will be referred to as the equivalent thickness and
generally it is 2-3mm thicker than the thickness of the base metal. This value can also
be considered as the 'effective' or the 'structural' thickness of the pipe.
The measurement will then be compared to this value, the equivalent thickness rather
than the thickness of the metal alone.
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Cast Iron Pipe Pilot Study
2.6. Nominal Data
Battelle provided original specifications for both diameters of pipe. The details are
presented below in Table 1: Nominal Dimensions. There is also an image of the cross-
section of the pipe shown in Figure 6: Pipe Wall Cross-Section. It closely matches the
values presented here.
YOI
1932
Type
Spun Cast
Equivalent
Cast Iron Cast Iron Lining
Dia Dia Thickness Thickness Thickness
(inch) (mm) (inch) (mm) (inch)
Iron 24 610 0.75 19.05 0.25
Thickness of Cast Iron without Concrete Lining
22.0 mm
0.866 inch
Lining
Thickness
(mm)
6.35
Table 1: Nominal Dimensions
2.7. Sensitivity Analysis
Echologics has committed a substantial amount of effort to reduce sources of error in
our assessments. However there are still variables that strongly affect the final result.
They are as follows:
Distance Measurement
A calibrated wheel is used for obtaining our distances, and distance measurements
were repeated 3-4 times for each location to ensure the best possible accuracy. For
example, on a total distance of 150m, an error of +2.5m resulting in a measured
distance of 152.5m will cause a positive error in the final result of approximately 17.5%.
An accurate distance measurement is therefore crucial to an accurate assessment. For
this reason, our preference is always to use line valves, as these provide the most
accurate distance measure, as it is a point-to-point measurement. If the pipe has
multiple bends and elevation changes between the sensor connection points, error in
the distance measurement increases, as it is not always easy to identify where the
bends occur.
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Cast Iron Pipe Pilot Study
Pipe Manufacturing Tolerances
The pipe laid will have small differences in thickness and due to manufacturer and
tolerances. This factor is usually 5-10% dependent on the manufacturer and the
material. This may lead to a pipe growing by a small percentage (5-10%) compared to
the nominal thickness used. This is particularly true of the older vintages of pipe
measured in this study. Generally, the materials data used for the calculation is chosen
using conservative estimates. The purpose of this is to provide a worst-case scenario to
the client i.e. assume that the pipe is manufactured to the better side of the tolerances
and calculate the remaining thickness based on this. This is not considered to be error
because the presented result actually represents the current condition of the pipe.
Variation in internal diameter of the pipe can also affect the final result. If the
manufacturing tolerances for the diameter are approximately 5-10% the corresponding
results on the calculated value will also vary by approximately 5-10%. This is
considered to be relatively insignificant if, in fact, the information provided by the client
is correct. This is not always the case and it will be discussed later in this section.
Repair Clamps on Previous Leaks
A small number of repair clamps should have an insignificant effect on the test results,
since the acoustic wave is primarily water borne and will bypass the clamps. It should
be noted that although the acoustic wave is primarily water-borne, it is a coupled wave
that moves simultaneously in the pipe (in an axi-symmetrical breathing mode), and in
the water as a compression wave. Thus the wave will generally skip across
discontinuities such as clamps, and reestablish itself in the pipe material beyond.
Variation on Young's Modulus
In general, a change in elastic modulus of 10% will cause a change in the calculated
thickness by approximately 10%. Therefore it is necessary to account for this variation.
The elastic modulus is known for common materials used in the manufacturing of
pressure pipe but this value can vary from manufacturer to manufacturer. This depends
on the manufacturing process and the quality of the material.
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Cast Iron Pipe Pilot Study
Replacement of short Pipe Sections for Leak Repairs
The effect of short pipe replacements will depend on the material used. For example, a
new 6-metre long ductile iron repair in a 100-metre long / 152 mm-diameter cast iron
pipe section of average condition, will produce a small error of +3.5% in predicted wall
thickness. However, the same repair made with PVC pipe would produce an
unacceptable error of -41%. Preferably, pipe sections selected for testing should be free
of repaired segments. However, if this condition does not exist, the effect of new pipe
segments can be accounted for provided that accurate information is available for the
location, length, material type and class of new pipe segments.
Inaccurate Records
In some cases the possibility exists that inaccurate information was provided by the
client, specifically referring to the pipe diameter and the pipe material. As described
above, small manufacturing variations in elastic modulus and internal diameter only
affect the final result by 5-10% but if the information supplied by the client is incorrect, it
is flawed by much greater magnitudes. For example, a common error would be to
mistake a 200mm pipe for a 250mm pipe. When the calculation is performed using an
internal diameter of 250mm, the remaining thickness may be 12.5mm. If the same
calculation is performed using an internal diameter of 200mm, the remaining thickness
is reduced to 9.3mm, a change of 3.2mm! In this case, the error caused a 35% over
estimation of the pipe wall thickness.
Another common problem arises when improper pipe material information is provided.
For example, if a pipe was thought to be spun cast iron when, in fact, it is ductile iron.
When the calculation is performed using the elastic modulus for spun cast iron
(131Gpa), the remaining thickness may be 11.6mm. If the same calculation is
performed for a ductile iron pipe (169Gpa), the remaining thickness drops to 8.9mm, a
change of 2.7mm! The error caused a 30% over estimation of pipe wall thickness.
It becomes obvious that accurate records from the client are an essential requirement
for providing accurate condition assessment results.
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Cast Iron Pipe Pilot Study
2.8. Sources of Error
The results of the sensitivity analysis provide insight into how the various material
properties and pipe dimensions can affect the final result. If one ignores error introduced
by manufacturing tolerances and inaccurate nominal information, the main source of
error is cause by improper sensor-to-senor distance measurements.
The average section of pipe tested during this project was 150m. If one assumes that
the sensor-to-sensor spacing can be measured accurately to within 1m, the resulting
error in the thickness calculation is approximately 5%. If however, there are multiple
bends in the pipe or significant elevation changes, the error in the distance
measurement may increase. For example, one bend in the pipe may introduce an
additional error of 1m. With a total distance error of 2m, the resulting error in the final
calculation is approximately 10%.
2.9. Negative Correlation Signals
There were several locations where correlation signals could not be acquired, or they
were of poor quality. This can happen for a number of reasons, and we typically find
that this occurs on a percentage of all of our projects. Although we have never had the
opportunity to fully explore the reasons for this, the following are some of the conditions
that we have encountered that have affected our measurements:
1. The presence of plastic repairs in metallic pipes can cause poor correlation
signals, and will also cause inaccurate thickness
2. Loose or worn components in fittings used for the measurements, such as valve
or hydrant stems.
3. Heavily tuberculated pipe, particularly old cast iron or unlined ductile iron may
attenuate the acoustic signals to such an extent that a correlation is of very low
quality.
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Cast Iron Pipe Pilot Study
2.10. Condition Assessment Data Interpretation
The condition of a pipe may be assessed based by judging it based on other pipes that
we have measured and then exhumed to determine the condition. For a full condition
assessment, it is recommended that our data be used in conjunction with soils
information, any ground potential measurements done, along with any pipe samples
exhumed during leak repairs. Acoustic non-destructive condition assessment cannot
pinpoint the source of degradation. For example, a reading of -20% pipe wall could
mean that the pipe is generally degraded along it's entire length, or the pipe could have
significant degradation at only one or two locations.
In the absence of other parameters, we have provided a gradation scale based on our
previous project experience and pilot studies. Based on our previous experience, we
have provided background on typical results found during the course of our condition
assessment surveys. Please note that the sample photos shown in the following section
are from a previously performed pilot study. They are to be used only to demonstrate
the typical levels of degradation found from previous testing. This is meant to act only
as a guideline in assessing the results of this study.
The images presented below show four pictures in each. The top left picture shows the
as-found condition of the pipe. The top right image shows an overview shot. The bottom
left shows a close up of the surface after it was sandblasted. The bottom right shows
the internal surface after it was sandblasted.
The descriptions below described results measured by Echologics, given by an
averaged measured loss in percent. The physical results given are the average
measured value at either end of the pipe, the average pit depth on the outside surface /
inside surface and the qualitative condition on the outside surface / inside surface.
2.11. Results of Pipe with 5% degradation
A section of pipe where 4.7% measured loss is shown in Figure 1. The nominal
thickness of this pipe was 12mm (0.47in), whereas the lab measured physical thickness
at either end of the sample was 11.4+/-2.7mm (0.45in +/-0.1in). The average pit depth
was 1.5mm / 1.9mm. The pipe was qualitatively described as very good / very good.
This again is an indication that the acoustic wave velocity from the acoustic mode of the
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Cast Iron Pipe Pilot Study
pipe that we are measuring is based on the average minimum structural thickness, not
the average physical thickness.
The sample was taken from an area with corrosive clay based soil. The figures indicate
that although there are local areas of corrosion, the pipe wall is generally in good
condition. Based on this type of result, a pipe at this level of degradation may have
occasional failures from corrosion holes but it is structurally sound.
2.12. Results of Pipe with 9% degradation
Figure 2 shows photographs of a section of pipe measured at 8.9% average loss. The
physical thickness of this pipe was measured at 8.8+/-0.8mm (0.35in +/-0.03in)(nominal
was 9mm), with average pit depth at 2.5mm / 3.0mm. The condition of the pipe was
rated as very good / moderate. The corrosion of this pipe was primarily localized
internally on the bottom of the pipe as can be seen in the right photo. The corrosion
appeared in this case more continuous perhaps due to sediment build up at the bottom
of the pipe. Overall the structural integrity of the pipe is good.
2.13. Results of Pipe with 47% degradation
Figure 3 provides photographs of a pipe with a measured 47.3% average loss of pipe
wall thickness (11.0mm, 0.43in nominal). In the lab the average physical thickness was
measured as 11.6+/-3.3mm (0.456in, +/-0.13in) and an average pit depth of 3.8mm /
2.5mm. The physical condition of the pipe was described as very poor / poor. Note that
there were also numerous through holes in the pipe evident after sand blasting. It is
interesting to note that the pipe was not leaking when measured, probably due to the
build up of tuberculation.
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Cast Iron Pipe Pilot Study
Figure 1: Photos of pipe with 4.2% measured loss
Figure 2: Photos of pipe with 8.9% measured loss
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Cast Iron Pipe Pilot Study
Figure 3: Photos of pipe with 47.3% measured loss
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Cast Iron Pipe Pilot Study
Guidelines for Interpretation of Results
Based on the results, we recommend the following guidelines for the interpretation of
our data:
• 10% or less: The pipe is in very good condition, but may still have minor levels of
uniform corrosion. Some localized areas of pitting corrosion may exist but it is
expected that the areas are isolated.
• 10-20%: Pipe is in good condition, there may be some moderate uniform surface
or internal corrosion, or more localized areas of pitting corrosion.
• 20-35%: Pipe may have significant localized areas of pitting corrosion, or
moderate uniform corrosion throughout.
• >35%: Pipe is in poor condition and may have numerous areas of pitting
corrosion, including significant uniform thinning of the pipe.
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Cast Iron Pipe Pilot Study
3. Methodology
3.1. Leak Detection
In general, it is more challenging to survey for water main leaks with a leak noise
correlator than using it to pinpoint a leak, which is known to exist, as there will be a high
incidence of negative (no leak) results. When many negative results are encountered,
the surveyor may begin to question the operation of the equipment, or his procedures.
Therefore, one of the main issues with testing pipes where there is no known leak is to
ensure that the proper steps are taken to ensure that the results are properly analyzed
so that the presence (or lack of) a leak may be definitively decided. Based on our
previous experience with leak detection surveys, and our familiarity with acoustic
technology, procedures were implemented for both on site, and follow-up analyses were
performed in order to make a definitive decision on whether or not a leak was present.
1. Sensors were attached on valves or hydrants as available at each site. Where
measurements were performed on valves, the sensors were placed on the tops
of valve keys that had been lowered onto the valves or placed directly on the
valve nut when possible (if the valve chamber was clear of debris).
2. The LeakfinderRT radio channels are color-coded blue and white, where blue is
always the right audio channel and white the left. For all measurements, the
locations of the blue and white channel were noted.
3. In general, all leak detection measurements were taken on the same segments
of pipe where the condition assessments were performed.
4. After placement of the sensors on the appropriate valve or hydrant, the fitting
was tapped, and listened to at the radio receiver to ensure that the sensor was
functioning, and that the radio signal was arriving properly at the receiver. This is
called a scratch test.
5. Where possible, sensor spacing was accurately measured using a calibrated
measuring wheel.
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Cast Iron Pipe Pilot Study
6. A correlation measurement was performed, and the signal was saved to the
computer, so that further analysis could be performed later in the office, and so
that the client could have a permanent record of the raw noise file if needed.
7. Where a positive signal was detected (a correlation peak with good signal
coherence), the location was immediately checked to determine if it
corresponded to a service line or other notable draws from the pipe. If this was
the case, several more correlations were conducted to see if the 'usage' stopped.
8. Where negative results were obtained (no clear correlation peak was obtained), a
series of checks was completed, including a review of coherence and of the blue
and white frequency spectra, to detect the presence of a PVC repair or some
other anomaly in the test section. Such checks have become part of our protocol
for leak detection surveys.
3.2. Condition Assessment
The following survey methodology was used:
1. For each location surveyed, the distance between the sensors was measured. A
very accurate measurement of the distance between sensors is required.
Although less important for leak detection measurements, an error in
measurement of even 3 feet over a 300 foot distance can lead to errors of 15% in
wall thickness estimation. The margin of error acceptable will be dependent on
the pipe type and the distance between sensors. Typically, for a cast iron pipe,
we have not found it difficult to obtain this measurement accuracy. There were
some cases where accurate pipe geometry was not available. For example,
elevation changes and curves in the road may create discrepancies between our
distance measurement along the surface and the physical distance of the pipe
underground. Any locations that presented this difficulty were noted and will be
discussed in the final results.
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Cast Iron Pipe Pilot Study
2. Sensors were placed on the fittings, either hot taps that were previously installed
or in potholes on the surface of the pipe, and a noise source was created,
typically at a location out-of-bracket (beyond one of the sensors). The noise
sources were either a running well, light impacting on valves or use of the
shaker. Some sites permitted the use of all 3, others were limited to 1 based on
space restrictions
3. The temperature of the water was recorded, generally at the time of testing, for
each of the test sites.
4. The data was stored as a raw wave file for further analysis and confirmation in
our offices. Data was reanalyzed and filtered to obtain an optimum correlation
peak.
3.3. Instrumentation
The leak detection was completed using Echologics' proprietary leak detection system,
LeakfinderRT. The system works by placing sensors on two water system fittings such
as valves or hydrants bracketing the leak. If a leak is present, the software then uses
the time difference it takes the leak noise to reach the two sensors to pinpoint the leak
location. The sensors used for the purposes of this project were surface mounted,
either on hydrant flanges, hydrant secondary valves or line valves. There were two
types of sensors used in this study:
• Echologics' proprietary Hydrophones for direct measurement of the water column
• Echologics' piezoelectric accelerometers, with a sensitivity of 1 V/g
Each sensor has its own specific attributes that make it preferable in certain situations.
The Hydrophone is particularly well suited to measuring asbestos cement and medium
to large diameter mains (12in and larger), as leaks on these pipes generally are
dominated by lower frequency content (200Hz and below). The standard piezoelectric
accelerometer has a slightly higher noise floor, and has better high frequency response,
making them more suitable for some measurements on smaller diameter (10in and
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Cast Iron Pipe Pilot Study
lower) metallic pipes that typically have higher frequency content (200 Hz and higher).
Radios used were 460 MHz or 433 MHz analogue units manufactured by Echologics.
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Cast Iron Pipe Pilot Study
4. Results and Discussion
First, general information regarding the site location and the pipe will be discussed.
Following this, the results of the demonstration will be presented first, followed by the
results of the background measurements and the corresponding condition assessment.
A map showing the site location and the general layout can be found in Figure 7: Site
Layout.
Table 2: Excavation Locations presents a list with the locations of the excavation pits. It
shows the approximate distance between pits and a corresponding description of the
type of excavation. The distances presented were not the same distances used when
performing data analysis.
For the Leak Detection Demonstration, the pipe was broken up into three longer
sections. For the Background and Condition Assessment measurements the pipe was
broken up into seven sections. More sections were chosen for the assessment
measurements in order to provide a better representation of the pipe condition.
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Cast Iron Pipe Pilot Study
Pipe excavation locations
EPA technology Demonstration
ID
1
A
B
4
C
2
D
E
5
F
3
Distance
Feet
0
250
510
581
809
1080
1173
1439
1580
1750
2057
2100
Name
Lauch Pit
Sensor Pit A
Sensor Pit B
Corp Valve 1 &2
Sensor Pit C
Corp Valve 3 45 & 6
Sensor Pit D
Sensor Pit E
Corp Valve? &8
Sensor Pit F
Fire Hydrant
Receive Pit
12" Discharge
Type
6x8 with trenchbox, 12" T, Reducer
3x3 to top of pipe
3x3 to top of pipe
6x8 with trenchbox, stone backfill
3x3 to top of pipe
6x8 with trenchbox, stone backfill
3x3 to top of pipe
3x3 to top of pipe
6x8 with trenchbox, stone backfill
3x3 to top of pipe
Pressure gage
6x8 with trenchbox, 12 inch T, Reducer
Table 2: Excavation Locations
Location
Sensor-to-
Sensor
Spacing (ft)
Pitl to Pit2 1080.7
Pit2 to Pit3 979.3
Pit4 to Pit5 1001.6
Pit! to PitA
PitA to PitB
PitB to PitC
PitC to Pit2
Pit2 to PitE
250.7
260.5
298.6
271
360.9
PitE to PitF 294.6
PitFtoPitS 312.7
Table 3: Sensor-to-Sensor Distances
21
-------
Cast Iron Pipe Pilot Study
4.1. Demonstration Results
The results of the demonstration tests are presented below in Table 4: Demonstration
Results. The column titled File # corresponds to the WAV file number in the name of the
file when it was recorded. It can be cross-referenced with the screenshots presented in
the Appendix. The column titled Type corresponds to the type of test that was provided
by Battelle. At each location there was four demonstrations the first of which, Demol
Cal, was a calibration test where the induced flow rate was known. The column titled
Location presents where the sensors were attached to the pipe. The column titled
Flowrate (GPM) presents either the known flow rate for calibration tests or the estimated
flow rate for the others. The column titled Result presents the outcome of the correlation
measurement, either negative or positive.
File
#
Id
If
ig
lh
2b
2c
2d
2e
3b
3c
3d
3e
Type
Demol Cal
Demo2
Demo3
Demo4
Demol Cal
Demo2
Demo3
Demo4
Demol Cal
Demo2
Demo3
Demo4
Location
Pitl
Pitl
Pitl
Pitl
Pit2
Pit2
Pit2
Pit2
Pit4
Pit4
Pit4
Pit4
to
to
to
to
to
to
to
to
to
to
to
to
Pit2
Pit2
Pit2
Pit2
Pit3
Pit3
Pit3
Pit3
Pits
Pits
Pits
Pits
Flowrate
(GPM)
0.6
Negligible
2.0 to 5.0
0 to 1.0
None
5.0 to 8.0
5.0 to 8.0
Negligible
8.0
Negligible
5.0 to 8.0
2.5 to 5.0
Result
Negative
Negative
Positive -
Positive -
Negative
Positive -
Positive -
Negative
Positive -
Negative
Positive -
Positive -
577
560
476
478
502
497
487
.6ft
.7ft
.8ft
.8ft
.9ft
.8ft
.4ft
from
from
from
from
from
from
from
Pitl
Pitl
Pit3
Pit3
Pits
Pits
Pits
Table 4: Demonstration Results
Section 1: Pit#1 to Pit#2, Demonstration in Pit#4
The calibration test, Demo 1, was performed with a known flow rate of O.SGpm. The
resulting correlation test presented a negative result. This suggests that a flow rate of
O.SGpm or less cannot be detected with hydrophones at a sensor spacing of 1080.7ft or
greater. Although the final result was negative this is still considered to be a successful
calibration test as it has defined a range that cannot be successfully correlated.
22
-------
Cast Iron Pipe Pilot Study
The flow rates in Demo 2, 3, and 4 were unknown. Demo 2 presented a negative
correlation test. This suggests that the flow rate is negligible and most likely to be close
to or below the calibration value, O.SGpm. Demo 3 presented a positive result at a
distance of 577.6ft from Pit #1. The character of the noise sources suggested a
moderate sized flow rate in the range of 2.0 to S.OGpm. Demo 3 presented a positive
result at a distance of 560.7ft from Pit #1. The coherence was very low and the
correlation peak was weak suggesting that the flow rate was low. It is estimated that this
flow rate is between 0 and I.OGpm but probably closer to I.OGpm as it is known that
0.6Gpm yielded a negative correlation.
Section 2: Pit#2 to Pit#3, Demonstration in Pit #5
The calibration test, Demo 1, presented a negative result with no flow out of the test
valves. This is as expected. Demo 2 and Demo 3 presented very similar results. The
correlated distances were within two feet of each other, 476.8ft and 478.8ft from Pit#3
respectively. Also, the character of the recordings was very similar suggesting that the
flow rates are almost the same. It is estimated that the flow rates are both between 5.0
and S.OGpm but the similarity in the signals suggests that it may be flowing from the
same orifice. Demo 4 presented a negative correlation result meaning that the flow rate
is close to or below 0.6Gpm.
Section 3: Pit#4 to Pit#5, Demonstration in Pit#2
The calibration test, Demo 1, was performed with a known flow rate of S.OGpm. The
corresponding correlated distance was 502.9ft from Pit#5. The coherence was very
strong and the correlation peak was prominent. Overall this test presented the loudest
of all file recorded suggesting that it is the highest flow rate of all the demonstrations.
