United States
Environmental Protection
Agency
State of Technology Report for
Force Main Rehabilitation
Office of Research and Development
National Risk Management Research Laboratory - Water Supply and Water Resources Division
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EPA/600/R-10/044
March 2010
Final
State of Technology Report for
Force Main Rehabilitation
by
Robert Morrison, P.E.
Tom Sangster
Jason Consultants, LLC
Lili Wang, P.E.
Wendy Condit, P.E.
Battelle Memorial Institute
Contract No. EP-C-05-057
Task Order No. 58
for
Ariamalar Selvakumar, Ph.D., P.E.
Task Order Manager
U.S. Environmental Protection Agency
National Risk Management Research Laboratory
Water Supply and Water Resources Division
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
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DISCLAIMER
The work reported in this document was funded by the United States Environmental Protection Agency
(EPA) under Task Order (TO) 58 of Contract No. EP-C-05-057 to Battelle Memorial Insititute,
Columbus, OH. The EPA, through its Office of Research and Development, funded and managed, or
partially funded and collaborated in, the research described herein. This document 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.
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FOREWORD
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the Nation's
land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities and the ability
of natural systems to support and nurture life. To meet this mandate, EPA's research program is
providing data and technical support for solving environmental problems today and building a science
knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect
our health, and prevent or reduce environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for investigation
of technological and management approaches for preventing and reducing risks from pollution that
threaten human health and the environment. The focus of the Laboratory's research program is on
methods and their cost-effectiveness for prevention and control of pollution to air, land, water, and sub-
surface resources; protection of water quality in public water systems; remediation of contaminated sites,
sediments and ground water; prevention and control of indoor air pollution; and restoration of eco-
systems. NRMRL collaborates with both public and private sector partners to foster technologies that
reduce the cost of compliance and to anticipate emerging problems. NRMRL's research provides
solutions to environmental problems by: developing and promoting technologies that protect and improve
the environment; advancing scientific and engineering information to support regulatory and policy
decisions; and providing the technical support and information transfer to ensure implementation of
environmental regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term research plan. It is
published and made available by EPA's Office of Research and Development to assist the user
community and to link researchers with their clients.
Sally Gutierrez, Director
National Risk Management Research Laboratory
in
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EXECUTIVE SUMMARY
Introduction
Force mains that carry sewage flows under pressure represent a special set of challenges for sewer
rehabilitation. Force mains represent about 7.5% of the wastewater system and they typically use
materials that are not commonly used in gravity sewer systems. Ductile iron (DI), cast iron (CI), steel,
and concrete pressure pipe are all material types that are frequently used for sewer force mains, especially
in larger diameters. All of these materials are susceptible to both internal corrosion from the sewage flow
(liquid and gaseous states), as well as external corrosion due to the environment in which the pipe is
buried.
Historically, the most common renewal technology employed has been to replace the main using open cut
construction. Part of the reason for that choice has been a lack of rehabilitation technologies appropriate
for sewer force mains. There is a wealth of technologies available for gravity sewers, but the field has
been limited for pressurized systems. Fortunately, that situation is changing as more vendors recognize
the growing opportunity in sewer force main rehabilitation. The other reason for replacement is that
sewer force mains tend to have a fairly high consequence of failure. A rupture of a sewer force main
could release millions of gallons of raw sewage into the environment posing significant health risks to the
general public. Cleanup costs can be staggering.
As some of the newer rehabilitation technologies develop a positive track record of use in sewer force
mains and confidence in their design approach and installation process strengthens, more utilities will be
willing to consider these trenchless technologies as potential renewal solutions. Trenchless methods have
proven themselves to be cost-effective for gravity sewer mains, especially when both direct and indirect
costs associated with a replacement program are considered. A similar outcome is expected for sewer
force mains once data on the effectiveness and longevity of these technologies and materials and life-
cycle costs become more readily available.
Recognizing that there would be some cross-over amongst the various rehabilitation technologies
common to water mains and gravity sewers, a series of technology-specific datasheets were created for
each identified rehabilitation technology deemed relevant to sewer force mains and are included as
Appendix A of this report. An effort was made to collect representative cost information, but often only
limited cost data were available.
Characteristics of Force Mains
The approximate length of the force main system in the US is 60,000 miles (96561 km). The Water
Environment Research Foundation (WERF) recently published a report titled "Guidelines for the
Inspection of Force Mains" (WERF, 2009). The data from this WERF survey are presented and
characterize the types of pipe materials used, diameter ranges, ages, location accessibility, and failure
modes and mechanisms for force mains. Ferrous pipe materials (i.e., CI, DI, and steel) represent on
average 63.4% of all pipes used for force mains. Over 91% of sewer force mains are between 4 and 36
inches (100 and 900 mm) in diameter, which are within the non-man entry size range and only 2% are
beyond 50 years in age. Over 91% of the force main pipes are buried. Only 5% of the total number of
force mains surveyed for the WERF project had some built-in redundancy.
Internal corrosion was rated as being responsible for ferrous force main failures 26.2% of the time, ahead
of all other known causes. External corrosion at 19.2% and third-party damage at 19.4% are the next
most common causes of failures in ferrous mains. The most common single cause of failure in non-
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ferrous force mains is third-party damage, which accounts for 37% of failures. Corrosion and structural
failure together account for 54% of failures.
Renewal Technologies
Renewal offeree mains includes repair, rehabilitation, and replacement. The estimate of renewal works
in force mains are between 250,000 and 600,000 linear feet (76,220 and 182,927 meters) or 0.08% to
0.19% of the total length on an annual basis. Replacement comprises between 200,000 and 500,000
linear feet (60,976 and 152,439 meters) offeree mains annually or some 0.1% to 0.15% of the total
length. The best estimate is that between 50,000 and 100,000 linear feet (15,244 and 30,488 meters) of
force mains in the US are rehabilitated annually. This represents some 0.02% to 0.03% of the overall
length. There are a variety of reasons for this lower rate of rehabilitation in sewer force mains. The first
is the lack of consistently reliable and cost-effective sewer force main inspection methods and the second
is the low number of rehabilitation technologies specific to force mains.
Force mains can operate with a wide range in pressures, from a few feet of head to hundreds, so there is
potentially a large number of technologies that can be adapted to force mains from other applications.
Vendors are constantly making improvements to their products so they should always be consulted before
using any of the identified technologies.
Repair
Repair of a failure or a deteriorated section of pipe is generally focused on only taking remedial action
with one or two sections of pipe. Oftentimes this work is done under emergency conditions. The first
objective is to prevent any further spill or damage to the environment and the second objective is to
restore service as quickly as possible. Repair can be broken down into open cut replacement of a
section(s) of pipe, spot repairs using cured-in-place-pipe (CIPP), mechanical sleeves or repair clamps, or
joint repairs using internal sleeves or external devices. Some examples of each are given in this report,
but repair is not a focus of this report.
Rehabilitation
In rehabilitation, the existing pipe becomes part of the renewal work. Rehabilitation methods will include
the use of spray-on linings, close-fit linings, CIPP, and woven hose lining systems. Technologies for
each of these rehabilitation categories are discussed in this report in addition to cleaning requirements
prior to rehabilitation. Because only limited rehabilitation work has been undertaken to date on sewer
force mains, many of the systems available were originally developed for water main rehabilitation, but
can be adapted to sewer force mains.
Spray-on linings have been one of the easiest methods of rehabilitating a pressurized main when the
primary objective is just to provide corrosion protection to the interior surface. Spray-on linings include
cementitious and polymer materials. Two polymers, epoxy and polyurethane, are used extensively in the
UK water industry to line water mains. Rapid cure time over cement mortar and resistance to soft water
have favored these materials. A new family of polymer spray-on linings, based on the use of polyurea, is
finding rapid acceptance for lining manholes, wetwells, and other structures exposed to corrosive
environments including pipes. One of the benefits of the use of polyurea is a very fast cure, with gel
times in 5 to 40 seconds. The liner can also be spray applied with a thickness up to 2 inches (50 mm).
This liner has the ability to serve as a semi-structural or structural liner and not just provide corrosion
protection.
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The use of close-fit liners is often called modified sliplining. It involves the use of a thin walled liner
with an outside diameter that is similar to the inside diameter of the host pipe. The key to installing the
liner is to temporarily reduce the liner diameter to facilitate its insertion into the host pipe. Once the liner
is in place, it is reverted back to its original outside diameter forming a close fit to the host pipe. The two
methods of temporarily reducing the diameter of the liner is symmetrical or fold-and-form. Polyethylene
(PE) pipe is used for the symmetrical reduction process, and both PE and polyvinyl chloride (PVC) for
fold-and-form.
CIPP is by far the leading method for the rehabilitation of gravity sewers. With the expiration of the
original patent on CIPP, many new variants have been introduced. The main differences are based on
tube construction, method of installation, curing method, and type of resin.
Woven hose linings differ from ordinary CIPP products by the construction of the tube reinforcement.
Rather than being made of a felt-type material, hose liners are made from either polyester, glass, or
aramid fibers that are woven into a hose-type configuration, similar to the type of construction used for
fire hoses. Three types of woven hose lining systems are discussed including adhesive-backed linings,
non-adhesive backed linings, and glass-reinforced thermoplastic linings.
Replacement
Replacement involves the installation of a new fully structural pipe to take over the functions of the
deteriorated force main. Several technologies are available for online and offline replacement.
Historically, the most common method has been offline replacement by open cut, as the work can be
undertaken with the existing main in operation and it results in a brand new pipe with a known design
life.
The second most common method of replacement has been sliplining. Sliplining involves the insertion of
a new pipe with a smaller outside diameter than the inside diameter of the pipe to be rehabilitated. Pipe
lengths can be fused together to create a long continuous string, frequently done with PE and Fusible
PVC™, which is then pulled into the host pipe. Alternatively, especially when site conditions prevent
pre-joining long strings of pipe, discrete pipe sections can be jointed one at a time and pushed into the
host pipe. PVC, DI, and fiberglass reinforced plastic/glass reinforced plastic (FRP/GRP) pipes are
typically sliplined in this fashion. Mechanically restrained joints can also be employed with these
materials, which would allow pulling of the pipe into place.
Pipe bursting involves the breaking up of the old pipe and pushing it into the surrounding soil by passing
a bursting or splitting device through it, while pulling a replacement pipe in behind the bursting head.
The replacement pipe is usually high density polyethylene (HDPE), PVC, or DI. In some cases, the
process can be used to expand the void created thus upsizing with the insertion of a larger diameter. Pipe
bursting has now been accomplished in diameters from 4 to 60 inches (100 to 1,500 mm). The three basic
bursting methods include static, hydraulic, and pneumatic bursting.
Offline replacement simply involves the installation of a new pipe without regard to the line and grade of
the existing pipe. Normally, the existing deteriorated pipe being replaced is kept in service (at reduced
operating conditions if necessary), while the new replacement pipe is being installed. Typically, methods
of offline replacement include open cut excavation and newer trenchless methods such as directional
drilling and microtunneling/pipe jacking. For microtunneling, FRP/GRP, polymer concrete, and steel
pipes can be used.
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Technology Selection Criteria
Aside from selecting renewal technologies on the basis of their fit to the force main's operating conditions
(e.g., pressure, burial depth, etc.), other site-specific parameters must be considered in the selection
process. The life-cycle cost of the renewal method and its impact on extending the life of the asset are
often the primary concerns in technology selection. As discussed in this report, studies in the US and UK
have shown the relative cost benefits of rehabilitation versus open cut replacement in urban environments.
Other site-specific factors that should be taken into consideration include post-renewal capacity needs,
accessibility, future operations and maintenance (O&M) requirements, the condition of the host pipe, and
the consequence of its failure (criticality).
All rehabilitation options will result in a reduced cross-sectional area. Spray-on linings and close-fit
liners will least impact flow capacity, while sliplining will have the greatest impact. Loss of capacity is
mitigated somewhat by improved friction factors. If capacity restraints exist, then replacement may be
the only feasible option.
Other items that can impact the selection of a renewal method are accessibility of the force main,
maintenance crews familiarity with the liner system and repair methods, and the criticality of the force
main. The higher the consequences associated with a failure, the more conservative the approach will be
towards renewal of the main. A partially deteriorated force main that has an extremely high consequence
of failure would be one that would probably be treated as fully deteriorated from the perspective of the
design of the rehabilitation system.
Design and Quality Assurance/Quality Control
The design of a rehabilitation product to renew the life of a distressed sewer force main ranges from an
inner corrosion barrier to an outright structural replacement. The factors that will control the design are
the condition of the existing main, including its expected remaining life if further deterioration is arrested,
and the operating conditions under which that main is used. The degree of deterioration is typically
broken down into one of two categories: (Impartially deteriorated, where the existing pipe is expected to
support all external loads (soil, live, surcharge), or (2) fully deteriorated where the existing pipe is not
structurally sound.
Design methods currently employed are for either interactive or independent liners and depend upon the
condition of the existing (host) pipe. Interactive liners are generally thin liners, in direct contact with the
inside wall of the existing pipe, with a lower ring tensile stiffness than the existing pipe. Interactive liners
should not be used in sewer force mains where the existing pipe has deteriorated to a point where it is not
expected to be able to carry the full internal pressure over the renewal design life. An independent liner is
one that is designed to carry the full internal working pressure and surge pressure itself independent of
any contribution from the host pipe.
Few rehabilitation products are designed specifically for use in a sewer force main. Therefore, design and
Quality Assurance/Quality Control (QA/QC) requirements and best practices may need to be adapted
from relevant American Water Works Association (AWWA) and American Society for Testing and
Materials (ASTM) standards.
The AWWA M28 Manual on Rehabilitation of Water Mains has established four classes of design: non-
structural (Class I), semi-structural (Class II and III), and fully structural (Class IV). Class I liners only
act as corrosion barriers, Class II/III liners are designed to bridge over small holes or gaps in the host
pipe, while Class IV liners will carry the full internal pressure without support from the host pipe.
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A whole host of ASTM specifications and AWWA standards cover the various types of materials and
installation practices that may be used in a renewal project. Many of these are included in this report,
along with a brief description. Some of the ASTM standards include non-mandatory design appendices,
which are all patterned after Appendix XI of ASTM F1216. ASTM F1216 is the standard practice for the
rehabilitation of gravity and/or pressure pipes using a CIPP inversion product.
For gravity applications, the design appendix in ASTM F1216 requires that the liner be designed to
support (without buckling) any external hydrostatic head if the host pipe is partially deteriorated and all
external loads (without buckling) if fully deteriorated. Of course, the determination of whether the host
pipe is partially or fully deteriorated is subjective. Likewise, depending on the ratio of the diameter of
any holes in the pipe to the pipe diameter, the liner is designed to either act as a flat plate with fixed edges
covering the hole or, if the host pipe is fully deteriorated, then as a thin ring under hoop stress from the
internal pressure. In both of these design cases, either the long-term flexural strength or the long-term
tensile strength is used. However, there is no standardized test method defined to determine either of
these properties for a CIPP product. It is up to each manufacturer to establish those long-term properties.
Based on a survey of CIPP producers, few if any have embarked on an extensive test program similar to
that required for the pressure design of FRP/GRP or thermoplastic pipes.
Most of the QC requirements in the ASTM and AWWA standards pertain to use in a gravity sewer or a
pressure water main. None combine the corrosion resistance necessitated by the sewer effluent and the
long-term tensile strength of a pressurized main. Post-installation closed circuit television (CCTV) is the
most common QC requirement for all liners followed by the retrieval of samples for physical property
verification. Leak tightness testing is also recommended.
Operation and Maintenance
Some of the best practices for O&M are cleaning, addition of cathodic protection, installation of
continuous corrosion monitoring, pressure monitoring, leak monitoring, and acoustic monitoring of
prestressed concrete cylinder pipe (PCCP) for wire breaks. These measures can be effective in either
prolonging the life of a buried sewer force main or allowing a utility to monitor real-time performance so
action can be taken as needed to repair, rehabilitate, or replace before a catastrophic failure occurs.
Proper cleaning can improve the capacity and hydraulic performance of a sewer force main. Cathodic
protection can arrest any further external electrochemical-induced corrosion of ferrous mains.
Continuous corrosion monitoring can be installed on new mains or added to existing mains. Ultrasonic
sensors measure loss of internal wall thickness. Leaks can be a precursor of failure and locating leaks in a
force main using acoustic devices can help to prevent catastrophic failures.
A rehabilitated main effectively adds to the range of material that must be potentially repaired in an
emergency. There are no set procedures for repair of rehabilitated (i.e., lined) force mains. This is an
area of concern for utilities and certainly makes them reluctant to line their mains because they do not
know how to deal with them when emergency repair becomes necessary.
Gaps Between Needs and Available Technologies
Little data are obtained on force main condition upon which assessment and subsequent rehabilitation
decisions can be based. So rehabilitation decision-making is often based on operational indicators such as
power consumption, air release valve operation, or main breaks. The renewal decision should be based
on three elements: the rate of deterioration of assets; the condition of critical locations; and whether
spending can be deferred. A first step is to establish risk-based assessment methods to identify force
mains with serious consequences of failure, either in operational or environmental and public impact
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terms, or both. A second step is to consider prioritization for external data collection. A method for
identifying high risk locations in terms of likelihood of failure based on environment and operating
characteristics could pinpoint high risk locations, which would be selected for direct inspection.
There is a clear need for assessment methodologies that can work with limited data. These could
potentially be based on Bayesian belief networks. There is also a need for inspection technologies that
can provide data more cost-effectively to support these assessment methodologies.
A gap exists in terms of a design procedure for CIPP in pressure applications to ensure that long-term
performance requirements can be met. Little data are available on the long-term performance of
rehabilitation solutions in real environments, which a designer can use to predict the remaining life of an
asset that incorporates one of these rehabilitation methods. Another capability gap is the access needed to
the main and the need to shut down, dewater, and clean the main for rehabilitation. This is an inevitable
feature of any internal rehabilitation technology, as it is for inspection technologies. This also places a
limitation on the use of rehabilitation in force mains.
Findings and Recommendations
Most of the renewal activity has been outright replacement of the force main either by open cut or
trenchless means. New products and technologies are now emerging for carrying out a direct condition
assessment on a buried force main, as well as rehabilitation methods for those found in distress.
One method of assisting owners in their efforts to apply some of these emerging technologies will be in
the publication of demonstration projects and case studies. Also, setting up a decision support system that
helps a utility ask the right questions so that a viable rehabilitation solution emerges is paramount.
It is clear that a system rehabilitation program needs to integrate several aspects and to have a broader
vision than merely the rehabilitation technology and its implementation. The elements that need to be
integrated within the scope of an asset management approach include inspection, assessment,
maintenance, and rehabilitation.
Key elements offeree main maintenance are regular cleaning, maintenance of cathodic protection
systems, and maintenance of air release valves. Inclusion of corrosion monitoring, pressure monitoring,
and leak monitoring should be considered.
The decision-making process relies on data from inspection to assess risk levels and to decide on
necessary actions. Determining the level of data or information required to support effective decisions is
a key aspect of the process. Too little data and the wrong decisions may be made; too much data and the
cost of obtaining the data may exceed its value in the process. Neither scenario is cost-effective. One of
the key data elements needed is verification of the long-term performance of pressure rehabilitation
systems. This should be a major objective of the demonstration project.
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CONTENTS
DISCLAIMER ii
FOREWORD iii
EXECUTIVE SUMMARY iv
FIGURES xii
TABLES xiii
DEFINITIONS xiv
ACRONYMS AND ABBREVIATION xvi
1.0 INTRODUCTION 1
1.1 Project Background 1
1.2 Project Objectives 2
1.3 Project Approach 3
1.4 Organization of Report 3
2.0 CHARACTERISTICS OF FORCE MAIN SYSTEMS 5
2.1 Material Usage 5
2.2 Diameter Distribution 5
2.3 Age of System 7
2.4 Force Main Location 7
2.5 Redundancy 9
2.6 Cause of Failure in Force Mains 9
2.6.1 Ferrous Force Mains 9
2.6.2 Non-Ferrous Force Mains 9
3.0: RENEWAL PRACTICES AND TECHNOLOGIES 11
3.1 Current Utility Practices and Market 11
3.2 Overview of Renewal Technologies 12
3.3 Repair 14
3.3.1 Open Cut Emergency Replacement 14
3.3.2 Spot Repair- Trenchless 14
3.3.2.1 Cured-in-Place Pipe 14
3.3.2.2 Sleeve 15
3.3.2.3 External Repair Clamps 15
3.3.3 Joint Repair 16
3.3.3.1 Internal Joint Repair 16
3.3.3.2 External Joint Repair 16
3.4 Rehabilitation 17
3.4.1 Cleaning Requirements 17
3.4.2 Spray-on Linings 18
3.4.2.1 Cement Mortar Linings 18
3.4.2.2 Reinforced Mortar Linings 19
3.4.2.3 Epoxy Spray-on Linings 19
3.4.2.4 Polyurethane Spray-on Linings 20
3.4.2.5 Polyurea Spray-On Linings 21
3.4.3 Close Fit Lining Systems 22
3.4.3.1 Symmetrical Reduction Close Fit Lining - PE 24
3.4.3.2 Fold-and-Form Close Fit Lining - PE 26
3.4.3.3 Fold-and-Form Close Fit Lining - PVC (Alloy) 28
3.4.4 Cured-In-Place Pipe 30
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3.4.4.1 Non-Structural to Semi-Structural CIPP Liners 31
3.4.4.2 Semi-Structural CIPP Liners 32
3.4.4.3 Structural CIPP Liners 32
3.4.5 Woven Hose Lining System 35
3.4.5.1 Adhesive-Backed Woven Hose Lining 36
3.4.5.2 Non-Adhesive Backed Woven Hose Lining 37
3.4.5.3 Glass-Reinforced Thermoplastic Liner 38
3.5 Replacement 39
3.5.1 Online Replacement 40
3.5.1.1 Sliplining 40
3.5.1.2 Pipe Bursting 42
3.5.1.3 Pipe Slitting 44
3.5.2 Offline Replacement 44
3.5.2.1 Open Cut 44
3.5.2.2 Directional Drilling 44
3.5.2.3 Microtunneling/Pipe Jacking 44
4.0: TECHNOLOGY SELECTION CONSIDERATIONS 46
4.1 Life-Cycle Costs 46
4.2 Capacity 48
4.3 Accessibility 48
4.4 Maintenance 49
4.5 Condition Assessment and Asset Criticality 49
5.0: DESIGN AND QA/QC 52
5.1 System Design 52
5.1.1 Redundancy in System Design 52
5.1.2 Pig Launchers/Retrieval for Cleaning and Inspection 52
5.2 Renewal Design 53
5.2.1 Degrees of Deterioration 53
5.2.2 Interactive vs. Independent 54
5.2.3 Design Loads 54
5.2.4 Other Considerations 56
5.3 Product/Material Standards 56
5.4 Design Standards 59
5.4.1 Design of Pressure Systems 61
5.4.1.1 Partially Deteriorated Case 61
5.4.1.2 Fully Deteriorated Case 63
5.5 Installation Standards 64
5.6 QA/QC Requirements 67
5.6.1 Short-Term- Factory and Field Requirements 67
5.6.1.1 PVC Short-Term QA/QC Requirements 67
5.6.1.2 PE Short-Term QA/QC Requirements 68
5.6.1.3 CIPP Short-Term QA/QC Requirements 68
5.6.2 Long-Term - Qualification Requirements 69
5.6.2.1 PVC Long-Term QA/QC Requirements 69
5.6.2.2 PE Long-Term QA/QC Requirements 69
5.6.2.3 CIPP Long-Term QA/QC Requirements 70
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6.0: OPERATION AND MAINTENANCE 71
6.1 Procedures to Prolong the Life of Existing Force Mains 71
6.1.1 Cleaning 71
6.1.2 Cathodic Protection 73
6.1.3 Continuous Corrosion Monitoring 74
6.1.4 Pressure Monitoring 75
6.1.5 Leak Monitoring 76
6.1.6 Acoustic Monitoring for Wire Breaks in PCCP 76
6.2 Maintenance and Emergency Repair of Rehabilitation Systems 77
7.0: GAPS BETWEEN NEEDS AND AVAILABLE TECHNOLOGIES 78
7.1 Data Gaps 78
7.2 Capability Gaps 79
7.3 Benefits, Costs and Challenges in Closing Gaps 79
8.0: FINDINGS AND RECOMMENDATIONS 81
8.1 What Systems Would Benefit Most from Being Demonstrated in Field Settings? 81
8.2 Key Parameters for Evaluation in Demonstration Projects 81
8.3 Guidance for Establishing a Comprehensive System Rehabilitation Program 83
8.4 Guidance for Maintenance Programs 83
8.5 Sound, Risk-Based, Decision-Making Process Development 84
8.6 Cost-Effectiveness of Decision-Making Processes 84
8.7 Timing for Rehabilitation Action 84
8.8 Demonstration/Verification of Pressure System Rehabilitation 85
9.0: REFERENCES 86
FIGURES
Figure 2-1. Pipe Material Usage for Sewer Force Mains 5
Figure 2-2. Diameter Distribution of Sewer Force Mains 6
Figure 2-3. Age of Force Mains 7
Figure 2-4. Location of Force Mains 8
Figure 2-5. Land Development over Buried Force Mains 8
Figure 2-6. Causes of Failure in Ferrous Force Mains 10
Figure 2-7. Causes of Failure in Non-Ferrous Sewer Force Mains 10
Figure 3-1. Renewal Approaches for Force Mains 11
Figure 3-2. Repair Approaches for Force Mains 14
Figure 3-3. Link-Pipe 12 inch Pressure-Seal 15
Figure 3-4. Romac SS2 Repair Clamp 15
Figure 3-5. AMEX 10 Mono Seal 16
Figure 3-6. Rehabilitation Approaches for Force Mains 17
Figure 3-7. Summary of Spray Lining Technologies 18
Figure 3-8. Typical Stress Strain Curve for Ferrocement 19
Figure 3-9. Summary of Close Fit PE Technologies 23
Figure 3-10. PE Close-Fit Liner Hole Spanning Capabilities 23
Figure 3-11. Roller Reduction Unit for PolyFlex 25
Figure 3-12. Illustration of PE Pipe Compression 25
Figure 3-13. Summary of Fold-and-Form Close Fit Lining Technologies 26
Figure 3-14. Relationship Between Diameter and SDR for Folding 28
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Figure 3-15. Subline Forming into "C" Shape 28
Figure 3-16. PolyFoldTM Banding 28
Figure 3-17. Summary of CIPP Technologies 31
Figure 3-18. Starline® 1000 36
Figure 3-19. Aqua-Pipe Construction 36
Figure 3-20. Aqualiner Installation Process 38
Figure 3-21. Summary of Replacement Technologies 40
Figure 3-22. Fusion of PVC Joint 41
Figure 3-23. Hobas Sliplining Pressure Joint 42
Figure 3-24. Static Bursting Head 43
Figure 3-25. Pneumatic Bursting Head 43
Figure 3-26. Permalok T7 Pressure Joint 45
Figure 4-1. Total Installation Cost in 2003 Dollars for Trenchless Rehabilitation Methods 46
Figure 4-2. UK Water Rehabilitation Costs 47
Figure 4-3. Belief Network for Risk of Failure in PCCP 51
Figure 4-4. Belief Network for Consequences of Failure in PCCP 51
Figure 6-1. Polyurethane Pipeline Cleaning Pigs 72
Figure 6-2. LPR Ferguson-Nicholas Cell 75
TABLES
Table 2-1. Percentage of Materials by Diameter Range 6
Table 3 -1. Summary of Renewal Technologies with Applicability to Force Mains 13
Table 3-2. Summary of Internal Joint Vendors 16
Table 3-3. Properties of Hunting Polyurea Spray-on Linings 22
Table 3-4. Pressure Class of PE 3408 based on AWWA C906 at 80 °F 24
Table 5-1. ASTM Material Standards for PVC Pipe 57
Table 5-2. ASTM Material Standards for PE Pipes 57
Table 5-3. ASTM Material Standards for CIPP 58
Table 5-4. ASTM Standards for FRP/GRP 59
Table 5-5. Design Standards for PVC Materials 59
Table 5-6. Design Standards for Polyethylene Materials 59
Table 5-7. Design Standards for Glass-Reinforced Thermosetting Plastic Pipe 60
Table 5-8. ASTM Design Standards for CIPP Materials 60
Table 5-9. ASTM Installation Standards for PVC Materials 64
Table 5-10. ASTM Installation Standards for FRP/GRP Materials 64
Table 5-11. ASTM Installation Standards for Polyethylene Materials 65
Table 5-12. ASTM Installation Standards for CIPP Materials 65
Table 5-13. Minimum Structural Properties of CIPP Products by ASTM F1216 66
Table 5-14. Minimum Structural Properties of CIPP Products by ASTM F1743 66
Table 5-15. Minimum Structural Properties of CIPP Products by ASTM F2019 67
Table 5-16. ASTMD5813 Chemical Solution Specifications 70
Table 7-1. Technology Gaps and Closure Costs and Benefits 80
Table 8-1. Parameters for Evaluation in Demonstration Projects 82
Xlll
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DEFINITIONS
Cured-in-place pipe (CIPP) - a hollow cylinder consisting of a polyester and/or glass reinforced plastic
fabric tube with cured thermosetting resin. The CIPP is formed within an existing pipe and takes the
shape of the pipe.