Demo 2 presented a negative correlation result meaning that the flow rate is close to or
below 0.6Gpm. Demo 3 presented a positive correlation result at a distance of 497.8ft
from Pit#5. The recording had good coherence and a good correlation peak suggesting
that there was a high flow rate. It is estimated that the flow rate for Demo 3 was
between 5.0 and S.OGpm. Demo 4 presented a positive correlation result at a distance
23
-------
Cast Iron Pipe Pilot Study
of 487.4ft from Pit#5. The coherence was lower than the previous test but the
correlation peak was strong. It is estimated that the flow rate was between 2.5 and
S.OGpm for Demo 4.
General Comments
In some cases distance discrepancies between 2ft and 17ft is seen when the simulated
leak is being generated in the same excavation pit. It is known that there is more than
one valve in each of the demonstration pits but the distance between valves in the pit is
unknown. It is assumed that the discrepancies are mainly due to the fact the valves are
approximately 5ft apart, thus accounting for the difference. However, some of the
difference may actually be due to signal processing error, which can get worse as the
signal-to-noise ratio decreases. This may be the case for Demo 4, in Section 1: Pit#1 to
Pit#2, Demonstration in Pit#4.
24
-------
Cast Iron Pipe Pilot Study
4.2.
Leak Detection Results
There were two positive leak locations discovered over the duration of the testing.
File #2a-Pit A to PitB
File 2a was recorded with the Blue station on the pipe in Pit B and the White station in
Pit A with sensor spacing of 260.5ft. The correlation function shown for this file indicates
a leak at a position was 91.5ft from the White sensor. A sharp correlation peak and
moderate levels of coherence indicates a flow rate of 2.5 - 5.0 Gpm for this leak.
The evidence presented here strongly indicates the presence of a leak and if this pipe
were to remain in service, it would be suggested to perform remedial action.
Correlation Function
-0.08 -0.06 -0.04 -0.02 0.00 0.02 0.04 0.06 0.08
Time (second)
Figure 4: Correlation result for File #2
File#7c-PitFtoPit3
The correlation function shown for File 7c was recorded with the Blue station mounted
to the pipe in Pit F and the White station mounted to the pipe in Pit #3 with a sensor-to-
sensor spacing of 312.7ft. The character of the signal suggests that there may be two
leaks at this location at a distance of 126.6ft and 144.6ft from the White station. The
weaker signal and wider correlation peak indicates a small leak, which sets the
estimated flow rate at 1.0 - 2.5 Gpm for each leak.
25
-------
Cast Iron Pipe Pilot Study
The evidence presented here is not entirely conclusive because the correlation peak is
not defined. If this pipe were to remain in service, it would be suggested to perform
further investigation by either using a ground-microphone to confirm a noise source or
potholing to confirm the presence of water.
Correlation Function
-1.0-"-1
-0.10 -0.05 0.00 0.05
Time (second)
0.10
Figure 5: Correlation Result for File #7
26
-------
Cast Iron Pipe Pilot Study
4.3.
Condition Assessment Results
The results of the condition assessment measurements are presented in Table 5:
Condition Assessment Results. Starting from Pit #1, six sections in a row presented
remaining equivalent thickness greater than 0.7-inches. This suggests that there may
be some deterioration in these sections and the pipe is in good structural condition. The
section showing the highest losses is between Pit F and Pit #3. It presented a remaining
equivalent thickness of 0.69-inches.
It should be noted that the sections tested presented results approximately 14%-20%
below the nominal values. This suggests that, overall; the pipe is still in good condition.
File #
la
2c
3c
4b
5d
6c
7b
Sensor-to-
Sensor Spacing
Location (ft)
Pitl to PitA
PitA to PitB
PitB to PitC
PitC to Pit2
Pit2 to PitE
PitE to PitF
PitF to Pit3
250.7
260.5
298.6
271
360.9
294.6
312.7
Average
Thickness
(inch)
0.73
0.74
0.75
0.71
0.71
0.72
0.69
Condition
Good
Good
Good
Good
Good
Good
Good
Table 5: Condition Assessment Results
27
-------
Cast Iron Pipe Pilot Study
5. Concluding Remarks
We thank you again for the opportunity to test the technology and we trust that this is
acceptable. Please do not hesitate to contact us if there are any questions regarding the
study.
Sincerely,
Echologics Engineering Inc.
Marc Bracken, M.A.Sc., P.Eng.
Dave Johnston, B.Eng. Materials Engineering
28
-------
Cast Iron Pipe Pilot Study
6. Appendix
29
-------
Cast Iron Pipe Pilot Study
Figure 6: Pipe Wall Cross-Section
-------
Cast Iron Pipe Pilot Study
Pit #2 (at 171+00: intersection of Wostport Rd and St. Matthews Ave.)
Pit Dimensions: 8 ft long x 5 ft wide with standard Irench box
Pipe Length Exposure: 8 ft at bottom
.il.ii'Hiit li stHlknl on None
Pit #3 (neai Ridgeway Ave. at location of 24" x 12" tee)
Pipe Length Exposure: 3 ft at centerline
I7';i. M n »"il l! ^rflrtl 1.1:1 Nuns
Pit Dimensions: 8 ft long x 5 ft wide urith standard trencti box
Pipe Length Exposure: 8 ft at bottom
Tap.Installation: One 24" K 12" tse (with adapters to 2' and 6")
Equipment instal'alran: 24" x 12* lap (or flushing purposes
Pit #1 (near Chenowoth Ln. at location of 24" x 12" tee)
Pit Dim.ensions: B ft long x 5 ft wide with slandaro trench box
Hipc Lcnglh txposjrc 8 1! al boltoii
Tap Inslalialion: One 24" x 12" iee (with adapters lo 2" and 6")
Pipe Length Exposure: 3ft* cenlerllne
Equipment Inslara'.ion None
Equipntenl Insiallation: 4 1DO psi Bourdon lube pressure gauge
WESTPORT RD
Cnenoweth Ln
to
Ridgeway Ave
vaarurri Excavflliori Keylw-ss (6 to 8 ciametefi
Fim Nydnml
Figure 7: Site Layout
-------
Cast Iron Pipe Pilot Study
FIT LeakFinderRT - Correlation Results (8.5 x 8.6 inches) _
Ptir
t Exit
M(xj
Blue Station Frequency Spectrum White Station Frequency Spectrum
2. 5+
-------
Cast Iron Pipe Pilot Study
LeakFinderRT - Correlation Results (8.2 x 8.6 inches)
- n x
Print Exit
Blue Station Frequency Spectrum
White Station Frequency Spectrum
6-0*02-
0.0-^0
UL
0 200 400 600 800
Frequency (Hz)
Coherence Function
1000
2.5+^
2.0+02-
"§ 1.5+0=-
±±
c
-------
APPENDIX E
RFT Inspection Condition
Assessment (EPA Demo)
Standard Analysis Report
Russell NDE RFT ILI Tool for
24-inch Cast Iron Pipe
Westport Road
Between Shelbyville Road and Ridgeway Ave
Louisville, Kentucky, USA
Project: Battelle 06170901
PO: BMI #225941
Inspection Date
Analysts/Reviewers
Report Revision:
September 4, 2009
YY, AS
0.2
E-1
PAGE1
5/15/2014
-------
Table of Contents
Table of Contents 2
Executive Summary 3
Pipeline Inspection Background 5
Pipeline Information ("the what and where") 5
Inspection Details ("the how") 6
Operation 6
Inspection 7
Field Notes 10
Calibration 11
Analysis Results 12
Location Reporting and Inspection Lengths 12
Analysis Results 12
Disclaimer 14
Compilation of Background Information for Report 14
Appendix 1: Remote Field Operation 15
Appendix 2: Site Sketch 16
Appendix 3: RFT Inspection results for the 24-inch cast iron pipe Westport Rd demo 17
-------
Louisville Westport Road Line
24-inch Cast Iron Water Main Assessment
Executive Summary
Battelle Memorial Institute contracted Russell NDE Systems to inspect a 24-inch cast iron main along
Westport Rd in Louisville, Kentucky, as part of a pipe assessment demonstration for the EPA. To
perform the inspection, Russell NDE custom developed a 24-inch See Snake RFT tool. The inspection
tool was completed at the end of August, 2009, and run through the line twice on September 3 and 4,
2009.
This report documents the RFT findings for the 24-inch Westport Rd main in Louisville. A total of 367
wall loss indications were found along the 2059ft main. A majority of these defects are less than or
equal to 60% deep, with a much smaller group in the 60-80% range. Only a few localized indications
sized 80% or deeper. In addition, the results from the 24-inch See Snake tool show that the deep
defects are concentrated within the first half of the line, leaving about half the line in relatively good
shape. The Pie chart and Table 1 provide a summary overview of the RFT findings and the measured
remaining wall thickness.
I Advanced (RW<20%)
1 Deep (20%B5%)
Advanced
1%
Shallow
59%
Medium
31%
• Figure 1. Defect break down according to minimum Local Remaining Wall.
-------
Feature Indication Summary: Louisville Westport Road Line
Total number of Pipe sections
Total number of regular Bell-and-Spigot Joints
Total number of Coupling Joints
Number of Elbows
Number of Possible Tees, branches and Crosses
Number of Possible Valves
Number of joints with different material properties (different nominal WT)
Number of Joints without Wall Loss Indications
Number of Joints with Wall Loss Indications
Total Number of Wall Loss Indications
Number of Joints with noise or other anomalies
170
168
0
0
2
2
0
24
146
367
8
• Table 1. Feature Indication Summary for Louisville WestPort Road line,
-------
Pipeline Inspection Background
Pipeline Information ("the what and where")
Client:
Battelle Memorial Institute / EPA
Location:
Westport Road
Between Shelbyville Road and Ridgeway Ave
Louisville, Kentucky, USA
See Appendix 2 for satellite image
Pipe Size:
Year Installed:
Nominal WT:
Material:
Access:
Internal Liner:
External:
Bends:
CP:
Features:
Length:
24-inch
1933
0.75" (19. 1mm)
Cast Iron
West most excavation ("launch pit")
Concrete
None
None
0.25-inch Thickness
Small service connections and possible hydrant branches
2059[ft]
> Table 2. Pipeline Information for Louisville Westport Road Line
-------
Inspection Details f'the how")
Operation
In preparation for the See Snake inspection, Battelle and MAC Construction fed a mule tape through
the 24-inch force main. The mule tape was used to pull a steel wireline through line, with the wireline
winch setup at the West excavation and a tagline winch setup at the East excavation. The inspection
tool was attached to both winches allowing it to be pulled in both directions.
The See Snake tool is self contained and does not require to be powered through a wireline. It can
handle pipe diameters in the range of 21 to 27-inches and has an overall length of 97-inches. The
figure below shows the tool in preparation for launch.
• Figure 2. See Snake smart pig being lowered onto tray in excavation provided by Mac Construction in preparation of launch.
Traveled distance was measured by running the west-side tether over an odometer wheel. The wheel
was mounted on a hydrant adapter, which in turn was positioned above ground in between the winch
truck and the excavation.
-------
Inspection
The tool was placed in the west excavation (exciter end first) and positioned with the detectors just
outside of the pipe prior to the pull beginning, making the edge of the pipe the datum point for the RFT
log. All footages found in the report are offset by 8ft from this datum point and are referenced to the
above ground zero-foot marker used by Battelle.
• Figure 3. Tool start position with hydrant adaptor and odometer wheel.
To prevent rubbing of the cable against the inside of the pipe opening, a roller system at the pipe
entrance was improvised in the field.
Two runs were performed; with the first one on September 3. Upon download and review of the
September 3rd data, the inspection speed was too determined too high, and the tool appeared to have
experienced significant surging during the inspection. As a result, it was decided to rerun the line the
next day at a lower speed.
On September 4th, the tagline winch at the east excavation began pulling the tool into the line shortly
after 8:30am at a target speed of 15 feet/min. The inspection took approximately 2.5 hours to
complete. The tool was disassembled in the East pit, and retrieved using the backhoe.
-------
See Snake tool description
The Russell NDE Systems' See Snake line of RFT tools are pipe inspection tools that employ Remote
Field Technology for measuring pipe wall thickness. RFT technology works by detecting changes in an AC
electromagnetic field generated by the tool. The field interacts with the metal in the encompassing pipe
and becomes stronger in areas of metal loss. The field interactions are measured by on board detectors,
and subsequently processed on the tool itself using A/D converters and digital processors. The processed
data is stored on board. Once all the data is acquired, dedicated analysis software is applied to generate
accurate information on the wall thickness of the line. Figure 4 below schematically shows the magnetic
coupling path between the exciter section of the tool and the detectors.
Exciter Coll
Lead To
Instrument and
Data Acquisition
Computer
Signal Flow Path
• Figure 4. Schematic of magnetic interaction between RFT tool and Pipe
The hard diameter of the tool is significantly smaller than the ID of the pipe to allow for protrusions, lining
and scale. Centralizers maintain a uniform annulus between the tool and the pipe. The connection with the
street-level world is made through a wire line, which runs over an odometer sheave to provide an accurate
distance reading of the tool.
The tool detects wall thinning caused by corrosion or erosion, as well as line features such as joint
couplings, branches and elbows. The range is limited by battery power for free swimming runs, and the
amount of wire-line on the winch for tethered runs.
8
-------
The complete system used to perform the waterline inspection includes the following equipment:
» 24-inch Waterline See Snake RFT tool with data download USB box.
» Odometer Hydrant Adapter, with supporting shoring rod.
» Cleaning Swab
» Wireline truck with winch fitted with 1 km of wireline.
» Odometer Adaptor Box
» Laptop running Distance Logger (1.2.3).
» Following data download and viewing software: Linx version 1.9.7, Merger Version 1.7.16, AdeptPro
MC1.5.
The image below shows the setup, with winch truck, hydrant odometer, shoring rod, and spent cleaning
swab. The wireline truck is aligned with the launch point to insure the straightest pull possible from the
winch to the entry point.
• Figure 5. Wireline Truck and hydrant setup during EPA demo September 2009.
-------
Field Notes
Examination Date:
Lead Technician:
Weather:
Target Distance:
Launch:
04 Sep.09 | Arrive Site: 07:00 Depart Site: 14:30
DER
Technician DCL, YMY, AS
Hot(100°F). Clear. Humid
21 00ft m
West most
excavation pit
Field Sketch & Site Observations:
Swabbing Performed
By:
No. Soft Swabs:
Operational Comments:
Distance^ 2059ft Run Direction: West to East
GIS Ref:
Appendix 2
Louisville Water Company and Russell NDE
1
No. Hard Swabs: 0
Run was performed twice, because of surging and high speeds during first inspection on Sep 3, 2009.
• Table 3. Inspection notes from Field Crew.
1O
-------
Calibration
Battelle prepared wall loss defects of different depths and size at selected locations along the length of
the pipe. The specifications of a number of these defects were shared with Russell NDE Systems to
allow calibration of the RFT equipment.
Unfortunately, the RFT data at the specified locations for the calibration defects was extremely noisy.
The noise was present on both the September 3rd data and the September 4th data, pointing at
possible magnetic permeability noise.
In general the magnetic permeability of a pipe section remains fairly constant over its length; however
it is possible for stresses or other external factors to locally change the permeability of the steel
material. This is quite unusual, but if present, the RFT tool (which measures magnetic fields far weaker
than the earth's magnetic field) would see these changes in the magnetic properties of the pipe. If the
magnetic permeability variations are very strong, they can become "noise" that masks potential
defects.
Possible causes for the permeability noise:
1) If the calibration defects were machined with no or little coolant, this could cause stresses in the
pipe around the defects and locally change the magnetic permeability.
2) If the machining equipment for the defects employed a magnetic base to clamp the equipment to
the pipe, the strong permanent magnets would alter the permeability significantly.
3) It is also possible that some of the other NDE techniques used permanent magnets for attaching
their external scanning devices, again these would leave large magnetic "imprints".
4) Finally, some of the other NDE techniques may have tried to magnetically saturate the pipes at
the defect locations. That process would also leave large magnetic imprints on the pipe.
For optimal RFT accuracy, a calibration is performed using pipe with the same nominal pipe properties
(WT and grade) as the pipe being inspected. However, in this case the data from the calibration
defects was too noisy to be usable. So instead the calibration was performed by running the tool
through a 24-inch calibration pipe in our yard and comparing the data from the cast-iron main to data
from the yard calibration.
Based on the above procedure, the defect accuracy is expected to be +20%/-20% for short (local) wall
loss, and +/-10% for long (general) wall loss. The above accuracy range is valid for indications
sufficiently removed from major features, such as Bell-and-Spigot connections.
11
-------
Analysis Results
Location Reporting and Inspection Lengths.
The logged distance data for the Louisville Westport Road Line was 2059ft, with zero set at the launch
hydrant Tee. The first three joints were not analyzed due to initial surging at the start, and because the
joints were the first to be removed as part of the replacement program.
Analysis Results
Features
All Bell-and-Spigot joints were clearly visible in the data. Some other large features were observed, but
they could not always be correlated back to above ground observations from the field crew. Valves and
tees branches are indicated were believed present.
• 12.2ft joint lengths were common throughout the line. For a detailed joint breakdown please see the
Pipe Tally table in Appendix 1, which provides locations of the Bell-and-Spigot.
• A number of major line features were noticed in the data. These are believed to be two valves and two
branches.
Anomalies
The inspection of the water line resulted in 367 wall loss indications. A histogram of the results show that a
majority of the defects are less than or equal to 50% deep, with a much smaller group in the 60-80%
range, and only a few defects 90% or deeper. More importantly the results from the See Snake tool show
that the deep defects are concentrated within the first half of the line, leaving about half the line in relatively
good shape.
Defect Histogram
8 60.00
f]
20-30 30-40 40-50 50-60 60-70 70-80
Defect Depth [in % of Wall thickness]
• Figure 6. Defect Histogram (for example the count at 70% deep are defects that are deeper than 60% but less than 70%).
12
-------
Defect depth [% of nominal thickness]
Defect Depth as a function of distance along the length of the pipe.
•
•
•
«*• . V
/•/*• . ****•• —
• » »* » «
« «
*»»*»«»»»•» »» *» «*
.-• • . «••: s.'-
-.••.• .- .:•••-•:: •;--<,: ... . ,. . • .
•«. . .•&•'.» •?.:••: -.t?.;i. ••%'."•.•.;
0. 00 200. 00 400. 00 600. 00 800. 00 1 000. 00 1 200. 00 1 400. 00 1 600. 00 1 800. 00 2000. 00
Distance [Ft]
• Figure 7. Defect Scatter graph
See appendix 1 for a complete list of recorded wall loss anomalies. Both location and clock position are
documented.
13
-------
Disclaimer
Russell NDE Systems Inc.
SCOPE OF SERVICES:
The agreement of Russell NDE Systems Inc. to perform services extends only to those services provided for in writing. Under no circumstances shall
such services extend beyond the performance of the requested services. It is expressly understood that all descriptions, comments and expressions
of opinion reflect the opinions or observations of Russell NDE Systems Inc. based on information and assumptions supplied by the owner/operator
and are not intended nor can they be construed as representations or warranties. Russell NDE Systems Inc. is not assuming any responsibilities of
the owner/operator and the owner/operator retains complete responsibility for the engineering, manufacture, repair and use decisions as a result of
the data or other information provided by Russell NDE Systems Inc. Nothing contained in this Agreement shall create a contractual relationship with
or cause of action in favor of a third party against either the Line Owner or Russell NDE Systems Inc. In no event shall Russell NDE Systems Inc.'s
liability in respect of the services referred to herein exceed the amount paid for such services.
STANDARD OF CARE:
In performing the services provided, Russell NDE Systems Inc. uses the degree, care, and skill ordinarily exercised under similar circumstances by
others performing such services in the same or similar locality. No other warranty, expressed or implied, is made or intended by Russell NDE
Systems Inc.
Compilation of Background Information for Report
Russell NDE Systems Inc undertakes to take every reasonable effort to generate an accurate "Condition Assessment Analysis" upon completion of
the "Data Acquisition Stage" of each "Infrastructure Condition Assessment Contract". This often requires fact checking against sources of information
from the client as well as third party contractors and vendors. Such information falls into the categories of Properties of the Pipe; (Material & Physical
properties), Pipe Fittings; (Dimensional and Positional information), Pipeline Design; (Plan & Profile Drawings - sub-surface piping, ISO Drawings of
surface infrastructure), Construction Methods for the Pipeline; (Shop Bends vs. Field Bends), Protection Infrastructure for the Pipeline; (Active or
Passive Cathodic Protection, Rock Guard exterior coating, interior lining, casings, etc.), Alterations to the Pipeline; (Repairs, Changes, Additions),
Corrosion/Erosion Information for the Pipeline; (Break History, Independent NOT Inspection of Dig Sites, Laboratory Analysis of Corrosion Deposits)
Ancillary Services used to complete the ILI Data Acquisition; (Nitrogen, Compressed Air, Water Pumping to propel the ILI to Target distance) and any
other related factors that may aid in obtaining the most accurate report results currently available.
14
-------
Appendix 1: Remote Field Operation
Background information on tool.
In the basic RFT probe shown in the figure below, there is one exciter coil and one detector coil. Both
coils are wound co-axial with respect to the examined pipe, and are separated by a distance greater
than two (2) times the pipe diameter. The actual separation depends on the application, but will
always be a minimum of 2 pipe diameters. It is this separation that gives RFT its name - the detector
measures the EM field remote from the exciter. Although the fields have become very small at this
distance from the exciter, they contain information on the full thickness of the pipe wall.
Energy flaw path
be — »^=
,_ ,
5
lead
The detector electronics include high-gain instrumentation amplifiers and steep noise filters. These
are necessary in order to retrieve the remote field signals. The detector electronics output the
amplitude and phase of the remote field signal to an on-board storage device. The data is recalled for
display, analysis and reporting purposes after the examination process is completed.
[1]AtB2.f2:250Hz
Presenting RFT data: Strip Chart display & Phase-Amplitude Diagrams.
A Strip Chart displays the detector data as a function of time or the axial distance along the length of
the pipeline. Phase and log-amplitude are the preferred quantities for the strip-chart display, because
they are both linear indicators of overall wall-thickness. The general convention for strip charts is that
deflections to the left represent metal loss, and deflections to the right wall thickening.
A phase-amplitude diagram is a two-dimensional representation of the detector output voltage, with
the angle representing phase with respect to a reference signal, and the radius representing
amplitude (ASNT E 2096). The detector signals are drawn as vector points in polar coordinates with
the angle representing the phase and the radius representing the amplitude. Axial distance
information is not available on amplitude-phase
diagrams; yet, they are used for sizing flaws.
By combining amplitude-phase diagrams with
strip charts, the distance information can be
included.
Phase amplitude diagrams are also known as
"voltage plane displays". On the voltage plane
display, the nominal signal is placed at (1,0).
Besides the detector information, the Voltage
Plane has a number of static components: the
origin, the x- and y-axes, and the exponential
skin depth reference curve. The curve starts at
0,0 (i.e. zero voltage, at origin), and follows a
spiral path that traces the path (locus) of the
phasors as the overall wall thickness of a
casing is decreased. Full circumferential flaws
fall directly on this curve (see figure on the right
for examples of full circumferential defect
indications).
15
-------
Appendix 2: Site Sketch
> Louisville Westport Road Line Site Sketch.
16
-------
Appendix 3: RFT Inspection results for the 24-inch cast iron pipe Westport Rd demo
Distance from
EPA zero feet
reference (ft)
8.00
12.50
24.50
36.55
38.99
44.05
48.74
60.94
70.77
73.16
74.94
81.74
85.41
92.41
94.29
97.54
99.40
105.94
106.96
108.53
109.73
111.30
112.59
114.62
115.67
Distance
from US B&S
(ft)
2.44
7.50
9.83
1.78
8.58
7.00
8.88
1.87
8.40
9.42
11.00
1.57
2.86
4.89
5.94
Joint #
1
2
3
4
5
6
7
8
9
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
53
<20
26
34
21
40
36
32
27
25
32
22
50
60
32
%
Remaining
47
>80
74
66
79
60
64
68
73
75
68
78
50
40
68
Actual
Remaining
(inch)
0.35
>0.6
0.56
0.49
0.60
0.45
0.48
0.51
0.55
0.56
0.51
0.58
0.38
0.30
0.51
Sample
number
66
333
889
1404
2871
4054
4341
4555
5373
5814
6656
6882
7273
7498
8284
8406
8596
8739
8928
9084
9328
9454
Channel
clock
position
looking
US
4:00
4:30
8:30
5:30
11:00
11:00
11:00
4:30
9:00
11:00
8:30
4:30
4:30
5:00
5:00
Comment
Start of run
B/S
B/S
B/S
Wall Loss Indication
Wall Loss Indication
B/S
B/S
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication - Major
Wall Loss Indication - Major
17
-------
Distance from
EPA zero feet
reference (ft)
117.10
121.90
123.96
125.29
134.12
137.57
146.33
148.67
158.42
161.20
165.48
170.63
172.18
177.42
182.83
185.11
191.75
192.53
195.17
197.06
198.53
199.91
202.52
207.46
215.37
216.87
219.48
220.78
Distance
from US B&S
(ft)
7.37
2.06
3.38
3.45
2.34
2.78
7.06
1.55
6.78
2.28
8.92
9.71
1.90
3.36
4.74
7.35
7.91
9.41
1.30
Joint #
10
11
12
13
14
15
16
17
18
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
54
46
35
45
65
70
44
59
70
65
36
34
55
35
98
92
73
58
58
%
Remainin
g
46
54
65
55
35
30
56
41
30
35
64
66
45
65
2
8
27
42
42
Actual
Remain!
"g
(inch)
0.35
0.41
0.49
0.42
0.26
0.23
0.42
0.30
0.23
0.26
0.48
0.49
0.34
0.49
0.02
0.06
0.20
0.31
0.32
Sample
number
9626
10203
10451
10610
11672
12087
13141
13423
14595
14930
15445
16064
16250
16880
17531
17805
18604
18698
19015
19243
19420
19585
19900
20494
21445
21625
21939
22096
Channel
clock
position
looking
US
4:30
12:00
12:00
4:30
11:00
4:30
9:30
4:30
4:30
4:30
10:30
8:30
3:30
8:30
4:30
4:30
4:00
9:30
4:00
Comment
Wall Loss Indication - Major
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Wall Loss Indication - Major
B/S
Wall Loss Indication - Major
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
18
-------
Distance from
EPA zero feet
reference (ft)
226.62
227.35
229.39
231.63
233.00
243.74
244.98
251.24
253.11
255.90
259.17
262.94
268.01
269.27
270.44
275.44
280.25
281.93
283.22
292.63
294.91
297.96
304.82
306.34
307.16
316.96
319.57
328.97
Distance
from US B&S
(ft)
7.13
7.86
9.91
1.38
1.24
7.50
9.37
3.27
7.04
1.26
2.42
7.42
1.69
2.97
2.29
5.33
1.53
2.34
2.61
Joint #
19
20
21
22
23
24
25
26
27
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
72
62
37
52
40
<20
41
52
46
67
43
64
34
64
70
87
63
63
36
%
Remainin
g
28
38
63
48
60
>80
59
48
54
33
57
36
66
36
30
13
37
37
64
Actual
Remain!
"g
(inch)
0.21
0.29
0.47
0.36
0.45
>0.6
0.45
0.36
0.41
0.25
0.43
0.27
0.50
0.27
0.22
0.10
0.28
0.28
0.48
Sample
number
22798
22885
23131
23400
23565
24857
25005
25759
25983
26319
26713
27167
27776
27927
28068
28669
29247
29450
29605
30737
31003
31358
32157
32341
32440
33619
33971
35238
Channel
clock
position
looking
US
4:30
9:30
10:30
10:30
3:30
10:30
4:00
3:00
11:00
4:00
3:30
3:30
10:30
4:00
4:00
4:00
4:00
3:30
4:00
Comment
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication - Major
Wall Loss Indication - Major
B/S
Wall Loss Indication - Major
Wall Loss Indication - Major
B/S
Wall Loss Indication
B/S
19
-------
Distance from
EPA zero feet
reference (ft)
332.31
341.45
344.04
353.64
356.81
365.83
378.05
390.32
398.28
402.50
406.06
411.03
414.77
419.82
422.74
425.00
426.95
429.01
439.16
441.97
442.61
443.63
445.86
447.78
451.29
452.83
455.47
457.52
Distance
from US B&S
(ft)
3.35
2.59
3.17
7.95
3.56
8.53
5.05
7.97
10.23
2.06
2.80
3.44
4.47
6.69
8.62
1.55
4.18
6.24
Joint #
28
29
30
31
32
33
34
35
36
37
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
51
23
61
<20
40
33
74
57
32
35
64
70
64
59
73
60
73
64
%
Remainin
g
49
77
39
>80
60
67
26
43
68
65
36
30
36
41
27
40
27
36
Actual
Remain!
"g
(inch)
0.37
0.58
0.29
>0.6
0.45
0.50
0.20
0.32
0.51
0.49
0.27
0.23
0.27
0.31
0.20
0.30
0.20
0.27
Sample
number
35642
36742
37009
38003
38358
39370
40840
42316
43272
43779
44208
44806
45255
45863
46214
46486
46721
46968
48190
48527
48604
48727
48995
49226
49647
49834
50150
50397
Channel
clock
position
looking
US
10:00
3:30
3:00
5:00
3:00
9:00
3:00
2:30
9:00
3:00
2:30
2:30
3:00
2:30
2:30
2:30
2:30
2:30
Comment
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Wall Loss Indication
B/S
B/S
B/S
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
20
-------
Distance from
EPA zero feet
reference (ft)
463.48
465.90
467.25
470.56
475.70
478.21
478.37
479.77
482.64
487.86
488.61
489.95
490.16
491.85
494.84
496.60
498.44
500.08
500.62
502.06
509.83
512.31
514.25
515.05
524.51
525.40
527.14
527.86
Distance
from US B&S
(ft)
2.42
3.77
7.08
2.50
2.66
4.07
6.93
0.75
2.09
2.29
3.98
6.97
8.74
10.58
0.54
1.99
9.76
1.95
2.74
0.89
2.62
3.35
Joint #
38
39
40
41
42
43
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
63
51
48
52
48
46
48
69
39
23
36
42
49
38
66
44
37
43
36
44
68
50
%
Remainin
g
37
49
52
48
52
54
53
31
61
77
64
58
51
62
34
56
63
57
64
56
32
50
Actual
Remain!
"g
(inch)
0.28
0.37
0.39
0.36
0.39
0.41
0.39
0.23
0.46
0.58
0.48
0.43
0.38
0.46
0.26
0.42
0.47
0.43
0.48
0.42
0.24
0.37
Sample
number
51114
51406
51568
51966
52584
52885
52904
53074
53418
54047
54137
54298
54323
54525
54885
55098
55319
55515
55580
55754
56689
56987
57221
57317
58454
58561
58770
58858
Channel
clock
position
looking
US
2:00
9:30
2:30
2:30
9:00
2:30
9:00
9:00
10:30
9:30
6:30
6:30
8:30
9:00
2:30
1:30
9:00
2:30
2:30
2:00
2:00
2:30
Comment
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
21
-------
Distance from
EPA zero feet
reference (ft)
528.43
531.62
532.18
533.30
536.57
537.84
538.29
539.14
539.35
543.49
544.95
545.64
548.77
550.39
550.56
551.46
561.00
563.37
564.92
569.06
573.28
575.84
576.20
576.85
577.18
579.34
585.40
587.19
Distance
from US B&S
(ft)
3.92
7.10
7.67
8.79
1.27
1.72
2.56
2.77
6.91
8.37
9.07
1.63
1.80
2.69
2.37
3.92
8.06
2.55
2.91
3.57
3.90
6.06
1.79
Joint #
44
45
46
47
48
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
24
35
66
41
46
38
60
44
36
48
42
34
43
51
40
49
64
39
51
46
32
45
46
%
Remainin
g
76
65
34
59
54
62
40
56
64
52
58
66
57
49
60
51
36
61
49
54
68
55
54
Actual
Remain!
"g
(inch)
0.57
0.49
0.25
0.44
0.40
0.46
0.30
0.42
0.48
0.39
0.43
0.49
0.42
0.37
0.45
0.38
0.27
0.46
0.37
0.40
0.51
0.41
0.40
Sample
number
58926
59309
59377
59512
59905
60057
60111
60213
60239
60737
60912
60996
61371
61567
61588
61696
62843
63128
63314
63812
64320
64627
64670
64750
64789
65048
65778
65996
Channel
clock
position
looking
US
9:00
8:30
2:00
8:30
2:00
7:00
2:00
12:00
2:30
2:30
2:30
9:00
2:00
2:00
9:30
1:00
1:30
10:30
1:30
11:00
1:30
1:30
1:30
Comment
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
22
-------
Distance from
EPA zero feet
reference (ft)
587.59
587.80
591.73
593.25
594.01
594.57
597.59
599.61
599.92
600.26
601.10
606.15
607.14
609.70
612.39
613.15
616.74
617.64
619.67
620.71
621.93
622.80
623.77
624.08
624.51
629.49
629.68
632.03
Distance
from US B&S
(ft)
2.18
2.40
6.33
7.84
8.60
9.17
2.02
2.32
2.66
3.50
8.56
9.55
2.69
3.45
7.04
7.94
9.98
11.02
0.87
1.85
2.16
2.58
7.56
7.75
10.10
Joint #
49
50
51
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
33
38
20
22
25
64
43
<20
32
29
24
30
50
46
27
47
22
<20
41
47
38
33
<20
42
21
%
Remainin
g
67
62
80
78
75
36
57
>80
68
71
76
70
50
54
73
53
78
>80
59
53
62
67
>80
58
79
Actual
Remain!
"g
(inch)
0.50
0.47
0.60
0.59
0.56
0.27
0.43
>0.6
0.51
0.53
0.57
0.53
0.37
0.40
0.55
0.40
0.58
>0.6
0.44
0.40
0.47
0.50
>0.6
0.43
0.59
Sample
number
66044
66070
66549
66734
66827
66896
67265
67507
67544
67585
67686
68294
68413
68720
69044
69135
69567
69675
69920
70045
70192
70296
70414
70451
70502
71101
71124
71406
Channel
clock
position
looking
US
9:00
1:30
1:30
6:30
10:30
1:30
1:00
8:30
1:30
1:30
10:30
6:00
1:30
2:00
11:00
5:00
11:00
4:30
2:00
1:00
9:00
1:30
4:00
9:00
10:30
Comment
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication -Major
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
23
-------
Distance from
EPA zero feet
reference (ft)
632.29
634.18
635.12
636.24
637.21
642.26
643.40
646.37
656.82
658.56
661.85
668.46
670.78
677.01
678.00
678.80
680.52
683.14
684.94
692.78
695.33
697.32
697.84
698.26
707.63
710.20
711.00
719.79
Distance
from US B&S
(ft)
10.36
0.93
2.05
3.03
8.08
9.22
10.44
3.29
9.90
6.22
7.21
8.02
9.74
1.79
9.63
1.99
2.50
2.93
2.57
3.37
Joint #
52
53
54
55
56
57
58
59
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
22
41
28
23
23
<20
38
<20
27
20
<20
<20
<20
24
31
38
<20
27
<20
28
%
Remainin
g
78
59
72
77
77
>80
62
>80
73
80
>80
>80
>80
76
69
62
>80
73
>80
72
Actual
Remaining
(inch)
0.59
0.44
0.54
0.57
0.58
>0.6
0.46
>0.6
0.55
0.60
>0.6
>0.6
>0.6
0.57
0.52
0.47
>0.6
0.55
>0.6
0.54
Sample
number
71437
71665
71780
71918
72038
72661
72801
73167
74396
74602
74998
75792
76072
76820
76939
77040
77243
77558
77773
78711
79017
79256
79319
79370
80496
80805
80901
81959
Channel
clock
position
looking
US
6:30
1:30
8:30
8:30
6:30
4:00
8:30
1:00
3:30
6:00
5:30
6:00
4:30
4:00
9:00
8:00
10:30
5:30
3:30
2:30
Comment
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
24
-------
Distance from
EPA zero feet
reference (ft)
722.29
727.55
728.00
729.16
729.76
732.00
733.56
738.67
741.34
744.22
746.53
748.20
752.41
752.71
754.47
756.43
758.90
759.82
763.17
763.40
764.70
765.25
765.43
768.64
770.60
771.43
771.76
774.75
Distance
from US B&S
(ft)
2.50
7.76
8.21
9.37
9.97
1.56
6.66
9.34
2.30
3.98
8.19
8.49
10.25
2.47
3.39
6.74
6.97
8.27
8.82
9.00
1.96
2.79
3.12
6.12
Joint #
60
61
62
63
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
55
63
63
22
47
49
39
49
46
40
36
21
<20
60
44
42
32
23
<20
44
23
26
48
36
%
Remainin
g
45
37
37
78
53
51
61
51
54
60
64
79
>80
40
56
58
68
77
>80
56
77
74
52
64
Actual
Remaining
(inch)
0.33
0.28
0.28
0.59
0.40
0.39
0.46
0.39
0.41
0.45
0.48
0.59
>0.6
0.30
0.42
0.43
0.51
0.58
>0.6
0.42
0.58
0.56
0.39
0.48
Sample
number
82260
82892
82946
83085
83158
83427
83615
84229
84551
84897
85175
85376
85883
85919
86130
86365
86663
86773
87176
87204
87360
87426
87448
87834
88070
88170
88209
88570
Channel
clock
position
looking
US
9:00
1:00
1:00
3:30
1:30
1:30
2:00
1:00
1:00
12:00
10:30
8:00
5:30
0:30
0:30
1:00
0:00
0:30
5:30
1:00
1:00
1:00
3:00
1:00
Comment
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
25
-------
Distance from
EPA zero feet
reference (ft)
775.08
778.21
780.84
782.04
783.17
784.16
784.19
785.58
789.53
790.10
790.46
792.97
795.03
795.51
795.78
797.40
798.97
799.72
800.85
800.94
802.27
803.16
805.18
807.55
808.83
814.59
815.08
817.31
Distance
from US B&S
(ft)
6.45
9.57
1.20
2.32
3.32
3.35
4.74
8.69
9.26
9.62
2.06
2.53
2.80
4.43
6.00
6.74
7.87
7.97
9.30
10.19
2.37
3.65
9.42
9.91
Joint #
64
65
66
67
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
43
25
24
44
32
42
59
32
<20
23
37
34
<20
63
33
36
22
36
39
<20
24
24
<20
51
%
Remainin
g
57
75
76
56
68
58
41
68
>80
77
63
66
>80
37
67
64
78
64
61
>80
76
76
>80
49
Actual
Remaining
(inch)
0.43
0.56
0.57
0.42
0.51
0.43
0.31
0.51
>0.6
0.58
0.47
0.50
>0.6
0.28
0.50
0.48
0.58
0.48
0.46
>0.6
0.57
0.57
>0.6
0.37
Sample
number
88609
88985
89301
89446
89581
89701
89705
89871
90347
90415
90458
90761
91008
91065
91098
91294
91482
91572
91707
91719
91879
91986
92228
92514
92668
93361
93420
93687
Channel
clock
position
looking
US
3:00
2:00
0:00
0:30
6:00
4:00
3:30
5:30
2:00
10:30
0:30
0:30
3:00
0:30
0:30
0:30
3:30
1:30
1:00
6:00
3:30
3:00
3:00
5:30
Comment
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication - Major
B/S
26
-------
Distance from
EPA zero feet
reference (ft)
819.10
819.20
823.49
824.84
826.56
829.75
833.04
839.47
841.87
843.05
844.39
845.49
847.74
854.04
861.01
862.01
863.82
866.35
868.91
878.53
885.41
889.22
890.81
893.39
897.61
903.06
905.56
909.37
Distance
from US B&S
(ft)
1.80
1.90
6.19
7.53
9.25
3.29
9.72
1.18
2.52
3.62
5.87
6.97
7.97
9.79
2.56
6.88
10.69
2.57
6.79
2.49
6.31
Joint #
68
69
70
71
72
73
74
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
31
26
59
48
30
34
29
20
<20
32
52
35
44
33
24
23
25
26
24
27
21
%
Remainin
g
69
74
41
52
70
66
71
80
>80
68
48
65
56
67
76
77
75
74
76
73
79
Actual
Remaining
(inch)
0.52
0.55
0.31
0.39
0.53
0.50
0.54
0.60
>0.6
0.51
0.36
0.48
0.42
0.51
0.57
0.58
0.56
0.56
0.57
0.55
0.59
Sample
number
93904
93915
94432
94594
94800
95184
95580
96353
96642
96784
96945
97077
97347
98105
98943
99064
99282
99585
99894
101051
101879
102336
102528
102837
103345
104002
104302
104760
Channel
clock
position
looking
US
8:00
10:30
12:30
12:30
12:30
12:30
7:30
12:30
12:30
12:30
8:00
11:30
11:30
5:00
3:30
8:00
8:00
8:00
12:30
11:30
9:30
Comment
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
27
-------
Distance from
EPA zero feet
reference (ft)
909.99
912.17
915.11
917.65
917.73
918.74
927.29
939.47
942.79
947.92
948.50
951.81
954.21
963.88
970.44
971.57
973.86
976.15
983.37
986.19
988.66
990.60
990.72
991.11
1000.58
1002.74
1003.67
Distance
from US B&S
(ft)
6.92
9.11
2.54
2.62
3.63
3.31
8.45
9.03
2.39
6.57
7.69
9.98
7.22
10.04
1.94
2.06
2.44
2.16
3.08
Joint #
75
76
77
78
79
80
81
82
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
<20
<20
27
<20
27
22
21
36
26
30
28
25
35
<20
<20
27
26
23
%
Remainin
g
>80
>80
73
>80
73
78
79
64
74
70
72
75
65
>80
>80
73
74
77
Actual
Remaining
(inch)
>0.6
>0.6
0.55
>0.6
0.54
0.59
0.60
0.48
0.55
0.52
0.54
0.56
0.49
>0.6
>0.6
0.55
0.56
0.58
Sample
number
104834
105097
105450
105756
105766
105887
106915
108380
108779
109397
109466
109865
110153
111316
112105
112241
112515
112791
113660
113999
114296
114529
114543
114590
115730
115989
116101
Channel
clock
position
looking
US
5:00
9:30
4:30
3:30
2:30
5:30
7:30
4:30
1:00
4:30
11:30
11:00
4:30
9:30
3:30
7:30
8:30
8:30
Comment
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication -part of the
same WL
Wall Loss Indication
B/S
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Wall Loss Indication - Major
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Line Feature: possible Valve
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
28
-------
Distance from
EPA zero feet
reference (ft)
1010.32
1012.84
1025.07
1037.26
1049.32
1053.14
1056.81
1061.38
1073.56
1082.88
1085.68
1090.81
1095.44
1097.91
1100.16
1107.42
1110.06
1122.16
1134.35
1146.54
1152.10
1154.42
1155.49
1158.72
1161.33
1166.22
1167.46
Distance
from US B&S
(ft)
9.74
3.82
7.49
9.32
9.76
2.24
9.51
5.56
7.89
8.95
2.61
7.50
8.73
Joint #
83
84
85
86
87
88
89
90
91
92
93
94
95
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
<20
34
52
<20
<20
<20
27
22
36
35
32
29
30
%
Remainin
g
>80
66
48
>80
>80
>80
73
78
64
65
68
71
70
Actual
Remaining
(inch)
>0.6
0.49
0.36
>0.6
>0.6
>0.6
0.55
0.59
0.48
0.49
0.51
0.53
0.52
Sample
number
116901
117204
118675
120155
121605
122065
122507
123056
124520
125641
125978
126595
127152
127449
127720
128593
128911
130366
132162
133205
133957
134271
134415
134854
135148
135699
135839
Channel
clock
position
looking
US
7:00
4:00
8:30
4:00
12:30
12:30
5:30
3:30
3:30
3:30
2:30
2:00
1:00
Comment
Wall Loss Indication
B/S
B/S (Tee or Branch?)