Folded pipe - pipe that has been manufactured and calibrated round, then subsequently cooled and
deformed into a folded shape for insertion into the existing pipe.
Force main - a pipe that transports raw sewerage and operates under pressure.
Formed pipe - a folded pipe that has been inserted into an existing pipe and expanded with steam heat
and pressure, and, if required by the manufacturer, with a squeegee device or "pig" to provide a close fit
to the existing pipe.
Hydrostatic design basis (HDB) - a long-term hoop tensile stress when applied to the pipe or liner
continuously for the specified time period (usually 100,000 or 438,000 hours) will result in failure of the
pipe or liner.
Partially deteriorated pipe - the existing pipe can support the soil and surcharge loads throughout the
design life of the rehabilitated pipe and the soil adjacent to the existing pipe must provide adequate side
support.
Fully deteriorated pipe - the existing pipe is not structurally sound and cannot support soil and live loads
or is expected to reach this condition over the design life of the rehabilitated pipe. This condition is
evident when sections of the existing pipe are missing, the existing pipe has lost its original shape, or the
existing pipe has corroded due to the effects of the fluid, atmosphere, or soil.
Non-structural - provides no load-bearing capacity to the pipe; primarily acts as a corrosion barrier.
Open cut - the use of excavation to install a new pipe or replace an existing one.
Rehabilitation - internal coatings, sealants, and linings used to extend operational life and restore much or
all of the pipe's hydraulic and structural functionality.
Renewal - improving the structural performance, flow capacity, corrosion resistance or water quality of a
deteriorated pipe by repair, rehabilitation, or replacement
Repair - used when the existing pipe is structurally sound, provides acceptable flow capacity, and can
serve as the support or host of the repair method.
Replacement - an existing pipe is usually replaced when it is severely deteriorated, collapsed, or
increased flow capacity is needed.
Semi-structural - a liner whose long term internal burst strength is less than the maximum allowable
operating pressure of the pipeline to be rehabilitated. Semi-structural liners are capable of bridging holes
and gaps in the host pipe.
xiv
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Sliplining - the installation of a smaller diameter replacement pipe inside an existing pipe leaving an
annular gap between the two. The replacement pipe can be continuous or made up of discrete segment
lengths.
Structural - a liner whose long-term internal burst strength equals or exceeds the maximum allowable
operating pressure of the pipeline to be rehabilitated.
Trenchless - the installation of a new pipe or liner with minimal or no excavation required.
UNIT CONVERSION FACTORS
1 meter = 3.2808 feet
1 km = 0.62 mile
1 millimeter = 0.03937 inch
°F=1.8(°C) + 32
MPa = 145 psi
lbar= 14.503 psi
Psig = psi+14.7
mm = 39.37 mil
lmile= 1.609km
1 US$ = 0.748 Euro
xv
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ACRONYMS AND ABBREVIATION
3-D three-dimensional
AASHTO American Association of State Highway and Transportation Officials
ACP asbestos cement pipe
AREA American Railway Engineering Association
ASCE American Society of Civil Engineers
ASTM American Society of Testing and Materials
AWWA American Water Works Association
AWWARF American Water Works Association Research Foundation (Now known as the Water
Research Foundation)
BEM broadband electromagnetic
CCP concrete cylinder pipe
CCTV close circuit television
CI cast iron
CIPP cured-in-place pipe
DI ductile iron
DIPS ductile iron pipe size
DOT Department of Transportation
DR diameter ratio
DSAW double submerged arc welded
DWI Drinking Water Inspectorate
EPA U.S. Environmental Protection Agency
EPB earth pressure balance
EPDM ethylene propylene diene M-class
ESCR environmental stress crack resistance
FRP fiberglass reinforced pipe
GBR Geotechnical Baseline Report
GDSR Geotechnical Design Summary Report
GRP glass reinforced plastic
GTI Gas Technology Institute
H2S hydrogen sulfide
HC1 hydrochloric acid
HDB hydrostatic design basis
HDD horizontal directional drilling
HOPE high density polyethylene
HDS hydrostatic design stress
HPL high pressure liner
H2SO4 sulfuric acid
xvi
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ID
US
IPLT
IPS
ISO
kN
LPR
MDPE
MFL
MOP
NASSCO
NRC
NRMRL
NSF
O&M
OD
OFWAT
PCCP
PE
PIPP
PPI
PPIC
PPL
psi
PU
PVC
PVCO
QA
QC
RBI
RCP
RPL
RPP
SDR
SIPP
SOT
TBM
TIM
TO
TTC
UL
inner diameter
intermediate jacking stations
International Pipe Lining Technologies
iron pipe size
International Organization for Standardization
kilo Newton
linear polarization resistance
medium density polyethylene
magnetic flux leakage
manual of practice
National Association of Sewer Service Companies
National Research Council, Canada
National Risk Management Research Laboratory
National Sanitation Foundation
operation and maintenance
outer diameter
Office of Water Service
prestressed concrete cylinder pipe
polyethylene
pulled-in place pipe
Plastic Pipe Institute
Pressure Pipe Inspection Company
pressure pipe liner
pounds per square inch
polyurethane
polyvinyl chloride
molecularly-oriented polyvinyl chloride
quality assurance
quality control
Risk-Based Investigation
reinforced concrete pipe
reinforce pressure line
reinforced pressure pipe
standard dimension ratio
spray-in place pipe
state -of-the -technology
tunnel boring machine
Tenbusch Insertion Method
task order
Trenchless Technology Center
Underwriters Laboratory
XVII
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UV ultraviolet
WERF Water Environment Research Foundation
WRc Water Research Center, UK
xvin
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1.0 INTRODUCTION
Force mains that carry sewage flows under pressure represent a special set of challenges for sewer
rehabilitation. Force mains represent about 7.5% of the waste water system and they typically use
materials that are not commonly used in gravity sewer systems. Ductile iron (DI), cast iron (CI), steel,
and concrete pressure pipe are all material types frequently used for sewer force mains, especially in
larger diameters. All of these materials are susceptible to both internal corrosion from the sewer flow
(liquid and gaseous states), as well as external corrosion due to the environment in which the pipe is
buried.
Redundancy is not common with sewer force mains so most run constantly and can only be taken out of
service for brief periods lasting a few hours at best. Consequently, little internal inspection offeree mains
is undertaken so the condition of many is largely unknown. It has only been in the past few years that
some utilities have started to develop programs for inspecting their underground force mains as part of an
overall asset management strategy. Many of these are a direct result of a consent decree.
Once a force main is inspected and its condition ascertained, a decision must be made on the next
appropriate step. If the condition is found to be good, scheduling another inspection in 10 to 15 years
might be appropriate. Force mains that are found to be failing or near failing should be candidates for
immediate renewal, especially those that are critical assets with significant negative consequences
associated with a failure. Historically, the most common renewal technology employed has been to
replace the main using open cut construction. Part of the reason for that choice has been a lack of
rehabilitation technologies appropriate for sewer force mains. There is a wealth of technologies for
gravity sewers, but the field has been limited for pressurized systems. Fortunately, that situation is
changing as more vendors recognize the growing opportunity in sewer force main rehabilitation. The
other reason for replacement is that sewer force mains tend to have a fairly high consequence of failure.
A rupture of a sewer force main could release millions of gallons of raw sewage into the environment
posing significant health risks to the general public. Cleanup costs can be staggering. Therefore, the
tendency when it comes to considering renewal of a force main is to err on the conservative side and go
with outright replacement.
As some of the newer rehabilitation technologies develop a positive track record of use in sewer force
mains and confidence in their design approach and installation process strengthens, more utilities will be
willing to consider these trenchless technologies as potential renewal solutions. This is especially true if
the rehabilitation technology is significantly cheaper than replacement with open cut construction. The
gap between funds needed to restore the integrity of the underground infrastructure to an acceptable level
of reliability and available funds is widening. One way to close the gap is to find more cost-effective
methods of rehabilitation than open cut replacement. Trenchless methods have proven themselves to be
cost-effective for gravity sewer mains, especially when both direct and indirect costs associated with a
replacement program are considered. A similar outcome is expected for sewer force mains once data on
the effectiveness and longevity of these technologies and materials and life-cycle cost information
become more readily available. This state-of-the-technology (SOT) report will begin to address those
needs.
1.1 Project Background
This report was prepared as part of the research being conducted under the U.S. Environmental Protection
Agency's (EPA's) Sustainable Water Infrastructure Initiative. Under this program, research is being
conducted to improve and evaluate innovative technologies that can reduce costs and increase the
effectiveness of the operation, maintenance, and renewal of aging drinking water distribution and
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wastewater conveyance systems (EPA, 2007). The outputs from this research program are intended to
assist EPA's program and regional offices to implement Clean Water Act and Safe Drinking Water Act
requirements; to help states and tribes meet their programmatic requirements; and to assist utilities to
more effectively implement comprehensive management of drinking water and wastewater treatment and
conveyance systems. This initiative is aimed at encouraging the introduction of new and improved
technologies into the US marketplace for water and wastewater rehabilitation, which will aid utilities in
providing reliable service to their customers and meeting their statutory requirements. As part of this
research effort, the EPA National Risk Management Research Laboratory (NRMRL) awarded Task Order
No. 58 titled Rehabilitation of Wastewater Collection and Water Distribution Systems under Contract No.
EP-C-05-057. This research project includes the preparation of a series of reports on the State Of
Technology in rehabilitation of sewer force mains, water mains, and gravity wastewater systems (mains,
laterals, and manholes). This report presents a comprehensive review and evaluation of existing and
emerging technologies to define the current state-of-the-practice and state-of-the-art for sewer force main
renewal. The report seeks to address some of the following questions posed in the EPA's Innovation and
Research for Water Infrastructure for the 21st Century Research Plan (EPA, 2007):
• Can emerging and innovative force main rehabilitation technologies be identified and
demonstrated in field settings to improve the understanding of their cost-effectiveness,
technical performance, and reliability?
• Can approaches and methods be developed for determining the long-term performance and
life-cycle cost-effectiveness of various force main rehabilitation systems?
• Can system design guidance based on lessons learned from rehabilitation be developed to
enhance long-term performance and system integrity and to allow for easier inspection,
maintenance, and rehabilitation?
• Can guidance be provided for operation and maintenance (O&M) programs, including
procedures to assess and optimize maintenance practices that reduce the need for
rehabilitation?
• Can a sound, risk-based, decision-making process for selecting optimal system rehabilitation
technologies and methods be developed based on long-term effectiveness, system
performance, structural integrity, consequence of failure, and life-cycle cost?
• Are decision-making processes for selecting optimal system rehabilitation technologies and
methods cost-effective, and do they adequately address relevant factors (e.g., long- and short-
term performance, cost, hydraulic effects, structural integrity, condition assessment,
maintenance, and consequence of failure)?
1.2 Project Objectives
The objective of this report is to provide a comprehensive review of the US market with respect to
rehabilitation of sewer force mains. The main portion of the report is a review of all known technologies
that could be utilized in the rehabilitation of sewer force mains. Some of these technologies have not yet
been used for this purpose, so one is cautioned to not only read the text in the report, but also the relevant
technology-specific datasheets listed in Appendix A for more details. The report includes a discussion of
what technologies exist for rehabilitating a partially versus fully deteriorated force main. It also includes
a discussion on the current design methodologies for semi-structural conditions (designed to only bridge
over small holes or gaps in a main) and fully structural conditions (designed to carry the full internal
pressure and external loads).
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Gaps between what's available versus what's needed have also been identified in this report. Clearly the
biggest need would be for a fully structural liner that could be installed in a live sewer. Achieving that is
unlikely, at least in the next decade, but many other gaps are being closed. For example, vendors are
embarking on more long-term testing programs to help document the performance of their liners in a
pressurized system so that they can be designed for a minimum 50-year design life.
1.3 Project Approach
There are technologies that can be used in multiple applications. Sewer force mains have similar design
characteristics to water mains. Both must carry working and surge pressures of the system and are
generally buried only 4 to 8 feet (1.2 to 2.5 meters), so both are subjected to live loads in addition to
trench loads. Water mains carry potable water so their influence on water quality is important, which is
not the case with a sewer force main. However, the effluent carried in a force main is far more corrosive
than potable or raw water, especially where gas pockets develop, so a force main must have the same
corrosion resistant characteristics as a gravity sewer. Consequently, some technologies that are suitable
for sewer force mains, providing they also are certified to meet National Sanitation Foundation (NSF) 61,
would also be applicable for a water main. Also, some technologies that are used to line a gravity sewer
can also be used in a low pressure force main.
Recognizing that there would be some cross-over amongst the various technologies, a series of
technology-specific datasheets was created for each identified rehabilitation technology that is relevant to
sewer force mains. These technology profiles are included as Appendix A of this report. This
information was gathered by researching the technology (through published literature, Web sites, trade
shows, case studies, and magazine articles) and completing the technology-specific datasheet as much as
possible with publicly-available information. Each datasheet was then sent to the vendor to review and
comment on the contents and to provide additional information as needed. As discussed in Section 4, an
effort was made to collect representative cost information, but often only limited cost data were available.
1.4 Organization of Report
The report is organized according to the following subjects:
• Section 1: Introduction - project background
• Section 2: Characteristics of Force Main Systems - materials used, diameters and age
distribution, and typical failure modes and mechanisms
• Section 3: Renewal Practices and Technologies - current utility practices and renewal market
including an overview of repair, rehabilitation, and replacement technologies applicable to
force mains
• Section 4: Technology Selection Considerations - life-cycle costs, capacity limitations,
accessibility, maintenance, asset condition, and asset criticality are all factors to consider in
the selection of the most appropriate renewal strategy
• Section 5: Design and Quality Assurance/Quality Control - system design and renewal
design, product and installation standards, design standards, short-term and long-term testing
requirements, and field QA/QC practices
• Section 6: Operation and Maintenance - procedures to prolong the life of a force main,
including cleaning, cathodic protection, monitoring, and other maintenance considerations
• Section 7: Gaps Between Needs and Available Technologies - data and capability gaps, key
parameters for evaluation in demonstration project
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• Section 8: Findings and Recommendations - an overall summary of the key findings of the
research
• Appendix A: Datasheets for rehabilitation technologies
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2.0 CHARACTERISTICS OF FORCE MAIN SYSTEMS
It is important to understand the characteristics of force main systems and the typical failure modes and
mechanisms in order to evaluate the most appropriate renewal technologies. The approximate length of
the force main system in the US is 60,000 miles. The Water Environment Research Foundation (WERF)
recently published a report titled Guidelines for the Inspection of Force Mains (WERF, 2009). As part of
this effort, Jason Consultants conducted an electronic survey of all WERF utility subscriber members.
Over 32 utilities responded to the survey with detailed data on their force main systems. The data from
this WERF survey are presented in the next few sections and characterizes the types of pipe materials
used, diameter ranges, ages, location accessibility, and failure modes and mechanisms for force mains
determined from field data.
2.1
Material Usage
Figure 2-1 shows the breakdown by pipe material type. DI pipe is the predominant material, representing
47.3% of the total. Ferrous pipe materials (i.e., CI, DI, and steel) represent on average 63.4% of all pipes
used for force mains. Polyvinyl chloride (PVC) pipe at 14.3% is the next largest category of pipe
material. Also, it can be seen that pre-stressed concrete cylinder pipe (PCCP) is used for 11.6% of sewer
force mains, this being predominantly in diameters 24 inches (600 mm) and above.
Other
0.3%
RCP
4.0%
Figure 2-1. Pipe Material Usage for Sewer Force Mains (WERF, 2009)
2.2
Diameter Distribution
For a breakdown by diameters, as shown in Figure 2-2, approximately 46.6% of all sewer force mains fall
into the diameter range 4 to 12 inches (100 to 300 mm). Another 22.7% is in the diameter range 14 to 20
inches (350 to 500 mm) and 22.2% in the diameter range 21 to 36 inches (525 to 900 mm). Over 91% of
sewer force mains are between 4 and 36 inches (100 to 900 mm) diameter, which are within the non-man
entry size range.
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Figure 2-2. Diameter Distribution of Sewer Force Mains (WERF, 2009)
Figures 2-1 and 2-2 show the overall breakdown of materials and diameters. However, the distribution of
materials varies significantly by diameter range. Table 2-1 shows the percentages of each material in
each diameter range.
Table 2-1. Percentage of Materials by Diameter Range (WERF, 2009)
•Material 4 12 inches 14 20 inches .21,f6 37 54 inches
DI
CI
PVC
HDPE
PCCP/CCP
Steel
FRP
ACP
RCP
Other/Not Known
Totals
46.8%
16.9%
28.4%
2.0%
1.0%
0.5%
0%
4.0%
0.1%
0.4%
100%
62.5%
12.7%
3.5%
1.0%
3.1%
2.0%
0.1%
12.2%
2.5%
0.5%
100%
46.0%
5.3%
0.9%
0.2%
26.1%
10.3%
0%
0.7%
10.4%
0.1%
100%
13.9%
0.1%
0.1%
0%
54.6%
12.9%
0%
5.0%
13.4%
0.1%
100%
>54
inches
3.1%
0%
0%
0%
58.1%
30.4%
0%
0%
8.4%
O.l%
100%
Note: DI = ductile iron; CI = cast iron; PVC = polyvinyl chloride; HDPE = high density
polyethylene; PCCP = pre-stressed concrete cylinder pipe; CCP = concrete cylinder pipe; FRP
fiberglass reinforced pipe; ACP = asbestos cement pipe; and RCP = reinforced concrete pipe
-------
The data in Table 2-1 show clearly that DI and PVC dominate up to 12 inches (300 mm) in diameter.
Over 93% of all PVC is in this range. DI is even more dominant in the 14 to 20 inch (350 to 500 mm)
range, followed by CI, and then asbestos cement. It remains the main material in the 21 to 36 inch (525 to
900 mm) range, but PCCP is the next most used material in this range, followed by reinforced concrete
pipe (RCP), and steel. CI and plastics including polyethylene (PE) and PVC are less widespread in this
size range. PCCP is by far the main material used above 36 inches (900 mm) in diameter, with steel also
representing a significant proportion of pipe.
2.3
Age of System
In contrast to the nation's water supply and gravity sewer systems, the use offeree mains to convey
sewage is relatively recent. As depicted in Figure 2-3, 68% of the force mains in use today have been in
service for 25 years or less. Another 30% have been in service between 25 and 50 years and only 2%
beyond 50 years. Other data sources gave similar results in terms of the age distribution offeree mains.
Typically no more than 2% is greater than 50 years old. This contrasts sharply with the water supply
sector in which the average age of water mains in the US is now 45 years with nearly half of pipes aged
more than 50 years old.
>50 years
Figure 2-3. Age of Force Mains (WERF, 2009)
2.4
Force Main Location
This information might be important in evaluating the accessibility to the external surface of the pipe. As
shown in Figure 2-4, over 91% of the force main pipes are buried, so access to the exterior surface will
require some form of excavation. Less than 1% is installed above ground where access would be easier
and less costly to achieve. A slightly larger percentage, approximately 1.2%, is installed sub-aqueously
where access will be the most difficult.
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Above Ground
0.8%
Not Known
7.0%
Sub Aqueous
.2%
Figure 2-4. Location of Force Mains (WERF, 2009)
As shown in Figure 2-5, 66% of the footage of buried force mains lies under undeveloped land, but 21%
of the buried footage would require removal of paved surfaces (asphalt or concrete). A location under
paved surfaces would imply some degree of disruption to traffic (road and pedestrian) for excavation.
Under Sidewalk
5%
Figure 2-5. Land Development over Buried Force Mains (WERF, 2009)
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2.5 Redundancy
Many force mains are located at critical points in sewerage systems. As a result, if they have to be taken
out of service due to a failure, then by-pass pumping or the use of honey trucks is necessary. One way in
which utilities plan for this is to install dual parallel force mains thus providing redundancy. During an
emergency, such as a failure in one line, the parallel line can be used to maintain a minimal level of flow
such that any upstream wetwell does not overflow or sewers become surcharged, or at least the use of
honey trucks (required to keep the sewage from swamping any lift stations) is minimized. The other
advantage in having a redundant line is the ability to take one line out of service for an intrusive (internal)
inspection and/or repairs.
Over 45% of utilities contacted indicated that they had at least one redundant force main in their system.
For those reporting in the affirmative, an average of 14% of the systems had some redundancy built in.
However, some utilities actually reported in the WERF survey having a larger number of redundant
systems than total force mains so this number is suspect. This limited sampling would suggest that
perhaps about 5% of the total number offeree mains do have some redundancy built in.
Parallel mains to enable one main to be out of service are seldom installed. Those utilities that do have
parallel mains generally installed them because extra capacity was needed over and above that available
from an existing main. The parallel main is then installed to provide additional capacity and not the total
capacity. Thus, the opportunity for redundancy and operational security is not taken.
Current practice is not to install parallel mains to provide redundancy. Installing alongside existing mains
considered critical is done only very occasionally.
2.6 Cause of Failure in Force Mains
Based on the WERF survey, almost universally, with 92% of the responders in the affirmative, utilities
attempt to identify the cause of the failure in the force main. The utilities were asked to identify the most
common factors relating to failures in their force mains. Various causes are discussed below. It is
important to understand the typical failure modes and mechanisms of force mains in order to select the
most appropriate repair, rehabilitation, and replacement technologies.
2.6.1 Ferrous Force Mains. Figure 2-6 shows that internal corrosion was rated as being
responsible for ferrous force main failures 26.2% of the time, ahead of all other known causes. External
corrosion at 19.2% and third-party damage at 19.4% are the next most common causes of failures.
Combining internal and external corrosion, corrosion appears responsible for failures in force mains in
nearly 46% of cases. After third-party damage, joint leakage at 15.2%, surge pressure at 10.2%, and
insufficient capacity at 9.8% are the next most significant causes offeree main failures.
2.6.2 Non-Ferrous Force Mains. Figure 2-7 shows the most common single cause of failure in
non-ferrous force mains is third-party damage, which accounts for 36% of failures. Corrosion and
structural failure together account for 54% of failures. It is considered likely that some of the structural
failures reported for cementitious pipes (AC, RCP, and PCCP) are due to corrosion. Figure 2-7 is based
on a weighted average of failure causes for each pipe material. The main causes of failure vary
significantly by pipe material. For each pipe material type, the main causes of failure are as follows: (1)
PVC - third-party damage, (2) PCCP - corrosion, (3) RCP - corrosion, (4) AC - third-party damage, and
(5) PE - third-party damage.
-------
Proper inspection offeree mains would allow a utility to identify signs of corrosion and leakage, which
represent 61% of the reported causes of failure in ferrous mains and 30% in non-ferrous mains. For
example, with information on remaining wall thickness of ferrous mains, a utility could plan on repair,
rehabilitation, or replacement before a force main fails. No amount of inspection can eliminate third party
damage, which is the second leading cause of failure overall and the leading cause in non-ferrous mains.
However, utilities can be prepared with proper emergency repair procedures in place.
Capacity
9.8%
3rd Party
Damage
19.4%
JointLeakage Extenal
Ib 2% Corrosion
Surge 1^.2%
Pressure
107%
Figure 2-6. Causes of Failure in Ferrous Force Mains (WERF, 2009)
Surge Pressure JointLeakage
7%
Figure 2-7. Causes of Failure in Non-Ferrous Sewer Force Mains (WERF, 2009)
10
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3.0 RENEWAL PRACTICES AND TECHNOLOGIES
This section covers current utility practices as well as a review of existing and emerging renewal
technologies for restoring structural and/or flow capacity to a distressed force main. As shown in
Figure 3-1, the renewal offeree mains includes repair, rehabilitation, and replacement. The simplest form
of renewal is a spot repair, usually implemented on a reactive basis to a failure. More extensive renewal
technologies are rehabilitation (using the existing fabric of the force main pipe) and replacement
(installing an entirely new independent pipe). This new pipe can be installed offline using a different
line or online using the same line and grade of the existing pipe. Both offline and online replacement can
involve trenchless technologies.
Renewal
I Rehabilitation I I Repair ""^
Use existing I I Use existing pipe I
pipe structure I t structure I
Replacement
No use of existing
pipe structure
Non-Structural «
Structural
Offline
Online
Figure 3-1. Renewal Approaches for Force Mains
3.1
Current Utility Practices and Market
The estimate of renewal works in force mains are between 250,000 and 600,000 linear feet (76,220 and
182,927 meters) or 0.08% to 0.19% of the total length on an annual basis. While this is significantly
less than the proportion for gravity sewers, force mains are in general not as old as gravity sewers, so their
condition may be expected to be better in general.
At this time, both repair and replacement are more widely used than rehabilitation in force mains. Repair
can be undertaken within a short shutdown period, thus obviating the need for by-pass pumping. This is
often a simple patching of a damaged or deteriorated area. On the other hand, replacement requires a
major intervention. From the limited data available, it is estimated that replacement is the preferred
approach for most utilities when faced with force main problems. Replacement comprises between
200,000 and 500,000 linear feet (60,976 and 152,439 meters) offeree mains annually or some 0.1% to
0.15% of the total length. There are no equivalent data on the frequency of repairs for force mains.
The current market for force main rehabilitation is small compared to repair and replacement. No
definitive data are available on the volume of force main rehabilitation since neither the utilities nor the
vendors report this information. The best estimate is that between 50,000 and 100,000 linear feet (15,244
and 30,488 meters) offeree mains in the US are rehabilitated annually. This represents some 0.02% to
11
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0.03% of the overall length. There are a variety of reasons for this lower rate of rehabilitation in sewer
force mains.
The first reason is the lack of consistently reliable and cost-effective sewer force main inspection
methods. Taking a force main out of service for internal inspection is extremely disruptive and costly and
external inspection can cover only a small part of the main. Thus, there is no viable sequence of risk
assessment, inspection, condition assessment, and rehabilitation as there is in gravity sewer networks.
The second reason is that few rehabilitation technologies have been developed specifically for force
mains. The technologies used in gravity sewers are generally not suitable for pressure applications, while
those for water mains are focused more on water quality and corrosion protection than structural
rehabilitation of the pipelines. Structural rehabilitation technologies for pressure pipes are in their
infancy. Some crossover is needed between the sectors to address this issue. The result is that two
management approaches are followed for force main asset management:
(1) Await failure and replace.
(2) Replace based on age and material rather than on actual condition.
Both strategies have their merits. Many force mains are small in diameter with almost half of force mains
12 inches (300 mm) in diameter or smaller. Inspecting these is difficult and costly and the cost of
obtaining the information may exceed its value. Also, the consequence of failure for many of these mains
may be low. Thus, awaiting failure and replacing with an emergency repair is a cost-effective strategy for
many small diameter, non-critical force mains.
Replacement based on age and material, possibly alongside failure history, is also a viable strategy. With
no direct condition assessment information available, condition cannot be a criterion.
However, neither strategy is adequate for critical force mains, where the consequence of failure is serious.
This is recognized by the utilities and drives their need for inspection technologies and assessment
methodologies that will provide information on likelihood of failure so that critical force mains can be
managed actively and cost-effectively repaired, rehabilitated, or replaced to avoid failure. Future
advances in force main inspection and an improved understanding of the host pipe condition may lead the
way for the increased use of rehabilitation technologies in critical force mains.
3.2 Overview of Renewal Technologies
Force mains can operate with a wide range in pressures ranging from just a few feet of head to several
hundred feet of head. Consequently, the list of potentially applicable renewal technologies is quite
lengthy. The designer must consider the operating conditions that the renewal will be subjected to before
selecting suitable candidates.
Some of the technologies presented in this report have not yet been used in a sewer force main to date,
even though they have properties that make them suitable for these applications. System vendors are
constantly making improvements and modifications to their products and services, so they should be
consulted before using any of these listed products in a force main application to ensure compatibility.
A technology-specific datasheet was created for most of the technologies reviewed in this SOT report and
are included in Appendix A. Table 3-1 summarizes the datasheets along with the diameter range and
upper pressure limit for the various renewal methods. Vendor contact information can be found on each
datasheet along with relevant case study information as available.
12
-------
Table 3-1. Summary of Renewal Technologies with Applicability to Force Mains
Diameter Pressure Appendix
Range, Limit, A
Technology Category Brand Name Vendor inches psi pg no.
Internal Repair
Spray-On Lining
Close-Fit Lining
CIPP
Woven Hose
Sleeve
Polyurethane
Polyurea
Symmetrical
Fold-and- Form
PE
Fold-and-Form
PVC
Expandable
PVC
Polyester Felt
Glass
Reinforcement
Carbon Fiber
Adhesive
Non-adhesive
Pressure-Seal
Skotchkote
Skotchkote
Swagelining
Tite Liner
InsituGuard™ -
Flexed
Rolldown
Subcoil
Mainsaver
Subline
InsituGuard -
Folded
Ultraliner PVC
Alloy Pipeliner
EX Pipe
AM-Liner II
Duraliner
Miner
Pressure Pipe
Liner (PPL)
National Liner
Paraliner FM
Reinforced
Pressure Liner
(RPL)
Nordipipe
Berolina Liner
Blue-Tek
Insitumain
Fibrwrap
CarbonWrap
Pipe Medic
Starline HPL-S
Aqua-Pipe
Saertex-Liner
(Lightstream)
Primus Line
Link-Pipe
3M E. Woods
3M E. Woods
Advantica
United Pipeline
Systems
Insituform Blue
Subterra
Subterra
Mainsaver
Subterra
Insituform Blue
Ultraliner
Miller Pipeline
American Pipe &
Plastics
Underground
Solutions
Miner Technologies
(Reynolds Miner)
Insituform
Technologies
National Environ
Tech Group
NOVOC
Performance Resins
Insituform
Technologies
Norditube
Technologies
BKP Berolina
Polyester GmbH
(CIPP Corp)
Reline America
Insituform Blue
Fibrwrap Corp.