B/S
B/S
Wall Loss Indication
Wall Loss Indication
B/S
B/S
Wall Loss Indication
B/S
Very noisy data right after B&S
lasting for about 69-inches
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
B/S
B/S
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
29
-------
Distance from
EPA zero feet
reference (ft)
1168.95
1170.91
1172.35
1177.33
1178.59
1183.10
1185.43
1195.31
1207.64
1219.78
1223.33
1227.06
1231.92
1240.40
1241.14
1244.14
1246.38
1251.43
1253.76
1256.30
1258.52
1266.84
1268.54
1280.85
1283.06
1290.61
1292.94
1295.53
Distance
from US B&S
(ft)
10.22
1.44
6.41
7.68
2.32
3.55
7.28
8.48
9.22
2.24
7.29
9.63
2.22
10.55
14.52
22.07
2.59
Joint #
96
97
98
99
100
101
102
103
104
105
106
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
49
23
20
50
35
28
24
28
26
<20
<20
<20
24
<20
22
27
24
%
Remainin
g
51
77
80
50
65
72
76
72
74
>80
>80
>80
76
>80
78
73
76
Actual
Remaining
(inch)
0.39
0.58
0.60
0.37
0.49
0.54
0.57
0.54
0.56
>0.6
>0.6
>0.6
0.57
>0.6
0.58
0.55
0.57
Sample
number
136007
136229
136400
136993
137144
137682
137961
139150
140633
142093
142520
142969
143553
144573
144662
145022
145292
145900
146180
146485
146753
147754
147958
149438
149704
150612
150892
151204
Channel
clock
position
looking
US
1:30
9:00
4:30
5:30
1:30
6:00
5:00
1:00
1:30
12:00
4:30
12:30
3:00
11:30
11:30
11:30
11:30
Comment
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
B/S
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Possible Slightly Open B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
3O
-------
Distance from
EPA zero feet
reference (ft)
1305.05
1317.24
1327.03
1329.35
1332.34
1336.47
1338.12
1338.97
1341.48
1348.77
1350.26
1351.46
1353.72
1355.99
1356.94
1362.50
1365.85
1368.06
1372.96
1372.99
1377.99
1380.50
1390.16
1402.36
1411.19
1414.49
1426.62
1438.81
Distance
from US B&S
(ft)
9.79
2.99
7.12
8.77
9.62
7.28
8.78
9.98
2.27
3.22
8.78
2.22
7.11
7.14
2.51
8.83
Joint #
107
108
109
110
111
112
113
114
115
116
117
118
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
30
22
<20
20
<20
21
25
33
20
36
<20
<20
24
24
20
<20
%
Remainin
g
70
78
>80
80
>80
79
75
67
80
64
>80
>80
76
76
80
>80
Actual
Remaining
(inch)
0.53
0.58
>0.6
0.60
>0.6
0.59
0.56
0.51
0.60
0.48
>0.6
>0.6
0.57
0.57
0.60
>0.6
Sample
number
152348
153774
154951
155231
155591
156088
156286
156388
156690
157566
157746
157890
158161
158435
158549
159217
159620
159887
160476
160479
161081
161383
162545
164011
165073
165470
166929
168430
Channel
clock
position
looking
US
10:30
7:30
5:30
9:30
5:00
11:30
9:30
9:30
11:00
5:30
6:00
11:00
10:30
3:30
11:00
10:00
Comment
B/S
B/S
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
B/S
Wall Loss Indication
B/S
B/S
B/S
31
-------
Distance from
EPA zero feet
reference (ft)
1450.94
1458.26
1461.16
1463.16
1475.34
1487.48
1499.68
1511.90
1520.38
1524.04
1536.23
1538.45
1543.45
1545.73
1548.40
1560.66
1572.86
1579.09
1585.00
1588.35
1591.17
1594.27
1597.20
1609.52
1621.71
1629.75
1633.90
Distance
from US B&S
(ft)
7.31
10.22
8.48
2.22
7.22
9.50
6.24
6.17
8.04
Joint #
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
<20
51
<20
<20
<20
<20
27
53
25
%
Remainin
g
>80
49
>80
>80
>80
>80
73
47
75
Actual
Remaining
(inch)
>0.6
0.37
>0.6
>0.6
>0.6
>0.6
0.55
0.35
0.56
Sample
number
169889
170768
171118
171359
172823
174283
175751
177219
178239
178680
180146
180413
181015
181289
181610
183084
184551
185302
186012
186415
186753
187127
187480
188961
190425
191328
191794
Channel
clock
position
looking
US
10:00
12:30
9:30
10:00
3:00
3:00
5:00
11:00
10:00
11:00
7:30
Comment
B/S
Wall Loss Indication
Wall Loss Indication
B/S
B/S
B/S
Possible Open B/S
B/S
Wall Loss Indication
B/S
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
B/S
B/S
Wall Loss Indication
B/S
Noisy data from 1588.4ft to
1590.7ft
Wall Loss Indication
Noisy data from 1594.3 to 1595.4ft
B/S
B/S
B/S
Wall Loss Indication
B/S
32
-------
Distance from
EPA zero feet
reference (ft)
1640.85
1646.09
1647.89
1648.84
1654.36
1655.79
1658.28
1666.05
1668.60
1670.48
1673.90
1678.19
1679.14
1682.71
1692.19
1694.80
1697.09
1697.59
1706.89
1709.15
1715.29
1719.04
1721.59
1731.23
1737.30
1739.79
1743.57
Distance
from US B&S
(ft)
6.95
1.80
2.74
8.27
9.70
7.76
10.32
3.42
7.71
8.66
9.48
2.28
2.78
2.26
8.40
2.55
6.08
8.56
Joint #
135
136
137
138
139
140
141
142
143
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
29
<20
26
43
28
<20
45
23
<20
<20
37
<20
<20
<20
29
40
%
Remainin
g
71
>80
74
57
72
>80
55
77
>80
>80
63
>80
>80
>80
71
60
Actual
Remaining
(inch)
0.53
>0.6
0.55
0.43
0.54
>0.6
0.41
0.58
>0.6
>0.6
0.47
>0.6
>0.6
>0.6
0.54
0.45
Sample
number
192570
193156
193372
193486
194150
194322
194622
195556
195863
196088
196500
197016
197130
197559
198699
199014
199289
199349
200467
200740
201477
201929
202219
203316
204047
204345
204800
Channel
clock
position
looking
US
4:30
5:00
5:30
5:30
5:30
4:30
9:30
5:00
9:30
8:00
5:00
9:00
9:30
8:30
9:30
8:30
Comment
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Valve
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Line feature - Branch?
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
33
-------
Distance from
EPA zero feet
reference (ft)
1747.09
1755.53
1758.26
1767.79
1774.42
1775.28
1775.45
1779.98
1786.98
1792.14
1796.46
1800.46
1800.48
1802.10
1804.38
1806.66
1811.46
1816.56
1819.36
1825.11
1826.29
1828.66
1830.32
1835.57
1837.57
1840.98
Distance
from US B&S
(ft)
6.63
7.49
7.65
6.99
4.32
8.32
8.34
9.97
2.28
7.08
2.79
8.55
9.73
1.66
6.90
8.91
Joint #
144
145
146
147
148
149
150
151
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
<20
<20
<20
<20
<20
24
<20
<20
<20
<20
29
<20
<20
<20
<20
%
Remainin
g
>80
>80
>80
>80
>80
76
>80
>80
>80
>80
71
>80
>80
>80
>80
Actual
Remaining
(inch)
>0.6
>0.6
>0.6
>0.6
>0.6
0.57
>0.6
>0.6
>0.6
>0.6
0.53
>0.6
>0.6
>0.6
>0.6
Sample
number
205224
206239
206567
207714
208498
208599
208619
209155
209996
210617
211136
211618
211620
211815
212089
212364
212941
213554
213890
214583
214724
215010
215209
215840
216081
216491
Channel
clock
position
looking
US
5:00
6:30
8:00
6:30
3:00
5:30
6:00
9:30
10:30
2:00
4:00
1:30
7:30
3:30
3:30
Comment
Noisy data from 1747.1ft to
1753.5ft
B/S
Noisy data from 1758.3ft to
1764.2ft
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Hydrant Branch
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
34
-------
Distance from
EPA zero feet
reference (ft)
1848.84
1850.49
1853.19
1855.11
1855.37
1861.66
1865.37
1867.67
1872.60
1872.83
1877.53
1878.99
1880.18
1884.05
1887.04
1889.76
1892.67
1897.15
1902.03
1904.47
1904.69
1914.24
1922.33
1923.96
1926.41
1936.27
1936.27
Distance
from US B&S
(ft)
7.86
9.52
1.93
2.19
8.47
2.29
7.22
7.46
1.46
2.64
6.52
9.51
2.91
7.39
2.44
2.66
8.09
9.72
9.86
Joint #
152
153
154
155
156
157
158
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
26
25
<20
<20
22
<20
<20
<20
32
<20
26
<20
<20
<20
<20
<20
<20
<20
<20
%
Remainin
g
74
75
>80
>80
78
>80
>80
>80
68
>80
74
>80
>80
>80
>80
>80
>80
>80
>80
Actual
Remaining
(inch)
0.56
0.56
>0.6
>0.6
0.58
>0.6
>0.6
>0.6
0.51
>0.6
0.56
>0.6
>0.6
>0.6
>0.6
>0.6
>0.6
>0.6
>0.6
Sample
number
217436
217636
217959
218191
218222
218978
219425
219701
220294
220322
220887
221063
221205
221671
222031
222357
222708
223247
223833
224128
224154
225302
226275
226471
226766
227971
227971
Channel
clock
position
looking
US
4:00
8:30
4:30
8:30
4:00
1:30
9:30
5:00
4:30
9:30
3:30
8:00
4:00
4:00
3:30
8:00
2:30
8:30
3:30
6:30
Comment
Wall Loss Indication - string of
several shallow indications
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Noisy data at 2:30 for most of joint
Wall Loss Indication
35
-------
Distance from
EPA zero feet
reference (ft)
1938.60
1946.15
1946.15
1947.21
1950.73
1956.99
1956.99
1962.86
1971.39
1975.05
1975.06
1977.59
1981.65
1983.05
1987.24
1989.12
1994.83
1999.43
2011.61
2020.54
2023.92
2035.90
2038.25
2044.14
2048.01
2054.73
2057.25
Distance
from US B&S
(ft)
7.54
8.61
6.27
8.53
2.55
6.60
8.00
1.89
7.60
8.93
2.35
8.24
6.71
9.24
Joint #
159
160
161
162
163
164
165
166
167
168
Pipe Wall
Thickness (inch)
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
% Loss
20
<20
23
<20
21
24
28
27
<20
23
<20
<20
21
<20
%
Remainin
g
80
>80
77
>80
79
76
72
73
>80
77
>80
>80
79
>80
Actual
Remaining
(inch)
0.60
>0.6
0.58
>0.6
0.59
0.57
0.54
0.55
>0.6
0.58
>0.6
>0.6
0.59
>0.6
Sample
number
228255
229163
229163
229291
229713
230467
230467
231173
232230
232684
232685
232977
233446
233607
234091
234323
235023
235587
237076
238149
238555
239996
240280
240988
241453
242261
242564
Channel
clock
position
looking
US
2:00
6:30
3:30
3:30
8:30
9:30
2:30
2:30
3:00
3:30
3:30
9:00
3:30
3:30
3:30
Comment
B/S
Noisy data at 2:30 for most of joint
Wall Loss Indication
Wall Loss Indication
B/S
Noisy data at 2:30 for first 4ft joint
Wall Loss Indication
B/S
Wall Loss Indication
B/S
Noisy data at 2:30 for most of joint
Wall Loss Indication
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication
Wall Loss Indication
B/S
B/S
Wall Loss Indication
B/S
B/S
Wall Loss Indication
Wall Loss Indication
B/S
Wall Loss Indication - several
minor indications
Wall Loss Indication
36
-------
Distance from
EPA zero feet
reference (ft)
2059.05
Distance
from US B&S
(ft)
Joint #
169
Pipe Wall
Thickness (inch)
% Loss
%
Remainin
g
Actual
Remaining
(inch)
Sample
number
242780
Channel
clock
position
looking
US
Comment
End of section
37
-------
APPENDIX F:
AESL Report (58 pp.)
F-l
-------
EPA Trials conducted on a 24lnch
Spun Cast Iron Pipeline on Westport
Road in Louisville, Kentucky
Report Number RP3042
-------
CONFIDENTIAL.
ADVANCED ENGINEERING SOLUTIONS LIMITED
DOCUMENT CONTROL
Client: Battelle
Address: 505 King Avenue
Columbus
Ohio
43201
Project: Condition Assessment for EPA Trails
Report: EPA Trials conducted on a 24!nch Spun Cast Iron Pipeline or
Westport Road in Louisville, Kentucky
Author(s): Craig Johnson
Authorised: Dick Treece
Report Issue Status
Issue
01
Date
25/09/2009
Description
First Issue
Author(s)
C Johnson
Authorised
RJ Treece
i
AUTHOR:
APPROVED:
Report RP3042
-------
CONFrOENTlAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
EXECUTIVE SUMMARY
Advanced Engineering Solutions Limited (AESL) were invited by Battelle, on behalf
of the Environmental Protection Agency (EPA), to conduct trials using condition
assessment technology that AESL have developed for the assessment of ferrous
pipelines. A water utility company in Louisville, Kentucky offered a 24inch cement
lined cast iron pipe on which to conduct the demonstrations. The field trails were
conducted the week commencing 17th August 2009.
This report is a continuation of the preliminary report, RP2035, and presents the
results of the pipeline inspections, a detailed structural / statistical analysis and
provides a review of the pipe's condition.
A detailed assessment of the pipe coating and wall condition was conducted at sites
F, L and 2,
During the inspection socket and spigot joints were identified throughout the pipeline
length.
The pipe internal surface is understood to be lined with cement mortar
approximately 5mm in thickness. The pipe's external surface was coated in bitumen
paint.
Overall, the wall thickness at the three condition assessment locations was found to
range from a minimum of 17.6mm to 20.8mm.
Internal and external defects were identified using the Magnetic Flux Leakage (MFL)
External condition assessment tool (ECAT) at all three inspection locations.
Machined defects and threaded holes were found to have been machined into the
pipe at site 2. It is understood that the holes were created for connections to be
fitted. The connections were required to simulate pipe leakage. The machined
defects identified at Site L were analysed in the same manner as the natural
defects. Sizes for these defects have been provided.
Report RP3042
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
CONCLUSIONS
» The pipeline section has been subject to a detailed inspection at 3 locations
* Internal and external corrosion was identified in each location and the depths
of defects estimated
• Estimates of ground and traffic loading have been made and combined with
the internal pressure to estimate pipeline stresses
» Statistical models of the external defect distributions have been derived and
extrapolated over the pipeline length
* Two excavation sites showed similar levels of corrosion with the third site
dissimilar and slightly worse
• Soils samples suggested that the soil varied from fairly corrosive to highly
corrosive along the route
• The statistical distributions have been extrapolated over the length under
consideration and corrosion perforations are predicted to exist if the
unexamined lengths are similar to the excavation locations
» Based on the estimated stresses, the defect distribution models, and the
assumed pipe material properties defects of sufficient depth to cause structural
failure of the pipe may be present.
Report RP3042
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
CONTENTS
DOCUMENT CONTROL ............................................ .....i
1 INTRODUCTION........ ...............1
2 SCOPE OF REPORT ................1
3 DETAILS OF MAIN [[[ .......1
3.1 Background Information ..................... „ , 1
3.2 General.. ....1
3.3 Hydraulic Profile , 2
3,4 Site Access ...........2
4 PIPE ASSESSMENT DATA ...................................2
4.1 Installation Details.................................. 2
4.1.1 Joints , 3
4.1.2 Pipe Protection , 3
4.1.3 Ground Conditions 3
4.2 Wall Thickness Measurements ...............4
4.3 Site Assessment....... .5
4.4 Visual Coating Assessment................................. ...............5
4.S Condition Assessment. ., 7
4.5.1 SiteF 7
4.5.2 Site 2 9
4.5.3 SiteL 12
4,6 Confidence Intervals ........14
5 STRUCTURAL ANALYSIS[[[ 15
5.1 Stress Analysis................................ ........15
5.2 Loading Regimes................... 15
5.2.1 Soil Overburden Loading., ..........15
5.2.2 Traffic loading 16
5.3 Membrane and Bending Stress 16
5.4 Analysis of Structural Significance of Corrosion 17
5.5 Fracture Mechanics Model 17
5.6 Results 18
5.7 Statistical Analysis of defects .....19
5.7.1 External Defects ...19
5.7.2 Internal defects 21
6 REMAINING LIFE[[[ 22
6.1 Perforation 22
6.2 Critical defects... 23
f DISCUSSION 24
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS burnt)
APPENDIX 1 Site Locations
APPENDIX 2 Coating Grids
APPENDIX 3 Soil Conditions
APPENDIX 4 Wall Thickness Measurements
APPENDIX 5 Site Photographs
APPENDIX 6 Confidence Intervals
APPENDIX 7 Stress Analysis Results
APPENDIX 8 Failure Assessment Diagrams
Report RP3042
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
1 INTRODUCTION
Advanced Engineering Solutions Limited (AESL) were invited by Battelle, on behalf
of the Environmental Protection Agency (EPA), to conduct trials using condition
assessment technology that AESL have developed for the assessment of ferrous
pipelines, A water utility company in Louisville, Kentucky offered a 24inch cement
lined spun cast iron pipe on which to conduct the demonstrations. The field trails
were conducted the week commencing 17th August 2009.
2 SCOPE OF REPORT
This report is a continuation of the preliminary report, RP2035 and presents the result
of the site inspections which includes a description of the pipe installation, wall
thickness measurements, and a coating/corrosion inspection for the spun cast iron
sections of the pipeline. The results of a detailed statistical analysis have also been
provided.
An analysis of the buried pipe section was conducted. This was used to estimate the
maximum stress under a minor road load at the pipelines previous operating
pressure.
The Appendices include a pipeline schematic including the inspection locations,
corrosion grids, Soil Conditions, wall thickness readings, site photographs,
confidence intervals and stress analysis results.
3 DETAILS OF MAIN
3.1 Background Information
For the purpose of the demonstration works a water utility company in Louisville, KY
offered a 762m length, 24-inch diameter Delavaud cast iron main. The pipeline was
laid in 1933. Joint leaks have been reported between 1973 and 2003 and one pipe
leak in September 2008. The pipeline is scheduled to be removed and replaced in
September 2009. It is understood that selected sections are to be retrieved for
further analysis in the form of destructive inspection. The results from the various
inspection technologies will be compared with the destructive measurements.
3.2 General
Location / Crossing: Westport Road, Louisville, Kentucky
Type: Minor Road
Number of Pipes: 1
Diameter: 24-inch
Material: Spun Cast Iron
Date Laid: 1933
Report RP3042
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
3.3 Hydraulic Profile
Duty: Potable Water
Current Operating Pressure: 3.6 - 4.0bar
Possible Test Pressure: 23.9bar (Taken from BS1211-1945 Class D
standard)
Supply/Outlet: Chenwith / Ridgeway
Pressure data has been provided by Abraham Chen of Battelle.
3.4 Site Access
Minor Road: Westport Road
o 10no excavations were accessible during the works. Soil analysis was
conducted in all the excavations and condition assessment was conducted in
3no excavations,
» The environment was tested prior to entering the excavation and throughout the
condition assessment works.
» Full circumference Magnetic Flux Leakage scans were successfully completed
at each of the inspection locations.
4 PIPE ASSESSMENT DATA
4,1 Installation Details
The 24inch diameter and 762m length spun cast iron pipeline was located below
Westport Road, Louisville, Kentucky.
In order to provide input data for structural analysis, information from a pipe
manufacturing specification is required, in this case the Client is unable to provide
an exact pipe specification and it is AESL practice to use a pattern of wall thickness
measurements and date laid to determine the most appropriate pipe specification
from available British Standards. The most appropriate standard available is
BS1211-1945 Class D. The principal structural details specified by this Standard are
given in Table 4,1 below.
TABLE 4.1 - PRINCIPAL STRUCTURAL DETAILS FOR MAIN SASH) ON STANDARD BS1 21 1-1945 CLASS D
Nominal Internal Diameter (inches)
Nominal Wall Thickness (mm)
Maximum Wall Thickness (mm)
Minimum Wall Thickness (mm)
Design Pressure* (bar) from Standard
Specified Minimum UTS (MPa) from Standard
Design Stress** {MPa) from standard
24
21.6
22.6
19.8
12,0
194
48
*Design pressure is calculated as 50% of the specified test pressure,
"Design stress is calculated as 25% of the Specified Minimum UTS.
Report RP3042
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
4.1.1 Joints
During the inspection socket and spigot joints were identified throughout the pipeline
length. 2no. socket and spigot joints were identified at site F and 1no socket and
spigot joint was identified at site 2. A socket and spigot joint was identified close to
excavation L. AESL were informed that this joint was leaking during the inspection of
this site,
4.1.2 Pipe Protection
The pipe internal surface is lined with cement mortar approximately 5mm in
thickness. This was identified by Batteile upon the removal of pipe sections as
shown in Figure 4.1. The pipe's external surface was coated in bitumen paint.
FIGURE 4.1 - PHOTOGRAPH PROVIDED BY BATTELLE OF PIPE GROSS SECTION
4.1,3 Ground Conditions
Soil measurements including resistivity, redox, pipe-to-soil potential and pH were
taken at every accessible excavation along the length of the pipeline.
Results from the soil survey were used to calculate a score according to the French
Standard AFNOR A05-250. This is a recognised method of evaluating the ground
corrosiveness to ferrous pipes using parameters such as, nature of the soil,
resistivity, moisture content and pH.
The results of the AFNOR score for each excavation has been provided in Table 4.2
below:
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TABLE 4.2 - SOIL DATA
SITE
SITE1
SITE A
SITEL
SITEB
SITEC
SITE 2
SITED
SFTEE
SITEF
SITE 3
AFNOR
SCORE
6
6
7
5
8
5
6
6
g
7
NATURE OF GROUND
Fairly Corrosive
Fairly Corrosive
Fairly Corrosive
Fairly Corrosive
Highly Corrosive
Fairly Corrosive
Fairly Corrosive
Fairly Corrosive
Highly Corrosive
Fairly Corrosive
The results of the soil properties have been provided in Table A3.1 in appendix 3.
FIGURE 4.2 - BLACK CONTAMINANTS IN THE GROUND
Black and green contaminants in the soil were evident within the sidewalls at some of
the excavations as seen in Figure 4,2.
4.2 Wall Thickness Measurements
The wall thickness was measured using an ultrasound technique while the integrity of
the pipe wall was determined by carrying out a series of scans with the External
Condition Assessment tool (ECAT).
The tolerance on the ultrasonic instruments is 0.01mm for both the Alphagage
(Sonatest Alphagage User Guide, Issue 1) and the Sitescan 140 (Sonatest Sitescan
140 Operators Manual, Issue 4).
10 ultrasonic measurements were taken at every 30-degree pipe orientation. In total
120 ultrasonic measurements were taken at each of the condition assessment
locations, sites 2, L and F.
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A summary of the results of the ultrasound wall thickness measurements are shown
in Table 4.3-4.5 below. A more detailed record of the ultrasound results is provided
in Appendix 4.
TABLE 4.3 - MEASURED WALL THICKNESS RESULTS -SFTE F
Location
Qncnlation from TDC (°)
Total Number of Readings
Min. Wall Thickness (mm)
Max. Wall Thickness (mm)
Mean Wall Thickness (mm)
Standard deviation
1
0
10
18.4
19.5
19.1
0.37
2
30
10
18.5
19.6
19.1
0.34
3
60
10
18 .1
19.4
18.7
0.42
4
90
10
18,0
19.2
18.6
0.39
5
120
10
18.4
20.0
18.8
0.45
6
150
to
18.D
19.5
18,8
0.47
7
180
10
1B.6
19.7
19.1
0.32
8
2tO
to
18,8
20.2
194
0.51
—
9
240
10
18.5
20.8
194
0.66
to
270
10
18.4
20.5
19,3
0.62
11
300
10
18,6
19.3
19.0
0.23
12
330
10
18.6
19.5
19.1
0.28
Overall
0-360
120
mo
20.8
19.0
0.49
TABLE 4.4 - MEASURED WALL THICKNESS RESULTS -STTE 2
Location
Orientation from TDC O
Total Number of Readings
Min. Wall Thickness (mm)
Max. Wall Thickness (mm)
Mean Wall Thickness (mm)
Standard deviation
1
0
10
18.1
19.3
18.6
043
2
30
10
18.0
1B.7
18,4
0.25
3
60
10
18.0
18.9
1S.4
0.33
4
90
10
17.8
18.8
18.2
0.36
5
120
10
18,0
192
18,6
0.41
6
150
10
17.8
19,5
18,4
0.56
7
180
10 ~l
18,3
19,2
18.6
0.30
B
210
10
18.2
193
18.8
0.40
9
240
10
18.3
19.3
18,7
0.32
10
270
10
17.6
18,8
18.3
0.40
11
300
10
17.9
19.2
18.5
0.50
12
330
10
18.0
19.0
18.4
0.3B
Overall
0-360
120
17.6
19.5
18,5
0.41
TABLE 4.S - MEASURED WALL THICKNESS RESULTS -SfTE L
Location
Orientation from TDC (°)
Total Number of Readings
Win Wall Thickness (mm)
Wait Wall Thickness (irn!
Mean Wall Thickness
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(1, 2, 3...n) in the grid is representative of one scanned length of the pipe up to the
number of scans completed in total (n) - see Figure 4.3. The results of the coating
assessment at site F is detailed in Table 4.6. The results of the coating assessment
at sites 2 and L are detailed in Appendix 2 Tables A2.1 and A2.2.
1000
gag
800 Cell Divisions (mm)
700
100
Cell numbers around the circumference of the pipe
FIGURE 4.3 - PIPE GRID DIAGRAM
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TABLE 4.6 - VISUAL COATING FAILURE DISTRIBUTION - PERCENTAGE COATING FAILURE AT SITE F
Circumferential Orientation (Degrees) X^^^X
>
t6Q
0
16
33
49
6S
82
98
115
131
147
164
180
196
213
229
245
262
278
295
311
327
344
% Coating (allure
per axial location
Axial Distance from Datum Point (mm)
3-101!
0
5
S
5
0
25
10
0
10
0
0
0
0
0
25
25
25
0
25
0
0
0
7
100-
200
0
5
0
0
0
5
0
0
15
0
0
0
20
5
25
50
25
10
25
0
0
0
8
200-
300
0
0
0
0
0
0
0
0
10
0
0
0
20
25
80
50
0
25
20
0
0
0
10
300-
400
0
0
0
0
0
0
0
0
5
0
0
0
0
20
80
25
0
0
5
0
0
0
6
40D-
500
0
0
0
0
5
0
0
0
0
0
0
10
0
20
70
30
0
0
0
0
0
0
6
500-
500
0
0
0
0
0
0
0
0
0
0
10
50
50
20
50
0
0
10
25
0
0
0
10
600-
700
0
0
0
0
0
0
0
0
0
25
30
50
50
50
25
5
25
50
75
0
0
.0
18
700-
8BO
0
0
0
0
0
0
0
0
0
25
20
25
50
50
10
25
20
25
50
0
0
0
14
800-
900
0
10
0
0
0
5
0
0
0
10
25
25
20
25
20
10
10
25
75
0
0
0
12
900-
1000
0
10
0
0
0
5
10
0
0
15
50
70
75
40
0
0
0
25
25
0
0
0
15
Overall area of coating Failure (%)
Total Cells Analysed
% Coating failure per
circumferential
location
0
3
1
1
1
4
2
0
4
8
14
23
29
26
39
22
11
17
33
0
0
0
11
220
4.5
Condition Assessment
4.5.1 Site F
An area of the bitumen paint coating at site F was in poor condition between 170°
and 280°.
Approximately 70 localised external pipe wall defects were identified using the ECAT
at site F. Further verification of the presence of these external defects was provided
by removing the corrosion product in these locations. The largest external defect
identified on-site was approximately 6.1mm in depth. After further analysis of the
MFL scans from the ECAT, approximately 240 external and 9 internal localised
defects were identified at site F.
The pipe's external surface area has been separated into grids similar to Figure 4.3.
Using the data collected from the ECAT magnetic inspection corrosion defects have
been identified and quantified. The maximum depth of corrosion in each cell in the
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corrosion grid has been reported and displayed. Therefore where there is more than
one defect located in the same cell the smaller of the two will not be displayed. As a
large amount of defects were identified at Site F only the largest 20 defects have
been chosen to be displayed on the grid in Figure 4.4. Internal and external defects
have been distinguished with an "I" and "E" following the defect depth. The defects
have been assumed to be hemispherical in shape.
V)
o
0
O)
c
.o
o
o
to
V-»
Ł
I
I
b
0
13
M
49
es
82
93
115
131
MT
164
1M
196
213
2K
24S
2BS
278
m
311
327
344
Axial Location
1234567B910
.Vr.f;j^i
KSmmlB
FIGURE 4.4- DEFECT PLOT FOR SITE F (20 LARGEST DEFECT DEPTHS)
Mechanical damage was identified on the pipe between 180° and 270° Evidence
suggests that the mechanical damage had not occurred recently because corrosion
was identified within the damaged area as shown in Figure 4.5 below.
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FIGURE 4.5 - AREA OF MECHANICAL DAMAGE
Hemispherical machined defects were indicated by the client on an adjacent spool to
the one which was scanned by the ECAT at Site F, as shown in Figure 4.6. These
defects were scanned and sized for calibration purposes.
FIGURE 4.6 * MACHINED HEMISPHERICAL DEFECTS
4.5.2 Site 2
External machined defects with various dimensions were identified in the pipe at Site
2. Because the defects were spread over a pipe length greater than 1m not all the
machined defects could be included in a single scanned length, A condition
assessment including ECAT scans was performed over aim length of the pipe. The
machined defects together with the internal and external natural defects included in
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this scanned length were sized using AESL's algorithms. Analysis of the MFL scans
identified approximately 225 localised external defects and 11 localised internal
defects at Site 2. Using the data collected from the ECAT magnetic inspection
corrosion defects have been identified and quantified. Only the largest 20 defects
have been chosen to be displayed on the grid in Figure 4.7.
V)
CD
a
CD
to
o
b
180
CO
Ł \w
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FIGURE 4.8 - EXTERNAL MACHINED DEFECTS
As shown in Figure 4.8, some of the machined defects were located beyond the 1m
scanned length. In total, seven machined defects were scanned using the MFL tool.
FIGURE 4,9 - THREADED HOLES
Threaded holes were machined into the pipe between an orientation of 45° and 90°
as shown in Figure 4.9 above. These holes were created for connections to be fitted.
The connections were required to simulate pipe leakage for other companies who
were testing leakage technology the following week. Three through wall threaded
holes were within the 1m scanned location during the inspection. The position of the
machined defects can be seen on the plot in Figure 4.10.
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FIGURE 4.11 - PHOTOGRAPH OF COATING DAMAGE
Mechanical damage was also identified on the pipeline at approximately 90° and
between 180°280° at this inspection location. Ext ernal defects were identified in the
pipe wall using the MFL tool. Due to the extent of the corrosion some of the external
defects could be verified visually without the need to remove corrosion product as
shown in Figure 4.12.
FIGURE 4.12 - PHOTOGRAPH OF EXTERNAL DEFECTS
Analysis of the MFL scans identified approximately 330 localised external defects
and 3 localised internal defects at site L Using the data collected from the ECAT
magnetic inspection corrosion defects have been identified and quantified. As in Site
F and 2 a large amount of defects was identified at Site L therefore only the largest
20 defects have been chosen to be displayed on a corrosion grid (Figure 4.13).
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Axial Location
65
82
184
180
CD
0)
CT
0
g
c
Ł 245
ŁJ 262
o m
295
311
327
JM
10
*
P 9rr\fr{n
•
•
•
•f.^rtyp
*
*
•
•
•
"H'Smmfty-
•
•
•
1 ' :.
FIGURE 4.13 DEFECT GRID FOR SITE L (20 LARGEST DEFECT DEPTHS)
The corrosion product within the natural defects was not removed at Site L as other
companies involved in the trials may have used this location following AESL's
departure.
4.6
Confidence Intervals
The defects presented within the defect grid for Site F has been tabulated below in
Table 4.7. Confidence intervals have been calculated for each defect identified.
The results for Site 2 and Site L have been included in Appendix 6.
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TABLE 4.7- CONFIDENCE INTERVAL FOR SITE F
ORIENTATION
65
115
229
82
278
327
49
295
295
131
49
49
49
278
0
311
295
147
147
49
AXIAL
LOCATION
707
732
819
674
1036
560
613
672
463
274
906
747
70S
292
652
704
836
444
766
377
DEFECT
SIZE
12.5
10,8
10,8
10.3
10,1
9.9
9,7
9.2
9.1
9.0
9.0
8.9
8.8
8.7
8.7
8.5
8.3
7.8
7.7
7.5
INTERNAL /
EXTERNAL
External
External
External
External
External
Internal
Internal
External
External
External
Internal
Internal
Internal
External
Internal
Internal
External
External
External
Internal
95 % CONFIDENCE
INTERVAL
10.9
9.5
9.5
9.1
8.9
8.8
8.7
8.2
8.1
8,1
7.9
7.9
7.7
7.8
7.6
7.4
7.4
7.0
6.9
6.3
14.3
12.2
12.2
11.6
11.3
11.0
10.8
10,3
10,1
10.1
10,2
10.1
10.0
9.8
9.9
9.8
9.3
8.7
8.6
8.9
5 STRUCTURAL, ANALYSIS
The following section outlines the stress and defect analysis carried out to evaluate
the structural integrity of the main.
5.1
Stress Analysis
The stress experienced by the main is a result of both internal and external pressure.
The internal pressure is caused by pressurised water flowing through the main. The
external pressure is determined by considering the soil overburden and the traffic
loading applied to the main at a particular location.
The pipe runs below ground under what is considered to be a minor road. The traffic
loading at each inspection location is considered to be minor road loading only.
The maximum operating pressure of the main prior to decommissioning was 4bar
(provided by A Cheng of Battelle).
5.2 Loading Regimes
5.2.1 Soil Overburden Loading
The soil overburden load acting on the pipe was calculated based on the rectangular
area directly above the pipe. The measured cover depth was taken to be the
distance from the surface to the crown. Assuming a soil density of 200Qkgm
load due to overburden was thus derived.
-3
the
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FIGURE 5.1 - ILLUSTRATES THE VOLUME OF SOIL OVERBURDEN ON THE PIPE
5.2.2 Traffic loading
The average intensity of the traffic load on the pipe due to multiple wheel loads,
including impact effects, is calculated from the following equation:
wq= IP a
Li L2
Where:
wq = Vertical load (pressure on top of pipe) due to surface applied live load
IP = Sum of individual wheel loads (A maximum axle weight 16.5 tonnes was
assumed for a minor road)
LI = length of the base of the live load distribution
l_2 = Width of the base of the live load distribution
a = Live load impact factor
From this equation the pressure on the surface of the pipe was calculated due to the
traffic loading (see Table 5.1).
TABLE 5.1 - INTERNAL PRESSURE AND LOADING
Site
F
2
L
Internal
Pressure
(bar)
4
Cover
depth (m)
1.08
1.07
1.73
Soil overburden
loading (Nm'l2)
21190
20993
33943
Minor road
loading (NmA2)
161865
Note - Any head loss (e.g. due to friction and elevation) is neglected.
5.3 Membrane and Bending Stress
Using bending theory, peak stresses in the pipe wall are estimated. It is recognised
that these stresses vary around the circumference however only the peak is applied
to estimate critical defect sizes. The pipe's circumference was split into six segments
to determine the orientation with the maximum stresses. The results of the derived
membrane and bending stress for minor road loading at each pipe orientation have
been provided in Tables A7.1-A7.3 in Appendix 7. The maximum loads are
summarised in the Table 5.2 below.
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TABLE 5.2 - SUMMARY OF MAXIMUM LOADS FOR EACH SITE
SECTION
F
2
L
LOAD CASE
Minor Read
Minor Road
Minor Road
AVERAGE WALL
THICKNESS (MM)
19.0
18.5
18.7
MAX MEMBRANE
STRESS (MN/M2)
7.0
7.2
7.1
MAX BENDING
STRESS (MN/MZ)
27.1
28.3
24.3
5.4 Analysis of Structural Significance of Corrosion
Internal and external localised corrosion was identified at all the inspection locations.
External corrosion ranged from 1.0mm (Site F) to 14.9mm (Site 2) in depth. Internal
corrosion ranged from 7.5mm (Site F) to 10.4mm (Site 2).
AESL apply a method based on British Standard 7910 which is based on fracture
mechanics theory. A fracture toughness of 10,3MN/m3'2 for spun cast iron was
assumed as a conservative value
Defects which are cracks are likely to give rise to more intense stress fields, and
hence smaller predicted critical defect sizes then non planar defects such as
corrosion pits. BS 7910 takes a conservative approach to assessing surface flaws
due to pitting corrosion, by modelling a pit as a planar flaw of the same depth and
shape.
5,5
Fracture Mechanics Model
The presence of defects in a pipe wall results in higher stress concentrations in the
surrounding area of the pipe wall around the defect and thus, increases the risk of
failure.
AESL have developed their own software based on BS 7910:2005, Guide to Methods
for Assessing the Acceptability of Flaws in Metallic Structures, which allows
predictions to be made of the critical depth of a defect that may initiate failure and
hence, the acceptability of any defects identified in the inspection.
The software takes into account the properties of the pipe material and the maximum
stresses likely to be induced on the main due to the loading regime. Conservative
values for the material properties have been estimated from published sources.
Table 5.3 below shows the values used for the Fracture Mechanics Method.
TABLE 5,3 - SS7S10 SOFTWARE INPUT DATA
SECTION
F
2
L
ULTIMATE
TENSILE
STRENGTH
(MN/MJ)
194
YIELD
STRENGTH
(MN/M*)
194
TOUGHNESS
{MN/M3'1)
10,3
OUTER
DIAMETER
(MM)
665
665
665
AVE. WALL
THICKNESS
(MM)
19.0
18.5
18.7
The maximum membrane stress and bending stress calculated in Section 5.3 were
then applied into the BS7910 software.
Assessment of acceptability of a defect is made by means of a Failure Assessment
Diagram (FAD) based on the principles of fracture mechanics. The vertical axis of
the FAD is a ratio of the applied conditions to the conditions required to cause brittle
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fracture; the horizontal axis is the ratio of the applied load to that required to cause
plastic collapse. An assessment line, seen as a box in the lower left corner of the
plot area in Figure 5.1 below, is also included in the FAD. Calculations for a flaw
provide the coordinates for an assessment point. Defects that fall within the
assessment lines are considered acceptable.
5.6
Results
The analysis showed that a 15.7mm deep defect of hemispherical geometry at Site F
would not be acceptable in terms of the risk of structural failure resulting from its
presence.
2.0
1.0 -
0.0
15.7rnm deep
defect
Unacceptable
Acceptable
0.0
1,0
Sr
2.0
FIGURE 5.1- FAD FOR SITE F
The FAD's for Site 2 and L have been provided in Appendix 8,
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Table 5.4 shown below summarises the critical defect depth for each of the Sites.
TABLE 5.4 - DEFECT OEPTH TO CAUSE FRACTURE
SECTION
F
2
L
LOAD
CASE
Minor road
Minor road
Minor road
CRITICAL DEFECT OEPTH AT
LOCATION OF MAXIMUM STRESS
(MM)
15.7
14.6
17,0
It must be noted that this estimation above is based on the presence of one singular
defect forming at a point of maximum stress. Defects found in close proximity to
each other are likely to give rise to a higher stress concentration and hence further
increase the risk of structural failure.
S.7 Statistical Analysis of defects
The inspection data from the three sites have been analysed using Extreme Value
Theory (EVT) allowing prediction of the size and number of the largest defects, using
information from the measured defects. Localised or pitting corrosion are known to
follow the Gumbel distribution, from the family of Extreme Value distributions.
The fastest progressing localised corrosion will cause the first perforation. Thus for
the phenomena of localised corrosion, an important factor is its maximum values, in
this case the depth of the deepest pits.
The Probability (ft(x)) and Cumulative (Fi(x)) Equations of the Gumbel distribution are
given below where a and A are location and scale parameters respectively;
f( \
fl(x) = —exp
a
The parameter '*' above represents the population of pits of different depths.
The pipe's external surface area at each inspection site was separated into grids,
similar to Figure 4.3 and the deepest single external and internal defect in each grid
was identified. The sample of pits was used to produce estimates of the distribution
parameters.
External and internal defects need to be analysed separately due to the varying
corrosion drivers involved with the two different environments,
5.7.1 External Defects
The length of the pipeline has been split into three sections. Each inspection location
represents one third of the length of pipeline. By analysing the three sections
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separately it was shown that Site F and Site 2 were statistically similar however Site
L was dissimilar to both F and 2. Therefore, two models were produced one to
include Sites F and 2 (represent 2/3 of the pipeline) and the other with Site L
(represent 1/3 of the pipeline).
Extreme value distributions have been fitted for the models over a length of 508m
(Site F and 2} and 254m (Site L). The distribution parameters used in the above
equation are shown in Table 5,5.
TABLE S.S -DISTRIBUTION PARAMETERS
SITE
Site F & 2
Site L
INTERNAL /
EXTERNAL
External
External
DISTRIBUTION
PARAMETERS
Alpha
Lambda
Alpha
Lambda
MOST LIKELY
VALUE
1.77858
2.98879
2,30153
4,34209
95% CONFIDENCE
LIMITS
0,261
0.372
0.345
0.396
These distribution parameters have been fitted using the method of maximum
likelihood, with the data below 4.5mm left censored. This gives greater emphasis to
the deeper defects in the model fit. An example of the illustration of fit is presented in
Figure 5.2.