Carbon Wrap
Quake Wrap, Inc
Karl Weiss
Technologies GmbH
(Gas Technology
Institute)
Sanexen
Environmental
Services
Saertex multicom
GmbH
Raedlinger Primus
Line GmbH
4-54
4-50
4-50
3-44
2-52
4-48
4-20
4-12
NA
3-60
4-48
4-30
6-15
6-12
6-30
4-120
8-60
6-120
6-96
8-72
5-48
6-40
6-48
6-36
>36
>36
>36
3-24
6-12
6-48
6-20
150
NA
NA
160
NA
150
232
NA
NA
NA
150
Low
pressure
Non-
pressure
Non-
pressure
NA
60
200
50+
NA
NA
60-250
45
NA
150
150
150
430
150
Non-
pressure
218-500+
NA
A-l
A-4
A-6
A-8
A-10
A- 12
A- 14
A-16
A-18
A-20
A-22
A-26
A-28
A-30
A-32
A-34
A-37
A-39
A-41
A-44
A-46
A-49
A-51
A-53
A-56
NA
A-58
A-60
A-62
A-64
13
-------
Table 3-1. Summary of Renewal Technologies with Applicability to Force Mains (Continued)
Diameter Pressure Appendix
Range, Limit, A
Technology Category Brand Name Vendor inches psi pg no.
Glass Reinforced
Thermoplastic
Sliplining
HDD
-
PVC
PE
Aqualiner
Fusible PVC
HOPE and
MDPE
Aqualiner
Underground
Solutions
Multiple producers
6-12
4-12 (C900)
14-36
(C905)
4-48
150
305
A-66
A-68
NA
3.3
Repair
Repair of a failure or a deteriorated section of a pipe is generally focused on only taking remedial action
with one or two sections of pipe. Often times this work is done under emergency conditions. The first
objective is to prevent any further spill or damage to the environment and the second objective is to
restore service as quickly as possible. Figure 3-2 illustrates the various repair technologies applicable to
sewer force mains.
Repair j
L Open Cut 1 1
Replacement II *
)0t 1
CIPP
Sleeve
Repair Clamp ( Internal Sleeve
External
Figure 3-2. Repair Approaches for Force Mains
3.3.1 Open Cut Emergency Replacement. One of the most common methods of repair,
especially for a burst type failure, is still to excavate and replace one or two sections of pipe. Depending
on the type of pipe material, special adapters may be necessary to rejoin the new pipe sections to the
existing pipe. This is true of PCCP where adapters and short sections are needed to replace a section.
Other materials (such as CI, DI, or PVC) can be spliced in using either repair clamps or mechanical
couplings with service restored very quickly.
3.3.2 Spot Repair - Trenchless. If not required under emergency conditions, there are other
options to spot repair a section of pipe that is distressed.
3.3.2.1 Cured-in-Place Pipe. Short sections of a cured-in-place pipe (CIPP) liner, suitably designed
for the operating pressure, can be installed over a short section of pipe that is distressed. However, to be
effective, the CIPP liner needs to adhere to the original pipe such that water cannot migrate between the
original pipe and the liner. Sealing the ends of the liner to the host pipe with an internal joint repair seal
(e.g., Weko-Seal®) is one way to ensure a water tight seal.
14
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Another new technology that is being used for the repair of pre-stressed concrete cylinder pipes that have
experienced wire breaks is the use of a carbon fiber composite on the pipe interior surface. The internal
surface has to be cleaned and then roughened, usually with water blasting. After roughening, the surface
is dehumidified to ensure a good bond with the epoxy resin. There are two approaches to the application
of the carbon fiber textile. Pipe Medic is a patented composite material available from Quake Wrap
where the carbon fiber is already embedded in a pre-cured epoxy resin. It resembles wall paper. A layer
of epoxy adhesive is applied to the PCCP internal surface and then the Pipe Medic sheet is uncurled and
rolled into the epoxy. The more traditional method of use has been to wet out the carbon fiber with epoxy
resin just before application and then apply the uncured epoxy and carbon fiber composite to the interior
surface. NSF 61 certified epoxy top coats are applied over the composite for potable water applications.
3.3.2.2 Sleeve. Link-Pipe, a Canadian manufacturer
of trenchless pipe repair products, has a product available
for use in a pressurized system (Figure 3-3). Pressure-
Seal™ Sleeves are available in diameters from 4 to 54
inches (100 to 1,350 mm), and standard lengths of 12, 18,
24 and 36 inches (300, 450, 600, and 900 mm). Pressure-
Seal™ is designed for sealing pressure pipes up to 150
pound per square inch (psi) (10.3 bar) and it is uniquely
suitable for old CI mains that have unpredictable variations
in manufacturing tolerances, roundness, and joint offsets to
which the sleeve will conform. Each sleeve is specifically
manufactured for each location so it is important to get an
accurate measurement of the inside diameter of the pipe.
Some problems have been reported when the diameter was not
closely measured.
Figure 3-3. Link-Pipe 12 inch
Pressure-Seal
The sleeve core is made of stainless steel SST-316 with internal locking mechanism. An outside gasket is
saturated with sealant that is mechanically pressed against the host pipe when the sleeve is expanded and
locked in place. The sealant is ambient temperature cured and seals the sleeve in place, creating a
mechanical bond by filling surface roughness as well as chemical adhesion, thus sealing the joints and pin
holes. Link-Pipe has other trenchless repair technologies (e.g., Link-Pipe PVC™), but these are not for
internal pressurized systems, rather they are designed to resist external soil loads.
3.3.2.3 External Repair Clamps. The second most
common method of repairing a break in a sewer force main,
aside from open cut replacement, is to place a full
circumferential repair clamp over the damaged section (Figure
3-4). The clamp must be wide enough to seal on adjacent pipe
wall that is structurally sound. If the wall is not sound, then
replacement is the only viable solution. There are a wide
variety of repair clamps, some coming in multiple pieces so
they can be placed around a damaged section of pipe without
removal of the pipe.
Figure 3-4. Romac SS2
Repair Clamp
15
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3.3.3
Joint Repair
3.3.3.1 Internal Joint Repair. The basic principal of most internal joint repair systems is a rubber
sleeve that bridges over the leaking joint, which is then compressed and sealed against the adjacent pipe
wall by expanding two stainless steel compression rings. For wastewater or water applications, the sleeve
is made of ethylene propylene diene M-class (EPDM) rubber.
These sleeves can also be used to seal a radial crack in a pipe wall or transition between two different pipe
materials. The AMEX 10® seal incorporates a medium density polyethylene (MDPE) backing band
behind the rubber seal to accommodate external hydrostatic pressure (Figure 3-5). The AMEX 10 Vario
can also be used to seal a longitudinal crack with its ability to span an extended longitudinal length by
stacking the sleeves. The sleeves have enough flexibility to allow some additional joint rotation without
leakage after installation. Naturally, for a good leak tight seal, the inner surface must be free of any
corrosion by-product and smooth. They have also been used to seal a steel slipliner, grouted inside a
PCCP pipe, to the PCCP pipe wall. Specially designed transition sleeves are required to accommodate
the large difference in internal diameter associated with this application.
As shown in Table 3-2, there are three primary manufacturers of internal joint repair sleeves.
M[?E Backing teni
•; retaining taint
EPDM [Utter 5*3
Figure 3-5. AMEX 10 Mono Seal
Table 3-2. Summary of Internal Joint Vendors
Miller Pipeline Corp.
AMEX, Gmbh
(Germany)
NPC, Inc.
1
Weko-Seal®
AMEX lO^Mono and
Vario
NPC Internal Joint Seal
16 to 216 inches
20 to 236 inches
18 to 122 inches
Max. Internal Pressure
300 psi
290 psi
30 psi
3.3.3.2 External Joint Repair. Most of the external joint seals on the market are designed to seal a
gravity pipe joint, with minimal internal pressure. There have been mechanical devices designed in the
past that will seal a leaking PVC bell joint with a displaced gasket, or one for a lead caulked CI joint,
which encapsulates the joint in a bitumastic material. However, the market for these specialty products is
very limited. The most common repair technique is to remove the offending joint rather than trying to
patch a repair.
16
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3.4 Rehabilitation
In this report, rehabilitation will focus on the renewal aspects of sewer force mains where the existing
pipe becomes part of the renewal work. If the rehabilitation is to provide only corrosion protection, or the
existing pipe is only partially deteriorated, then the remaining structural strength of the existing pipe is
incorporated into the fabric of the completed system. For fully deteriorated situations, the existing pipe
acts merely as a right-of-way for the installation of the structural liner.
As shown in Figure 3-6, rehabilitation methods will include the use of spray-on linings, close-fit linings,
CIPP, and woven hose lining systems. Technologies for each of these rehabilitation categories are
discussed in this report in addition to cleaning requirements prior to rehabilitation. Because only limited
rehabilitation work has been undertaken to date on sewer force mains, many of the systems available were
originally developed for water main rehabilitation, but can be adapted to sewer force mains. Sewer force
mains have some characteristics in common with water mains. Both tend to be relatively shallow buried
and both operate under internal pressure. However, they also have some significant differences. An NSF
61 certification is not required for a force main as it does not carry potable water for human consumption.
Force mains also do not have service connections, which must be reinstated to restore service to
stakeholders. Force mains transport raw sewage, which can release hydrogen sulfide (H2S) gas at high
points or near discharges, leading to microbiological corrosion of the pipe material. Also, it is usually
very difficult to take a force main out of service for an extended period of time (unless redundancy
exists), which will necessitate by-pass pumping during any cleaning or rehabilitation effort.
Rehabilitation
L
Cleaning
,, ... Close-fit
Spray-on Linings
CIPP * Woven Hose
Linings
; <_ j '
Figure 3-6. Rehabilitation Approaches for Force Mains
3.4.1 Cleaning Requirements. All of the rehabilitation methods require some cleaning of the
interior surface of the original pipe. The extent of cleaning will depend on the chosen method of renewal.
Spray-on linings will require the most extensive cleaning as the lining material must adhere to the surface,
followed by close-fit and CIPP liner products. Sliplining is considered a replacement method, but it
requires the least intensive cleaning as contact with the host pipe is not achieved.
Cleaning methods for force mains would include power boring, which is recommended for spray-on
polymer liners, foam pigs, mechanical scrapers, and water jet cleaning. Chemical cleaning with
hydrochloric (HC1) acid is intended mainly for the removal of tuberculation (ferric oxide) and is therefore
17
-------
more appropriate to a water main where the cleaning solution can be easily re-circulated. More
information on cleaning methods and technologies is covered in Section 6.
3.4.2 Spray-on Linings. Spray-on linings have been one of the easiest methods of rehabilitating a
pressurized main when the primary objective is just to provide corrosion protection to the interior surface.
Spray-on linings are either cementitious or polymer based as shown in Figure 3-7.
With a large population of unlined CI water pipe in the US, it is not surprising that one of the more
common methods of rehabilitation has been to apply a cement mortar lining in water distribution
networks. In the UK, where water supplies tend to be more "soft" than in the US, cement mortar linings
were first supplanted by spray epoxy liners and then by polyurethane (PU) linings which today dominate
80% of the UK spray-on liner market. The main advantage of PU over epoxy is the fast 30-minute cure
time. The equipment and application are essentially the same.
3.4.2.1 Cement Mortar Linings. Cement mortar lining is not suitable for the conveyance of
aggressive (soft) water, nor would it be recommended for the rehabilitation of a sewer force main. It
involves centrifugally casting cement mortar against the wall of the pipe with sufficient velocity to
densely pack and adhere the mortar. The interior mortar lining is then mechanically trowelled to provide
a smooth surface. Cement mortar lining is most commonly used for corrosion protection in ferrous water
pipes, but is not suitable for sewer force mains.
Spray-on
Lining
Polymer
Reinforced
Epoxy
Polyurethane
Polyurea
Figure 3-7. Summary of Spray-on Lining Technologies
18
-------
3.4.2.2 Reinforced Mortar Linings. A modification of cement mortar lining is to incorporate some
steel reinforcement in the mix to accommodate structural needs. One such modification, ferrocement,
uses fine wire mesh to reinforce the mortar mix, enhancing its tensile strength and crack resistance.
Figure 3-8 illustrates the typical stress-strain performance of a ferrocement composite. The crack
resistance of the composite is dependent on the relative volume of mesh reinforcement to mix.
m
UI
m
u
Z
W
Tensite Stress-Strain
Curve of Composite
Contribution ol Mainx
•!equ
-------
are, however, several communities (e.g., Charlotte-Mecklenberg) that have used epoxy lining extensively.
One of the limitations to epoxy lining for water mains has been the need to get NSF 61 certification. This
involves not only having the material certified, but also the delivery system as any unmixed or uncured
resin or hardener can pose a chemical hazard. There are over 41 companies which have their epoxy
products certified to NSF 61 as suitable for lining either water tanks and/or water mains (with diameter
restrictions). Not all of the listed resins are actively promoted for lining water mains. Some of the more
commonly used resins are similar to those used in the UK. A few examples of these products are listed
below:
• 3M Scotchkote 162 PWX
• Fyfe Company Tyfo™ PWC
• Hunting Industrial Coatings - Waterline
• Mercor Products - GeoPox GX 104
• NeoPoxy NPR-2000
• Nitoline
• NSP Specialty Products - NSP 120
• Raven Lining Systems - AquataPoxy A-6 and A-61
• Subterra - ELC
In 2007, the American Water Works Association (AWWA) standard AWWA C620 Spray-Applied In-
Place Epoxy Lining of Water Pipelines, 3-inch (75-mm) and Larger was published providing the first
national standard for epoxy lining. Up to this point, only a WRc guidance note was available. The epoxy
is a two-component material containing 100% solids by volume and must be capable of adhering to dry
and moist surfaces.
Prior to spin application of the epoxy, the host pipe's interior surface must be free of corrosion by-
products, deposits, loose and deteriorated coatings, oil, grease and accumulations of water, dirt and debris.
Power boring, drag cleaning, or abrasive pigging followed by foam swabbing is the preferred method of
preparing the inner surface.
For water main applications, one coat of epoxy with a minimum dry film thickness of 40 mils (1 mm) is
recommended. A dry film thickness of 80 mils (2 mm) is achievable and would be preferred for any
sewer force main applications given the higher corrosion potential offered by the effluent.
3.4.2.4 Polyurethane Spray-on Linings
Standard Polyurethane
Polyurethanes, which are a two-part poly-isocyanate, have virtually replaced the use of epoxy liners in the
UK. Polyurethane liners represent 80% of the UK market. They are applied using the exact same spin
equipment as epoxies. The thickness of the minimum dry film recommended is 40 mils (1 mm), the same
as epoxy, but the cure time is only 30 minutes. Consequently, the outage time for carrying out a
polyurethane lining operation can be less than 6 hours which, in a water distribution project, may negate
the need for any alternative water supply, thus saving money. The following polyurethane coatings are
approved by the DWI in the UK:
• 3M E. Wood Ltd - Scotchkote 169, Scotchkote 169HB, and Scotchkote 169LV
• Subterra - Fast-Line and Fast-Line Plus
20
-------
Hi-Build Polyurethane
3M (E. Wood)
One of the pioneers in the development of epoxy and polyurethane liners was E. Wood Ltd., a UK
company. They were acquired by 3M in 2008. E. Wood has developed a hi-build polyurethane liner,
which can be considered a semi-structural liner (i.e., one capable of bridging over holes in the host pipe).
This product was called Copon Hycote 169HB, but has been renamed Skotchkote for distribution in the
US. The product has DWI approval in the UK for use in a potable water system.
Copon Hycote underwent trials at Yorkshire Water and South West Water in 2004 and 2005, respectively
and was commercialized in 2005. Well over 200 km of water pipe have been lined to date. The smallest
diameter has been 4 inches (100 mm) and the largest 20 inches (500 mm). Bristol Water, a UK water
company with a poor burst history and water quality, is lining pipe with a 1.5 mm thickness where water
quality is dubious and 3 mm in areas prone to breaks. Since undertaking this program, Bristol Water has
not experienced a single break.
Tests have been carried out at Bradford University on 4 inches (100 mm) diameter pipes with 0.4 inches
(10 mm) and 1 inch (25 mm) gaps. The liner failed in the pipe with the 0.4 inches (10 mm) gap at 1,015
psi (70 bar) and 391 psi (27 bar) in the pipe with the 1 inch (25 mm) gap. The thickness of the liner
applied was not reported.
It is envisioned that this new emerging material could also be utilized in a sewer force main, providing the
inner surface can be sufficiently cleaned to allow proper adhesion. So far, this has not been demonstrated.
3.4.2.5 Polyurea Spray-On Linings
Standard Polyurea
A new family of polymer spray-on linings, based on the use of polyurea, is finding rapid acceptance for
lining manholes, wetwells, and other structures exposed to corrosive environments. One of the principal
benefits of the use of polyurea is a very fast cure, with gel times in 5 to 40 seconds and 80% cure in just 5
minutes. Structures can be put back into service 30 minutes after the application of the polyurea. Full
cure is achieved in 24 hours. The other primary benefit is the ability to spray apply a thickness from 0.25
to 2 inches (6 to 50 mm). The thick liner means this spray-on lining system also has the ability to be used
as a semi-structural or even a structural liner.
Innovative Painting and Waterproofing. Inc.
Innovative Painting and Waterproofing has developed a robotic delivery system that allows the spray
application of polyurea to pipes as small as 6 inches (150 mm) in diameter. These materials are not yet
NSF 61 listed, but could be used in a sewer force mains where that requirement does not pertain. The
bond strength to concrete on flat work is reported to be 350 to 800 psi (24 to 55 bar) and on sand blasted
white metal over 2,000 psi (138 bar).
PolySpray
Hunting Specialized Products produces three lines of polyurea spray-on linings, which range from
flexible to stiff, based on the flexural modulus of elasticity. Table 3-3 identifies the physical properties
for Hunting's polyurea. The Flexible HE800 is tantamount to rubber with 800% elongation. For design
purposes (e.g., ASTM F1216), Hunting reports that the long-term (50 year) flexural creep modulus would
be 50% of the values listed in Table 3-3. In the case of the Fully Structural FS250 material, the flexural
modulus is comparable to some CIPP products.
21
-------
Table 3-3. Properties of Hunting Polyurea Spray-on Linings
Tensile (ASTM D638) Flexural (ASTM D790)
Strength Modulus Elongation Strength Modulus Shrinkage
Type psi psi % psi psi %
Flexible HE800
Semi-Structural
SS100
Fully Structural
FS250
1,700
3,400
12,000
1,200
41,200
160,000
800
100
20
1,400
4,300
9,300
22,500
93,000
250,000
0
0.5
1
3M
3M Water Infrastructure has announced a new product, Scotchkote™ Spray In Place Pipe (SIPP) 269
Coating, which is a patent pending-polyurea blend. The Scotchkote™ SIPP 269 Coating just received
certification against NSF 61 for use in potable water applications. The reference to a coating is
misleading as the material is actually intended to be used as a liner. Little technical data were available at
the time of this report. It is understood that the Trenchless Technology Center (TTC) will be conducting
some long-term performance tests on this polyurea material.
Nano-Enhanced Polyurea
The TTC at Louisiana Tech University is working with one vendor of polyurea resins to develop a nano-
enhanced version of polyurea, which would have even higher flexural modulus, well above the 250,000 to
375,000 psi (17,241 to 25,862 bar) achievable with today's standard technology. The trade off with the
higher modulus is a lower elongation, but 5% elongation should be adequate for most pipe rehabilitation
projects.
3.4.3 Close-Fit Lining Systems. The use of close-fit liners is often called modified sliplining. It
involves the use of a thin walled PE liner with an outside diameter that is similar to the inside diameter of
the host pipe. The key to installing the liner is to temporarily reduce the liner diameter to facilitate its
insertion into the host pipe. Once the liner is in place, it is reverted back to its original outside diameter
forming a close-fit to the host pipe. The reinstatement of connections and fittings often requires special
techniques and fittings.
As shown in Figure 3-9, close-fit liners can be classified into two broad categories including those that
achieve temporary diameter reduction through: (1) a symmetrical reduction process; and (2) a fold-and-
form process. In the case of the symmetrical diameter reduction process, these can rely upon either axial
tension or radial compression to reduce the diameter. Fold-and-form liners, depending on diameter, can
be pre-folded and coiled into spools at the factory or deformed on site.
Close-fit liners are usually thin walled (standard dimension ratio [SDR] > 33) so they maximize the
retention of flow cross-section. There are a range of products from which to choose including thin semi-
structural liners to thicker fully structural liners. On the other hand, most liners are "non-standard" PE
diameters and require special fittings. Many of the early technologies came from the UK and were
subject to licensing and other commercial arrangements with international companies.
22
-------
Figure 3-9. Summary of Close-Fit PE Technologies
The installation of a close-fit liner is similar to sliplining in that the liner is pulled or pushed into the
existing pipe except with close-fit liners additional stages are needed for the diameter reduction prior to
insertion and then reversion after insertion. Also, the host pipe needs to be more extensively cleaned than
for ordinary sliplining given the close-fit of the liner. Some additional potential issues can occur during
installation of these relatively thin liners as follows:
• Accuracy in the alignment of pipes for butt fusion welding is more critical
• Tensile forces during pull in of the liner need to be monitored and controlled
• Limiting surface damage to no more than 10% of thickness during installation is more
difficult to achieve with a thin liner.
Despite some of these concerns, the use of a close-fit liner can be one of the more cost-effective ways to
rehabilitate a partially deteriorated sewer force main. As Figure 3-10 illustrates, a PE liner is capable of
bridging significant gaps in the host pipe. As an example, a 36-inch (900-mm) diameter SDR 50 PE liner
(t = 0.71 inch) in a system with an operating pressure of 150 psi (10.3 bar), can span a hole of 9 inches
(225 mm) in diameter in the host pipe.
Cl
Ul
a.
a.
a>
x
<
SDR Ratios
0.60
0.50 -
0.40 -
0.30 -
0.20 -
0.10 -
0.00
10
12
14
16
OPERATING PRESSURE (BAR)
Figure 3-10. PE Close-Fit Liner Hole Spanning Capabilities
23
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3.4.3.1 Symmetrical Reduction Close-Fit Lining - PE
Tension Based (Static Die, Roller Die) Symmetrical Reduction
In the tension-based, symmetrical-reduction process, the diameter of the PE pipe is temporarily reduced,
while maintaining a circular cross section, by pulling the pipe through a static die or simultaneously
pushing it through a series of concentric rollers. The advantages of a tension based close-fit PE liner are
its quick installation and relatively low cost. However, winch loads can be very high, and, with insertion
clearances relatively small, the process is susceptible to jamming at obstacles (e.g., an offset joint). Local
obstacles can lead to incomplete reversion and high residual tensile stresses that can create problems for
fittings. Also, the liner pipe must be pulled into the existing pipe all at one time without stoppage or
release of tension. If the pipe reverts during installation, there is no way to move it.
Swagelining
Swagelining was originally developed by British Gas for rehabilitating gas mains and is now offered by
Advantica. It is one of the original symmetrical-reduction PE pipes using the static die method. The
starting PE pipe, made of PE 3408 (80), initially has a larger outside diameter than the inside diameter of
the pipe to be lined. After sections of the PE pipe are butt fused together to form a continuous pipe, the
PE pipe is pulled through a reduction die to temporarily reduce its diameter. This reduction is maintained
by the tension exerted from the pulling cable. After the pipe has been pulled through the existing pipe,
the pulling force is removed and the PE pipe returns to its original diameter. Swagelining has been used
for diameters from 3 to 44 inches (75 to 1,100 mm) and in diameter ratios (DRs) from 11 to 42. With the
lower DR products, the resulting close-fit PE liner can be considered a fully structural liner for pressure
applications. The pressure class of PE pipe, based on the current AWWA standard C906-07, is given in
Table 3-4. As most sewer force mains tend to operate at pressures well under 80 psi (5.5 bar), a DR 21
PE pipe is probably the thickest that would ever be considered for a rehabilitation project. The pressure
rating of PE pipe is sensitive to the maximum operating temperature that the system will experience. For
operating temperatures between 81 to 90°F, the pressure class is derated 10%, and for 91 to 100°F a 20%
derating is applied. The pipe manufacturer should be consulted for adjustments above 100°F.
Table 3-4. Pressure Class of PE 3408 based on AWWA C906 at 80°F
Pressure Class
Dimension Ratio psi kPa
32.5
26
21
17
13.5
11
51
64
80
100
128
160
352
441
551
689
883
1,103
Note: Based on AWWA C906 at!
Tite Liner®
Tite Liner was introduced into the US in 1985 and, since then over 8,000 miles of the PE liner has been
installed. Tite Liner is marketed by United Pipeline Systems, a division of Insituform Technologies. Tite
Liner is a symmetrically reduced PE liner where the continuous pipe made up of previously butt fused
sections is pulled through a roller reduction unit which radially compresses the liner outer diameter. Once
the liner is in place, the tension is released and the Tite Liner expands radially to fit the inside of the
existing pipe. Tite Liner has primarily been used in the oil and gas industry to provide internal corrosion
protection and abrasion resistance to steel pipes. In the case of the water and wastewater industry, Tite
Liner has been used as a semi-structural (Class III) liner given its relatively thin wall thickness. Tite
24
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Figure 3-11. Roller Reduction
Unit for PolyFlex
Liner is custom made with an outside diameter smaller than the host pipe's inside diameter and is
available in either PE3408 (80) or PE4710 (100) resins with diameters from 2 to 52 inches (50 to 1,320
mm). An insertion length of up to 2,600 feet (800 meters) has been achieved.
PolyFlex™
Another example of a roller die tension based system, which also
incorporates some of the features of a compression based system
is the new PolyFlex product offered by Insituform Blue.
PolyFlex's introduction in 2008 was primarily targeted at the
potable water industry, as PolyFlex is an NSF 61 certified
material. However, PolyFlex has also been considered for use on
sewer force mains (Regina, SK in Canada). After butt fusing the
sections of PE pipe into a continuous line, the pipe is both pushed
and pulled through the roller reduction unit. The outside diameter
of the pipe is reduced up to 20% by the roller reduction unit
(Figure 3-11). The pipe can be pulled through lines with up to
22.5 degree bends. After the line is in place the tension is released
and the pipe radially expands back to its original diameter. PolyFlex is available in diameters from 4 to
63 inches (100 to 1,600 mm). PolyFlex is made from PE4710 (100) resin, which has improved toughness
and better crack propagation properties than PE3408 (80). Consequently, the hydrostatic design basis
(HDB) is higher too. Unfortunately, the higher HDB is not yet recognized in the current AWWA C906
standard so, in the strictest sense, this improvement cannot be fully capitalized on yet. PolyFlex can be
either a semi or fully structural liner with pressure rating up to 150 psi (10.3 bar) in the smaller diameters.
Compression Based (Roller Die) Symmetrical Reduction
In a compression based system, the PE pipe is pushed through a die consisting of a series of concentric
concave rollers (see Figure 3-12). The diameter reduction is associated with a thickening of the pipe wall
rather than an increase in length. The majority of the diameter reduction is retained after passage through
the reduction equipment. After insertion of the liner, it is reverted to its original diameter using water
pressure. The advantages of the compression system is lower winch loads, possible separation of the
reduction and insertion stages, more tolerance of obstructions in the host pipe, ability to stop and start the
insertion process, and minimum residual tension in the installed liner. The equipment for compression
reduction can have a high capital cost, especially given its diameter specific nature.
Pipe |
Rat dawi MKhin*|
PI jmrtqr |pf IffiMl Pjpe|| Prtftauriied Water I Ho ArnuEir Spam |
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Revert It
Figure 3-12. Illustration of PE Pipe Compression
25
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Rolldown
Rolldown was developed in the late 1980s by Subterra (a division of Daniels Contractors Ltd., UK) as a
complement to Swagelining and was used in the British Gas renovation program. Rolldown uses
standard grade PE (PE3408) and is available in diameters from 4 to 20 inches (100 to 500 mm).
Depending on diameter and starting DR of the stock liner, pressure ratings up to 232 psi (16 bar) are
achievable. Rolldown has been installed up to 5,000 feet (1,524 meters) in one insertion. The PE pipe
holds its reduced diameter indefinitely prior to reversion, which allows for interruptions during the
insertion process which is not possible with a tension-based system. The string of PE pipes can be pulled
through a bend of up to 11.25 degrees. After insertion, the line is reverted to its original diameter by
water pressure. Standard couplings are attached to the ends of the PE pipe and used to reconnect to
fittings or the existing main.