The distribution fits pass Anderson and Darling statistical tests for goodness of fit,
adjusted for censored data, at better than the 5% levei.
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Illustration of Fit
5.85
-0.96
-1.81
4.5 6 7.4 8.9 10.4 11.9 13,4
RGURE 5.2- ILLUSTRATION OF FIT FOR PITTING EXTERNAL DEFECTS FOR SITE F & 2
The results of the statistical analysis are shown in Table 5.6 for the whole pipeline
length. 220 cells were inspected at each of the locations.
TABLE 6,8- STATISTICAL ANAYSIS RESULTS FOR FULL PIPELINE LENGTH
SECTION
Site F & 2
SiteL
INTERNAL /
EXTERNAL
External
APPROXIMATE
EXTRAPOLATED
LENGTH (M)
508
254
AVERAGE
WALL
THICKNESS
(MM)
18.8
18.7
ESTIMATED
DEEPEST
PIT (MM)
TW*
TW*
ESTIMATED
NUMBER OF
PERFORATIONS
ALONG
EXTRAPOLATED
LENGTH
15
>50
"If the deepest defect equals the average wail thickness then ft Is said to be through wall (TW)
Thus if the pipeline is similar elsewhere to the observed location then it is estimated
there is currently a number of through wall external defects along the whole length of
the pipeline.
5.7.2 Internal defects
Extreme value theory may not be applicable to the internal surface because the
pipeline is cement lined and the internal defects probably correspond to the local
coating failures. As such surface of the pipeline would not corrode in a way which
could be appropriately represented by an extreme value distribution.
ReportRP3042
21
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
A number of internal defects were identified from the scans. The estimated number
and sizes of the internal defects located at each of the sites are given in Table 5.7
below:
TABLE 5.7 - INTERNAL DEFECTS
SITE
f
2
I
ORIENTATION 0
327
49
49
49
49
0
311
0
49
311
344
327
344
115
344
98
245
82
327
115
16
49
33
AXIAL
LOCATION
(MM)
560
613
906
747
708
652
704
701
377
317
404
383
38(r~"—~ 1
245
232
41
384
588
314
205
522
284
504
DEFECT
SIZE (MM)
9,9
9.7
9.0
8.9
8.8'
8.7
8.5
8.2
7.5
10.4
10.3
10.2
9.9
9.9
9.8
9.8
9.4
9.3
9.3
8.8
10.3
9.9
9.2
Note: the table above may not match the defects illustrated in the corrosion grid in
section 4 as the grid only displays the maximum internal or external defect in each
cell whereas the table above identifies all the internal defects which were estimated
with the MFL tool.
6
REMAINING LIFE
6.1
Perforation
The table below summarises the deepest 5 pits estimated at each location. Similar
to Table 5.7, the defects listed in Table 6,1 may not match the defects illustrated in
the corrosion grid in section 4 as the grid only displays the maximum defect in each
ceil whereas the table below identifies all the internal / external defects which were
estimated with the MFL tool.
Report RP3042
22
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
TABLE 6.1 - DEEPEST DEFECTS
SITE
F
2
L
ORIENTATION 0
65
115
229
82
278
16
16
344
327
311
147
180
245
115
229
AXIAL
LOCATION
(MM)
707
732
819
674
1036
854
647
714
785
317
561
120
375
110
348
EXTERNAL /
INTERNAL
External
External
External
External
External
External
External
External
External
Internal
External
External
External
External
External
DEFECT
SIZE (MM)
12.5
10.8
10.8
10.3
10.1
14.9
11.7
11.5
10.7
10.4
14.5
14.4
14.3
13.6
13.5
The statistical models of external defects described in section 5.7.1 suggest that if
the remainder of the pipeline is similar in its age and exposure to the examined areas
then there are likely to be a number of defects equal to the wall thickness. This
would suggest that the life to leakage for this pipeline is minimal.
Iron corrosion product is a matrix of iron and oxides of iron and does have some
residua! strength. A through wall corrosion defect in iron may remain in situ.
Therefore it is possible for through wall corrosion to occur without the presence of a
leak.
6.2
Critical defects
The table 6.2 summarises the estimated critical defect sizes at which failure of the
line may occur, at the points of maximum stress.
The statistical analysis model of external defect distribution has been applied to
estimate the likely number of critical defects near highly stresses portion of the
pipeline. These numbers are given below:
TABLE 6.2- STATISTICAL ANAYS1S FOR MAX STRESS LOCATION FOR RILL PIPELINE LENGTH
SECTION
Site F & 2
SiteL
INTERNAL /
EXTERNAL
External
APPROXIMATE
EXTRAPOLATED
LENGTH P)
508
254
CRITICAL
DEFECT
DEPTH {mm)
14.6
17
ESTIMATED
DEEPEST PIT (MM)
14.6
17
ESTIMATED NUMBER
OF CRITICAL
DEFECTS WITHIN
EXTRAPOLATED
LENGTH
13
>50
Extreme value analysis has been conducted on the highly stressed portion of pipeline
to estimate the number of critical defects along the pipeline length. The statistical
analysis model estimates that more than 60 critical defects may be present along the
pipeline length.
Report RP3042
23
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
Based on the estimated maximum stresses, the defect distribution models, and the
assumed pipe material properties defects of sufficient depth to cause structural
failure of the pipe may be present.
7 DISCUSSION
Advanced Engineering Solutions Limited (AESL) were invited by Battelle, on behalf
of the Environmental Protection Agency (EPA), to conduct trials using condition
assessment technology that AESL have developed for the assessment of ferrous
pipelines. A water utility company in Louisville, Kentucky offered a 24inch cement
lined cast iron pipe on which to conduct the demonstrations. The field trails were
conducted the week commencing 17th August 2009.
During the inspection socket and spigot joints were identified throughout the pipeline
length.
A detailed assessment of the pipe coating and wall condition was conducted at sites
F, L and 2.
Soil measurements including resistivity, redox, pipe-to-soil potential and pH were
taken at every accessible excavation along the length of the pipeline. Soil samples
were given to Battelle to determine the moisture content. The soil samples were
classified as being corrosive to highly corrosive in areas.
Internal and external defects were identified using the Magnetic Flux Leakage (MFL)
External condition assessment tool (ECAT) at all three inspection locations.
Extensive external defects were identified at each of the three sites inspected. A
minimal amount of internal defects were identified which could suggest that the lining
had broken down in localised areas.
Machined defects were indicated by the client in a pipe spool adjacent to the spool at
site F and in the spool examined at site 2. Both these areas were scanned using the
MFL tool. The machined defects identified at Site L were analysed in the same
manner as the natural defects. Sizes for these defects have been provided.
Threaded holes were found to have been machined into the pipe at site 2. It is
understood that these holes were created for connections to be fitted. The
connections were required to simulate pipe leakage.
Statistical analysis predicts that greater than 65 through wall defects would be
present along the pipeline length. Also, greater than 60 critical defects have been
predicted to be present in the highly stressed locations of the pipeline.
7.1 Issues & Future improvements
Material properties were not provided by the client and therefore have to be taken
from the most suitable standard available. As there are uncertainties of the material
properties this will cause uncertainties in the stress analysis and the subsequent
critical defect depths predicted. The identification of historic American standards for
Cast Iron pipe would enable more appropriate assessment of original dimensions,
material properties and test pressures.
Report RP3042 24
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
As well as the material properties being dissimilar, there may also be variations in the
soil properties and hence the corrosion driver along the pipeline length. This may
affect the validity of the statistical extrapolation process. The soil samples which
were analysed provide a snapshot of the soil properties only. These properties may
vary depending on climate conditions.
AESL sizing software is based on calibration scans of flat-bottomed corrosion
defects, with different pipes of different wall thicknesses, and potentially different
magnetic properties. ASEL realise that natural defect's shape and actual depth is
more complex and recognise that further work is required to replicate this.
The fracture mechanics software designed from BS7910 models defects as a planer
cracks. This is a conservative approach to fracture mechanics. Stress varies around
circumference of the pipeline, the maximum stress usually being located around the
pipe spring level or top and bottom dead centre. Critical defects, which are estimated
using the software, are based on a singular defect being present at a point of
maximum stress. Defects found in close proximity to each other are likely to give rise
to a higher stress concentration and hence further increase the risk of structural
failure.
AESL uses both UK and Australian traffic loading models. It would be more
appropriate to apply local standards for the derivation of traffic loads.
8 CONCLUSIONS
« The pipeline section has been subject to a detailed inspection at 3 locations
* Internal and external corrosion was identified in each location and the depths of
defects estimated
» Estimates of ground and traffic loading have been made and combined with the
internal pressure to estimate pipeline stresses
» Statistical models of the external delect distributions have been derived and
extrapolated over the pipeline length
a TWO excavation sites showed similar levels of corrosion (Site F & 2) with the
third site dissimilar and slightly worse (Site L)
« Soils samples suggested that the soil varied from fairly corrosive to highly
corrosive along the route
• The statistical distributions have been extrapolated over the length under
consideration and corrosion perforations are predicted to exist if the
unexamined lengths are similar to the excavation locations
• Based on the estimated stresses, the defect distribution models, and the
assumed pipe material properties defects of sufficient depth to cause structural
failure of the pipe may be present.
Report RP3042 25
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
Appendix 1 Site Locations
Report RP3042 26
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CONFIDENTIAL
ADVANCED B*aiNEaill« 3OLUT1OH3 UWTED
FIGURE A1.1 INSPECTION LOCATIONS
Report RP3O42
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS UNITED
Appendix 2 Coating Grid
Report RP3042 28
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CONFIDENTIAL
ADVANCED ENGINEER we SOLUTIONS LIMITEO
TABLE A2.1 ViS UAL COATING FAILURE DISTRIBUTION - PERCENTAGE COATING FAILURE SITE 2
270
180
la
BB
Ł
o
Circumferenlia
i
90
0
16
33
49
65
82
98
115
131
147
164
180
196
213
229
245
262
278
295
311
327
344
% Coating failure
per axial location
Axial Distance from Datum Point (mm)
J-100
50
10
40
50
25
5
25
100
100
100
90
100
100
100
100
100
40
50
to
5
20
10
56
100-
200
40
15
25
20
25
5
20
80
100
90
90
100
100
100
100
100
70
70
10
10
10
10
54
200-
300
20
10
30
40
15
20
20
80
90
100
80
100
100
100
100
100
75
20
20
5
5
15
52
300-
400
10
20
50
20
40
50
50
80
60
100
90
100
100
100
100
100
75
70
25
20
5
20
59
400-
500
20
25
50
75
70
75
100
100
80
100
SO
100
100
100
100
100
80
90
40
25
10
25
70
500-
600
40
75
75
80
90
75
100
80
80
100
80
90
100
100
100
100
50
75
50
40
20
25
74
600-
700
60
90
80
100
100
90
100
100
100
100
100
100
100
100
100
100
70
so
100
80
25
80
89
700-
800
30
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
90
100
70
25
80
91
800-
900
20
50
30
75
100
100
100
100
100
100
100
100
100
100
100
100
100
50
75
70
75
70
83
900-
1000
10
20
25
20
70
75
eo
100
100
100
100
100
100
100
100
100
100
70
75
70
75
20
73
Overall area of coating failure (%)
Total Cells Analysed
% Coating failure per
circumferential
location
30
42
51
58
64
60
70
92
93
99
91
99
100
100
100
100
76
67
51
40
27
36
70
220
Report RP3042
29
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CONFIDENTIAL
ADVANCED ENGINEER)NG SOUUTIOMS LIMITED
TABLE A2.2 VISUAL COATING FAILURE DISTRIBUTION - PERCENTAGE COATING FAILURE SITE L
Q
o
ieo
entatton (Degrees)
O
Ctreumferentia
0
16
33
49
65
82
98
115
131
147
164
180
196
213
229
245
262
278
295
311
327
344
% Coating failure
per axial location
Axial Distance from Datum Point (mm)
3-1 OC
20
5
0
0
0
0
5
0
0
0
0
0
0
0
0
25
50
15
0
0
0
5
6
100-
200
20
5
5
0
10
0
20
0
10
0
0
0
0
0
0
15
25
15
5
5
0
0
6
200-
300
10
0
5
0
0
10
5
0
0
0
0
0
0
0
10
20
40
20
0
0
0
5
6
300-
400
5
0
0
0
10
0
0
0
0
0
0
0
D
0
20
10
50
20
0
0
0
5
5
400-
500
15
0
0
0
5
15
5
0
5
0
10
10
5
10
25
10
25
25
0
0
5
0
8
500-
600
5
0
0
0
5
5
0
0
0
0
0
0
0
10
0
0
25
40
0
0
0
0
4
600-
700
25
5
10
5
0
5
5
0
0
0
5
0
0
0
0
10
15
40
10
5
5
5
7
700-
300
40
0
5
5
0
10
0
0
0
0
0
0
0
0
0
0
20
60
20
0
5
0
8
800-
900
15
0
5
0
0
20
0
10
0
0
0
0
0
0
0
5
15
50
0
15
10
0
7
900-
1000
10
0
0
5
0
5
10
0
0
10
10
20
0
0
0
0
0
25
0
20
0
0
5
Overall area of coating failure (%)
T.WCM.MW
% Coating failure per
circumferential
location
17
2
3
2
3
7
5
1
2
1
3
3
1
2
6
10
27
31
4
5
3
2
6
220
Report RP3042
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
Appendix 3 Soil Conditions
Report RP3042 31
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ENGJI&ERINQ SOLUTIONS LIMITED
TABLE AS.1 - SOIL DATA
SIT61
SITE A
51TEL
SITES
srrec
SITES
SfTED
SITEE
SITEF
SITES
PH
8.50
7.30
7.25
7.SO
8,50
7.26
700
780
6.2S)
6,00
Pspe 5o Scsl
-587
-561
-601
-518
-614
-615
-5S7
-649
-645
-991
Redo*
160
7T
218
119
148
110
141
123
10*
120
Depth to Crown
1210
1290
1730
1200
1QSO
1070
1300
1300
1080
11SO
Resistivity
2669
2450
1206
4?M
81T
2400
1436
119fl
637
1631
Moisl'jre
Moist
Walls; Moist
Bed: Saturated
Sidewalls: MoisS
Moist
Dry; Mast
Motet
Dry
fty
Moist
Moist
Moisture
Content
25.S
24,2
23,5
26.6
23.1
22.8
23.5
27.9
24.3
2B.9
Soil
Clay and siopy
with trac&s of
green and black.
colour
Clay
Clay
Sandy Clay wttti
traces of Naek
Sandy Clay wlh
traces of black
Clay w»ift traces
Clay sandy with
traces of black
Sandy clay with
stores. S^ac5<
and brown m
ootour
Dense Clay
C&ay ana stony
Ease of
Rerao«sl
SijH
Stiff
Sttewali: sBB
Stiff
Stiff
Stiff / Fitm
Stiff
Slift
Rnn
Sffi
Commenta
S?orrn drain was located ir* the
ejecavation. Slorm dmin was cut open
lor !fce excavaSion. Water was
pumped oui pnor to soil analysis.
Leak was located at a joint dose lo
~&i® insspsc&on location. Excava^cp
was pumped pnor ana during the
inspection WQ&KS..
B(Sy*nsn from road sujiscs saepmg
through 1Ł&e 3Oi?
Started to rain heavily during test.
Surface was saturated witrt rain
water. Selowthe surface 1^ gfourtd
was Mo^stfdry. SoN in ajtcava!so« wail
is campacl&d
Report RP3O42
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
Appendix 4 Wall Thickness Measurements
Report RP3042 33
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
TABLE A4.1 - MEASURED WALL THICKNESS RESULTS -SITE F
Location
1
2
3
4
5
6
7
8
9
10
Orientation from TDC (°)
0
19.3
19.6
19.0
18.8
18.8
18.9
19.4
20.1
19.3
19.0
30
19.5
19.4
19.1
19.2
18.9
18.7
.JM-j
19.5
19.9
20.1
60
19.5
19.3
19.4
19.0
18.8
19.1
18.9
19.0
20.8
20.5
90
19.5
191
120
1S.2
19.2
18.9 . 18.7
nfj7
18.9
18.7
19,0
19.6
18.8
19.6
18.6
20.0
19.2
18.9
19.9
19.7
19.2
150
19.3
19.1
18.S
18.7
18.6
19.1
18.8
20.2
18.8
19.0
180
18.8
18.9
18.7
18.7
18.6
19.5
19.7
18.9
19.2
18,9
210
19.1
1B.8
18.3
|_1M_|
18.5
19.0
19,2
19.3
19.4
19.6
240
18.8
18.7
18.1
18,0
18.7
18.0
19,0
18.8
19.1
19.0
270
HiT^
18.5
18.2
18.2
18.4
18.1
18.6
19.0
18.5
18..4
300
19-3
19.6
19.0
18.8
18.8
18.9
19.4
20,1
19.3
19.0
330
19.5
19.4
19.1
19.2
18.9
18.7
19.3
19.5
19.9
201
TABLE A4.2 - MEASURED WALL THICKNESS RESULTS - SITE 2
Location
1
2
3
4
5
6
7
8
9
10
Orientation from TDC (°)
0
18.7
18,6
18,6
18.0
18.1
19.2
19.2
19.2
18.8
18.2
30
18,4
LJM_
18,0
18,0
18.4
18.3
19.1
18.5
18.6
18.3
60
18.1
18.1
18.1
18.0
18.4
18,0
18.5
18.6
18.4
18.8
90
18.1
18.0
18.5
17.8
18.0
18.5
18.5
19.0
18.5
17.8
120
18.5
18.0
18.7
17,9
18.9
18.1
_JM-i
19.2
18.7
17.6
150
18,3
18.3
18,8
18.7
18.9
17.9
18.7
18.3
18.3
18.1
180
19,3
18.6
18.9
18.6
18.2
17.8
18.5
19.3
18.6
18.2
210
19.1
18.5
18.0
18.8
18.9
18.2
18.4
18.8
18.7
18.6
240
18.8
18,7
_JM_i
18.3
19.2
18.3
18.3
_JM_i
19.2
18.5
270
19.1
18.3
18.2
18.3
18.8
19.5
18,6
18,2
19.3
18,8
300
18.7
18.6
18.6
18.0
18.1
19.2
19.2
19.2
18,8
18.2
330
18.4
18.4
18.0
18.0
18.4
18.3
19.1
18.5
18.6
18.3
TABLE A4.3 - MEASURED WALL THICKNESS RESULTS - SITE L
Location
1
2
3
4
5
6
7
8
9
10
Orientation from TDC (")
0
19.1
19.3
19.2
18.9
19.0
19,2
19.1
18.9
_!M_J
19.0
30
19.0
19.5
18.8
18.1
19.0
19.0
18.9
19.2
19.4
19.2
60
19.0
18.9
18.9
18-7
19.0
19.0
18.7
18.9
19.2
18.8
90
!___,
18,7
18.7
18.6
18.6
18,7
19.1
18.8
19,3
18.6
120
18,5
18.9
18.6
18.6
18.8
18.5
18.7
18.8
19.1
18.5
150
|_1M_
18.3
18.2
18,2
18.8
18.3
19.0
18.6
19.0
18.1
180
18.4
18.2
18.1
18.1
18.6
18.5
18.8
19.0
18.3
18.4
210
18.7
18.5
18.9
18.0
18.3
18.5
18.8
18.7
19.1
18,6
240
18.6
18.7
18.9
18.0
18.4
18.7
18,2
18.2
19.1
18.5
270
18,5
19.0
18.7
18.4
18.3
18,9
18.5
18.5
18,9
18.3
300
19.1
19.3
19.2
18.9
19.0
19.2
19.1
18.9
19,2
19.0
330
19.0
19.5
18.8
18.1
19,0
19.0
18.9
19,2
19.4
19.2
Report RP3042
34
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
Appendix 5 Site Photographs
Report RP3042 35
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
SiteF
FIGURE AS.1 - PHOTOGRAPH OF EXCAVATION LOCATION
Report RP3042
36
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
FIGURE A5.2 - PHOTOGRAPH OF PIPE IN EXCAVATION
Report RP3042
37
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CONFIDENTIAL
ADVANCED EMGWEERING SOLUTIONS LIMITED
FIGURE A5.3 - PHOTOGRAPH OF COATING / CORROSION GRID
FIGURE A5.4 - PHOTOGRAPH OF MFL TOOL ON THE PIPE
Report RP3042
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
FIGURE A5.5 - PHOTOGRAPH OF MECHANICAL DAMAGE AND CORROSION
Report RP3042
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
Site 2
FIGURE A5.6 - PHOTOGRAPH OF EXCAVATION LOCATION
FIGURE AS.7 - PHOTOGRAPH OF COATING / CORROSION GRID
Report RP3042
40
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
FIGURE A5.8 - PHOTOGRAPH OF MFL TOOL ON THE PIPE
FIGURE A5.9 - PHOTOGRAPH OF MACHINED DEFECTS IN THE PIPE
Report RP3042
41
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
FIGURE A5.10 - PHOTOGRAPH OF MACHINED THREADED HOLES IN THE PIPE
Report RP3042
42
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
Site L
FIGURE A5.11 - PHOTOGRAPH OF EXCAVATION LOCATION
FIGURE A5.12- PHOTOGRAPH OF PIPE IN EXCAVATION
Report RP3042
43
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
FIGURE A5.13 - PHOTOGRAPH OF COATING / CORROSION GRID
FIGURE A5.14 - PHOTOGRAPH OF MFLTOOL ON THE PIPE
Report RP3042
44
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
FIGURE AS. 15 - PHOTOGRAPH OF DEFECTS IDENTIFIED ON THE PIPE
FIGURE A5.16 - PHOTOGRAPH OF COATING DEFECTS
Report RP3042
45
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
FIGURE A5.17 - PHOTOGRAPH OF MECHANICAL DAMAGE TO THE PIPE
Report RP3042
46
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS UMTTED
Appendix 6 Confidence Intervals
Report RP3042 47
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COHFIOENTIAL
AOVANCCO EMSINCIWNS SOLUTIONS LIMITED
TABLE A8.1 - CONFIDENCE INTERVAL FOR SITE 2
ORIENTATION
16
16
344
327
311
0
344
0
327
115
344
98
196
245
82
327
0
147
196
164
AXIAL
LOCATION
853
646
714
785
316
691
403
953
3S3
r 245
232
40
1042
384
587
314
651
628
205
456
DEFECT
SIZE
149
11,7 I
11 5 I
10?
10.4
10,3
103
103
102
99
98
9,8
96
9.4
9.3
INTERNAL /
EXTERNAL
95 % CONFIDENCE
INTERVAL
External j 12.7
External
Extamai
External
internal
Extern at
Internal
JOJ_^
10.1
9.4
9,4
9.1
93
External j 9.0
internal I 92
Internal ! 8.9
Internal
Internal
External
Internal
Internal
9 3 Internal
88
88
8.3
8 1
External
8,8
8.7
8.5
8,4
83
82
7.8
Extema i 7.8
Internal
Extern*.
7.7
74
17.5
13.4
«— «. - -W.T.I- -in
13.2
12,2
11.5
117
11.4
11.6
114
11.0
10.9
10.9
10.8
10.5
10.5
10.4
9.9
9.9
99
93
TABLE A6.2- CONFIDENCE INTERVAL FOR SITE L
ORIENTATION
147
180
245
115
229
164
147
229
147
164
245
98
180
245
262
18
1S4
196
147
49
AXIAL
LOCATION
561
121
376
110
348
931
1044
828
477
480
948
500
986
22S
449
504
361
422
842
283
DEFECT
SIZE
14,5
14,4
14.3
136
135
INTERNAL 1
EXTERNAL
External
External
External
External
External
13.2 j External
12.8
12,2
12 1
11.7
11.0
11.0
10,9
10.9
103
External
External
Extsmal
__B
-------
CONFIDENTIAL
ADVAf*CED ENGINEERING SOLUTIONS LIMITED
Appendix 7 Stress Analysis Results
Report RP3042 49
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS UMTED
TABLE A7.1-MEMBRANE AND BENDING STRESS PIPELINE SITE F
Circumferential
position (degrees)
Oto 15
15 to 30
30 to 45
45 to 80
60 to 75
75 to 90
Slress
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Minor road loading
7.0
27 1
6.9
23.5
6.8
13.5
6,3
9.3
6,1
20.8-
6.0
26,7
TABLE A7.2 -MEMBRANE AND BENDING STRESS PIPELINE SITE 2
Circumferential
position (degrees)
Olo15
15 to 30
301045
45 to 60
60 to 75
75 to 90
Stress
Membrane SIress (MPa)
Bending Stress (MPa)
Membrane SIress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending SIress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Minor road Loading
7.2
28.8
7.1
24.9
6.9
14-4
6.S
9,8
6,3
22.0
6,1
28.3
TABLE A7J -MEMBRANE AND BENDING STRESS PIPELINE SITE L
Circumferential
position (degrees)
Oto 15
15 to 30
30 to 45
45 to 60
601075
75 to 90
Stress
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPaJ
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Stress (MPa)
Bending Stress (MPa)
Membrane Strets (MPa)
Bending Stress (MPa)
Mitior road loading
7.1
24.3
7-1
21.1
6.9
12-2
6.5
8,3
6,3
18.6
6.2
24.0
Report RP3042
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CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS UMITEQ
Appendix 8 Failure Assessment Diagrams
Report RP3042 51
-------
CONFIDENTIAL
ADVANCED ENGINEERING SOLUTIONS LIMITED
2.0 -
1.0 -
0.0
0.0
2.0
10 -
0.0
0.0
17.0mrn deep
defect
1.0
Sr
FIGURE A8.1 - FAD FOR SITE L
14.6mm deep
defect
1.0
FIGURE A8.2 - FAD FOR SITE 2
2.0
2.0
Report RP3042
52
-------
APPENDIX G:
RSG Report (22 pp.)
G-l
-------
ACN: 077903541
11/7 Commercial Court T: +61393356122
Tullamarine 3043 F: +61393356733
MELBOURNE AUSTRALIA
www.rocksolidgroup.com.au
Incorporated in Australia
Offices:
O USA O Canada
O United Kingdom O Czech Republic
O Hungary O Hong Kong
DATE:
30 September 2009
CLIENT:
Battelle
CONTRACT NUMBER:
95786
JOB TITLE:
ADDRESS:
EPA Demonstration of Condition Assessment
Technologies for Water Mains.
LOUISVILLE,
KENTUCKY.
UNITED STATES OF AMERICA.
AUTHORS:
MARTIN ROUBAL
PROJECT MANAGER
MARK DISHON
NDT SPECIALIST
• NON-DESTRUCTIVE & GEOPHYSICAL TESTING •
-------
TABLE OF CONTENTS
1. EXECUTIVE SUMMARY 3
2. INTRODUCTION 4
3. TECHNOLOGY DESCRIPTION 4
4. EQUIPMENT 5
5. FIELD TESTING 5
5.1 Field Testing Details 5
5.2 Survey Method 6
6. RESULTS 8
7. BEM INTERPRETATION 8
8. SPECIFIC SITE INTERPRETATION 10
9. NOT CONCLUSIONS & RECOMMENDATIONS 11
APPENDIX A NOT RESULT 13
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
1. EXECUTIVE SUMMARY
Rock Solid Group Pty. Ltd. (RSG) was commissioned by Battelle to participate in a condition
assessment program trial on a 24" diameter Cast Iron (CI) water main in Louisville, KY. RSG was
also commissioned to undertake post survey processing and analysis of the data collected as well as to
provide a written report detailing all findings. The CI water main was scanned externally using the
HSK (Hand Scanning Kit) non-destructive testing technique, as well as the CAP (Crown Assessment
Probe).
Field testing was conducted from the 24th through to 28th August 2009 by an RSG technician.
Battelle selected a total of nine (9No.) 5-ft long sections to be scanned along the full length of the
pipeline. 100% coverage of the full circumference was achieved on all four (4No.) of the HSK scans
(excluding adjacent to protrusions such as valves). Another five (5No.) scans were completed using
the CAP where only the top portion of the pipe was scanned.
The date of construction of these pipes is unknown. The nominal thickness of the pipe is believed to
be approximately 0.650"- 0.700", however this information should be taken as anecdotal only.
Scanning was conducted externally through negligible external coating and soil on the pipes surface,
i.e. unprepared surface. The design specifications provided are based on verbal information provided
to RSG by Battelle.
From the results obtained it appears that there is some noticeable cylinder thickness loss in most of
the pipe sections scanned. There does not appear to be a common wall thinning trend for the entire
pipeline length. Most of the wall thinning trends tend to be section specific. Refer to Section 8 -
Specific Site Interpretation for description of the condition of the specific scanned sections.
The minimum wall thickness obtained by BEM has been recorded as 0.627" from Site 5 (Pit C).
It must be noted that all plots have the same display parameters and scale to allow for comparisons
between scans.
Description of the condition can be found under section 8 - SPECIFIC SITE INTERPRETATION
and must be read in conjunction with Appendix A - NDT RESULTS.
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
2. INTRODUCTION
Rock Solid Group Pty. Ltd. (RSG) was commissioned by Battelle to participate in a condition
assessment program trial on a 24" diameter Cast Iron (CI) water main in Louisville, KY. RSG was
also commissioned to undertake post survey processing and analysis of the data collected as well as to
provide a written report detailing all findings. The CI water main was scanned externally using the
HSK (Hand Scanning Kit) non-destructive testing technique, as well as the CAP (Crown Assessment
Probe).
Field testing was conducted from the 24th through to 28th August 2009 by an RSG technician.
3. TECHNOLOGY DESCRIPTION
The HSK & CAP utilizes Broadband Electro-Magnetic (BEM) technology and can be considered a
'pulse eddy current' system. This technology is a derivative of geophysical equipment which has
been used in the mineral exploration industry for more than eighty years and is therefore based on
well established physics principles.
RSG's background knowledge of this technology and experience in its use in the exploration industry
has allowed for the modification of it for non-destructive testing (NDT) inspections.
Ultrasonic testing, or UT as it is commonly referred to, is probably the most well established material
testing technique for assessing ferrous pipe wall conditions. However to call this technique NDT is
really a misrepresentation. To not remove coatings or linings or to not 'polish' surfaces for good
sensor contact means yielding low confidence data.
BEM was developed because existing and available techniques and devices could not give the level of
detail and data confidence required for assessments of assets without misrepresentation or
unacceptable commercial risk.
External pipe wall condition assessments are typically carried out on all types of ferrous pipelines to
explore the integrity of the ferrous pipe wall.
Advantages of the HSK & CAP external inspection system of NDT include:
• Scanning is not limited by the diameter of the pipe.
• Ability to survey through thick coatings (50mm+) of materials such as paint or tar commonly
found on many buried and exposed pipelines.
• The line does not have to be taken off-line, as readings are taken from the outside of the pipe.
The technique scans through the full wall of pipe registering corrosion or flaws within the full
wall thickness.
• Negligible effect of outside stray current fields potentially contaminating resulting data.
Where stray fields are identified - these can be clearly seen in captured data - variations in
data capture parameters are possible since the device is non-frequency dependent.
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
4. EQUIPMENT
The equipment selected for the NDT scanning of the pipelines was a HSK & CAP system. These
ultra-sensitive instruments are capable of generating comprehensive magnetic and electromagnetic
images, measuring intensity variation of ferrous material corresponding to the characteristics of pipe
wall conditions for identification of degradation due to corrosion or abrasion.
The HSK approach involves an operator to place the antenna on the pipes surface, normally in an
excavation pit such as in this project, and ideally with an accurate reference system. Data is acquired
and stored on a laptop outside if the pit and the operator moves the antenna around the pipes
circumference, and then along the pipes length. Full coverage (100%) is normally obtained in
scanning pipes using the HSK method, apart from where obstacles are encountered, such as valves &
joints. Refer to Section 5.2 Survey Method for the standard reference system when using the HSK
method.
The CAP approach does not require manned entry into the excavation pit. In project work, the pipe
would have vacuum excavation applied to the crown region of the pipe and only the area excavated
would be available for scanning and assessment. CAP scans do not provide a detailed assessment of
the 'full' circumference of the pipe but it allows the client to sample many more locations along the
pipes length whilst keeping to a limited budget. Refer to Section 5.2 Survey Method for the standard
reference system when using the CAP method.
5. FIELD TESTING
Field testing was conducted from the 24th through to 28th August 2009 by an RSG technician.
Details of the nine (9No.) locations tested can be found below.
5.1 Field Testing Details
Site 1 - Pit L (HSKMethod)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. Up to 5' in pipe length was available for external scanning. Of this 5ft, 4ft was
available for the full circumference. The last foot of pipe was not fully excavated therefore part of
the invert could not be scanned. Post-survey processing indicated noise in the BEM data at the
crown of the pipe over the first two feet of pipe which is possibly due to nearby underground
services.
Site 2 - Pit F (HSKMethod)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. Up to 5' in pipe length was available for external scanning. 100% coverage was
obtained for the whole 5ft pipe section.
Site 3 - Pit A (CAP Method)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. A pit of approximately 2ft wide was accessible for external scanning with the CAP
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
tool. Within this 2ft long pit, 1ft length was able to be scanned at 7" wide (around
circumference). Scanning was achieved from approximately 11 o'clock to 1 o'clock.
Site 4 - Pit B (CAP Method)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. A pit of approximately 3ft wide was accessible for external scanning with the CAP
tool. Within this 3ft long pit, 2ft length was able to be scanned at 7" wide (around
circumference). Scanning was achieved from approximately 11 o'clock to 12 o'clock (not
centered on pipes crown).
Site 5 - Pit C (CAP Method)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. A pit of approximately 3 1A ft wide was accessible for external scanning with the
CAP tool. Within this 3 1A ft long pit, 2 1A ft length was able to be scanned at 7" wide (around
circumference). Scanning was achieved from approximately 11 o'clock to 1 o'clock.
Site 6 - Pit D (CAP Method)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. A pit of approximately 1 1A ft wide was accessible for external scanning with the
CAP tool. Within this 1 1A ft long pit, 1ft length was able to be scanned at 7" wide (around
circumference). Scanning was achieved from approximately 10 o'clock to 11 o'clock.
Site 7 - Pit 2 (HSKMethod)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. Up to 5' in pipe length was available for external scanning. 100% coverage was
obtained for the whole 5ft pipe section apart from the where the valves protruded the pipe wall.
Site 8 - Pit F (HSKMethod)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. Up to 10' in pipe length was available for external scanning. 100% coverage was
obtained for the whole 10ft pipe section. Site 8 is in the same pit (F) as Site 2 but on a different
pipe section separated by a bell & spigot joint.
Site 9 - Pit E (CAP Method)
24" ID Grey Cast Iron Pipe; ~ 0.650"- 0.700" nominal wall thickness; negligible coating; cement
mortar lined. A pit of approximately 1 1A ft wide was accessible for external scanning with the
CAP tool. Within this 1 1A ft long pit, 1ft length was able to be scanned at 7" wide (around
circumference). Scanning was achieved from approximately 9 o'clock to 10 o'clock.
5.2 Survey Method
The most preferred procedure is to use pre-plotted grid paper with 2" intervals, taking individual
readings around the circumference. The paper would be wrapped around the outside of the pipe
allowing for accurate reference points of each individual reading taken.
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
The NDT grid with survey orientation is schematically illustrated in Figure 1. Scanning would be
undertaken from the outside of the pipe along the circumference starting and finishing at the crown of
the pipe.
\
(
(
n
:• I ! I
\
\
'. \ \
1 i ! 1
\ '
H
i
\
! ! ! I
~i
t , ,
i
n
'• /
Figure 1. Typical Survey Grid Along a Pipe Section.
For this particular project, chalk was used to mark a reference grid on the pipes external surface.
All HSK scans for this project started at the crown of the pipe, moving around the circumference over
the invert, and finishing back at the crown of the pipe, see Figure 4 below.
/ Southern Springline
I Layout of Scanning Grid
\
-------
Rigid Housing
Flexible Antenna
—~T
Figure 3. Typical CAP Scan Setup. Figure 4. Diagram of CAP Design.
6. RESULTS
The collected data was processed using a multi stage screening and processing procedure.
Determination of percentage intensity variation of ferrous material was obtained to facilitate
interpretation of pipe characteristics.
The processed data is presented in Appendix A as plots showing the apparent wall thickness of the
pipes.
Results have also been provided in excel format with X & Y co-ordinates corresponding to the
position of the data readings, and Z Co-ordinate corresponding to apparent wall thickness. All
measurements are in inches. Apparent wall thicknesses collected at each reading can be found under
the attached file "Battelle01_Data Summary.xls."
7. BEM INTERPRETATION
In a signal to thickness measurement, high amplitude signals represent thicker ferrous material within
the sensor's range of influence while a decrease in signal amplitude corresponds to reduction in
ferrous material quality or thickness. With accurate calibration, a thickness conversion against
amplitude reduction can be obtained.
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
Information from our existing database has been combined with specific frequency ranges for
conversion to percentage signal variation. These have then been used to predict the ferrous wall
condition.
Occurrence of micro structures within the ferrous material makes it impossible to determine an
absolute thickness conversion. An added complexity is that the response is averaged over an area and
volume scanned by the sensors, in this case approximately 2"2 (for HSK scans), or I"2 (for CAP
scans).
These limitations render the measurements of an absolute conversion difficult and thus only a relative
or apparent thickness correlation is provided in the interpretation.
a) Averaged Area of Readings
Each sensor averages over an area of approximately 2" square. This means that any anomaly or flaw
within or on the pipe wall must be viewed as a percentage of the overall volume of ferrous material
scanned. It is therefore important to note that a surface scratch or an isolated pit, unless of significant
size with respect to the scanned area, will not be seen as significant and may not have enough impact
to affect a particular reading.
It is also not possible to assess whether a noted wall thinning is as a result of ferrous loss on the front
or the back of the pipe wall or a combination of both. Similarly a cluster of pits will appear as a
general wall thinning rather than a pit cluster.
The BEM plots are a good representation of the area of each flaw and flaw trends. However, a clear
understanding of the HSK operation & antenna orientation with respect to the flaw is crucial when
determining size of flaws. More often than not a common situation is that a low response from
certain number of sensors does not equate to a flaw of that size. i.e. See Figure 3 below, and note that
a low response captured from three x 2" sensors would not necessarily be a flaw of 6" in size.
Antenna
( Sensor 1 j (
Sensor 2 J (_
Sensor 3
K
Sensor 4 J
2"
Flaw
Steel Pipe
Figure 5. Representation of Sensors Responding to Flaw.
Similarly, a flaw small in area ( < 2"x 2") may be scanned by up to four different sensors, resulting in
a thickness contour plot indicating a larger flaw area of lesser wall thinning than the actual situation.
b) Apparent Wall Thickness
It is not possible to tell whether the pipe wall is thinner or whether the metallurgy of the wall has been
altered. Thinning may be the result of original manufacture or abrasion while pipe alteration to rust
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
10
or graphitisation is a replacement type process rather than a wall thickness reduction based on a
physical measurement.
Corroded or altered ferrous material remains conductive and therefore has electromagnetic properties.
As a result it has an effect on the overall response recorded by the BEM signal.
It is however important to note that the response from corroded or altered material is significantly
weaker and therefore the recorded data is not affected to any great extent. It is also important to
understand that corroded or altered material still provides some level of structural support and more
importantly, provides an effective barrier for further corrosion since it effectively 'coats' the fresh
ferrous material.
c) Heat Effect
Pipes can be affected by heat processes such at the welding of steel pipes. This heating of the pipe
can potentially alter the metallurgy of the steel. The altered metallurgy of the steel can create an area
on the pipe that is more susceptible to corrosion. These processes can alter the way the HSK responds
to ferrous material. This is can be evident in the scan plot and is exhibited as an apparent drop or rise
in pipe wall thickness in close proximity of welds.
d) Manufacture Processes
Pipes can also be affected by manufacturing processes such as rolling. These processes can alter the
way the BEM responds due the affected area. This will be evident in the scan plot and is exhibited as
an apparent drop or rise in pipe wall thickness that is normally evident in a consistent trend.
8. SPECIFIC SITE INTERPRETATION
Site 1 - Pit L
The scan shows areas of reduced thickness to a minimum of 0.654" with the average thickness
around 0.735". Relative high degree of wall thinning on this scanned section appears to be near
the crown of the pipe, and relatively moderate wall thinning at the pipes haunches. There was a
section at the pipes invert that could not be scanned due to the pipe not being fully excavated at
this location. There are also two sections where the BEM data could not be processed as there
was noise interference in close proximity to this region. It is believed that as the noisy
interference was only observed in this single area that it is due to a nearby underground source
such as electricity cables.
Site 2 - Pit F
The scan shows areas of reduced thickness to a minimum of 0.678" with the average thickness
around 0.745". There are isolated areas of relative high degree of wall thinning on this scanned
section appears to be near the crown of the pipe, and relatively moderate wall thinning at the pipes
haunches. Due to the thinning appearing in isolated areas and not that of a particular trend, it is
probable that this type of wall loss is due to pit clusters or graphitisation.
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
11
Site 3 - Pit A
The scan shows areas of reduced thickness to a minimum of 0.662" with the average thickness
around 0.737". This CAP scan only covers a small area limited to the excavation, however
relatively moderate corrosion still appears to have been recorded near the crown of this pipe
section.
Site 4 - Pit B
The scan shows areas of reduced thickness to a minimum of 0.680" with the average thickness
around 0.719". This CAP scan only covers a small area that is limited to the excavation, however
relatively moderate corrosion still appears to have been recorded near the crown of this pipe
section.
Site 5 - Pit C
The scan shows areas of reduced thickness to a minimum of 0.627" with the average thickness
around 0.703". This CAP scan only covers a small area that is limited to the excavation, however
relatively severe corrosion appears to have been recorded across the majority of this scan near the
crown of this pipe section.
Site 6 - Pit D
The scan shows areas of reduced thickness to a minimum of 0.666" with the average thickness
around 0.689". This CAP scan only covers a small area that is limited to the excavation, however
relatively moderate corrosion still appears to have been recorded near the crown of this pipe
section.
Site 7 - Pit 2
The scan shows areas of reduced thickness to a minimum of 0.688" with the average thickness
around 0.735". There appears to be relatively moderate-to-severe corrosion on the southern
haunch of the pipe, as well as a fairly convincing trend of moderate corrosion at the invert of the
pipe.
Site 8 - Pit F
The scan shows areas of reduced thickness to a minimum of 0.711" with the average thickness
around 0.748". There appears to be relatively moderate corrosion on both the southern and
northern haunches of the pipe, but more-so on the northern side.
Site 9-Pit E
The scan shows areas of reduced thickness to a minimum of 0.704" with the average thickness
around 0.709". This CAP scan only covers a small area that is limited to the excavation, and
negligible wall thickness variation was recorded at this location. After confirmation of original
wall thickness, an assumption could be made if general wall thinning has occurred over this entire
scanned section.