3.4.3.2 Fold-and-Form Close-Fit Lining - PE. Another method of achieving a close-fit PE liner is
to fold the PE pipe into a "C" or heart shape to facilitate insertion of the liner into the host pipe, and then
to revert the liner back to its original round shape by the use of heat and/or pressure to form a close-fit.
The folding process can be carried out in the factory or on site, depending on the diameter of the PE liner.
A further distinction can be made, as illustrated in Figure 3-13, for factory-folded liners, as to whether the
reversion uses heat to help re-round the PE pipe. Both factory-folded and on-site folded technologies, as
shown in Figure 3-13, are discussed below.
Fold-and-Form
Factory
Folded
Hot
Installed
J
U LINER
On-site
Folded
Cold
Installed
SUB LINE
POLYFOLD
Figure 3-13. Summary of Fold-and-Form Close-Fit Lining Technologies
Factory-Folded PE Close-Fit Lining
Uliner and Sureliner (shown in Figure 3-13) are no longer commercially available.
Subcoil
Subcoil is another close-fit PE liner jointly developed by Subterra and United Utilities. Subcoil is a
close-fit PE pipe that is factory folded and held in a "C" shape. The pipe is shipped to the jobsite on large
spools. After insertion, the liner is pressurized with water at ambient temperature breaking the temporary
bands holding the pipe in a "C" shape and reverting the pipe back to its original dimensions. Proprietary
couplings are then attached to the end of the exposed pipe sections and make-up pieces inserted to
reconnect to the existing main. Insertions of up to 3,500 feet (1,067 meters) have been achieved. Subcoil
26
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is produced by Wavin and Glynwed Pipe Systems in diameters from 4 to 12 inches (100 to 300 mm) and
is made from PE3408 resin. The liner is only intended to be a semi-structural liner (Class II). At the
present time, Subcoil is not distributed in the US.
Mainsaver
Originally called Cemfil, Mainsaver was first introduced in the UK in 1999 and later in the US in 2006.
Marketed by Mainsaver out of Golden, CO, approximately 5,000 feet (1,524 meters) of the product has
been installed in several municipal water systems in the Rocky Mountain region. Annual installations of
Mainsaver are expected to grow to 20,000 feet (6,098 meters) per year. Mainsaver is a flexible MDPE
tube with integral grout key hooks on the outside surface. Before insertion of the tube, any open service
connections are robotically plugged so that grout cannot migrate. After the tube is inserted into the main,
a proprietary grout is placed between the tube and the host pipe, and a rounding swab is driven through
the tube by air pressure. The swab progressively expands the tube and distributes the grout against the
interior surface of the host pipe. Air pressure is maintained for 16 hours to allow time for the grout to
hydrate. After hydration, the liner is inspected with closed circuit television (CCTV) and infrared
thermography (as a QC check against grout voids). Mainsaver's RoboTap is used to remotely reinstate
any plugged service connections and special end seals are installed to protect the ends of the new liner.
The liner can be laid through 22.5° long radius elbows and renewal lengths of up to 500 feet (152 meters)
are possible. The cementitious grout provides corrosion protection to the underlying ferrous mains, while
the PE liner ensures water quality. Mainsaver is not a fully structural liner, but rather a semi-structural
liner that relies upon adhesion to the host pipe for strength (Class III). It can be used with ferrous or
cementitious pipes. Mainsaver is available in diameters 4 to 12 inches (100 to 300 mm). The total
thickness of the PE and grout is approximately 3/16 inches (3 mm). It can bridge a maximum hole size of
2.4 or a gap of 0.4 inches (10 mm) with pressures up to 294 psi (30 bar). The cost for installing
Mainsaver was said to be comparable to cement mortar lining, but no cost data were provided.
On-Site Folded PE Close-Fit Lining
The close-fit PE liners that are available in larger diameters tend to be on-site folded products. The
relationship between the diameter of pipe and the maximum thickness (lowest SDR) that can be folded is
given in Figure 3-14. Note that the higher strength PE4710 (PE100) is less capable of being folded than
the standard grade.
1600 -
1400 -
1200 -
1000 -
Maximum
Diameter-mm 80°
600 -
400 -
200 -
0
26 33 42 50 61
Liner SDR
80
Figure 3-14. Relationship Between Diameter and SDR for Folding
27
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Figure 3-15. Subline
Forming into "C" Shape
Subline
Subline, offered by Subterra, is a close-fit and fold-and-form liner made
of standard grade PE (PE3408). After butt-fusion welding, the
continuous liner is pushed through a former that folds the liner into a
"C" shape and temporarily maintained by restraining bands (see Figure
3-15). After insertion, the liner is pressurized with water at ambient
temperature breaking the bands and reverting the pipe back to its
original dimensions. The liner can negotiate up to 45° bends during
insertion. Proprietary couplings are then attached to the end of the
exposed pipe sections and make-up pieces are inserted to reconnect to
the existing main. Installations of up to 3,500 feet (1,067 meters) are
achievable. Subline is designed to be a thin-wall PE liner that bridges
over holes and gaps in the host pipe (semi-structural - Class II) and
comes in diameters from 3 to 60 inches (75 to 1,600 mm). Thicknesses
range from 0.12 to 0.80 inches (3 to 20 mm).
PolvFold™
In 2008, Insituform Blue introduced two close-fit PE liner products, one
being a fold-and-form product called Polypoid (Figure 3-16). Like
PolyFlex, PolyFold is made with the improved toughness and crack
resistant PE4710 (PE100) resin. PolyFold is available in diameters from
4 to 63 inches (100 to 1,575 mm) and pressure ratings up to 150 psi (10.3
bar). With NSF 61 certification, PolyFold also is suitable for potable
water applications. PolyFold is site folded into a "C" by pushing the
continuous PE pipe through a folding machine and then banding the
folded shape. A diameter reduction of up to 40% can be achieved, which
greatly facilitates the insertion of PolyFold into an existing pipe.
PolyFold can easily navigate bends up to 22.5°. Once the liner is in place,
it is cut to length, end fittings are attached, and the liner is pressurized to
snap the bands. Depending on the pressure and diameter, PolyFold can
either be a semi-structural or fully structural liner for a sewer force main.
3.4.3.3 Fold-and-Form Close-Fit Lining - PVC (Alloy)
Factory-Folded PVC Close-Fit Lining
All of the fold-and-form liners based on PVC resin formulations are factory-folded as heat is required to
deform the liner.
Ultraliner PVC Alloy Pipeliner™
PVC Alloy Pipeline was first introduced in 1994 by Ultraliner and since then the company has installed
over 4.5 million feet (1.37 million meters) of liner. The usage of Ultraliner appears to be equally
dispersed across its diameter range of 4 to 30 inches (100 to 750 mm). PVC Alloy Pipeliner™ has been
used in 36 states and is approved by 30 State Departments of Transportation (DOTs) for use on drainage
culverts, which is one of Ultraliner's largest markets.
Ultraliner PVC Alloy Pipeline is a solid wall PVC pipe manufactured from virgin PVC homopolymer
resin with no fillers, which is later modified with special additives to improve ductility and toughness.
The Pipeliner™ is collapsed flat and coiled on a reel in continuous, jointless lengths. Small diameters (12
Figure 3-16. PolyFold™
Banding
28
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inches [300 mm] and less) are folded in the field prior to insertion, while larger diameters (15 inches [375
mm] and above) are deflected to a smaller profile (approximately 50%) at the manufacturing plant. The
PVC Alloy Pipeliner™ does not shrink longitudinally or radially after installation (memory reset by heat
and stretching to new dimensions) to achieve a tight fit. The material has very high abrasion resistance
and ductility. Ultraliner's base materials are NSF 61 listed, but the system has not yet been certified by
NSF61.
For gravity applications, the PVC Alloy Pipeliner can be considered a fully structural, independent liner
with flexural modulus ranging from 145,000 psi (10,000 bar) ((F1871) to 280,000 psi (19,310 bar)
(F1504). However, there are no long-term pressure regression test data available to support its use as a
fully structural pressure pipe liner. The liner has been used for low pressure applications (up to 80 psi
[5.5 bar]) as a semi-structural liner (Class II) in diameters up to 15 inches (375 mm). Like most PVC
products, the modulus and long-term properties need to be re-rated downwards at temperatures above
80°F. The design of the liner is based on the appendix in the two standard practices, ASTM F1867 and
F1947, which are identical to Appendix XI in ASTM F1216.
For installation, access is required at both ends. The host pipe is cleaned and the Pipeliner is pulled into
the existing pipe. Once in place, both ends are plugged and the Pipeliner expanded with steam and air
pressure to reset the PVC alloy's memory. Installation and processing of the liner takes 4 to 5 hours,
excluding any time needed to reinstate fittings and connections, and demobilization. Excavation is
required to reinstate fittings (valves, hydrants, connections) and special fittings are needed to seal the liner
to the existing pipe.
PVC Alloy Pipeliner tends to be more competitive on small-scale projects (short lengths, small diameter)
given low mobilization and setup costs compared to other trenchless rehabilitation methodologies such as
CIPP. Large scale (>25,000 feet or 7,622 meters) 8 inch (200 mm) PVC Alloy projects can receive bids
in the $22 to $25 per linear feet range, while smaller scale 8 inch projects can see prices in the $40 per
linear feet range.
EX Pipe
Miller Pipeline offers a fold-and-form PVC pipe called EX Pipe. EX Pipe is a high strength,
unplasticized PVC manufactured to meet ASTM F1504. EX Pipe is only available in diameters of 6 to 15
inches (150 to 375 mm) and has never been used in a pressure application according to Miller Pipeline.
EX Pipe is only installed by Miller Pipeline crews. The EX Pipe is softened with heat in a pipe warmer
trailer and then continuously inserted into the host pipe via manholes or other access points using a
winch. After insertion, using steam and air pressure, the pipe is expanded approximately 10% to fit
tightly within the existing pipe. Pressure is maintained until the liner cools down to 100°F. The liner can
be installed through 90° bends and small diameter changes. Although Miller Pipeline has not offered EX
Pipe for pressure applications (also does not have an NSF 61 listing), the pipe does have a flexural
modulus of 340,000 psi (23,448 bar) and tensile strength of 6,000 psi (414 bar) which is only 25% below
that of standard PVC pressure pipe. It would appear reasonable that with some long-term pressure
regression testing, EX Pipe would have a market for low pressure rehabilitation in sewer force mains.
But without this testing, EX Pipe cannot be considered a viable rehabilitation candidate for sewer force
mains at this time.
AM-Liner II®
Produced by American Pipe & Plastic, AM-Liner II has been installed in over 100 miles of gravity
sewers, but has not been used in any pressure applications. AM-Liner II is available in diameters of 6 to
12 inches (150 to 300 mm) and SDKs 26 to 32.5 and conforms to ASTM F1871 (Type A Folded/Formed
PVC Liner).
29
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On-Site Expandable PVC Close-Fit Lining
Duraliner™
Duraliner from Underground Solutions is a patented, stand alone structural liner (Class IV) made of PVC
and available in diameters of 6 to 30 inches (150 to 760 mm). Duraliner is NSF 61 certified, so it also is
acceptable for potable water applications. Duraliner is a PVC pipe that meets all of the requirements of
AWWA C900 and C905 prior to modification by expansion. The final product meets the requirements of
AWWA C909.
The outside diameter of the starting PVC pipe stock is sized smaller than the inside diameter of the host
pipe. Sections of the Duraliner pipe are then butt-fused together forming a continuous pipe. The pipe is
then inserted into the cleaned and previously inspected host pipe. Special end caps are fitted to the ends
of the pipe along with temperature sensors. The PVC pipe is heated with steam, and then pressure is
applied to expand the material tightly against the walls of the host pipe. It takes approximately 90
minutes to fully expand the stock pipe. After cooling, the end fittings are removed and the expanded new
pipe cut to length and reconnected to the system. Insertion lengths ranging from 700 to 1,500 feet (213 to
457 meters) are possible. The liner can even navigate through a 45° elbow. The expansion of the PVC
reorients the molecular chain in the circumferential direction, thereby increasing the tensile strength.
Underground Solutions states that the HDB increases from 4,000 to 7,100 psi (276 to 490 bar). This more
than compensates for the reduction in wall thickness caused by the expansion. Molecularly oriented
polyvinyl chloride (PVCO) pipe has been used in Europe for over 20 years.
3.4.4 Cured-In-Place Pipe. The first installation of a CIPP product was in a 70 m length of
1,175 x 610 mm brick sewer in Hackney, East London. It was installed in 1971 and a small number of
other projects were undertaken by the inventor Eric Wood, and his partners Doug Chick and Brian
Chandler, who formed Insituform Pipes and Structures, Ltd. before they licensed Edmund Nuttalls, a civil
engineering contractor in 1973. Nuttalls Permaline Division performed approximately 380 projects
before they were bought back by Insituform Group in 1986. It is estimated that about 40,000 miles of
CIPP liners have been installed worldwide, perhaps 25,000 by Insituform companies.
It is by far the leading method for the rehabilitation of gravity sewers. With the expiration of the original
patent on CIPP, many new variants have been introduced. Figure 3-17 highlights the main differences
based on tube construction, method of installation, curing method, and type of resin.
The original CIPP product was a needled felt tube, impregnated with polyester resin, which was inverted
into a sewer through a manhole and cured using hot water. Insituform still markets this product today for
gravity sewers. Interestingly, the developer of the original CIPP product was actually trying to develop a
liner for rehabilitating pressure pipes. However, they found it easier to get trials in gravity sewers so the
pressure aspect was forgotten until some 20 years later. Now, a multitude of new CIPP products can be
classified as either semi-structural or fully structural for pressure applications. A few also have an NSF
61 listing and can be used for potable water.
For this report, discussion of the relevant technologies is organized into non-structural, semi-structural,
and fully structural CIPP as outlined below. The tube construction, installation method, cure method, and
resins used are discussed for each CIPP technology.
30
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C1PP
Variants
1 Tube | 1 Installation 1 1 Cure | 1 Resin |
1 Construction 1 1 Method 1 1 Method 1 1 Type I
' Resin
| Composite 1
Fibre Reinforced
Composite
Resin !•
'i
Inversion
1 Method
Pull In
1 Method |
if
!
1 * ll
Hot
Water
, _
Composite
Polyester
Vinyl
Ester
Epoxy
Ultra Violet
Light
Figure 3-17. Summary of CIPP Technologies
3.4.4.1 Non-Structural to Semi-Structural CIPP Liners
Hot Water/Steam Cured
Miner® CIPP
Inliner was first introduced in 1986. Since its introduction, over 9 million feet (2.7 million meters) of
Inliner have been installed. Inliner is supplied by Inliner Technologies, LLC (a Layne Christensen
company) and is installed by Reynolds Inliner, LLC. Inliner is available in diameters of 4 to 120 inches
(100 to 3,000 mm), with thicknesses ranging from 0.12 to 2.4 inches (3 to 66 mm). Inliner is not NSF 61
listed, so it is not suitable for potable water applications. Inliner offers its CIPP liner for pressure
applications, with a maximum recommended pressure of 60 psi (4 bar).
However, no long-term pressure regression testing has been conducted to support a long-term design
stress for the material. Inliner has been used in at least one force main (Largo, FL) where approximately
500 feet (152 meters) of an 8 inch (200 mm) DI main was lined. The DI main had corroded to the point
where it collapsed in one area when stepped on by a maintenance person. The operating pressure in the
portion of the lined main was reported to be less than 5 psi (0.35 bar). Inliner Technologies uses
isophthalic polyester resin, epoxy vinyl ester and "enhanced" polyesters. The "enhanced" resin is a filled
isophthalic polyester resin, which would increase stiffness, but sacrifice some strength and chemical
resistance. The flexural modulus of the standard isophthalic is 250,000 to 380,000 psi (17,241 to 26,207
bar), while the enhanced ranges from 400,000 to 450,000 psi (27,586 to 31,034 bar). However, flexural
and tensile strength is slightly lower for the "enhanced" resin. The felt tube is made of a non-woven
needled felt made of polyester fibers. An outer layer of impermeable thermoplastic material
(polyethylene or polyurethane) is used to protect the resin from water and contaminants. Inliner can be
installed using the inversion or pulled-in-place method. For inversion, the tube is inflated with either
water or air pressure. If using the pull-in-place method, a calibration hose or removable bladder is
inverted inside the felt tube after the tube is pulled into place. Curing is by either hot water or steam.
31
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3.4.4.2 Semi-Structural CIPPLiners
Hot Water/Steam Cured
Insituform PPL® (Pressure Pipe Liner)
PPL was first introduced in 1995. Since then, 44 miles of PPL has been installed in the US. The
interactive liner is available in diameters from 8 to 60 inches (200 to 1,500 mm), with the ability to span
over small holes and gaps in a host pipe for pressures up to 200 psi (13.8 bar). Insituform has a special
epoxy resin that is NSF 61 certified for potable water, otherwise vinylester is used. The tube is made of
Insituform's standard non-woven felt tube, but with some special glass reinforcement included for added
tensile and flexural properties. The initial flexural modulus of PPL is 250,000 psi (17,241 bar) and
flexural strength is 6,500 psi (448 bar). For spanning over holes, the flexural strength is reduced to one
third of the initial value for long-term performance. In addition, a factor of safety of 2 is utilized. The
PPL sock is saturated either in the factory or on site. The tube is then positioned in the existing pipe
using water pressure to invert the tube inside out and to form a close-fit. PPL can be installed in lines
with bends up to 90°. Typical renewal lengths are from 200 to 1,000 feet (61 to 305 meters). After
positioning, the tube is cured with circulating hot water. After curing, the liner is allowed to cool down to
90°F. The ends are cut and sealed using expandable stainless steel bands and elastomeric seals. After
installation, the liner is CCTV inspected for any abnormalities. Samples are collected and tested to
confirm that the physical properties meet the design assumption. Also, a pressure test to twice the
operating pressure, or operating pressure plus 50 psi (3.4 bar) (whichever is least), is recommended.
National Liner®
National Liner was introduced in 1995. National EnvironTech Group, the technology supplier for
National Liner, reports that over 200 miles of liner have been installed, with most of that for gravity sewer
applications. National Liner has only been used for pressure pipe installations in the past few years. Two
of the nationally licensed contractors have both reported using National Liner for sewer force main
applications. National Liner does not have a NSF 61 listing, so it is not suitable for potable water.
National Liner is available in diameters of 6 to 120 inches (150 to 3,000 mm), with wall thicknesses
ranging from 4.5 to 33.5 mm (0.18 to 1.34 inches) with the standard felt tube. Greater thicknesses are
reportedly possible. The liner is made of a non-woven, needled polyester felt that is shop or site
impregnated with a polyester resin. For pressure applications, a vinylester resin is used. National
EnvironTech Group offers a maximum operating pressure of 50 psi (3.4 bar) with its standard felt tube,
but higher pressures with a new glass fiber composite tube are reportedly under development. The liner
with a felt tube would be considered a semi-structural liner (Class II/III), and, with the glass fiber,
considered a fully structural liner (Class IV). National Liner is installed using the inversion method, with
either a column of water or pressurized air. Either hot water or steam is used for cure depending on the
method of inversion. Any excess resin mechanically locks the tube to the host pipe by filling in cracks.
3.4.4.3 Structural CIPP Liners
Paraliner PW and Paraliner FM
A relatively new product, Paraliner was introduced by NOVOC Performance Resins, LLC in October
2007. Approximately 10,000 feet (3,049 meters) of potable water mains were lined with Paraliner PW in
2008. The liner is available in diameters of 6 to 96 inches (150 to 2,400 mm) and with thicknesses from
0.18 to 2.07 inches (4.5 to 52 mm). Paraliner PW or FM is impregnated by the installation contractor
with a 100% solids NOVOC vinyl ester resin that contains no styrene. The "green" solution has no EPA
reportable components and is NSF 61 certified (by Underwriters Laboratory [UL]) for use in potable
water. As a result of no styrene, curing times are reduced 30% to 50% over conventional CIPP liner.
Minimal shrinkage due to 100% solids also ensures a tight fit to the host pipe. The tube consists of one or
32
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more layers of absorbent non-woven felt fabric, with some fiberglass added for enhanced properties. The
outside layer of the tube is coated with an impermeable, flexible membrane that contains the resin. The
reported physical properties are impressive, with a flexural modulus of 940,000 psi (64,828 bar), flexural
strength of 16,000 psi (1,104 bar) and tensile strength of 16,000 psi (1,104 bar). However, NOVOC
reported a burst pressure in an 8 inch sample with a 6 mm (0.24 inch) wall of 230 psi (16 bar). This only
equates to a hoop tensile strength of 3,833 psi (264 bar), far lower than the 16,000 psi (1,104 bar)
claimed. Prior to installation of the liner, the host pipe must be well cleaned using mechanical scrapers or
power boring. The liner can either be installed by inversion or pulled into place by a winch. With
inversion, the liner is cured using hot water. If pulled into place, the liner is inflated with air and then
steam cured. Thermocouples are used in either case to monitor the exothermic reaction. The liner can be
installed through an elbow of up to 45°. After cure, the liner is allowed to cool down to 100°F before
relieving any pressure and then the ends are cut and sealed using Weko-Seals, or an equivalent. Service
connections can be reinstated robotically, but all large connections and fittings must be excavated and
reinstated using mechanical fittings. Depending on diameter, the maximum renewal length would be
1,000 feet (305 meters). In addition to CCTV inspection, pressure testing to 120% of the working
pressure is recommended after completion of the lining.
Insituform RPP™ (Reinforced Pressure Pipe)
Insituform RPP was first introduced by Insituform Technologies in 1998 and, since then, 19 miles of the
custom engineered CIPP product has been installed. RPP is designed to restore the structural integrity to
distressed pressure pipes and prevent internal corrosion and/or erosion. It is a fully structural (Class IV)
liner capable of carrying the full internal pressure and external load. Insituform RPP is available in
diameters of 8 to 72 inches (200 to 1,800 mm), with thicknesses up to 1 inch (25 mm). RPP is not
suitable for potable water applications. Insituform RPP has been used on several sewer force main
projects. The datasheet in Appendix A contains information on two force main installations. A
maximum pressure of 80 psi (5.5 bar), diameter dependent, is recommended by Insituform Technologies.
The design of Insituform RPP is predicated upon ASTM F1216, Appendix XI. 3.2 for the fully
deteriorated pressure pipe condition. The initial tensile strength of the liner is 6,000 psi (414 bar). For
internal pressure design, a long-term tensile strength equal to one third of the initial value is used, along
with a factor of safety of 2. Insituform Technologies has carried out some limited long-term pressure
regression testing, but has not yet met the ASTM log time distribution requirements. The CIPP tube is a
sewn tube consisting of two or more layers of absorbent non-woven synthetic fiber combined with glass
fiber reinforcement. The outside layer of the tube is coated with a translucent flexible plastic material for
visual inspection during resin impregnation. A vinyl ester resin is used. The interior must be very clean
with no protrusions. Inversion lengths of 200 to 1,000 feet (61 to 305 meter) can be achieved and elbows
of up to 45° negotiated by the liner. After curing, the ends are cut and sealed using expandable stainless
steel bands and elastomeric seals. A pressure test of twice the operating pressure, or operating pressure
plus 50 psi (3.5 bar), whichever is less is recommended. The limit on make-up water is 20 gallon/inch
diameter/mile/day.
Nordipipe™
Nordipipe was first introduced in Sweden in 2002, later in Hong Kong, and then more recently in Canada.
Through 2008, there have been no installations in the US. Norditube Technologies, the US promoter of
Nordipipe, is a subsidiary of Sekisui-CPT Company. It is estimated that about 12 miles of Nordipipe are
being installed each year. Nordipipe is a fully structural CIPP product that incorporates a glass fiber
reinforced layer (chopped strand mat) between two non-woven felt layers. The tube is impregnated with
either epoxy (potable water) or vinylester resin. A PE coating is on the interior, which allows Sekisui to
have an NSF 61 listing for potable water applications (BNQ in Quebec) when used in conjunction with
the epoxy resin. The vinylester resin is roughly half the price of the epoxy. Nordipipe is available in
diameters from 5 to 48 inches (125 to 1,200 mm), with thicknesses from 0.18 to 0.94 inches (4.5 to 23.5
mm). The pressure rating of the liner is dependent on diameter and ranges from 250 psi (17.2 bar) for a 6
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inch (150 mm) liner down to 60 psi (4 bar) for a 48 inch (1,200 mm) liner. The pressure rating and
diameters would cover over 75% of the sewer force mains in the US. Sekisui reports that they lined a 12
inch (300 mm) sewer force main in Hamburg, Germany using vinylester resin and a 16 inch force main in
the UK, with epoxy. There is currently no ASTM product standard. The design of the CIPP liner would
be predicated on Appendix XI of ASTM F1216. The CIPP liner is installed via inversion, using air
pressure or a water column, and is cured with either steam or circulating hot water. Up to 600 feet (183
meters) can be installed and elbows up to 45° navigated by the liner during insertion.
Berolina Liner
One of the latest glass reinforced CIPP liners to enter the US market is Berolina Liner from BKP Berolina
Polyester GmbH in Berlin, Germany. BKP Berolina has licensed the CIPP Corporation to be the sole
nationwide US provider of this new liner. The liner was first used in Europe in 1997 and then outside
Europe beginning in 2001. There have not been any US installations yet, but Berolina Liner has been
used in Canada (Hamilton, Ontario). The Berolina Liner is composed of glass fiber and/or polyester webs
impregnated with polyester or vinylester resin. Uniquely, the layers are overlapped and staggered giving
the tube variable stretching capability. After placement of a protective film sleeve covering the lower half
of the host pipe, the liner is installed by pulling it in place, which can be accommodated by the axial
strength of the glass fiber. The tube is calibrated by inflating with compressed air (7.5 psi [0.5 bar]) and
can be inspected with a CCTV camera before polymerization. Once it is confirmed that the liner is
correctly placed, it is then ultraviolet (UV) cured. The liner has a protective inner film and a UV-resistant
outer film. The inner film is removed after installation. The outer film prevents resin from migrating into
laterals, but also from entering cracks in the host pipe. The outer film also prevents styrene emissions. A
renewal length of up to 1,200 feet (366 meters) is possible. Interestingly, the Berolina Liner is designed
with ring stiffness classes of SN1250 to SN10000 (MPa), which equates to the same ring stiffness classes
in AWWA C950 for direct buried GRP pressure pipe (namely SN9 to SN72 psi). As yet, BKP Berolina
has not undergone any long-term pressure regression testing per ASTM standards, which could be used to
establish a hydrostatic design basis, as is done for glass reinforced plastic (GRP) or thermoplastic pressure
pipes. BKP Berolina claim they have done considerable long-term testing per European and Japanese
standards, but no data have yet been produced. They have done 10,000 hour creep tests. Also, Berolina
Liner did have the lowest permeability of all CIPP liners when tested by IKT in Germany in 2008. The
Berolina Liner is available in diameters from 6 to 40 inches (150 to 1,000 mm) with thicknesses ranging
from 0.08 to 0.47 inches (2 to 12 mm). BKP Berolina's newest liner, called Berolina-LP-Liner (low
pressure), is currently undergoing testing and will be introduced for pressures up to 45 psi (3 bar). This
will probably accommodate 50% of the sewer force main market. The Berolina Liner conforms to the
European standard, EN 13566-4, and the draft International Organization for Standardization (ISO)/DIS
11296-4. As yet there is no ASTM standard for this product, but work is underway preparing a new
standard that will cover this type of product. The design basis for this liner is either ASTM F1216
Appendix XI or the German standard ATV-M 127-2. This German standard is well known in Europe,
but has limited value in the North American market. BKP Berolina does have an impressive list of
QA/QC requirements that are performed in their factory on the liner (some are qualification or type tests),
as well as recommended QC tests after installations. The technical datasheet in Appendix A contains
details on these requirements.
Blue-Tek®
Brandenburger GmbH, located in Landau, Germany, was an early developer of resin pre-impregnated
laminates (prepregs) for sewer rehabilitation that used UV light curing. In 1997, Brandenberger formed
UV Re line .tec GmbH and began the promotion of their technology outside Germany. Brandenburger
now has affiliates in the US, Canada, UK, and Mexico with over 5 million feet (1.5 million meters)
installed in 24 countries around the world. Reline America, Inc., located in Saltville, VA, was established
in 2007 to distribute the Blue-Tek CIPP liner to licensed contractors. Reline America now claims they
have made significant improvements in the original technology and are transferring that know-how back
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to Brandenburger. The product is called Blue-Tec in Germany, Eco CIPP in the UK and UV CIPP in
some other countries. Blue-Tek is primarily marketed for gravity sewer applications. Blue-Tek does not
have NSF 61 certification, so it's not suitable for potable water applications. Application forNSF 61 is
being considered for the future. Blue-Tek is a glass reinforced CIPP liner that is UV-cured. The liner
strength stems from a seamless, spirally wound glass fiber tube that is impregnated with polyester (ortho)
or vinylester resins. All wet out is performed in the Saltville plant. The seamless liner has an inner and
outer film, with the outer film blocking UV light. Care is needed to ensure the outer film is not damaged
during installation. The inner film is removed after curing. The glass reinforcement used is Owens
Coming's Advantex® EC-R glass, which is a highly acid resistant glass fiber. Blue-Tek is available in
diameters from 6 to 48 inches (150 to 1,200 mm) and can be used in circular, oval, and egg-shaped pipes.
Reline America reports that liners up to 60 inches (1,500 mm) will be available in the near future. The
short-term flexural modulus is l.lxlO6 psi (7.6 x 104bar), with increases to 2.16xl06 psi (14.9 x 104bar)
possible. For long-term modulus, a reduction factor of 1.6 is used. The short-term tensile strength is
reported to be 20,000 to 26,000 psi (1,379 to 1,793 bar). No long-term test data are available which limits
the Blue-Tek liner to semi-structural applications. The product conforms to ASTM F2019 and would be
designed in accordance to ASTM F1216, Appendix XI. Renewal lengths of up to 1,000 feet (305 meters)
are achievable. Blue-Tek is winched into the existing pipe and inflated with air pressure (6 to 8 psi [0.4 to
0.55 bar]) and then cured using a UV light train. Reline America promotes its Quality-Tracker™ System
for tracking the entire curing process (seven steps) with a data logger and retrieval system. In addition to
CCTV inspection of the line before and after curing, a record of the liner's inner air pressure during
curing, the curing speed (feet/min), and resin reaction temperatures (infrared sensors) are all monitored.
Reline America claims that minimal styrene is released into the environment with their process.
InsituMain™ by Insituform Blue
In 2009, Insituform introduced its latest addition to their CIPP product line referred to as InsituMain.
InsituMain is a fully structural Class IV CIPP liner that has an NSF 61 certification and is suitable for
both potable and non-potable pressure applications, including sewer force mains. InsituMain is available
in nominal diameters of 6 to 36 inches (150 to 900 mm) and for pressures up to 150 psi (10 bar). The
InsituMain system has a polyethylene layer on the inside pipe surface that increases the pipe's
smoothness, reduces surface friction, minimizes reduction in flow, and provides an additional corrosion
barrier for the pipe. It is composed of an epoxy composite layer, which is reinforced with glass and/or
polyester fiber materials (depending on a number of design elements including the host pipe diameter and
internal pressure requirements). The InsituMain product is saturated with epoxy resin, either on the job
site or in an authorized wet out facility, inserted into the host pipe either by inversion or by pulling-in, and
cured with either hot water or steam. The InsituMain system, which adheres to the host pipe, provides a
continuous, structural pipe. Because the liner does adhere to the host pipe, special fittings to seal the ends
are not required.
3.4.5 Woven Hose Lining System. Woven hose linings differ from ordinary CIPP products by the
construction of the tube reinforcement. Rather than being made of a felt type material, hose liners are
made from either polyester, glass, or aramid fibers that are woven into a hose-type configuration, similar
to the type of construction used for fire hoses. The weaving pattern can be varied to give different
properties in the circumferential and axial direction. Typically, hose liners are pulled into place rather
than installed by inversion as they have relatively high axial strength. Three types of woven hose lining
systems are discussed below including adhesive-backed linings, non-adhesive backed linings, and glass-
reinforced thermoplastic linings. It is also noted whether or not the lining system is semi-structural or
structural in nature.
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3.4.5.1 Adhesive-Backed Woven Hose Lining
Semi-Structural (Class II, III) Woven Hose Lining
Starline® HPL-S
Karl Weiss Technologies, located in Berlin-Zehlendorf, Germany, has developed a complete line of CIPP
products for the gas, water, and wastewater industries. For natural gas applications, Karl Weiss has been
working with the Gas Technology Institute (GTI) to refine and test a new High Pressure Liner (HPL).
The Starline HPL-G liner was first installed in 2004 in the US. Karl Weiss reports that Battelle carried
out long-term tests demonstrating the suitability of the liner for gas pipes in the US. The hose liner, based
on an epoxy resin system, has been tested in accordance with the German standard DVGW VP 404,
which includes aging strength, fluid strength, sealing characteristics, peel strength, and creep strength
against internal pressure. The German Association of Gas and Water (DVGW - Deutsche Vereinigung
des Gas und Wassesfaches e.V.) has certified the liner for a maximum pressure of 430 psi (30 bar) with a
50 year lifetime, according to Karl Weiss. By modifying the liner coating, the HPL liner is also available
for drinking water transmission. Starline 1000 (see Figure 3-18) is the liner designated for drinking water
applications in Germany. It is available in diameters of 3 to 24 inches (75 to 600 mm). Although the
liner meets the German DVGW W270 Recommended Practice for
Drinking Water and the KTW recommendations of the Federal
Institute of Health (Bundesgesundheitsamt), the application for
NSF 61 certification has only been initiated with approval
expected in 2010. Starline 3000 UV is a liner that is designed to
be fully self-supporting, not dependent on the adhesion of the liner
to the host pipe. It is also UV-cured. Starline HPL-W and
Starline HPL-S are Karl Weiss's equivalent to the high pressure
gas pipe, except these are designed for drinking water and
wastewater applications and in particular where long installation
lengths are needed.
Structural (Class IV) Woven Hose Lining
Figure 3-18. Starline* 1000
Aqua-Pipe®
Sanexen Environmental Services of Quebec, Canada, in conjunction with the National Research Council
(NRC) of Canada, developed the new structural hose liner Aqua-Pipe primarily for use in potable water
applications (Figure 3-19). Aqua-Pipe have both the BNQ Standard 3660-950 certification (Canada) and
NSF 61 certification for use in drinking water systems. The majority of early installations were in Eastern
Canada, principally Quebec Province, with a later introduction to the US in 2004. To date, over 800,000
feet (243,902 meters) of Aqua-Pipe has been installed in North America. Aqua-Pipe is composed of two
concentric, tubular, plain-weave polyester jackets with the inner
jacket bonded to a polyurethane elastomer. This watertight
tubular elastomer membrane is compatible with drinking water.
The polyester jackets are impregnated with epoxy resin on site
in refrigerated trucks. The Louisiana Tech University TTC has
been running tests on Aqua-Pipe for Sanexen. Based on this
testing, the physical properties of the Aqua-Pipe liner are
reported to be higher than the minimums in ASTM F1216
and/or F1743. The flexural modulus is 290,000 psi (20,000
bar). The flexural strength is 6,500 psi (448 bar) and the tensile
strength is 8,700 psi (600 bar). The tensile strength in particular
is nearly three times the ASTM minimums. The TTC has also
carried out a combination of creep tests (to obtain creep
Figure 3-19. Aqua-Pipe Construction
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coefficients for a three-dimensional [3-D] finite element analysis modeling for long-term performance)
and a 500,000 pressure cycles test (60 to 120 psi [4 to 8 bar]), which has given the combined effect of
creep and fatigue. TTC also reported that the testing has demonstrated that ASTM D 2207 is a reasonable
design approach for relining of pressure pipes with CIPP liners. They found the behavior of the resin-
fiber composite under cyclic loading to be interesting (measured both deformation and strain) and will be
reporting the results later in 2009. Aqua-Pipe is available in diameters of 6 to 12 inches (150 to 300 mm)
with larger diameters planned in the future. The liner is structural and is custom designed to handle up to
150 psi (10 bar) operating pressure and 6 feet (1.8 meters) of soil cover. The excess resin bonds the liner
to the host pipe, filling any small holes or cracks. The hose liner is installed by pulling in place pipe
(PIPP) with lengths of up to 500 feet (152 meters) between access pits possible. After CCTV and
cleaning the main, any service connections are mapped and plugged robotically with small plastic caps.
This is to keep the excess epoxy resin from plugging the service connection. A calibration pig is driven
through the liner using water pressure, which presses the liner tightly against the host pipe. Hot water is
circulated through the liner to cure the epoxy resin. After cure, a robotic tool is positioned at each service
connection and a hole is precisely drilled through the liner and the plugs removed to restore service.
3.4.5.2 Non-Adhesive Backed Woven Hose Lining
Structural (Class IV) Woven Hose Lining
Saertex-Liner'8 (Lightstream)
Saertex multiCom GmbH, located in Saerbeck, Germany, first introduced its CIPP liner in Europe in
1996 and later in the US in 2007. The only licensed installer of Saertex-Liner in the US is International
Pipe Lining Technologies (IPLT) in California. IPLT calls the Saertex liner Lightstream. The global
utilization rate of Saertex-Liner has been about 100 miles per year since 2008. The Saertex-Liner is
available in diameters of 6 to 48 inches (150 to 1,200 mm) and with wall thicknesses of 3 to 12 mm (0.1
to 0.5 inches). The hose liner is not marketed for pressure applications and does not have an NSF 61
certification. Like many of the other fully structural CIPP liners, Saertex-Liner's structural portion is
made of several layers of Advantex E-CR glass fiber reinforcement impregnated with either a polyester or
vinylester resin. The glass fiber is woven into a hose by Saertex in Germany and shipped to a US
warehouse in Littleton, Colorado. The liner has an inner, styrene-tight film, which is removed
immediately following the curing process. An external styrene-tight film, along with an opaque film that
protects against UV exposure and damage during installation forms the outer surface. The liner is
winched into place after placing a sliding film along the invert of the host pipe. The liner can be either
UV-cured or steam cured (catalyst included for steam curing option). Saertex liners range from semi-
structural to fully structural for gravity applications and are produced in two classes: Saertex-S and
Saertex-M. The flexural modulus of the S-liner is 1.74* 106 psi (12 x 104bar), and its flexural strength is
36,250 psi (2,500 bar). For long-term flexural modulus properties, a diminution factor of 1.35 is
recommended for the S-liner. The M-liner has a lower flexural modulus and strength (see the datasheet in
Appendix A for details). Unfortunately, Saertex multiCom has published no tensile strength data for its
liners as they have not yet offered their liners for pressure applications. From what little data are
available, the Saertex-Liner appears to have similar strength and stiffness levels to other CIPP pressure
products. However, the use of Saertex-Liner for sewer force main applications, although technically
possible, would have to be considered experimental at this time.
Primus Line®
Primus Line is an emerging new technology from Raedlinger Primus Line Gmbh of Cham, Germany.
Primus Line was introduced in Germany in 2001. Raedlinger reports that it has been supplying between
20 and 30 km of Primus Line each year since 2008, but all of this is located in Germany. Primus Line is
available in diameters from 6 to 20 inches (150 to 500 mm) with thicknesses ranging from 6.5 to 9 mm
(0.3 to 0.4 inches). It has been certified for drinking water applications in Germany, but not yet in the
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US. Primus Line is a seamless, woven hose made of aramid (Kevlar®) fiber in single or double layer
designs (depending on pressure) embedded in a high performance plastic matrix. Kevlar has eight times
the tensile strength of steel. The folded pipe is pulled into an existing pipe from a reel. This is not a CIPP
product so no curing is required. Pressure is used to inflate the liner which then becomes self-supporting.
For water or sewer applications, the inner liner is coated with polyethylene. There is also an outer coating
of wear resistant PE. Primus Line is also used for oil and gas applications in which the liner is coated
with TPU. The main benefit of Primus Line is its ability to handle high pressure. With a single layer of
woven fabric, the pressure rating for 6 inch (150 mm) diameter is nearly 500 psi (34.5 bar) and for 20
inch (500 mm) diameter it is rated at 218 psi (15 bar). The rating can be higher with a double fabric layer.
Primus rates its product based on a factor of safety of 2.5 against the burst strength, but also claims that
long-term creep pressure tests have been conducted in accordance to DIN 16887 and ISO 9080. The
product has a safety coefficient of 2.0 applied to the extrapolated 50 year strength. The only available
product standards for Primus Line are German, namely KTW and W270 for drinking water in Europe,
and DVGW Testing Basis VP 643 (June 2004). For insertion, the existing pipe must be CCTV inspected
and any sharp protrusions that might damage the liner are ground smooth. The Primus Line is pulled
from a reel (up to 6,000 feet [1,829 meters]) into the pipeline. A special pulling head is used to help
protect the liner from any remaining sharp objects. The rate of installations can be up to 1,200 feet (366
meters) per hour. The maximum pulling force is 100 kilo Newtons (kN) and a load cell with recorder is
used to monitor that this force is not exceeded. The main drawback of the Primus Line is that a very
special, proprietary connector is needed to join the line to a welded or flanged connection on the original
pipe. This special connector requires a resin to be injected and cured before the line can be pressure
tested and put back into service. One potential application for the Primus Line might be as a by-pass
pipe. It is very light weight (1.6 to 9.1 kg/m), quick to unreel, and set up.
3.4.5.3 Glass-Reinforced Thermoplastic Liner
Structural Woven Hose Lining
Aqualiner
Aqualiner is an emerging technology that appears to have great promise. It is still undergoing
development trials in Europe and has not yet been commercially released. The developer, Aqualiner, is a
consortium of three UK water companies, a Danish contractor, and a plastics consultant. All of the field
trials have been with Wessex Water in the UK. The Aqualiner installation process is shown in Figure 3-
20. Aqualiner involves winching a glass fiber reinforced polypropylene sock into a deteriorated pipe, and
once the sock is in place, pushing a heated pig with a silicone rubber inflation tube through the sock,
melting the thermoplastic sock against the pipe wall. The inversion bag presses the molten thermoplastic
composite sock against the pipe wall where it cools to form a solid glass reinforced thermoplastic liner.
Pressure in the inflation bag is kept at 45 psi (3 bar) until the liner cools, at which point the bag is deflated
and removed. There is no mixing of chemicals and no environmental releases. The liner is fully
structural (Class IV), capable of handling the internal pressure, and external loads. An application for UK
approval for potable water is in process (DWI Regulation 31) as well as for certification for NSF 61.
Aqualiner will also be able to meet the strain corrosion requirements of Table 6 in EN 13566-4:2002,
which is similar to those in ASTM D3262. Aqualiner will be available in diameters of 6 to 12 inches
(150 to 300 mm) (eventually 18 inches [450 mm]) and will have a 150 psi (10 bar) pressure rating.
Renewal length of up to 500 feet (152 meters) for 12 inch (300 mm) pipe can be undertaken. There are
no product standards yet for this new class of liner product. The closest applicable standard might be EN
ISO 15874 Polypropylene for Hot and Cold Water Installations. Likewise, there are no design standards,
with EN 13566-4:2002, Plastic Piping Systems for Renovation of Underground Sewerage Networks
(CIPP) the most applicable.
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AQUALINER PIPE LINING SYSTEM
THERMOPLASTIC
COMPOSITE SOCK
EXPANDS TO ID OF THE
PIPE. WHERE IT COOLS
AND CONSOLIDATES
3 COMPRESSOR
PRESSURISED
ELEPHANT
CONTROLS FEED
RATE OF PIG
Figure 3-20. Aqualiner Installation Process
3.5
Replacement
Replacement is a form of renewal. Replacement involves the installation of a new fully structural pipe to
take over the functions of the deteriorated main. Several technologies are available for online and offline
replacement as summarized in Figure 3-21. Historically, the most common method of rehabilitation has
been offline replacement of an underground main by open cut construction. While it is expensive, offline
replacement has several benefits for the operating utility as follows:
• It results in a new pipeline with known condition and designed to current standards.
• Offline replacement can be undertaken with the existing force main in operation so there is no
disruption to service.
• Offline replacement offers the opportunity to build parallel to the existing line in order to
create some redundancy, allowing future inspection and maintenance works to be undertaken,
while maintaining service.
• Cost may not be much higher than rehabilitation when the cost of by-pass pumping during
rehabilitation is taken into account.
Fortunately, new trenchless methods of construction have yielded a wide variety of replacement methods
that now limit the amount of excavation required to a minimum. These trenchless methods fall into both
online and offline methods. Online is where the new pipe is laid to the same line and grade as the
deteriorated pipe being replaced. With online replacement, by-pass of the existing pipe is needed during
the replacement construction. Sliplining, pipe bursting, and pipe splitting are examples of online
replacement. Offline replacement consists of installing a new pipe using a different line and possibly
grade as the existing pipe. Normally, a by-pass of the existing pipe is not necessary with offline
replacement. Once the new line is in place and has been leak tightness tested, flow is then diverted to the
new line and the deteriorated main is retired from service. Directional drilling, microtunneling/pipe
jacking, pilot tube boring, and auger boring are examples of trenchless offline replacement methods.
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Stipiining
Pipe Bursting
Pipe Splitting
Replacement ( / Open Cut
MicrotunneMng
Pipe Jacking
Pilot Tube
Boring
Auger Boring
Figure 3-21. Summary of Replacement Technologies
3.5.1 Online Replacement. The following sections will cover the online replacement methods in
greater detail and highlight some of the recent advances in the trenchless replacement technologies.
3.5.1.1 Sliplining. The second most common method of replacement has traditionally been
sliplining, particularly for large diameter pipes. Sliplining involves the insertion of a new pipe with a
smaller OD than the inner diameter (ID) of the pipe to be rehabilitated. Typically, the OD of the new pipe
is a minimum of 2 inches less than the ID of the existing pipe. This can be relaxed for smaller diameters,
straight runs, and when there are no offset joints that could interfere with the movement of the new pipe.
The most common pipe material used for pressure sliplining has been PE. The PE can be in the form of a
coil, a long welded string, or discrete lengths. Fusible PVC is now also gaining popularity as a slipliner.
In large diameters, steel, DI, and GRP/FRP pipes have all been used as pressure slipliners. The new pipe
can either be pulled or pushed into the existing pipe. The annulus between the two pipes is often filled
with a low density grout to anchor the new pipe while increasing its buckling resistance.
Sliplining is a relatively low cost, easy method of installation that is not disruptive to adjacent utilities or
structures. All connections and fittings require excavation for reinstatement. The main disadvantage is
the reduction in flow capacity from downsizing the inside diameter. This can be offset to a certain degree
by the improved flow properties (lower frictional resistance) that many new plastic sliplining pipes offer.
Another disadvantage is the difficulty in finding any leaks that may develop in the new slipliner. Any
water or sewerage could migrate long distances between the slipliner and the host pipe before exiting at a
weak point in the host pipe. The external visible evidence of a leak could be far removed from the actual
leak in the liner.
Fused Pipe Lengths
Polyethylene, with butt-welded joints, has been used extensively for replacement using the sliplining
method. The axial strength of a butt-welded HOPE joint is equal to the material, so this makes HDPE
ideal for pulling into an existing pipe. Polyethylene pipe is normally sized with the OD equal to the
nominal diameter. However, on large projects, some PE vendors will tool up and custom manufacture a
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pipe size that minimizes the interstitial gap and therefore loss of capacity. The thickness of HDPE can
also be a negative factor for flow, especially for high pressure. An SDR 11 is needed for a 160 psi
(11 bar) pressure rating and SDR 17 for a 100 psi (7 bar) pressure rating. Of course, this is based on
using the pipe as a fully structural pipe since a slipliner is independent, not interactive, with the existing
host pipe.
FusiblePVC™
In 2003, Underground Solutions introduced a patented
PVC pipe product that could be butt fused together,
much in the same manner as HDPE (Figure 3-22).
Their first commercial installation was in January 2004
and since over 2 million linear feet (0.6 million meters)
have been installed. FusiblePVC has been used in over
43 states, plus Canada and Mexico. The primary use
has been for pressurized potable water, reclaim, and
wastewater lines.
M
The resin and compound meets the PVC formulation in Figure 3-22. Fusion of PVC Joint
PPI Technical Report #2, so the same hydrostatic design stress may be used (2009). The fusible pipe
meets both AWWA C900 and AWWA C905, is made in DI pipe size (DIPS) and iron pipe size (IPS) OD
series, and is NSF 61 certified for use with potable water. With the proprietary formulation, the fused
joint is nearly as strong (minimum 95%) as the pipe wall.
With the fully restrained butt-fused joints, FusiblePVC can be used for directional drilling, pipe bursting,
and sliplining. The same equipment that is used for butt welding PE pipe can be used for PVC.
However, the fusion temperature, time, and pressure are different and only technicians that have been
trained and certified by Underground Solutions are permitted to fuse joints. Certification lasts one year.
Fusible C-900®, designed for water distribution systems, is available in diameters of 4 to 12 inches (100
to 300 mm) with DRs of 14, 18, and 25. Fusible C-905®, designed for water transmission systems, is
available in diameters of 14 to 36 inches (350 to 900 mm) with DRs of 14, 18, 21, 25, 32.5, 41, and 51.
AWWA C-900 and C905 incorporates a long-term factor of safety of 2 with no surge allowance.
Transient pressure is added to working pressure for maximum pressure and is not to exceed 1.6 times the
pressure class of the pipe. Underground Solutions also produces FPVC™, which is Fusible PVC in
diameter dimensions other than the DIPS and IPS series in the AWWA standards.
For sliplining, the host pipe would be moderately cleaned and a CCTV inspection made. The degree of
cleaning is not as stringent as for close-fit liners. Depending on site logistics, the Fusible PVC can be
strung out and the joints butt fused above grade prior to insertion or butt fused in the ditch. The fused
PVC is then winched into the host pipe, following the maximum recommended pull force which is based
on either an axial stress of 2,600 psi (179 bar) or a factor of safety of 2.25 against joint strength,
whichever is less. Sliplining lengths of 3,500 feet (1,067 meters) in a single pull have been completed.
Discrete Pipe Lengths
Some of the same diameter and thickness considerations apply when sliplining with discrete pipe lengths.
Normally, discrete pipe lengths will have bell and spigot joints or coupling joints with an outside diameter
greater than the barrel of the pipe. Often, it is the outside dimension of this joint that will control the
nominal diameter for insertion. Some pipe manufacturers make a special low profile joint to facilitate the
insertion. The process for the insertion of discrete pipe lengths is to set up and assemble each pipe joint
one at atime in the ditch. Next, the column of pipe is jacked forward by the length of each pipe section,
before making the next joint assembly. Discrete pipe sliplining is favored when job site logistics are not
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favorable to stringing out a long line of butt-welded pipes. Some pipe materials also have joints that can
be mechanically locked together. When this feature is invoked, the pipe string can be advanced by either
pulling or pushing or a combination of the two, thereby increasing the length that can be sliplined from
one access pit to the next. One of the limitations of using discrete pipe
lengths is that rubber ring joints will normally only allow angular rotations
ranging from about 1/2° to 3.5° depending on material and diameter.
Therefore, any deviations in the host pipe's joints exceeding these values
may require special attention. Also, pipe lengths may have to be non-
standard to accommodate short radius curves. For sewer force mains,
PVC, DI and GRP/FRP pipes could all be used for discrete sliplining.
Hobas Pipe USA, US Composite Pipe (Flowtite™), Ameron, and Future
Pipe are manufacturers of large diameter GRP/FRP pipe that have been
used for sliplining of both pressure and non-pressure wastewater lines
(Figure 3-23). Pipe diameters from 12 to 144 inches (300 to 3,600 mm)
are available. Sliplining Pressure Joint
In the case of PVC, Certainteed Corp. manufactures the Certa-Lok™ restrained joint for trenchless water
and sewer applications. Certa-Lok is based on the use of a special coupling into which two nylon splines
are inserted that lock into grooves in the spigot end of the pipe. A rubber gasket is included for water
tightness. The C900/RJ and C905/RJ Certa-Lok PVC products are UL listed and suitable for pressure
applications ranging from 150 to 200 psi (10 to 14 bar) dependent on DR ratio and standard. Certa-Lok
pipe is available in diameters from 4 to 16 inches (100 to 400 mm). Another example of a restrained PVC
joint is the TerraBrute™ pressure pipe from IPEX. The TerraBrute joint is a steel ring and pin system,
that incorporates a rubber ring gasket for sealing. It is reported that the joint can take up to 120,000 Ib of
axial force in the 12 inch (300 mm) diameter size. The TerraBrute joint was specifically developed for
horizontal directional drilling (HDD) applications, but can also be used for sliplining.
3.5.1.2 Pipe Bursting. Pipe bursting involves the breaking up of the old pipe and pushing it into the
surrounding soil by passing a bursting or splitting device through it while pulling a replacement pipe in
behind the bursting head. The replacement pipe is usually HOPE, PVC, or DI. In some cases, the
process can be used to expand the void created, thus upsizing with the insertion of a larger diameter. For
diameters 12 inches (300 mm) and under, upsizing up to 50% is possible and for diameters over 12 inches
(300 mm) upsizing by up to 25% is achievable with the right soil conditions and adjacent structures far
enough away to avoid damage. Upsizing by over 50% is considered experimental.
Pipe bursting has now been accomplished in diameters from 4 to 60 inches (100 to 1,500 mm). The
bursting method works best on friable pipes, including CI, asbestos-cement, non-reinforced concrete,
PVC, and clay pipes. There are three basic bursting methods — static, hydraulic and pneumatic bursting.
Pipe splitting, which is a form of bursting for materials like DI and steel, is a fourth type that will be
covered in the next section. Fusible PVC replacement pipe should only be used with the static bursting
method.
The type of soil affects the ability of the bursting head to expand the hole and therefore the amount of
upsizing. Obviously bursting is not possible in rock or pipes that are concrete encased. Also, shallow
buried pipes risk surface displacement. As a general rule of thumb, the minimum depth of the existing
pipe should be 10 times the difference in diameters of the existing pipe's OD and the expander's OD.
With increasing depth of soil burial, the force needed to expand the hole also increases. The foundation
of adjacent structures and other utilities can be damaged if too close to the bursting activity. The distance
should be a minimum of 18 inches (450 mm) for normal bursting, larger for upsizing. Expansion pits can
be dug adjacent to structures or utilities to relieve the soil pressure.
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Since the original pipe is destroyed in the bursting process, the new pipe must be designed to carry all of
the operational loads, including internal pressure, external soil pressure, and traffic loads. After insertion
of the new pipe behind the bursting head, the soil will tend to close back on the pipe providing support.
The design of the pipe is similar to direct burial pipe based on soil-pipe interaction. Actually, some of the
most demanding loads may be exerted on the new pipe during the installation. The new pipe will see
flexural loads as it enters the launch pit, axial tensile loads due to friction and pipe weight, external
buckling pressure due to soil fill and groundwater, and possible surface damage from contact with shards
of the old pipe.
Static Pipe Bursting
Static bursting was originally developed by British Gas to replace CI
gas mains. It works well with CI and asbestos cement pipes. Pipe
diameters from 2 to 60 inches (50 to 1,500 mm) can be burst using the
static method, which relies upon brute force to shatter the existing
pipe. Lengths up to 400 feet (122 meters) typically can be burst using
the static approach although much longer lengths can be burst under
the right combination of ground conditions and bursting equipment.
TT Technologies Grundoburst® and Hammerhead Hydroburst® are Figure 3-24. Static Bursting Head
two examples of equipment designed for static bursting, as
illustrated in Figure 3-24.
Pneumatic Pipe Bursting
With pneumatic bursting, an air operated hammer shatters the old pipe
with impact as the bursting head is pulled through the line. Pneumatic
bursting works well with the same materials as the static method, plus
PVC. Broken pieces are pushed outward by a rear expander, which
can also upsize the resulting void. Diameters from 4 to 60 inches (100
to 1,500 mm) and lengths up to 500 feet (152 meters) typically are
burst with the pneumatic method. TT Technologies Grundocrack® is
an example of pneumatic pipe bursting equipment (Figure 3-25).
Figure 3-25. Pneumatic Bursting Head
Hydraulic Pipe Bursting
Hydraulic pressure is used to expand the burster, which breaks the old pipe and pushes the pieces into the
surrounding soil. An expansion cone can also be accommodated for upsizing. The hydraulic method can
be used with the same materials as the static method and in diameters from 6 to 20 inches (150 to 500
mm). Xpandit™ is an example of equipment designed for hydraulic pipe bursting.
Tenbusch Insertion Method
The Tenbusch Insertion Method (TIM™) deviates from the static and dynamic pipe bursting methods.
Instead of using the bursting head to pull a new pipe into the void created by the burst, Tenbusch jacks the
new pipe in place of the existing deteriorated pipe. The leading element is a heavy steel guide pipe,
which maintains alignment within the center of the old pipe. Behind the lead is the cracker, which
fractures the old pipe, followed by a cone expander that radially expands the fractured pipe into the soil.
This is followed by the front jack which is a hydraulic cylinder that acts like an intermittent jacking
station to provide the axial thrust to the leading equipment. The front jack bears against the pipe (via an
adapter) that is also being jacked into the void. Lubricant is introduced at the adapter to minimize
friction. The lead equipment is designed to be disassembled at a 4 feet (1.2 meters) diameter receiving
manhole and removed. With the Tenbusch method, only rigid pipes that can withstand the high axial
jacking loads are used for the replacement. This is mainly clay and DI pipe.
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3.5.1.3 Pipe Slitting. Pipe slitting is a variation of the static method incorporating cutting wheels in
advance of the bursting head. The cutting wheel slits the ductile pipe, such as DI or steel, allowing the
bursting head to then open up the slit pipe. All other aspects are similar to static bursting. Pipe slitting
has been carried out on pipes from 6 to 24 inches (150 to 600 mm) in diameter.
3.5.2 Offline Replacement. As the name implies, offline replacement simply involves the
installation of a new pipe without regard to the line and grade of the existing pipe. Normally the existing
deteriorated pipe being replaced is kept in service (at reduced operating conditions if necessary), while the
new replacement pipe is being installed. Once the new pipe is in place and has been leak tightness tested,
a switchover is made.