9. NOT CONCLUSIONS & RECOMMENDATIONS
Rock Solid Group Pty. Ltd. (RSG) was commissioned by Battelle to participate in a condition
assessment program trial on a 24" diameter Cast Iron (CI) water main in Louisville, KY. RSG was
also commissioned to undertake post survey processing and analysis of the data collected as well as to
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
12
provide a written report detailing all findings. The CI water main was scanned externally using the
HSK (Hand Scanning Kit) non-destructive testing technique, as well as the CAP (Crown Assessment
Probe).
Field testing was conducted from the 24th through to 28th August 2009 by an RSG technician.
The date of construction of these pipes is unknown. The nominal thickness of the pipe is believed to
be approximately 0.650"- 0.700", however this information should be taken as anecdotal only.
Scanning was conducted externally through negligible external coating and soil on the pipes surface,
i.e. unprepared surface. The design specifications provided are based on verbal information provided
to RSG by Battelle.
From the results obtained it appears that there is some noticeable cylinder thickness loss in most of
the pipe sections scanned. There does not appear to be a common wall thinning trend for the entire
pipeline length. Most of the wall thinning trends tend to be section specific. Refer to Section 8 -
Specific Site Interpretation for description of the condition of the specific scanned sections.
The minimum wall thickness obtained by BEM has been recorded as 0.627" from Site 5 (Pit C).
As it is known that this pipe has been taken offline and no longer in use, RSG have no further
recommendations for BEM assessment of this pipeline.
Description of the condition can be found under section 8 - SPECIFIC SITE INTERPRETATION
and must be read in conjunction with Appendix A - NDT RESULTS.
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
13
APPENDIX A NDT RESULT
Rock Solid Group Pty Ltd, 11/7 Commercial Court, Tullamarine, Australia 3043
Tel: (+613) 9335 6122 Fax: (+613) 9335 6733
Email: info@rocksolidgroup.com.au
Web: www.rocksolidgroup.com.au
-------
Battelle - Site 1 - Pit L
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
Crown
Northern
Springline eo
Invert
Crown
This section
was not fully
excavated
Southern
Springline20"
Apparent Wall
Thickness
(Inches)
0.79
0.78
0.77
0.76
0.75
0.74
0.73
0.72
0.71
0.7
0.69
0.68
0.67
0.66
0.65
0.64
0.63
0.62
10"
20"
30"
40"
50"
Along Length of Pipeline
SOLID
GROUP
ABN: 86 760 170 879
LEGEND:
+ Scan Location
/r-0.8xmickness Contour
EPA DEMONSTRATION OF CONDITION
ASSESSMENT TECHNOLOGIES FOR
WATER MAINS, LOUISVILLE, KY
OCT 2009
ID: Site 1
PitL
Battelle
PROJECT NO.:
95786
PREPARED BY:
MARK DISHON
SEPT 2009
-------
Battelle - Site 2 - Pit F
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
Crown
80"
Southern70"
Springline
Invert
60"
50"
40"
30"
Northern ,
Springline'
10"
Crown >o-
Apparent Wall
Thickness
(Inches)
1
0.79
0.78
0.77
0.76
0.75
0.74
0.73
0.72
0.71
0.7
0.69
0.68
0.67
0.66
0.65
0.64
0.63
0.62
10"
20"
30"
40"
50"
Along Length of Pipeline
SOLID
GROUP
ABN: 86 760 170 879
LEGEND:
+ Scan Location
-0.8xmickness Contour
EPA DEMONSTRATION OF CONDITION
ASSESSMENT TECHNOLOGIES FOR
WATER MAINS, LOUISVILLE, KY
OCT 2009
ID: Site 2
PitF
Battelle
PROJECT NO.:
95786
PREPARED BY:
MARK DISHON
SEPT 2009
-------
Battelle-Site3-PitA
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
(CAP Scan Only)
Northern
Haunch
6'
Crown
12" 13" 14" 15" 16" 17" 18" 19" 20" 21
22"
23"
Southern
Haunch
Along Length of Pipeline
Apparent Wall
Thickness
(Inches)
0.8
0.79
0.78
0.77
0.76
'o.75
0.74
0.73
0.72
0.71
0.7
0.69
0.68
0.67
0.66
0.65
I 0.64
0.63
0.62
0.61
'0.6
mm
(HWP
ABN: 86 760 170 879
LEGEND:
r
+ Scan Location
O.S^Thickness Contour
EPA DEMONSTRATION OF CONDITION
ASSESSMENT TECHNOLOGIES FOR
WATER MAINS, LOUISVILLE, KY
OCT 2009
ID: Site 3
Pit A
Battelle
PROJECT NO.:
95786
PREPARED BY:
MARK DISHON
SEPT 2009
-------
Battelle - Site 4 - Pit B
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
(CAP Scan Only)
Northern
Haunch
Crown—^ 6"
2" 4"
Southern
Haunch
6" 8" 10" 12" 14" 16" 18" 20"
< Along Length of Pipeline >
22"
Apparent Wall
Thickness
(Inches)
0.79
0.78
0.77
0.76
0.75
0.74
0.73
0.72
0.71
0.7
0.69
0.68
0.67
0.66
I 0.65
0.64
0.63
'o.62
SOLID
GROUP
ABN: 86 760 170 879
LEGEND:
r
+ Scan Location
O.S^Thickness Contour
EPA DEMONSTRATION OF CONDITION
ASSESSMENT TECHNOLOGIES FOR
WATER MAINS, LOUISVILLE, KY
OCT 2009
ID: Site 4
PitB
Battelle
PROJECT NO.:
95786
PREPARED BY:
MARK DISHON
SEPT 2009
-------
Battelle - Site 5 - Pit C
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
(CAP Scan Only)
Northern
Haunch
Crown
5"
Southern
Haunch
10" 15" 20"
Along Length of Pipeline >
25"
Apparent Wall
Thickness
(Inches)
0.79
0.78
0.77
0.76
'o.75
0.74
0.73
0.72
0.71
0.7
0.69
0.68
0.67
0.66
0.65
0.64
0.63
'o.62
SOLID
GROUP
ABN: 86 760 170 879
LEGEND:
r
+ Scan Location
O.S^Thickness Contour
EPA DEMONSTRATION OF CONDITION
ASSESSMENT TECHNOLOGIES FOR
WATER MAINS, LOUISVILLE, KY
OCT 2009
ID: Site 5
PitC
Battelle
PROJECT NO.:
95786
PREPARED BY:
MARK DISHON
SEPT 2009
-------
Battelle - Site 6 - Pit D
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
(CAP Scan Only)
Crown
Apparent Wall
Thickness
(Inches)
-11
•6'u
4"--
2"--
1"--
0"-
+ + +
0"
Southern
Haunch
2" 3" 4" 5" 6" 7" 8"
< Along Length of Pipeline >
9"
10"
11"
'0.62
SOLID
ABN: 86 760 170 879
LEGEND:
r
+ Scan Location
0.8xmickness Contour
EPA DEMONSTRATION OF CONDITION
ASSESSMENT TECHNOLOGIES FOR
WATER MAINS, LOUISVILLE, KY
OCT 2009
ID: Site 6
Pit D
Battelle
PROJECT NO.:
95786
PREPARED BY:
MARK DISHON
SEPT 2009
-------
Battelle - Site 7 - Pit 2
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
70"
60"
Northern
Springline
50"
40"
Invert >
30"
20"
Southern
Springline
10"
Crown >o"
:
^— »
§
i
I
0
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- + — ^^+~+ + + -ft +
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+ f+ + 4l+\+ + + + ^ — -^^+/^^~>-^y /+ /+ +__J^_± =
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+(+^-(+ +) + + + +(+ + + +\ f + +/-y~-~+ + (+ (-
H- ^v+ + + + + + + +\ + /TN + + 1+ V+/ + + 77"
+ + + + + + + + + +\4-V+Vp\ 4^ — =f+ j* \ (+ r
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\ ^ / / A ) /
+\ + + +( + + + + + + + + + 1 ( + ) i + + / +/-
r~\ i ^ / /
Apparent Wall
Thickness
(Inches)
7 ^lo.79
k-| 0.78
1 0.77
Ulo.76
^0.75
— ^0.74
0-70
./o
07O
./^
n 71
u. / i
0-7
. i
n RQ
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OR7
.D(
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n RC;
• U.DO
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.D'f
; — | 0.63
^0.62
10" 20" 30" 40" 50"
< Along Length of Pipeline >
LEGEND:
+ Scan Locat
^O.S^Thickness C
TITLE:
On CLIENT:
ontour
PROJECT N
si ^©©^§©yE)
H ©KIP
^"jl ABN: 86 760 170 879
EPA DEMONSTRATION OF CONDITION ID: Site 7
ASSESSMENT TECHNOLOGIES FOR Pit 2
WATER MAINS, LOUISVILLE, KY
OCT 2009
Battelle
D.: PREPARED BY: DATE:
95786 MARK DISHON SEPT 2009
-------
Battelle - Site 8 - Pit F
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
Crown
Northern
Springline
Invert
Southern
Springline
Crown
To Site 2
90" 100" 110"
Apparent Wall
Thickness
(Inches)
0.79
0.78
0.77
0.76
0.75
0.74
0.73
0.72
0.71
'o.7
0.69
0.68
0.67
0.66
I 0.65
0.64
0.63
'o.62
Along Length of Pipeline
(HWP
ABN: 86 760 170 879
LEGEND:
+ Scan Location
-0.8xmickness Contour
EPA DEMONSTRATION OF CONDITION
ASSESSMENT TECHNOLOGIES FOR
WATER MAINS, LOUISVILLE, KY
OCT 2009
ID: Site 8
PitF
Battelle
PROJECT NO.:
95786
PREPARED BY:
MARK DISHON
SEPT 2009
-------
Battelle - Site 9 - Pit E
EPA Demonstration of Condition Assessment Technologies
24" Diameter Cast Iron Pipe
(CAP Scan Only)
Crown
5"
4"
3"--
2"
9 o'clock-
(Southern Haunch) 0" 1"
3" 4" 5" 6"
Along Length of Pipeline
8"
10"
Apparent Wall
Thickness
(Inches)
0.79
0.78
0.77
0.76
0.75
0.74
0.73
0.72
0.71
0.7
0.69
0.68
0.67
0.66
,0.65
0.64
0.63
'o.62
SOLID
GROUP
ABN: 86 760 170 879
LEGEND:
r
+ Scan Location
O.S^Thickness Contour
EPA DEMONSTRATION OF CONDITION
ASSESSMENT TECHNOLOGIES FOR
WATER MAINS, LOUISVILLE, KY
OCT 2009
ID: Site 9
PitE
Battelle
PROJECT NO.:
95786
PREPARED BY:
MARK DISHON
SEPT 2009
-------
APPENDIX H:
Technology Vendor Letters (8 pp.)
H-l
-------
APPENDIX H
Technology Vendor Letters
-------
TECHNOLOGIES
Response to Final Report
Pure Technologies Ltd.
The following comments are in response to the draft copy of Battelle's report entitled, "Field
Demonstration of Innovative Condition Assessment Technologies for Water Mains at Louisville,
Kentucky, Part 2: ACOUSTIC PIPE WALL ASSESSMENT, INTERNAL INSPECTION, AND EXTERNAL
INSPECTION".
In July, 2010 Pure Technologies (Pure) announced the acquisition of the Pressure Pipe
Inspection Company (PPIC) and now represents all of the technologies demonstrated by both
parties during the 2009 demonstrations,
Technology Advancements
The following is a summary of all technology advancements related to the 2009 demonstrations
in Louisville, KY.
Acoustic Pipe Wall Assessment
• PWA: During the 2009 field trials, Pure demonstrated SmartBail* Pipe Wall Assessment
(PWA) and PPIC (now part of Pure) demonstrated Sahara* Wall Thickness Assessment
(WTA). Since PWA's method of capturing data provides higher resolution than WTA,
PWA has since been applied to the Sahara platform. A new dual-hydrophone system
has been developed for Sahara and as such, Sahara PWA has replaced Sahara WTA.
Internal Inspections
» Sahara: During the 2009 field trials, the Sahara leak detection and video inspections
were performed during separate runs and required a sensor head change. Since then, a
combined audio/video sensor head has been developed, which allows leak detection
and video inspections to be performed simultaneously in the same run.
• PipeDiver™: The PipeDiver RFEC tool was equipped with a center detector and six petal
detectors during the fietd trials; however the results from the center detector were only
reported due to the lack of calibration data at that time. Since 2009, Pure has
performed several pilots with the 6 detector system.
* Magnetic Flux Leakage: Realizing the need for high-resolution inline inspections of
ferrous water mains, Pure acquired Electromechanical Technologies (EMTEK) and their
suite of inline MFL tools in 2011. EMTEK has advanced the MFL technology to
incorporate extra high-resolution (XHR) technology, which is able to scan through inner
pipe linings up to 1 inch thick and is proven to detect pitting as small as >» inches in steel
pipe. XHR-MFL is a premium technology complementing Pure's PWA and RFEC
technologies.
-------
Nestle roth, J Bruce
Subject: FW; New fifes waiting for you at Battelle's File Exchange
From: Dave Johnston rmailto:DJohn5ton@echolQgics.confi]
Sent; Friday, September 09, 2011 8:35 AM
To: Nestleroth, J Bruce
Cc: Marc Bracken
Subject: RE: New files waiting for you at Battelle's File Exchange
After careful review of the report I am happy to say that we do not have any comments or concerns about the
report itself. It was very well written and we feel that the conclusions were fair.
In hindsight, we learned, and are continuing to learn from the results of the report. Currently we are reviewing
the results in detail to try and establish a more accurate model of the sensitivity of the method i.e. the ability to
find smaller, more isolated pockets of corrosion. This will allow us to make more educated conclusions from a
set of results.
In addition to this, we have been continually improving the accuracy and the precision of the method. The most
recent development involves a calibration device to account for local water conditions,
One of the most interesting things that was discovered during the field testing in Louisville was the discovery
that we could identify the existence of air pockets. As you will recall it actually impeded our ability to perform
the tests during our first mobilization. Using what we learned on-site we have developed a procedure to identify
large air/gas pockets in water and sewer mains.
Again, we would like to thank you for the opportunity to participate in this study and we would be happy to
participate in another, not only to promote Echologics, but to learn from the experience and continue to improve
the technology.
Kind Regards
Dave Johnston
I
-------
RUSSEI I
Russell (PICA) Comments
Comments on the report results
1) We are not surprised by the fact that PICA'S 24" Tool provided the most accurate and
informative information. Russell (PICA) has had over 20 years of developing this
technology for a range of pipeline and other applications and, while this particular Tool size
was brand new at the time, the fundamental technique has plenty of experience in similar
materials and applications (just different pipe sizes). The colour map below shows an
example of See Snake data. The image is the RFT wall thickness representation for the pipe
length between joints 24 and 25. The reported 70% and 87% deep defect are clearly visible,
as are a number of smaller less severe indications.
Figure 1. Colour map of See Snake RFT data for pipelength between joints 24 and 25. Red localized
indications depict areas of substantial wall loss (WL).
2) We were pleased to see that the excavation and confirmation of defects was done in a very
careful, professional and accurate manner. During retrieval of pipes it is very easy to mis-
number the pipe, but in this case there was a great deal of care and attention given to this
important aspect of the project.
3) Russell (PICA) had manufactured the 24" Tool especially in order to be able to participate
in this technology evaluation. The report correctly states that the Tool used was not
suitable for live launch (free swimming). This is mainly because we did not have time to
add an odometer section before the time window for the evaluation expired. Normally, this
inspection would have been performed in free-swimming mode, and the problems that we
had in coordinating the winches that were attached to both ends of the Tool would not have
been an issue. The speed of the Tool in a pipeline that is in service is controlled by the water
flow, and surging is not usually an issue.
4) Since the technology demo, Russell has transferred its water and waste water inspection
business to PICA: Pipeline Inspection and Condition Analysis Corp., which now has offices
in Edmonton, Toronto, Vancouver and Montreal (all Canada) and Charlotte, NC.
www.picacorp.com. Tools are available in sizes from 3" to 28".
-------
Lessons learned from the inspection
1) We had not used a two-winch set-up before. The first run resulted in surging because we
could not keep the two winches synchronized. After the first run, we realized that the
trailing winch only needed to be operated in low speed (i.e. rather than trying to rely on a
mechanical brake to hold back the winch drum). This improvement allowed the winch that
was pulling to have a steady toad, and reduced surging to almost zero.
2} The assembly of the Tool took too long. This was because the Tool was new, and was
shipped in three sections. In future, we plan to pre-assemble the three parts of the Tool
above ground and launch the Tool into an in-service pipeline through launch piping.
3) For similar technology demos we recommend performing low-field electromagnetic type
inspections prior to inspection technologies subjecting the pipe to strong magnetic fields (if
tool and personnel scheduling and availability allow).
Improvements made since the demo
1) The Tool is now configured for free-swimming, pressurized pipeline service.
2) The Tool now has on-board redundant odometers
3) If the application calls for a tethered operation, we have a Standard Operating Procedure to
prevent surging
4) Improved resolution and pressure proofing of the detectors
5) PICA-USA Office opened in Charlotte.
2
-------
BEM TECHNOLOGY UPDATE
Rock Solid Group Pty. Ltd.
The following is a summary of major advancements which have occurred in BEM
technology since the scanning conducted in the EPA Louisville, Kentucky trials by Rock
Solid Group in August 2009.
Technology Advancements
Software
In 2011 RSG launched its new acquisition software MetCon©. This software greatly
increases the ability for the operator to report the wall condition on site in real-time as
well as many other benefits such as the ability to make a judgement about the ferrous
material being scanned.
EXTERNAL INSPECTIONS
Hand Scanning Kit (HSK} - 2010 saw the launch of the HSK 300 system which is now
equipped standard with a full range of 1" & 2" sensor antennae allowing for a selection
of desired sensitivity. Besides the battery pack, the HSK 300 can now also be to be
powered from a car cigarette lighter or mains power allowing for unrestricted time use.
Furthermore, the HSK 300 can now be integrated with Master or Slave Switchers
allowing the HSK 300 to power many tens of antennae at the same time. Previously
non-scannable pipe components such as elbows can now be tackled easily.
Crown Assessment Probe (CAP) - 2011 saw the launch of a commercially available 1" &
2" sensor pipe crown scanning tool. Operating on the back of the HSK 300 the CAP is
now being used commercially in scanning of pipe segments through keyholes or
potholes, greatly enhancing site safety.
Full Assessment Probe (f AP) — On the back of the success of the CAP the development
of the FAP has been completed. The FAP allows for the full encirclement of the pipe
with BEM antennae in a keyhole or pothole achieving a 100% pipe wall coverage about
the exposed section of pipe with no need for manned entry, greatly enhancing site
safety.
Wall Assessment Probe (WAP) - 2011 saw the launch of a commercially available 1" &
2" sensor wall scanning tool. It is ideal for and has been applied to the scanning of water
storage tanks and the like. Operating on the back of the HSK 300 the WAP is now being
used commercially to scan large patches of tank walls simultaneously.
INTERNAL INSPECTIONS
Hand Scanning kit (HSK) -The HSK has been applied to the internal scanning of pipe wall
and elbows where manned entry is available. Specifically pipe components such as
elbows, which do not lend themselves to PIG scanning can now be assessed with both 1"
& 2"sensor antennae.
Pipe Inspection Gauge (PIG) - Although minor pipe lengths were scanned using
remotely operated PIG units equipped with BEM technology the launch of significant in-
line scanning occurred in early 2010. The ability to now control numerous BEM consoles
with the aid of enhanced software, switching devices which allow the simultaneous
operation and endless power supply through tethered systems, commercially available
in-line PIG systems operating BEM technology are now available.
D
ROCK
11/7 COMMtkCAL COURT,
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AUSTRALIA JO^i
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-------
Technology Update
I.NGIMJ'.KIXU
wu.mnss MI>
AESL's ECAT High Flux Magnetic Pipeline Inspection Tools
AESL's magnetic inspection tools are routinely used for the external inspection of
grey cast iron, ductile cast iron, wrought iron and steel pipelines, usually for water
and gas supply networks.
Since the completion of field trials in Louisville, AESL has undertaken a programme
of technology improvements to the mechanical and electronic design of the
inspection too) design, and all aspects of the data assessment process and
supporting software. The main elements of the improvement programme are
summarised below:
Development of ECAT Inspection Tools
AESL's condition assessment and prediction process requires inspection of the full
pipe circumference, using our own magnetic inspection tools. The overall tool profile
has now been reduced, to minimise the down hole clearances needed for access and
improve the operational usability of the tools.
The mechanical and electronic design has also been updated to give:
• Improvements to the magnetic circuitry to optimise the inspection performance
• Reduced levels of background noise within data signals to improve performance,
particularly on grey iron pipe materials
• Increased number of inspection sensors and faster rates of data transfer
« Increased on-board storage for inspection data and additional options for data
transfer or downloading
Development of Calibration and Data Analysis Software
Mechanical and electronic elements of the
inspection tool design have been revised to
improve the quality and repeatability of
inspection performance.
Data analysis software has been further
developed to improve the identification and
sizing of defects within the inspection data.
Software based calibration procedures have
been revised to optimise the overall inspection
process.
Development of Defect Sizing Algorithms
Defect sizing algorithms have been developed, based on the inspection outputs from
machined defects within a range of pipe specimens of different material, diameter,
wall thickness etc. Parameters investigated to improve the algorithms include
• Influence of defect shape on sensor output and inspection accuracy
• Optimisation of sensor location, orientation, performance
• Benefits of alternative sensor types and configuration.
MW/CJ 30/09/2011
-------
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