3.5.2.1 Open Cut. Historically, the most often used renewal method of a deteriorated sewer force
main is open cut replacement. Force mains, like water mains, are generally not buried very deep so the
cost of open cut excavation is less than for deep gravity sewer mains. However, other indirect costs such
as disruption to traffic and the general public or interference with other underground structures can raise
the cost of open cut replacement to a point where rehabilitation or replacement with trenchless means is
more cost-effective.
3.5.2.2 Directional Drilling. Directional drilling is a trenchless excavation method. First, a small-
diameter pilot hole is drilled along the designed directional path. The drill head can be steered both
horizontally and vertically and is equipped with a head-location device (sonde) for shallow drilling
applications. The pilot hole is then enlarged and finally the replacement pipe is pulled in to the reamed
hole. Typical pipes that can be pulled into the hole are steel, HDPE, PVC, and DI. Steel pipe would
either have welded joints, or mechanically-locked joints such as Permalok. Butt-welded joints are used
with HDPE and either fusible joints on PVC or mechanically-locked joints such as Certalok from
Certainteed or Terrabrute by IPEX. The radius of curvature commonly used for designing drill paths is
1,200 times the nominal diameter of the pipe. This is based on established practice for steel pipe. HDPE
and PVC, which have greater flexibility than steel could accommodate a tighter radius if needed.
Diameters that have been installed by HDD are 2 to 60 inches (50 to 1,500 mm) and lengths up to over
10,000 feet (3,049 meters). HDD has been especially useful on river crossings and for the installation of
service connections. In 2005, the American Society of Civil Engineers (ASCE) released a manual of
practice (MOP #108) for Pipeline Design for Installation by Horizontal Directional Drilling (ASCE,
2005).
3.5.2.3 Microtunneling/Pipe Jacking. Microtunneling or pipe jacking involves the installation of a
new pipe behind a tunneling shield or tunnel boring machine (TBM). On short to medium length drives,
the pipe string and shield are driven forward by hydraulic jacks operating from a drive shaft (on long
drives, intermediate jacking stations may also be installed at intervals along the pipe string). Once the
TBM reaches the reception pit, it is removed. The jacked pipes can be the replacement pipes themselves,
or they can serve as a casing for subsequent installation of the replacement pipes by sliplining.
With the different types of tunneling machines available, including slurry and earth pressure balance
(EPB) machines, with cutting heads to handle rock and mixed ground conditions, a wide variety of
ground conditions can be handled. A Geotechnical Design Summary Report (GDSR) and a Geotechnical
Baseline Report (GBR) typically are used to define the geotechnical parameters of a tunneling project so
that there is a clear understanding of the geotechnical conditions expected on a project. Diameters from 6
to 120 inches (150 to 3,000 mm) can be microtunneled and curved alignments with joint deflections of up
to 5% can be accommodated (although curved alignments currently are uncommon in the US).
The selection of the right jacking pipe is paramount. Typically, the loads imposed on the jacking pipe
during installation are going to control the pipe design. Jacking loads of up to 1,000 tons are possible, so
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the jacking pipe needs to have high axial compressive strength and stiffness. "In wall" joints are used to
avoid projections beyond the OD of the shield and to minimize friction between the pipe wall and the soil.
Bentonite slurry is usually introduced between the pipe barrel and the soil to minimize friction, but
smooth, non-porous pipe surfaces are also beneficial. The intermediate jacking stations (US) used on
long drives are operated in sequence so that only sections of the jacking pipe are slid through the ground
at any one time. This minimizes the jacking force needed to drive the tunneling machine and pipe column
forward.
Typical pipes that have been used for jacking of pressure pipes are GRP, polymer concrete, reinforced
concrete, steel, and DI. PVC can also be jacked, but requires a large number of US, making it somewhat
uneconomical.
GRP
Hobas pipe, which is a centrifugally cast glass-reinforced plastic mortar pipe, has been used on a large
number of intermediate diameter (24 to 84 inches [600 to 2,100 mm]) microtunneling projects. Hobas
pipe, with its tight tolerances on OD and relatively high axial compressive strength, has dominated the
gravity sewer microtunneling market in Houston, TX. Although the pipe itself might be capable of
carrying internal pressure, the joint used for microtunneling does not lend itself to pressure applications.
A variation on ordinary GRP pressure pipe for microtunneling is produced in Germany by Hume Rohr.
Hume Rohr is a manufacturer of precast concrete pipe. They purchase GRP pressure pipe from the
Flowtite® producer near Dresden and then use the GRP as an inner mold casting a concrete pipe outside.
The end result is a composite of concrete and GRP with the concrete handling the axial jacking loads
during installation and the GRP handling the internal pressure. With GRP's inherent corrosion resistance,
this composite provides a very suitable jacking pipe for a sewer force main replacement. Unfortunately,
there are no producers of this composite pipe concept in North America at the moment.
Polymer Concrete
A variation to the composite made of GRP and concrete is the polymer concrete pipe. There is a standard
specification (ASTM D6783) for polymer concrete pipe. Meyerhof in Germany was one of the pioneer
developers of polymer concrete pipe. Meyer's Polycrete® is now produced by US Composite Pipe in
Zachary, Louisiana. Polycrete is a composite consisting of polyester resin, sand, aggregate, and a mineral
filler. Polymer concrete, which actually doesn't use any cement, uses 9% to 10% by weight of polyester
resin to bond the silicate aggregate, creating a dense, corrosion resistant matrix. The pipe is produced
using a vertical casting process, similar to concrete pipe. The joint has a 316 stainless steel collar
mounted integral to the pipe wall for microtunneling applications. With an average axial compressive
strength of 15,000 psi (1,034 bar), the Meyer Polycrete pipe has ample strength for jacking forces. The
pressure limitation of the joint is only 35 psi (2.4 bar), so the pipe's usefulness as a replacement pipe for a
sewer force main is limited.
Steel
Permalok is an interlocking pipe joining system. Permalok is produced by Permalok Corporation in
St. Louis, MO and is available in diameters from 30 to 120 inches (750 to 3,000 mm). The steel pipe is
manufactured by the rolled and welded cylinder method utilizing the double submerged arc welded
(DSAW) process. The joint is an integral, machined press-fit connection incorporating a double "o" ring
gasket, which is intended to be used for low to medium pressures (up to 300 psi [21 bar]). The joint is
assembled in the field by the jacking frame. The T7 profile (Figure 3-26), which is the pressure joint, was
introduced in 2002. Once assembled, the Permalok joint is flush with the exterior and interior surfaces of
the pipe rendering it suitable for both pipe jacking and HDD applications. Coatings and linings suitable
for a variety of applications are available from Permalok. Permalok, with the right lining, would be a
candidate for replacing a sewer force main using microtunneling/pipe jacking or HDD.
Figure 3-26. Permalok T7 Pressure Joint
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4.0 TECHNOLOGY SELECTION CONSIDERATIONS
Aside from selecting renewal technologies on the basis of their fit to the force main's operating conditions
(e.g., pressure, burial depth, etc.), other site-specific parameters must be considered in the selection
process. The life-cycle cost of the renewal method and its impact on extending the life of the asset are
often the primary concerns in technology selection. Other site-specific factors that should be taken into
consideration include post-renewal capacity needs, accessibility, future O&M requirements, the condition
of the host pipe, and the consequence of its failure (criticality). All of these items are explored here. As
discussed in Section 5, other technology-specific factors that play a role in technology selection are
corrosion resistance, long-term HDB, temperature derating, duration of by-pass pumping, use of non-
standard pipe materials and dimensions, and the methods for reinstatement of fittings and connections.
4.1
Life-Cycle Costs
Renewal technology selection is guided by consideration of life-cycle costs over the remaining life of the
asset or its extended life with the renewal. In principal, the concept is to break down all costs associated
with an alternative (including the alternative of doing nothing) into a net present value for comparative
purposes by discounting future expenditures and the remaining salvage value of the asset. Present costs
would include the capital funds needed for renewal of the underground asset including engineering and
construction. Each alternative may also have a different life expectancy and different future O&M costs.
In surveying vendors of rehabilitation products, they were each asked to provide capital costs and some
guidance on the nature of future maintenance that might be required for their technology. Without
exception, all replied nothing out of the ordinary was needed for O&M. Cost data were collected to the
extent possible as outlined in Appendix A. However, the availability of this data was limited. Figure 4-1
illustrates representative cost data from a collection of bid tenders from across the US on various
trenchless installation methods (Simicevic and Sterling, 2003). These costs were collected in 2002 and
2003, so current costs will be higher, but the relative comparison is still valid.
1 1 1 1 1
10" 20" 30" 40" 50" 60" 70" 80" 90" 100" 110" 120" 130" 140" 150" 160" 170" 180" 190" 200"
Diameter
Figure 4-1. Total Installation Cost in 2003 Dollars for Trenchless Rehabilitation Methods
(Simicevic and Sterling, 2003)
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Capital Costs
The TTC collected bid tenders from all over the US on various trenchless installation methods and
published a report in 2003 highlighting the results. The report compared installation costs for open cut
replacement for pipes and manholes with pipe rehabilitation or replacement including CIPP, sliplining,
fold-and-form, deformed and reformed, spray-on linings, pipe bursting, HDD, microtunneling, pipe
jacking, localized pipe and joint repairs and manhole rehabilitation including cementitious and polymer
spray coatings, preformed manhole inserts, and manhole liners. Although the cost data are from 2003, it
is still one of the best documented reports on installed costs of trenchless technologies.
The Office of Water Service (OFWAT), which is the UK Water Services Regulation Authority, has also
collected information from the UK water industry on rehabilitation costs for water mains (OFWAT,
2005). This includes close-fit liners, polymer spray-on linings, sliplining, HDD, and pipe bursting.
OFWAT surveyed 13 water utilities and obtained installed cost data on these various rehabilitation
methods. A benchmark cost was then determined based on the mean value. The open cut replacement
data were further broken down into rural, suburban, and urban segments. Figure 4-2 is a summary chart
comparing the cost of four rehabilitation options to open cut replacement. "Insert" is a close-fit
polyethylene liner. The data do show the favorable cost impact of carrying out epoxy lining and insertion
of a close-fit PE liner versus open cut replacement. When compared to an urban environment, all of the
rehabilitation methods are more cost-effective than the open cut replacement option.
Cost For Rehabilitation - OFWAT
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Figure 4-2. UK Water Rehabilitation Costs (OFWAT, 2005)
O&M Costs
One potential difference in operational cost would be pumped energy requirements. Reduced diameters,
associated with sliplining and liners, means higher velocities to maintain the same flow quantities.
Higher velocities translate into higher head loss (proportional to the square of the velocity). This can be
offset to some degree by a lower friction factor, which many of these new polymer products possess. The
bottom line is energy requirements for pumping operations may be increased to overcome the additional
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head loss to maintain flow capacity. This cost needs to be factored into the decision process when
considering alternatives.
Future expenditures could include the cost of repairing a major break in a main, or carrying out some
renewal on the main in future years. These costs, especially the timing and cost of a break, can be
difficult to quantify, but some estimate is needed for a life-cycle cost comparison.
All else being equal, the renewal alternative with the lowest present value based on a life-cycle cost
analysis would be the selected option. However, there are usually other considerations that must also
come into play and have a bearing on the choice of renewal technologies as discussed below.
4.2 Capacity
Some consideration must be given to the capacity requirements of a system whenever a sewer force main
asset reaches its end-of-life and a decision is to be made on either renewing or replacing the asset. This
often requires hydraulic modelling of the wastewater system in combination with population density
forecasts. This model will help to determine if the existing force main is of adequate size, whether it
could be downsized to allow for certain renewal technologies, or if upsizing is needed to handle predicted
future flows from growth.
Sliplining of a sewer force main is going to result in a loss of cross-sectional area and therefore capacity.
With a 5% reduction in inside diameter, which is essentially the minimum that could be sliplined, the
corresponding loss of capacity with no change in friction factor is 10%. A 10% inside diameter
reduction, which is more normal, will result in a 19% loss of capacity. Unless that type of capacity loss
can be tolerated, or cost-effectively accommodated with pump upgrades, sliplining is going to fall by the
wayside as an effective option. A pump upgrade to maintain or improve capacity is an expensive option,
but still merits consideration.
Most of the PVC and PE close-fit liners and CIPP lining products will result in a very modest 0.5% to 3%
reduction in inside diameter of the pipe. The improved flow characteristics of these smooth liners,
usually with Hazen & Williams flow coefficients of 145 or higher, compensate for the slight reduction in
cross-sectional area. These solutions will generally work when the present system offers sufficient
capacity.
If future growth dictates that greater capacity will be required, then the options for rehabilitation narrow
to either offline replacement with a new, larger diameter pipe or pipe bursting with upsizing. The
diameter limit on upsizing is generally limited to one or maximum two pipe diameter sizes. Larger
upsizings have been successfully completed, but should be carefully evaluated as to the equipment
capabilities and the effect on nearby structures.
4.3 Accessibility
Accessibility will affect both the cost to renew a sewer force main, as well as the chosen technologies.
Fully deteriorated pipelines in rural areas, with no environmentally sensitive areas to cross, and not likely
to inconvenience the general public, will be more cost-effective to fully replace using conventional open
cut construction as opposed to the use of a structural lining in the existing pipe. That comparison may
change in the future as new structural spray-on linings become available.
Conversely, pipelines in congested areas with traffic and underground utilities to contend with, either
partially or fully deteriorated, are ideal candidates for some form of either online replacement or
rehabilitation. Pipe bursting needs to be carefully controlled if the main is in close proximity to other
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utilities or foundations. For partially deteriorated mains, close-fit liners can be extremely cost-effective
for rehabilitating a main especially in congested, built up areas. The City of New York had a
deteriorating 150 year old 48 inch (1,200 mm) CI water main running down Madison Avenue. Insituform
Blue was able to install 10,000 feet (3,049 meters) of its new interactive HOPE liner (PolyFlex DR 50) in
several stages with minimal disruption to traffic and business.
Some pipelines even get "misplaced" and end up with structures built directly over them. Jason
Consultants recently had a project where a 48 inch (1,200 mm) PCCP water main was found to be in
significant distress. Eight manufactured homes were located directly on top of this main. In this case,
rehabilitation was the only viable cost-effective solution. The pipeline was sliplined with steel pipe of a
smaller diameter and the annular space was grouted.
4.4 Maintenance
One of the issues continually raised by O&M personnel is the question of repairing a break in a sewer
force main that has been rehabilitated or sliplined. Utilities usually keep on-hand repair clamps,
replacement pipe sections and special adapter fittings so an emergency repair can be made on a main that
bursts at an inconvenient time. Crews are trained to work with those pipe materials that are
predominantly used by the utility and are knowledgeable about how to repair a burst or leaking joint in
such materials. The methodology for repairing a break in a ferrous main that has been lined with a close-
fit PE liner or a CIPP liner is not generally known. As such, O&M personnel are reluctant to accept
rehabilitation options over offline replacement with known materials. The industry has to do a better job
of developing training tools and repair kits to alleviate this concern. Otherwise, cost-effective
rehabilitation schemes are being overlooked in favor of replacement.
4.5 Condition Assessment and Asset Criticality
Condition assessment plays a major role in asset management decisions and provides indirect and direct
data on the host pipe condition to assist in decision-making between repair, rehabilitation, and
replacement technologies. Improvements in condition assessment practices may lead to a better
understanding of the host pipe condition and therefore increased confidence in the use of semi- or fully-
structural rehabilitation technologies.
Due to the difficulties associated with inspecting force mains, especially those that cannot easily be taken
out of service for more than a few minutes, little if any inspection is carried out by most utilities. WERF,
in recognizing this growing need for condition assessment, funded a research project to develop
guidelines for inspecting sewer force mains. Originally, the target of the research was on ferrous mains,
which represents over 58% of the force main population, but later it was expanded to cover all possible
force main materials. The recently published report is titled Guidelines for the Inspection of Force Mains
(WERF, 2009) and can be reviewed for detailed information on the SOT for force main inspection and
condition assessment.
Risk-based investigation (RBI) involves consideration of both the likelihood of failure and the
consequence of a failure for a given pipe system. Criticality is often expressed as the product of these two
factors. Assets with a high consequence of failure may warrant further investigation by gathering both
indirect and direct data on the host pipe condition. Indirect data can include factors such as the age of a
pipeline, whether the pipeline has any external corrosion protection or is installed in an environment
considered corrosive, history of previous failures in the main, presence of inoperative air release valves,
operating conditions (pressure, surge, burial depth) versus the pipe's original design rating, and more.
External or internal inspection can also yield direct data on the pipe condition. Inspections might include
either small portions or the entire pipeline being surveyed for signs of deterioration. In the case of a
49
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ferrous main, this can be an internal or external inspection using electromagnetic or ultrasonic tools to
measure the remaining wall thickness. For PCCP, it might include acoustic monitoring to locate active
wire breaks. If the PCCP main can be taken out of service, then an internal electromagnetic survey is
possible where cumulative wire breaks are detected. Many other tools are available for inspecting a
sewer force main (WERF, 2009).
The results of the indirect and direct investigation can then be fed into a mechanistic model to determine
the likelihood of failure. Figure 4-3 is an example of a belief chart for assessing the risk of a structural
failure in PCCP pipe based on indirect evidence. This type of model is pipe material specific with
predictions made of the remaining factor of safety or remaining life of the pipeline. The other aspect to
carrying out a risk assessment and criticality ranking is to evaluate and quantify the consequences of a
failure in a pipeline. Figure 4-4 illustrates a belief network for a PCCP pipe to estimate the consequence
of failure, but would be equally valid for any pipe material.
Often the consequences of a failure can be put in terms of costs. For example, it might be based on the
direct cost to repair a broken pipe and provide temporary service during the repair if needed, the cost to
clean up local flooding or repair adjoining property damaged as a result of a major rupture, and/or indirect
costs associated with the socio-economic impact of a failure. The socio-economic costs can often exceed
the cost expended in the immediate repair of the broken main. This is especially true for sewer force
mains where raw sewerage can cause damage to the environment and adjacent property resulting in
significant clean-up costs.
Sewer force mains that convey a major portion of a municipality's sewage, with no backup or
redundancy, would have a high consequence of failure rating. Here, local knowledge of the system is
extremely important in making these determinations. From the standpoint of what action may be
warranted, certainly pipelines that have a high likelihood for failure combined with significant
consequences associated with such a failure (e.g., a high criticality rating) deserve urgent attention. Plus,
the higher the consequences associated with a failure, the more conservative will be the approach towards
renewal of the main. A partially deteriorated force main that has an extremely high consequence of
failure would be one that would probably be treated as fully deteriorated from the perspective of the
design of the rehabilitation system.
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Predicted Risk of Structural Failure
Figure 4-3. Belief Network for Risk of Failure in PCCP
[ 3rd Party Claims ]
[ Damage claims ]
Figure 4-4. Belief Network for Consequences of Failure in PCCP
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5.0 DESIGN AND QA/QC
This section will review the existing design concepts that pertain to the renewal of a force main. The
design methods currently employed are for either interactive or independent liners and depend upon the
condition of the existing (host) pipe. A complete review of most applicable ASTM standards is included.
These standards are broken down by material type and functionality including product/material, design,
and installation practices. The section also covers the QA/QC aspects of renewal by looking at short-term
factory and field requirements, as well as long-term qualification requirements. The latter are notably
lacking for many products offered for both a pressurized and corrosive environment.
5.1 System Design
5.1.1 Redundancy in System Design. Force mains are often located at critical points in a utility's
sewerage system. They typically carry a large percentage of a utility's untreated wastewater and in a few
cases all of the flow to the wastewater treatment plant is conveyed through force mains. Despite the
critical nature of sewer force mains, less than 5% have any redundancy built into the system (WERF,
2009). The use of redundancy in system design appears to be a more frequent practice in Europe than the
US. If a line is taken out of service due to a failure, by-pass pumping or the use of honey trucks is
necessary. Those that do have a redundant line can use it during a failure to maintain a minimal level of
flow, avoiding overflowing wetwells, and surcharging upstream sewers. The other advantage to having a
redundant line is the ability to take a force main out of service for an extended period of time to allow for
either an intrusive (internal) inspection or for extended repairs or rehabilitation.
With redundancy very limited, most utilities have not been in a position to carry out in-depth inspections
and assessments of their force main systems. Consequently, many utilities in the past have merely reacted
to problems, such as failures, when they occur rather than being proactive in attempting to assess the
force main's in situ condition. Little is known about the condition of sewer force mains in US utilities,
but that is gradually changing, primarily as a result of EPA consent decrees requiring municipalities to
carry out condition assessment of their force mains.
Heretofore, there has been very little rehabilitation of sewer force mains due to lack of redundancy and
the availability of reconstruction products for pressure sewers. The redundancy issue isn't going to
change overnight, although more utilities are considering investing in redundancy with new projects. Any
attempt to rehabilitate a sewer force main, aside from outright replacement while the main remains in
service, is going to either require by-pass pumping or a renovation technology that can be installed very
quickly during a limited outage. The latter doesn't exist at the moment so by-pass pumping is the norm.
As a result of vendor success in the gravity field with CIPP and reformable thermoplastic pipe products,
adaptations of these products are now starting to find their way into the pressure sewer field.
5.1.2 Pig Launchers/Retrieval for Cleaning and Inspection. Like redundancy, pig launchers and
retrieval systems are not commonly designed into sewer force mains. Some utilities, like St. Petersburg,
FL, have installed pig launchers and retrievals on most of their sewer force mains and use them on a
regularly scheduled basis to clean each main. Keeping the mains clean maintains capacity and reduces
pumping (energy) requirements.
It is only within the past few years that some leak detection tools have become available to allow for
limited assessment of a force main with little interruption in service. These tools can be introduced into
the flow stream and are either tethered (Sahara®) or free swimming (SmartBall®) and will locate leaks and
gas pockets in a force main. These tools can be launched through 2 inches (50 mm) (Sahara®) or 4 inches
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(100 mm) taps (SmartBall®) in a force main and do not require sophisticated launchers and retrievers.
The minimum pipe diameters for these leak locators are 12 inches (300 mm).
Researchers are also working on perfecting smart pigs that can be used in a live force main. The oil and
gas industry have relied upon intelligent pigs for many years to assess the condition of their transmission
mains. These smart pigs utilize ultrasonic or electromagnetic technology to measure the remaining wall
thickness and find pitting or areas of graphitization in a ferrous pipe. Adaptations for use in a force main
include the use of gas or liquid coupling for ultrasonic transducers. Pigs based on magnetic flux leakage
(MFL) are heavy, but newer pigs based on remote field (See Snake) and eddy current (broadband
electromagnetic [BEM]) technology are finding use in the water and wastewater industry. The See Snake
can be used in a live force main, while the BEM has a limitation on the pressure head.
Acoustic emission monitoring of PCCP to locate active wire breaks is a technology that is now well
employed. Acoustic monitoring does not require launchers or retrievers. Early technology deployed a
string of hydrophones into the flow stream, but that has largely been replaced with the use of externally
mounted accelerometers. The accelerometers are mounted directly on an air release valve or the mortar
coating of the PCCP.
5.2 Renewal Design
The design of a rehabilitation product to renew the life of a distressed sewer force main range from just an
inner corrosion barrier or entail outright structural replacement. Obviously, the factors that will control
the design are the condition of the existing main, including its expected remaining life if further
deterioration is arrested, and the operating conditions under which that main is used. Mains that are
currently operating at full capacity, or are expected to be so in the near term, are not good candidates for
placing a thick liner or sliplining with a smaller diameter pipe, as these will further reduce capacity.
Certainly, some of the newer liners and sliplining pipes have very favorable flow characteristics (i.e., low
friction factors), but that is not always sufficient to make up for the reduced cross-sectional area available
to the flow. If a loss of capacity cannot be tolerated, then the most viable renewal strategy is going to be
replacement.
5.2.1 Degrees of Deterioration. Assuming that some minor loss of flow capacity is acceptable,
then the first thing a designer has to consider is the condition of the force main. The ASTM standards of
practice for reconstruction products have categorized the condition of existing pipes into either partially
deteriorated or fully deteriorated conditions. These conditions are defined as follows (adapted from
ASTMF1216):
• Partially deteriorated - Existing pipe can support the soil and surcharge loads throughout the
design life of the rehabilitated pipe. The pipe may have longitudinal cracks and up to 10%
distortion of the diameter.
• Fully deteriorated - Existing pipe is not structurally sound and cannot support soil and live
loads or is expected to reach this condition over the design life of the rehabilitated pipe. This
condition is evident when sections of the pipe are missing, the pipe has lost its original shape,
or the pipe has corroded.
What is apparent from these definitions is they are more relevant to gravity sewers than to pressurized
mains. There is no consideration given to the existing pipe's ability to safely carry the internal working
pressure or surge pressure. If a ferrous pipe has lost 40% of its wall thickness and is still handling the
internal working pressure with reasonable factors of safety on hoop tensile stress, is this a partially
deteriorated or fully deteriorated pipe? Or, what about a ferrous pipe that has lost 80% of its wall
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thickness? It can still support the overburden soil and live loads, yet does not have an acceptable factor of
safety on pressure. According to the ASTM F1216 definition, this is a partially deteriorated pipe, while
most engineers might claim fully deteriorated based on its pressure capability.
The ASTM standards for new products coming into the market place designed to reconstruct pressurized
mains need to be modified to reflect a better understanding on what constitutes the various degrees of
deterioration that a pressurized main can undergo without failure. This will be important for sewer force
main renewal, as well as water main renewal.
5.2.2 Interactive vs. Independent. Liners for sewer force main renewal fall into two categories:
interactive or independent. Interactive liners are generally thin liners, in direct contact with the inside
wall of the existing pipe, and which have a much lower ring tensile stiffness than the existing pipe. When
pressurized, the existing pipe with the higher hoop stiffness will carry a proportionately higher percentage
of the tensile ring load. Consequently, interactive liners should not be used in sewer force mains where
the existing pipe has deteriorated to a point where it is not expected to be able to carry the full internal
pressure over the renewal design life. Examples of this might be a ferrous main that has suffered
extensive external corrosion with no protection, and has through-hole pitting over a significant portion of
the system. Placing a liner on the interior will arrest any internal corrosion and can be designed to bridge
over small holes and gaps, but will do nothing to stop any further external corrosion, which will
eventually lead to failure. In this case, the independent liner would be preferred.
An independent liner is one that is designed to carry the full internal working pressure and surge pressure
itself independent of any contribution from the host pipe. Slipliners are, by design, independent liners as
they are not in direct contact with the existing pipe (unless grouted in place) and will expand
circumferentially under pressure, but not transfer hoop load to the existing pipe. Some liner products start
off as interactive, as they will be close-fit, but have sufficient inherent strength to carry the full internal
pressure should the host pipe fail. These would then be considered independent liners.
The AWWA M28 Manual Rehabilitation of Water Mains has established four classes of design for
rehabilitation, ranging from non-structural to fully structural (AWWA, 2001). These definitions or
classes are more relevant to the design of sewer force mains than those found in the current ASTM
standards. The four classes are described below:
Non-Structural
• Class I - provides no structural support, only acts as an internal corrosion barrier and
improves water quality.
Semi-Structural
• Class II - resists external hydrostatic pressure from groundwater, bridges over holes and gaps
in the host pipe, but not able to carry the full internal pressure independently, adheres to the
interior surface of the host pipe.
• Class III - same as II except not dependent on adherence to the host pipe wall.
Full Structural
• Class IV - independently capable of resisting external hydrostatic pressure from
groundwater, and can handle the full internal pressure without support from the host pipe.
5.2.3 Design Loads. Depending on the state of deterioration of the existing main, the renewal liner
can be designed to be either a corrosion barrier or an outright pipe replacement. Some of the loads that
must be considered depend on the state of distress in the existing pipe, and include:
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External Loads
• Soil Cover (trench or embankment)
• Surcharge
• Live Load (e.g., HS-20 wheel load - dual wheel load of 16,000 Ib uniformly distributed over
a surface area of 10 inches x 20 inches (250 mm x 500 mm) as recommended by the
American Association of State Highway and Transportation Officials [AASHTO] and Cooper
E-80 rail load - axle load of 80,000 Ib on 5 feet (1.5 meters) centers as recommended by the
American Railway Engineering Association [AREA])
• External hydrostatic head from groundwater (only a factor when the main is not under
internal pressure)
Internal Loads
• Working Pressure
• Surge Pressure
• Test Pressure
Other factors that also enter into the design are corrosion, temperature, fatigue and erosion/abrasion
considerations. High points in a sewer force main are potential pockets for gas accumulation, especially
if air release valves are inoperative. These tend to be areas where microbiological corrosion, due to the
bacterial formation of sulfuric acid (H2SO4), takes place. Any new liner must be resistant to these effects.
The pressure rating of most thermoplastics and reinforced thermosetting resin pipes are based on long-
term pressure regression testing at ambient temperature. Similar testing at higher temperature has shown
that derating of the pressure class is necessary. The AWWA standards for PVC and PE pressure pipes
contain derating tables for continuous operations at elevated temperatures of about 73.8°F. In the case of
glass-reinforced thermosetting pipe, one needs to contact each individual manufacturer for their derating
recommendations. One would expect that the thermoplastic and thermosetting resin liners offered for
rehabilitation would be no different than their pipe cousins.
Due to the presence of solids, force mains are far more abrasive environments than potable water mains.
It has been reported that some force mains with concrete liners (PCCP and asbestos-cement) have had a
channel eroded down the invert (King County, Tel Aviv, Israel). At low velocities of approximately 1.5
feet (0.46 meters) per second or less, large solids tend to tumble along the invert of the pipe until they are
broken up into smaller particles that can be suspended in the waste stream. The erosion appears more
prevalent at the beginning of the force main and gradually tapers off over a long run. There has also been
a report on a steel force main with a bitumastic liner that has lost nearly all of the liner and up to 70% of
the pipe wall in the bottom one-third of the pipe from the abrasive effects of the effluent (Regina, SK in
Canada). Therefore, the design of a renewal liner for a sewer force main must take the potential for
erosion into consideration. Fortunately, the newer materials used for lining sewers generally have good
abrasion resistance. Polyethylene has been shown to have excellent abrasion resistance in tests conducted
at Darnstad University in Germany.
It has been documented that the long-term performance of PVC can be limited by its fatigue resistance to
cyclic pressure loading. This first surfaced on irrigation distribution systems where the buried PVC
distribution piping was subjected to very frequent cyclic loading from valve operations. Pumped sewer
force mains are similar as lift station pump(s) are constantly cycling in and out as the sewage level in the
wetwell triggers the starting and stopping of the pumps. The Unibell PVC Pipe Association has published
a design guideline for the use of PVC pipe in sewer force mains. This guideline provides
recommendations on maximum pressure ratings based on the number of pressure cycles expected in the
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pipe's design life. Once again, it would be reasonable to expect that any renewal liner using PVC
material would be affected similarly by cyclic loading and should be designed accordingly.
5.2.4 Other Considerations. Force mains do not have frequent service connections as in a water
main, but nonetheless there are usually pressurized connections to other incoming or outgoing mains, air
release valves at high points, and other inline fittings (valves, elbows, etc.). The protocol with practically
all force main rehabilitation systems, except independent slipliners, is to terminate the liner with a special
mechanical fitting that seals the end of the liner with the existing host pipe, and then incorporate a ductile
or CI fitting for the connection to the fitting or valve. Slipliners, such as full thickness PE and PVC pipes,
can be re-connected in the same manner as ordinary pipe made of these same materials. Electrofused
fittings for PE and DI fittings for PVC are common.
Another important design consideration in a renewal project is the intended design life of the rehabilitated
system. The renewal can be a fully structural replacement for the existing pipe, in which case a design
life of 50 years is desired. Or, the renewal may only be a corrosion barrier (Class I) or a close-fit semi-
structural liner (Class II or III) with a design life dependent on the continued structural performance of the
existing pipe. If the existing pipe is incapable of handling the internal pressure due to external corrosion,
then the design life of the renewal liner is going to be limited to that of the existing pipe. As reported in a
recent report (WERF, 2009), the majority of sewer force mains are under 25 years of age with few over
50 years, which is quite different from the age distribution of the nation's water distribution system.
Consequently, it is reasonable to expect that any renewal liner should be able to extend the design life of a
sewer force main for at least another 25 years.
5.3 Product/Material Standards
The two main national organizations within the US that undertake development of consensus standards
covering materials, products, testing methods and installation methodologies are ASTM and the AWWA.
These bodies provide a forum for producers, users, and those having a general interest (e.g., government,
academia) to write standards that best meet their needs. Representatives from each interested field are
involved in the standards process, but the producer community normally takes a leading role. AWWA
standards are solely dedicated to the water industry. Some products or linings that are used in the water
industry may also have a place on the wastewater side. Epoxy linings are a good example of dual
potential use. The National Association of Sewer Service Companies (NASSCO) has also developed
some excellent guideline specifications and manuals of practice. Producer companies are solely involved
in the NASSCO specifications so the user community's interests may not be fully appreciated.
The body of standards can be broken down into four areas - product/material standards, design standards,
and installation standards, and manual of practices. Some of the standards serve more than one purpose.
The purpose of this report is not to provide a detailed review of each pertinent standard, but rather to
highlight some of the more important standards and especially those that are relatively new within the
past 5 years and may have a use for sewer force main renewal.
ASTM Product/Material Standards
This section summarizes product/material standards by pipe type including those defined for PVC, PE,
CIPP, and FRP/GRP materials.
PVC Materials
The following ASTM standards in Table 5-1 cover PVC materials used for renewal.
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Table 5-1. ASTM Material Standards for PVC Pipe
Specification No. Title Application
ASTM F 1504
ASTM F 1871
ASTMD2241
Standard Specification for Folded Polyvinyl Chloride
(PVC) Pipe for Existing Sewer and Conduit
Rehabilitation
Standard Specification for Folded/Formed Polyvinyl
Chloride Pipe Type A for Existing Sewer and Conduit
Rehabilitation
Standard Specification for Polyvinyl Chloride (PVC)
Pressure-Rated Pipe (SDR Series)
4-15 inch folded PVC for non-
pressure sewers
4-18 inch folded PVC for non-
pressure sewers
Pressure rated PVC pipe
ASTM F1504
This product standard is nearly identical to ASTM F1871, except that the minimum flexural modulus is
280,000 psi (19,310 bar) (PS-1, cell 13223-B). With the higher flexural modulus, pipe stiffness values
are also higher for the same DR ratio. Pipe stiffness (a measure of the flexural stiffness of the pipe ring in
resisting vertical load) ranges from 10 psi (0.7 bar) for DR 50 (PS-1) to 41 psi (2.8 bar) for DR 35 (PS-3).
Diameters covered range from 4 to 15 inches (100 to 375 mm), with starting DR range of 35 to 50. The
final DR will depend on the amount of expansion (or contraction) induced in the PVC liner as it conforms
to the host pipe. Typical QC test requirements include diameter and thickness dimensional checks, pipe
flattening, impact resistance, pipe stiffness, flexural properties and acetone immersion, and heat reversion
for extrusion quality.
ASTM F1871
Diameters covered range from 4 to 18 inches (100 to 450 mm), with a DR range of 26 to 41. Pipe
stiffness (which is dependent on the flexural modulus and DR ratio) ranges from a high of 41 psi (2.8 bar)
for DR 26 to 11 psi (0.76 bar) for DR 41. The "A" in Type A is an arbitrary designation of PVC
compounds with a minimum modulus of tension of 155,000 psi (10,670 bar) and a maximum of 280,000
psi (19,310 bar). The minimum tensile strength is 3,600 psi (248 bar) and flexural modulus 145,000 psi
(10,000 bar). Although this specification states the application is for non-pressure sewers, pipe meeting
this specification could be used in a low pressure sewer force main.
ASTMD2241
This standard covers PVC pipe made in standard thermoplastic pipe DRs and pressure rated for water.
PVC pipes meeting this specification would be suitable for inline replacement of an existing sewer force
main by the sliplining method.
Polyethylene Materials
The following ASTM standards in Table 5-2 cover PE materials used for renewal.
Table 5-2. ASTM Material Standards for PE Pipes
Specification No. Title Application
ASTMF1533
ASTMD2239
ASTMD3035
Standard Specification for Deformed Polyethylene (PE)
Liner
Standard Specification for Polyethylene (PE) Plastic Pipe
(SIDR-PR) Based on Controlled Inside Diameter
Standard Specification for Polyethylene (PE) Plastic Pipe
(DR-PR) Based on Controlled Outside Diameter
3-18 inch deformed PE liner for
non-pressure
Pressure rated PE pipe based on
ID
Pressure rated PE pipe based on
OD
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ASTMF1533
The renewal process involves installing a deformed PE liner into an existing pipeline and then reforming
the liner with heat and pressure to fit tightly to the bore of the original pipeline. PE pipe used for a liner
under this specification shall be PE 2406 or PE 3408 (ASTM D3350), with a Plastic Pipe Institute (PPI)
recommended HDB of 1,250 or 1,600 psi (86 or 110 bar), respectively. Nominal pipe diameters range
from 3 to 18 inches (75 to 450 mm), with a DR range of 17 to 32.5. Other non-standard sizes are also
covered providing the materials meet the minimum requirements in this standard. Typical QC test
requirements include outside diameter and wall thickness checks, tensile strength, tensile elongation, and
flexural modulus. Environmental stress crack resistance (ESCR) is a qualification test, with level 3 of
ASTM D3350 as a minimum.
ASTM D2239 or ASTM D3035
Pipe meeting these standards would be suitable for inline replacement of a sewer force main by the
sliplining method, providing the reduction in flow capacity can be accommodated.
CIPP Materials
The following ASTM standards in Table 5-3 cover CIPP materials used for renewal.
Specification No.
ASTMD5813
Table 5-3. ASTM Material Standards for CIPP
Standard Specification for Cured-In-Place
Thermosetting Resin Sewer Pipe
Application
4-132 inch CIPP used in gravity
systems
ASTMD5813
Three types and two grades of CIPP liners are described in this standard. The type of liners range from
those designed to only provide chemical resistance and prevent exfiltration (Class I) to those designed for
use in either a partially deteriorated (Class II) or a fully deteriorated pipe (Class III). The grades are
distinguished by whether the tube is impregnated with polyester resin (Grade 1) or an epoxy resin (Grade
2). ASTM D5813 also has two chemical resistance requirements. The one requirement stipulates that
samples shall be capable of exposure for one year to five different chemical solutions (1% nitric acid, 5%
sulfuric acid, 100% ASTM Fuel C, 100% vegetable oil, 0.1% detergent, and 0.1% soap) and still retain
80% of their flexural modulus. The other requirement is similar to that imposed on glass-reinforced
thermosetting plastic pipes (ASTM D3262 or ASTM D3754) and is commonly referred to as strain
corrosion. For this requirement, samples must be capable of being deflected to meet certain strain
requirements (see Table 2 of D5813) over specific time periods of up to 10,000 hours, while exposed to
1.0 N sulfuric acid (i.e., 5%).
Glass-Reinforced Plastic
The following ASTM standard in Table 5-4 covers FRP/GRP materials used for renewal. ASTM D3754
combines the pressure requirements of ASTM D3517 Fiberglass Pressure Pipe with the chemical
resistance (strain corrosion) requirements of ASTM D3262 Fiberglass Sewer Pipe.
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Table 5-4. ASTM Standards for FRP/GRP
Specification
No.
ASTM D3754
Application
Standard Specification for Fiberglass ... Sewer and
Industrial Pressure Pipe
8-144 inch GRP pressure pipe for
force mains, pressures up to 250 psi
5.4
Design Standards
This section reviews design standards for PVC (Table 5-5), PE (Table 5-6), FRP/GRP (Table 5-7), and
CIPP (Table 5-8) systems.
Table 5-5. Design Standards for PVC Materials
Specification
No. Title Application
ASTM F 1867
ASTM F 1947
AWWA M23
Standard Practice for Installation of Folded/Formed
Polyvinyl Chloride (PVC) Pipe Type A for Existing Sewer
and Conduit Rehabilitation
Standard Practice for Installation of Folded Polyvinyl
Chloride (PVC) Pipe into Existing Sewers and Conduits
PVC Pipe - Design and Installation
Design appendix same as F 1216.
Design appendix same as F 1216
for gravity.
Working pressure rating; buried
pressure pipe design
ASTMF1867
This standard contains a non-mandatory design appendix for the use of formed PVC in either a partially
deteriorated or fully deteriorated pipe. The design method is the same as in ASTM F1216 for CIPP
products. In the case of a partially deteriorated pipe, where the existing pipe is expected to carry any soil
or live load, the formed pipe is designed to resist buckling from external hydrostatic pressure due to
groundwater or internal vacuum. In the case of fully deteriorated pipe, the formed PVC is designed to
resist buckling from soil, live load, and any external hydrostatic pressure.
ASTM F1947
This standard describes the rehabilitation procedures of sewer liner by the insertion of a folded PVC pipe
and has a design appendix (non-mandatory) that is the same as Appendix XI in ASTM F1216 for gravity
pipe. No design equations are offered for pressure applications.
AWWA M23
The AWWA manual on PVC pipe design provides information on the general properties of PVC
materials and manufacturing methods. The long-term pressure capacity of PVC pipe is defined, along
with recommended factors of safety. The design of PVC pipe for external loads is primarily focused on
limiting vertical deflection. Longitudinal bending, which might be important for HDD applications, is
also covered by this manual.
Specification
No.
ASTM F1606
Table 5-6. Design Standards for Polyethylene Materials
Standard Practice for Rehabilitation of Existing Sewers
and Conduits with Deformed Polyethylene (PE) Liner
Application
Includes a design appendix for
non-pressure applications.
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AWWA M55
PE Pipe - Design and Installation
Working pressure ratings; buried
pipe pressure design, sliplining
guidelines
ASTMF1606
This standard also contains a non-mandatory design appendix. As the practice is only intended to cover
gravity installations, the liner is designed to resist buckling from hydrostatic groundwater pressure in the
case of a partially deteriorated host pipe or hydraulic, soil, and live load in the case of a fully deteriorated
host pipe. Unlike the standard practices for deformed PVC pipe, the design formula for the partially
deteriorated condition does not include an "enhancement factor" (K) to reflect the confinement
contribution of the host pipe to the liner's buckling resistance. However, there is a note included that
does introduce the enhancement factor to the modified Timoshenko formula.
AWWA M55
The AWWA manual on PE pipe design is very comprehensive, similar to the PVC pipe manual. Perhaps
the most important section in the manual deals with the determination of the working pressure rating of
PE based on the hydrostatic design basis. Surge calculations and allowance are also covered by the
manual. The manual also provides guidance on the installation of PE pipe taking into consideration its
thermal specific weight properties, which can be important in a sliplining application.
Table 5-7. Design Standards for Glass-Reinforced Thermosetting Plastic Pipe
Specification
No.
AWWA M45
Fiberglass Pipe - Pressure Pipe Design
Application
Most comprehensive design
approach, covers direct buried
FRP/GRP pipe
AWWA M45
AWWA M45 offers a comprehensive design method for the use of glass-reinforced plastic (i.e.,
Fiberglass) pipe in a pressurized system. The design is suited for buried pipe and takes account of the
interaction of external loads and internal pressure on FRP/GRP pipe's long-term performance.
Calculations include pipe deflection to limit bending strain and buckling. Many of the design principles
can be used for a sliplining application, especially if the FRP/GRP pipe is to be a fully structural solution.
Table 5-8. ASTM Design Standards for CIPP Materials
Specification
No.
ASTMF1216
Application
Standard Practice for Rehabilitation of Existing Pipelines
and Conduits by the Inversion and Curing of a Resin-
Impregnated Tube
Appendix XI most frequently
used for renewal products.
Covers pressure.
ASTMF1743
Standard Practice for Rehabilitation of Existing Pipelines
and Conduits by Pulled-in-Place Installation ofCured-in-
Place Thermosetting Resin Pipe (CIPP)
Refers to F1216, Appendix XI
for design
ASTMF2019
Standard Practice for Rehabilitation of Existing Pipelines
and Conduits by the Pulled in Place Installation of Glass
Reinforced Plastic (GRP) Cured-in-Place Thermosetting
Resin Pipe (CIPP)
Refers to F1216, Appendix XI
for design
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It was reported at the EPA-sponsored International Forum on Rehabilitation in Edison, NJ in September
2008 that a new hydrostatic buckling model, with imperfections quantified, is being prepared for ASTM
F1216. ASTM F 12 16 is described below.
5.4.1 Design of Pressure Systems. As outlined above, deteriorated pipelines are classified as
either partially or fully deteriorated based on their ability to continue to resist internal pressure and
external load. A partially deteriorated pressure pipe would have some evidence of pinhole leaks or
leaking joints, but would be capable of withstanding the internal operating pressure and any external loads
(soil, live, and hydrostatic groundwater). In this case, the renewal liner is designed to be a close-fit to the
existing pipe and the hoop tensile stresses are carried by the host pipe. However, the liner is designed to
support any external hydrostatic pressure (only a factor when the line is not under pressure) and to be able
to span over any holes or gaps in the host pipe.
A fully deteriorated pressure pipe is one with large holes or gaps (most probably caused by severe internal
or external corrosion) and is unable to withstand the operating pressure of the system. A partially
deteriorated pipe, which is expected to continue to corrode and deteriorate over its remaining design life,
would also be considered a fully deteriorated pressure pipe in terms of the design of a renewal liner. Here
the renewal liner needs to be designed to carry not only the full internal pressure, but also any external
loads, including soil, live, and hydrostatic groundwater. In essence, the liner is a replacement for the
existing pipe.
As is clear from the introduction to this section, Appendix XI in ASTM F 12 16 is the most commonly
accepted design method for CIPP and deformed/reformed thermoplastic pipes. It is interesting to note
that the design appendix in ASTM F1216 is not mandatory, so in theory there is no obligation to use this
design method when using CIPP products.
5. 4. 1. 1 Partially Deteriorated Case. In the case of a partially deteriorated pipe, two basic equations
are used in the design. The hydrostatic buckling resistance of the liner is calculated by the following
formula:
where:
P = groundwater load, psi
K = enhancement factor of the soil and existing pipe adjacent to the new pipe (a
minimum value of 7 is recommended for design)
EL = long-term (time corrected) flexural modulus of elasticity for the liner, psi
(i = Poisson's ratio (0.3 assumed)
DR = dimension ratio (diameter/thickness) (D/t)
C = ovality reduction factor
N = factor of safety (2.0 is suggested)
The above equation is patterned after the classic Timoshenko elastic buckling formula for an infinitely
long cylinder subjected to uniform external hydrostatic pressure. Modifications include the addition of
the "enhancement factor" K and the ovality reduction factor. The enhancement factor is based mainly on
hydrostatic buckling experiments published by Aggarwal and Cooper (1984) where buckling
enhancement from the existing host pipe could range from 5 to 20 times greater than the free-standing
liner. The ovality factor compensates for ovoid pipes and conservatively reduces the liner's resistance
(refer to ASTM F 12 16 for the equation for C).
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Most of the controversy over the application of the above formula stems from one's interpretation of the
time corrected value for the modulus of elasticity, EL. The note to Appendix X 1.1 in ASTM F1216 states
that the choice of value depends on the estimated duration of the application of the load (P) in relation to
the design life of the structure (and should be obtained from the manufacturer's literature). If the total
duration of the load is estimated to be 50 years, either continuously or over the sum of intermittent
periods, then the appropriate choice for EL will be that given for 50 years of continuous loading.
However, no method of test for determining the long-term modulus, EL, is referenced in ASTM F1216 or
any of the product standards. Therefore, the method of determination could vary considerably depending
on the method employed by the manufacturer. A flexural creep test under constant load would be one
way of arriving at a value, but the value here will also be dependent on the load. The ISO standards for
GRP pipe do contain requirements for the manufacturers to carry out long-term flexural creep or
relaxation tests, and then to report the results for design purposes. The creep and relaxation tests
specified have been set up to yield similar results independent of the method chosen. It would seem
logical that the CIPP industry should consider adopting a similar methodology for their liner materials
given that they too are composites made from the same resins (polyesters, vinyl-esters and epoxies). As
this long-term property is key in the design of all gravity CIPP and deformed/reformed thermoplastic
pipes, a great deal of development effort is exerted by renewal liner manufacturers to enhance this value.
The addition of glass fiber is one example of such enhancement.
The other criteria that must be met in a liner for a partially deteriorated host pipe is to bridge over any
holes or gaps. Here, depending on the ratio of the hole diameter to pipe diameter, the liner is assumed to
behave like a circular flat plate with fixed edges covering an open hole and subjected to transverse
pressure only. This condition applies when the following equation is satisfied:
- < l.S3f-f/2
D ^'DJ
where:
d = diameter of the hole or opening, inch
D = mean inside diameter of the original pipe, inches
t = thickness of CIPP liner, inches
When this condition applies, the liner acts as a flat plate in bending to span the hole and the following
formula applies:
where:
OL = long-term (time corrected) flexural strength for CIPP, psi
A similar note is included for the selection of OL as EL, namely choosing a value that is consistent with the
load duration. Assuming that a 50-year design life is expected from the liner, then a value for the long-
term flexural strength of the liner material under constant load for 50 years is needed. As in the case of
EL, no test method is stipulated. This is another example where the CIPP liner industry could take a page
out of the GRP pipe handbook and adopt one of their test methods. The ISO standard for GRP pipe
includes a test method for determining the long-term ring bending strength of a composite ring subjected
to constant loading in an aqueous environment.
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The above equations have been primarily developed for use with CIPP products, while the
deformed/reformed thermoplastic products have also adopted them. As there are few if any design
guidelines for spray-on coatings, the TTC has been carrying out some tests on spray coatings for the
rehabilitation of pressurized pipelines. The main purpose of the testing is to generate an empirical design
equation to determine the needed thickness of a polyurethane lining given an internal operating pressure
and size of damage zone. To do this, an experimental program has been conducted that consists of testing
panels of a spray-on polyurethane coating, which are clamped into a test frame and subjected to uniform
pressure on one side of the frame with the other side open to atmosphere. The openings in the test frame
have been 3 and 4.5 inches (75 and 113 mm) in diameter. In addition to monitoring the pressure at which
the test panels fail, the amount of deformation or bulge of the test panel was also measured and compared
to analytical and finite element analysis model predictions. At the time of writing this report, the TTC is
in the process of expanding the testing to other spray-on coatings (polyurea) with the intention to develop
a generalized equation that incorporates key mechanical properties of the coating materials. With new
structural spray-on lining systems entering the US market, this work will be very welcomed.
5.4.1.2 Fully Deteriorated Case. In the fully deteriorated case, the liner is designed to resist without
buckling all of the external loads, including groundwater, soil, negative internal pressure (vacuum), and
live loads. The equation offered in ASTM F1216 has been borrowed from the AWWA design manual for
Fiberglass Pressure Pipe, M45. The equation takes into consideration the soil support offered to the
original host pipe and the liner:
where:
qt = total external pressure on pipe (including negative internal pressure), psi
Rw = water buoyancy factor (0.67 min. - see F1216 for equation)
B' = coefficient of elastic support (see F1216 for equation)
I = moment of inertia = t3/12, in4/in
D = mean inside diameter of the original pipe, inches
C = ovality reduction factor
N = factor of safety
E's = modulus of soil reaction, psi
EI = long-term modulus of elasticity, psi
Values for the modulus of soil reaction may be found in ASTM D3839.
As the liner pipe must be capable of supporting the full internal pressure without support from the original
pipe, the required design thickness may be calculated from the following formula which relates the hoop
tensile stress in a thin ring to the internal pressure:
p _ I
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up to each individual manufacturer. Both the fiberglass and thermoplastic pipe industries have
established standardized methods for obtaining the HDB of their products. The HDB is a material
property and is obtained by evaluating stress (strain) rupture data derived from testing pipe at various
stress (strain) levels over extended periods of time with at least one data point beyond 10,000 hours. A
similar approach by the CIPP industry for pressure applications in fully deteriorated conditions would
standardize the design parameters used.
5.5
Installation Standards
The following section reviews the ASTM installation standards for PVC (Table 5-9), FRP/GRP (Table 5-
10), PE (Table 5-ll),and CIPP (Table 5-12) materials.
Specification No.
ASTM F1867
Table 5-9. ASTM Installation Standards for PVC Materials
Standard Practice for Installation of Folded/Formed Poly
(Vinyl Chloride) (PVC) Pipe Type A for Existing Sewer
and Conduit Rehabilitation
Application
Winching of folded PVC Type A
with heating and expansion by
pressure
ASTM F1947
Standard Practice for Installation of Folded Poly (Vinyl
Chloride) (PVC) Pipe into Existing Sewers and Conduits
Similar to F1867. Diameters 4-
15 inch covered.
ASTMF1867
This standard covers the procedures for installing a pipe meeting ASTM F1871. Flow stoppage or by-
pass pumping is required for the insertion. All protrusions greater than 12.5% of the inside diameter
should be removed. Changes in pipe sizes can be accommodated providing the liner thickness is designed
for the expansion. The liner can be pulled through bends up to 30°. The liner pipe (may be pre-heated to
180°F) is winched through the existing pipe. Pulling force should be limited to 50% of yield at 212°F.
Using heat (steam) and pressure (typically 3 to 5 psi [0.2 to 0.33 bar]), the liner is expanded beyond
extrusion memory to contact the wall of existing pipe. Dimples are formed at service connections. After
expansion, the pipe liner is cooled to 100°F before relieving the pressure. In addition to CCTV inspection
and leak tightness testing, field samples are prepared by expanding the folded PVC inside a mold pipe of
the same diameter of the existing pipe and a minimum of one diameter in length. Dimensional checks
(diameter, wall thickness) and flexural and tensile properties are measured on the field sample.
ASTM F1947
This standard covers the procedures for installing a folded PVC pipe meeting ASTM F1504. This
standard is similar to ASTM F1867. An optional elastomeric containment tube may be used to protect the
folded pipe during installation and to act as a waterproof barrier against infiltration and for containment of
the steam. Expansion pressures are in the range of 8 to 10 psi (0.55 to 0.70 bar). Pipe diameters covered
are 4 to 15 inches (100 to 375 mm). The inspection and acceptance requirements differ from ASTM
F1867 in that no tensile properties of the formed pipe are checked, only the flexural modulus. The
minimum flexural modulus is 280,000 psi (1931 bar) (cell classification 13223 per ASTM D1784).
Table 5-10. ASTM Installation Standards for FRP/GRP Materials
Specification No.
ASTMD3839
Underground Installation of Flexible
Reinforced Thermo setting Resin
Pipe and Reinforced Plastic Mortar
Pipe
Application
Direct burial, not suitable for
sliplining or microtunneling
applications
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ASTMD3839
This standard provides procedures for the installation of fiberglass pipes in typical soil conditions. Pipes
with diameters up to 144-inches (3,657 mm) and pipe stiffness from 9 to over 72 psi (0.62 to over 5 bar)
can be installed following the guidelines embedded in this practice. Soils are classified into stiffness
classes and corresponding compaction levels recommended to achieve a minimum passive soil modulus
(E') of 1,000 psi (70 bar). Situations for handling running soils and trench supports are included. This
standard is only applicable for direct buried pipes.
Table 5-11. ASTM Installation Standards for Polyethylene Materials
Specification No.
ASTM F1606
Standard Practice for Rehabilitation of Existing Sewers
and Conduits with Deformed Polyethylene (PE) Liner
Application
Covers installation of deformed
PE liner meeting ASTM F1533.
ASTM F1606
After cleaning and inspection of the existing pipe, the deformed PE pipe is pulled directly through the
insertion point to the termination point. The pulling force should not exceed the axial strain limits of the
deformed pipe, which is accomplished by limiting the pulling force to a tensile stress of 1,500 psi (103
bar) or 50% of the yield. The steam temperature for reforming is to be between 235°F and 260°F, with
pressure starting at 29.2 psi (2 bar) and rising to 40.7 psi (2.8 bar). The reformed pipe is cooled to 100°F
with the internal pressure increased to 47.7 psi (3.3 bar), while the liner is cooled to ambient temperature.
Acceptance testing includes dimensional checks of the outside diameter and installed wall thickness,
along with flexural and tensile properties of a reformed field sample prepared at the insertion or
termination point. CCTV inspection is also recommended.
Table 5-12. ASTM Installation Standards for CIPP Materials
Specification No.
ASTMF1216
Standard Practice for Rehabilitation of Existing Pipelines
and Conduits by the Inversion and Curing of a Resin-
Impregnated Tube Rehabilitation
Application
Covers 4-96 inch CIPP inversion
insertion and hot water or steam
cure.
ASTMF1743
Standard Practice for Rehabilitation of Existing Pipelines
and Conduits by Pulled-in-Place Installation ofCured-in-
Place Thermosetting Resin Pipe (CIPP)
Covers 4-96 inch CIPP pulled in
place insertion, inflation with
calibration hose, and hot water or
steam cure.
ASTMF2019
Standard Practice for Rehabilitation of Existing Pipelines
and Conduits by the Pulled-in-Place Installation of Glass
Reinforced Plastic (GRP) Cured-in-Place Thermosetting
Resin Pipe (CIPP)
Covers 4-48 inch CIPP pulled in
place insertion, air inflation and
steam or UV light cure.
ASTMF1216
This reconstruction process can be used in gravity and pressure applications. The CIPP product is
expected to have the minimum structural properties in Table 5-13. As part of the inspection and
acceptance process, F1216 requires that two samples be prepared fortesting, one taken from an
intermediate manhole or at a termination point that has been inverted through a like diameter pipe with a
suitable heat sink, and the second fabricated from material from the tube and the resin/catalyst system and
cured in a clamped mold. Physical property testing includes short-term flexural and tensile properties.
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For pressure applications, a hydrostatic pressure test is suggested for twice the working pressure or
working pressure plus 50 psi (3.5 bar), whichever is less. The allowable leakage rate over the one-hour
test is 20 gallon/inch diameter/mile/day.
Table 5-13. Minimum Structural Properties of CIPP Products by ASTM F1216
Minimum Value
Property Test Method psi
Flexural Strength
Flexural Modulus
Tensile Strength
(pressure pipe only)
D790
D790
D638
4,500
250,000
3,000
ASTM F1743
This process may be used in a variety of gravity and pressure applications. CIPP products conforming to
ASTM D5813 would be installed following this standard practice. An outer impermeable plastic coating
may optionally be perforated to allow resin to be forced through and out against the existing pipe wall
during the calibration with pressure. The minimum initial physical properties of the CIPP product are
presented in Table 5-14. This practice also contains a chemical resistance requirement. On a
qualification basis, the cured resin/fabric tube matrix must retain 80% of its flexural modulus after one
year exposure at 73.4°F to five different reagents. The exposure is not under a strained condition.
Recommended inspection practices includes obtaining at least three, and preferably five, samples of the
CIPP taken at either intermediate manholes, or termination points, or fabricated from material placed and
cured in a clamped mold. In addition to testing for the flexural properties, for pressure applications,
tensile testing is also required. If the CIPP is fiber reinforced with oriented or discontinuous fibers, then
tensile testing in both the axial and circumferential direction is recommended. Pressure pipes should be
subjected to a hydrostatic pressure test of twice the working pressure, or working pressure plus 50 psi (3.5
bar), whichever is less. If required by the purchaser, a delamination test in accordance to D903 is also to
be made.
Table 5-14. Minimum Structural Properties of CIPP Products by ASTM F1743
Minimum Value
Property Test Method psi
Flexural Strength
Flexural Modulus
Tensile Strength
(pressure pipe only)
D790
D790
D638
4,500
250,000
3,000
ASTMF2019
The reconstruction process can be either for gravity flow or pressure applications. CIPP liners meeting
ASTM D5813 would be installed under this practice. Isophthalic polyester, vinylester, or epoxy
thermosetting resins may be used. For cleaning of the line for pressure applications, cable attached
devices or fluid propelled pigs are recommended. After CCTV inspection and cleaning, a sliding plastic
foil is first installed covering the lower third of the circumference to reduce friction and damage to the
CIPP liner. After insertion, the calibration hose is inflated and the liner cured. The calibration hose is
removed after cure. As in all of the CIPP standard practices for acceptance, samples of the CIPP liner are
either cut from a section at an intermediate manhole or at a termination point of like diameter section, or
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from material taken from the fabric tube along with the resin/catalyst system and cured in a clamped
mold. Since the glass fiber material can be bi-axial, samples are marked to designate the axial and
circumferential direction. Testing includes short-term flexural and tensile properties. The minimum
acceptable properties under this standard are shown in Table 5-15.
Table 5-15. Minimum Structural Properties of CIPP Products by ASTM F2019
Minimum Value
Property Test Method psi
Flexural Strength
Flexural Modulus
Tensile Strength
D790
D790
D638orD3039
6,500
725,000
9,000
In addition, wall thickness measurements are made (with no point measurement to be less than 85% of the
average design specified thickness) and a CCTV internal inspection is completed. As F2019 covers
pressure applications, a pressure and leak tightness hydrostatic pressure test is included with a
recommended test pressure of twice the working pressure or working pressure plus 50 psi, whichever is
less. Allowable leakage is 20 gallon/inch diameter/mile/day.
5.6
QA/QC Requirements
Few rehabilitation products are destined specifically for use in a sewer force main. Consequently, most of
the QC requirements in the ASTM and AWWA standards pertain to either use in a gravity sewer or a
pressure water main. None, except ASTM D3754, which covers fiberglass pipe for sewer and industrial
pressure pipe, combines the corrosion resistance necessitated by the sewer effluent and the long-term
tensile strength of a pressurized main. As more rehabilitation work is undertaken in the field of sewer
force mains, new standards or revisions to existing standards should follow to reflect this unique
application and need.
QC is a procedure or set of procedures intended to ensure that a manufactured product or performed
service adheres to a defined set of quality criteria or meets the requirements of the client or customer. QA
is defined as a procedure or set of procedures intended to ensure that a product or service under
development (before work is complete, as opposed to afterwards) meets specified requirements.
Typically in the world of construction, the QA aspects of a project are intended to assure the owner that
the contractor's or vendor's QC practices are adequate to deliver the product or service that the owner has
contracted.
Some of the product standards do require the manufacturers to undertake qualification or "type" testing,
which is intended to demonstrate the long-term performance of the liner under the intended use
conditions. However, the amount of this testing is very limited. Post-installation CCTV is the most
common QC requirement for all liners followed by the retrieval of samples for physical property
verification. More details on these requirements can be found in the following sections on short-term and
long-term QA/QC requirements in factory and field settings.
5.6.1 Short-Term - Factory and Field Requirements
5.6.7.7 PVC Short-Term QA/QC Requirements
Folded PVC
The short-term QC requirements in the factory for folded PVC pipes include pipe flattening, pipe impact
strength, pipe stiffness, extrusion quality (acetone immersion, heat reversion), and flexural properties.
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Dimensional checks on the pipe diameter and wall thickness are also included. The pipe flattening and
impact requirements are designed to primarily ensure that the pipe can be folded and reformed during the
installation without damage, while the stiffness and flexural properties relate to the design. There are no
QC requirements on measuring tensile strength, while the Type A material is to be made from virgin PVC
with a minimum tensile strength of 3,600 psi (248 bar).
Neither of the ASTM standard practices for the installation of folded PVC pipes (F1867 and F1947) is for
pressure applications. Consequently, the only field QC requirements pertain to gravity service. A low
pressure leakage test with a limiting exfiltration level of 50 US gallon/inch diameter/mile/day is
recommended. Samples of the rounded pipe are also retrieved at the insertion point, with diameter,
thickness and flexural properties measured. For the Type A material, ASTM F1867 also includes testing
for tensile properties (3,600 psi [248 bar] minimum).
5.6.1.2 PE Short-Term QA/QC Requirements. In pressure applications, the majority of the
rehabilitation that has been undertaken with PE pipe has been either with pipe bursting or sliplining.
Pipes used in these applications normally meet either AWWA C901 or C906, or the ASTM specification
for OD controlled pipe, ASTM D3035. Typical factory QC requirements in each case include visual
inspections for workmanship (no cracks, holes, foreign inclusions, etc.), diameter and wall thickness
checks, density measurements (per ASTM D1248), sustained pressure tests (subject the wall to a hoop
stress equal to the hydrostatic design stress), burst pressure tests (1.6 times the HDS for PE 3408),
environmental stress cracking tests, elevated temperature sustained pressure tests, and apparent ring
tensile strength tests.
In the case of sliplining, the original pipeline is visually inspected in the field by CCTV to locate problem
areas, including offset joints, crushed walls, obstructions and the location of service connections. The
only ASTM standard practice for the insertion of PE pipe, F585, is for gravity applications and includes
only a low pressure exfiltration test for acceptance, which is not particularly useful in a force main
application. The AWWA M45 PEPipe - Design and Installation manual provides some guidelines on
the use of PE pipe for pipe bursting and sliplining, but does not contain any specific field QC test
requirements except recommending a hydrostatic pressure test for acceptance.
Deformed PE
In the factory, deformed PE liners are dimensionally checked, plus evaluated for ESCR, tensile strength,
tensile elongation, and flexural modulus. These tests are part of the normal qualification and QC
requirements. The PE liner is required to have a minimum HDB, which would previously have been
demonstrated through type testing. The HDB rating of the resin is used for pressure design. The only
ASTM standard practice for the insertion of a deformed PE liner in a sewer, ASTM F1606, is for gravity
applications. QC requirements include a CCTV inspection of the liner after insertion and reversion, an
exfiltration or low pressure air test for leakage, and taking samples at the insertion or termination point for
further analysis. This would include diameter and wall thickness checks, plus measurement of flexural
modulus and tensile strength.
5.6.1.3 CIPP Short-Term QA/QC Requirements. As such, there are no ASTM CIPP product
specifications covering pressure applications, but ASTM D5813 Standard Specification for Cured-in-
Place Thermosetting Resin Sewer Pipe does require the fabric tube to have a minimum tensile strength of
750 psi (52 bar). This pertains more to handling and insertion needs than actual in situ performance.
Once the CIPP liner is installed, the recommended QC practice in all of the ASTM standards is for
samples to be cut from a representative section of the cured CIPP liner and then tested for short-term
flexural strength and modulus and short-term tensile strength. Two methods (ASTM D3039 and ASTM
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D638) are offered for determining the tensile strength. The minimum value is 9,000 psi (621 bar) as
specified in ASTM F2019, which is the only standard practice for pressure applications.
Wall thickness measurements are also made on the retrieved samples. There is no requirement for
measuring the wall thickness of the in situ liner. Theoretically, this is now possible with the use of a laser
profiler. The inside surface of the original pipe would first be surveyed with the profiler and then the
liner's inside surface after cure. Assuming the liner hasn't shrunk away from the inner surface of the
original pipe, the thickness of the liner could then be determined from these two survey measurements.
Ultrasonic tools are also being developed that not only can be used to measure the thickness of the in situ
liner, but also its flexural modulus of elasticity. This could be especially important to an owner who may
want to check on the condition of an old liner to determine if any deterioration (loss of thickness or
modulus) has taken place.
Another QC requirement often required is leak tightness testing, which in the case of a pressure pipe has a
limit of 20 US gallon/inch diameter/mile/day. The recommended pressure level in ASTM F2019 is twice
the working pressure or the working pressure plus 50 psi (3.5 bar), whichever is less.
The last field QC requirement is a visual inspection, usually by CCTV, to check workmanship. No dry
spots, lifts, or delaminations that would affect the liners long-term performance are permitted. Excessive
wrinkles are also not permitted, especially those that impede flow or cleaning equipment.
5.6.2 Long-Term - Qualification Requirements
5.6.2.1 PVC Long-Term QA/QC Requirements. PVC pipe meeting AWWA C900 or C905, or
ASTM D2241 Standard Specification for Polyvinyl Chloride (PVC) Pressure-Rated Pipe (SDR Series) is
subjected to long-term pressure regression testing to establish an HDB for the pipe. Pipes are tested per
ASTM D1598 and the results analyzed in accordance with ASTM D2837. A Hydrostatic Design Stress
(HDS) is determined, which is the maximum tensile stress the material is capable of withstanding
continuously with a high degree of certainty that failure of the pipe will not occur. Fusible PVC and
Duraliner are the only two PVC products made from standard AWWA C900 or C905 stock, so these are
qualified.
Folded PVC
There are no long-term qualification requirements in the folded PVC liner standards. Only one
manufacturer of a folded PVC product, Ultraliner, stipulates that this product could be used for a low
pressure sewer force main renewal. At some point in the future, a requirement similar to that in AWWA
C900 or AWWA C905, where reformed pipes are subjected to long-term pressure regression tests needs
to be established. This would then allow design of a reformed PVC liner to act as a fully structural pipe
for 50 years. At the present time, that information is not available.
5.6.2.2 PE Long-Term QA/QC Requirements. PE pipe meeting AWWA C901 or C906, or ASTM
D3035 is similar to PVC in that these products are also subjected to long-term pressure regression testing.
These tests establish a basis for the long-term pressure rating of the products. There are no other long-
term tests for standard PE pipe.
Deformed PE
PE used for deformed liners under ASTM F1533 is to be made from materials that have a PPI HDB of
either 1,600 psi (110 bar) for PE 3408 or 1,250 psi (86 bar) for PE 2406. However, there is no
requirement for the reformed PE liner to demonstrate that it has a similar HDB rating.
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5.6.2.3 CIPPLong-Term QA/QCRequirements. ASTM D5813 includes a long-term qualification
test for chemical resistance, which includes two requirements. The first is that the CIPP specimens retain
80% of their flexural modulus of elasticity after one-year exposure to six chemical solutions. Table 5-16
lists the solutions and their concentrations.
Table 5-16. ASTM D5813 Chemical Solution Specifications
Chemical Concentration
Solution %
Nitric acid
Sulfuric acid
ASTM Fuel C
Vegetable oil
Detergent
Soap
1
5
100
100
0.1
0.1
The other chemical resistance requirement is the strain corrosion test requirement of ASTM D3681,
developed for fiberglass pipes used in gravity sewers. Eighteen (18) samples are deflected to achieve four
different tensile bending strains on the inside surface of the liner and with exposure to H2SO4 The
samples must last without failure for the specified time period associated with each strain level. This
qualification test is intended to ensure that the liner is capable of withstanding up to 5% long-term vertical
deflection when exposed to 5% H2SO4 and will last 50 years. This requirement may be valid for a direct
buried pipe or perhaps a liner that is destined to be fully structural and capable of supporting all external
loads, but is not realistic for a liner installed in a partially deteriorated sewer force main.
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6.0 OPERATION AND MAINTENANCE
This section reviews best practices for O&M that can be effective in either prolonging the life of a buried
sewer force main or allowing a utility to monitor real-time performance so action can be taken as needed
to repair, rehabilitate, or replace the force main before a catastrophic failure occurs. Proper cleaning can
improve the capacity and hydraulic performance of a sewer force main. Several other methods are
available for improved O&M, including cathodic protection to arrest the effects of external corrosion,
linear polarization resistance (LPR) to determine a rate of external corrosion, ultrasonic transducers to
monitor loss of internal wall due to corrosion, pressure monitoring, leak detection, and acoustic
monitoring of PCCP for wire breaks. These are all methodologies that a force main owner can employ to
better manage and prolong the life of the buried asset. As discussed below, the ability of a utility's repair
crews to skillfully carry out emergency repairs on lined force mains is also cited as one deficiency that
limits the use of renewal technologies over replacement, even when their life-cycle costs are lower.
6.1 Procedures to Prolong the Life of Existing Force Mains
6.1.1 Cleaning. Unlike gravity sewers, force mains are not designed to be self-cleansing. Asa
result, solids, fats, and greases can accumulate in the main. Operational records can show when a force
main is in need of cleaning. One useful indicator is the volume of flow per unit of electricity consumed
(m3/kW); if this reduces significantly then it indicates greater resistance to pumping, which is likely to be
build-up of debris or encrustation on the pipe surface. Many contractors report that cleaning offeree
mains, usually by pigging, produces a greater impact than cleaning of water mains. Cleaning methods fall
into two categories: those that dislodge the solids so that they are carried away with the wastewater flow
and those that remove the solids from the pipeline. Pigging, vacuum jetters, and bucket dredging remove
the solids. High pressure water jetting and mechanical rodding are methods that dislodge the solids.
Water jetting may be used for cleaning pressure pipelines, but there is also a wide range of tools ranging
from wire brushes and squeegees to motor-driven flails for use in iron pipes. In some cases, the pressure
in the main may be used to force a pig through the entire line, with no need for winching. The bullet-
shaped pigs are commonly made of polyurethane and have surface coatings and/or wire brushes that
scrape off the deposits as they travel through the pipeline.
The most commonly used pig for cleaning is the versatile poly pipeline cleaning pig, which is thrust
through the pipeline by hydraulic or pneumatic pressure to clean the interior walls, remove debris, and
flush liquids from the pipeline. A selection of such pigs is shown in Figure 6-1.
Pigging requires high volumes of water at high pressure to force the pig through the line. Volumes above
100 gal/min may be required even in quite small mains and a significant pressure should be applied. Care
must be taken not to exceed the design pressure of the pipe itself during pigging. Large volumes of debris
and sludge can accumulate at the downstream end of the pigged pipeline and these must be captured to
avoid their flowing into the sewer system and simply moving the problem further downstream.
Pigging also requires access to the force main for pig insertion. Force main systems are seldom, if ever,
designed with pigging in mind, so this may be a major operation unless access can be provided at the
pump station. Since force mains generally terminate at a manhole or discharge into a gravity sewer,
recovery of a pig is relatively straightforward.
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Figure 6-1. Polyurethane Pipeline Cleaning Pigs
(Photo courtesy of Pipeline Pigging Products)
High Pressure Water Jetting
Jetting has become very common, yet is limited in its capabilities. It is currently the most popular
cleaning method for gravity sewers and is widely used throughout the world. Jetting machines range
from compact van-pack units for cleaning small diameter drains, through trailer-mounted jetters of
various power ratings, to full tanker-jetters (which may also combine vacuum removal) up to the largest
unit of a water recycling facility.
Although high pressure jetting can achieve excellent results if used wisely, it also has the potential to
make a bad situation worse and to create problems where none existed. Jetting a cracked or fractured
pipe may cause the fragments to become loose and fall into the pipe, creating a collapse and a blockage.
Persisting with high pressures in an attempt to remove the blockage can wash away the pipe surround,
resulting in further destabilization and perhaps even subsidence at the surface. Leaving a high pressure
jet in one position for more than a few seconds may puncture the pipe or damage the wall, even if the
pressure is below the recommended maximum.
There is some risk in jetting at high pressure in plastic pipes, notably uPVC. Generally, the wall
thickness of a solid wall uPVC pipe is such that high pressure jetting is unlikely to cause serious damage,
although excessive pressures should be avoided. The main concern is with structured wall polymeric
pipes where most of the strength is provided by external ribs or corrugations, and the inner wall can be
quite thin (sometimes less than 2 mm). Structured wall pipes were introduced to reduce the required
quantity of material (and hence the weight and cost) for medium to large diameters, while providing
adequate stiffness to resist external loads.
The main drawback of high-pressure jetting is that the debris in the sewer can be flushed downstream
rather than being removed. Jetters may be excellent for clearing localized blockages, but are less well
suited to dealing with large volumes of silt or similar material over long lengths of sewer.
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Drain Rodding
Simple drain rods are an obvious low-tech alternative to water jetting for small-bore pipes. For small
diameter pipes, old-fashioned drain rods are still the most common tool for blockage clearance and can be
very effective. The limitation is that there is little control and no feedback as to whether the blockage is
adequately cleared. Another drawback is that the rods may simply be pushing the problem somewhere
else. Nevertheless, this is an effective method for removing small blockages in small diameter sewers. It
is less well-suited to force mains because they generally have higher flow rates than gravity sewers so are
less likely to have loose debris in the invert.
Removal
Pipe cleaning and blockage clearance should involve more than just passing the problem downstream,
which jetting and rodding may do. letters are better than rods in this respect, since they break up
accumulations of debris into finer material, which is more likely to be carried in the flow and dispersed.
Where there are greater volumes of debris that would almost certainly settle out further downstream, a
common solution is to use a combination jetter/vacuum machine to simultaneously flush the sewer and
suck out the resulting sludge. Some of the larger and more sophisticated units incorporate water filtering
and recycling systems, together with compression of the solids so they take up less space and are easier to
dispose.
Flushing
Flushing involves simply pouring a large volume of water into a sewer as quickly as possible so that the
sudden increase in flow will wash away any accumulations of debris. It is an attempt to replicate the
effect of a summer storm on a combined sewer. Today, such a procedure would be carried out using a
large-capacity tanker-jetter, possibly with recycling and filtering facilities. Flushing is seldom used since
it has been largely superseded by jetting. Jetting uses less water and is a more controllable and reliable
technique. Flushing is also not well-suited to force mains since it does little more than repeat the normal
operation of the main.
Air Scouring
Air scouring is flushing with a twist. The "twist" in air scouring is using alternating volumes of air and
water to flush the pipe. The air and water travel along the pipe in separate discrete volumes with
approximately 75% air and 25% water. The air causes the water to move with high velocity and
turbulence, scouring away sediment, soft scale deposits, and biofilm. Common air compressors provide
the air. Both fluids are fed continuously and separately into discrete volumes by themselves. Air
scouring is more aggressive than flushing and should be used with caution if the pipe's structural
condition is poor. The AWWARF research report, Investigation of Pipe Cleaning Methods, provides
further details on the equipment setup for this method (AWWARF, 2003).
6.1.2 Cathodic Protection. Approximately 60% of ferrous force mains reportedly have some
cathodic protection applied. Steel pipes are more commonly protected with a cathodic protection system
because the electrical continuity of welded joints makes this a practical solution. It is more complicated
for DI pipe where electrical connectors (bonding) need to be placed across all bell and spigot joints.
Cathodic protection is an electrochemical method used to prevent or control corrosion of buried or
submerged metallic structures. They are active systems that rely on the application of electric current to
control corrosion. If current is interrupted, corrosion will progress at the normal rate for the
material/environment combination; if the supplied current is inadequate for complete protection,
corrosion will progress at a reduced rate. After a cathodic protection system has been installed and
adjusted to provide adequate protection, currents and potentials should remain relatively stable; changes
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in currents or potentials indicate a problem. There are two principal types of cathodic protection system:
impressed current and sacrificial anode as follows:
• Impressed Current Cathodic Protection. An impressed current system uses a rectifier to
convert alternating current to direct current. This current is sent through an insulated wire to
the anodes, which are special metal bars buried in the soil near the pipeline. The current then
flows through the soil to the pipeline and returns to the rectifier through an insulated wire
attached to the pipeline. The pipeline system is protected because the current going to it
overcomes the corrosion-causing current normally flowing away from it.
• Sacrificial Anode Cathodic Protection. Sacrificial or galvanic anode systems employ reactive
metals as auxiliary anodes that are directly electrically connected to the pipeline to be
protected. The difference in natural potentials between the anode and the pipeline metal, as
indicated by their relative positions in the electro-chemical series, causes a positive current to
flow in the electrolyte, from the anode to the pipeline. Thus, the whole surface of the
pipeline becomes more negatively charged and becomes the cathode. The metals commonly
used as sacrificial anodes are aluminum, zinc, and magnesium. These metals are alloyed to
improve their long-term performance and dissolution characteristics.
Maintenance and monitoring of cathodic protection systems is seen as very important by the operating
utilities. System performance can be monitored by measuring the supplied current, by measuring the
potential of the structure, or (preferably) by a combination of the two methods. Scheduled maintenance
may include inspection and adjustment of equipment items, such as current rectifiers or anodes;
unscheduled maintenance may include troubleshooting and repair of items identified as defective during
scheduled inspections, such as anode beds or electrical conductors.
Cathodic protection systems need to be checked at least once every two to four years to make sure they
are functioning. Unfortunately, all too often, the systems are ignored until there is a failure in the
assumed to be protected pipeline. Testing the system is relatively straightforward, but special equipment
is necessary to perform the test. Each cathodic protection system has a test box(es) installed to facilitate
checking the system. Transformer rectifier outputs may be displayed by telemetry at central control
stations. Many cathodic protection systems are increasingly being controlled and monitored by remote
computers and modem links. An important aspect of good maintenance techniques is record keeping.
Without proper record keeping, a maintenance program is essentially useless. Proper record keeping not
only provides historical data for future cathodic protection design, but also often provides clues as to the
source of a detected deficiency. The required recordkeeping for proper maintenance is relatively simple.
6.1.3 Continuous Corrosion Monitoring. Knowing where conditions exist that can give rise to
corrosion is an important element in buried pipeline operation, including force mains. Corrosion of
ferrous pipes may be external or internal.
Likely locations of internal corrosion in force mains are at high points where air may be present and at
downstream discharges. Well-designed pressure pipe systems have air valves at high points and records
showing frequent air valve operation and significant volumes of air being bled can indicate potentially
corrosive conditions. Most force mains discharge to gravity lines and at the discharge point the pipe
seldom runs full. The presence of air can cause corrosion at these locations.
The risk of external corrosion can be identified from knowledge of the soil and groundwater conditions.
Procedures for establishing the corrosivity of soils are well established. Environmental factors that
determine the likelihood of corrosion on a buried ferrous force main are: soil resistivity; soil moisture
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content; soil and groundwater pH; chlorides; sulfates; redox potential; and known corrosive
environments.
Continuous corrosion monitoring systems can be installed when new pipelines are laid, or can be added
retroactively to existing pipelines. Monitoring implies a series of surveys, planned and organized, to
obtain more comprehensive information on conditions over time. By defining changes in corrosion
conditions overtime, this represents a longer-term commitment compared with one-time corrosion
inspections or surveys. It also represents a deeper commitment to quantifying the rate of corrosion and
determining underlying causes of corrosion damage. It has been noted that the rate of corrosion
ultimately determines how long a process can be operated usefully and safely. Thus, there is value in
knowing this rate to identify when maintenance action needs to be taken. Most importantly, to generate
real value from corrosion monitoring initiatives, the information gathered over time has to be translated
into effective corrosion mitigation or control programs.
Corrosion monitoring is mainly used in installations such as critical operations in chemical processing
plants and oil and gas wells and offshore pipelines. Its use in force mains could not be documented at this
time, but that may change in the future. GE Inspection Technology has acquired the technology for an
ultrasonic sensor that is actually made up of a series of 14 thin transducers, all in a flexible band that is
240 mm long by 40 mm wide. This band can be wrapped around the outside of a ferrous pipe in either
the circumferential or axial direction. The accuracy of the transducers is reported to be 0.2 mm. A
coaxial cable is led to a box at grade level where periodic measurements of the 14 transducers can be
made with the DL datalogger. The Rightrax M2 has been used on steel pipe, but not yet on DI pipe.
Another approach is the use of a corrosion potential indicator called, LPR (Figure 6-2). Developed in
Australia by Tyco Water, this is used to evaluate external corrosion in the form of pitting based on soil
aggressivity. This is not a new concept, but Tyco Water has refined the approach. LPR soil testing is an
electrochemical soil testing technique using soil samples taken from the pipe depth to obtain a
quantitative measure of soil corrosivity and rate of corrosion. Previous attempts at measuring soil
corrosivity by a range of chemical and physical
parameters have not been very successful because what
is obtained is the thermodynamic tendency for
corrosion to occur. The LPR approach provides a
corrosion rate that can be extrapolated to allow a
quantitative time to failure to be calculated. The
process involves the use of a specially developed cell
that provides a measure of the combined effects of
several soil parameters. Comparison of the results from
LPR surveys and direct measurement of pitting have
shown a close relationship. The assessment and time to
failure calculation takes into account the pipe class, age,
length of main, and type and life of the pipe coating.
external DC
power supply
working
j_
*•
electrode K
.SO]J
reference
electrode
"inert"
counter
electrode
Figure 6-2. LPR Ferguson-Nicholas Cell
The method is stated to have the advantages of being: relatively low cost; non-intrusive, able to be
undertaken with the line in operation; and proven on a number of inspections. The interpretation of
results requires specialist skills. Results can be extrapolated in time and space to provide projections of
potential failure. The LPR is currently used in Australia and Hong Kong, but has not been used in North
America to date.
6.1.4 Pressure Monitoring. Stress in a pipe wall is a function of internal pressure. When a pipe is
known to be deteriorated, reducing the operating pressure can extend its service life and reduce the risk of
its failure. Transient pressure monitoring is becoming an accepted O&M procedure in water supply and
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could also be used in force mains. Pressure sensors are attached to the pipe and monitored over a period
of time. This monitoring can be done remotely and the data captured and analyzed to provide a graphical
display of pressure over time. Pressure monitoring can indicate potential risk due to fatigue loading of the
pipe and to transient pressure surges. Force mains, in which pumps are frequently started and stopped,
undergo significant cyclical loading. Transient pressures, also known as surge or water hammer events,
are the result of sudden changes in the velocity of liquid in a pipeline. Even very short-term (less than 1
second) pressure transients can cause damage to pipes if they are repeated frequently. Transient pressures
that exceed the structural strength of the pipe can cause damage in the form of rupture or more frequently
cause latent damage that results in a failure in the future. PVC can be especially vulnerable to fatigue
failure, especially older pipes where formulations are different from those used today. Similarly, negative
pressures can also be a source of damage to pipes.
6.1.5 Leak Monitoring. Leakage in a pressurized main can be a precursor of failure. Typically,
over time, leakage will increase and eventually may disrupt the bedding and support of a buried pipeline.
That can lead to differential settlement and either a failure at a joint or in the barrel of the pipe.
Consequently, identification of the location of leaks in a force main could be an important element in any
condition assessment program, as well as in the normal operation of a force main.
Leaks can fall into two categories: joint leaks and pipe wall leaks. Leaks arising from perforations in the
pipe wall have greater significance. Not only can they be a source of pollution, but they are also a clear
indicator of significant corrosion and an indicator of potential future failure. At the very least, they
provide a focus on where to use structural integrity investigation methods.
Just 21% of the responding utilities to the WERF research project on inspection offeree mains (WERF,
2009) stated they have performed leak detection on force mains. The most common method for leak
detection reported was a field hydrostatic test, where either loss of pressure or fluid is used to identify the
presence of a leak in a line. Of course, this requires isolation of the line for the duration of the test and
will not pinpoint the actual location of the leak. The hydrostatic field test is usually limited to new lines
as part of the acceptance requirements.
Leak detection uses a variety of techniques including acoustic, hydrophones, tracer gas and infrared
thermography. Leak detection is of importance in the investigation offeree mains and a number of new
developments are providing cost-effective tools for this purpose. External technologies fall broadly into
two types: acoustic sticks (listening devices) and correlators. Ferrous force mains have similar leakage
defects as are found in ferrous water mains and some of the tools from the water industry could be used
with some adaptation. In-line leak detection can be an effective means of undertaking leak surveys on
ferrous force mains. It is a relatively new development for force mains having been initially developed
for potable water main leak investigation. Virtually all diameters and pipe materials can be investigated
with the mains in normal operation. The two principal technologies used in water mains are Sahara®,
offered by Pressure Pipe Inspection Company (PPIC) and SmartBall® by Pure Technologies, Ltd. Both
have been used successfully in force mains and have the added benefit of being able to detect and locate
air pockets, which can be indicators of corrosion in force mains. Sahara® employs a tethered hydrophone,
while the SmartBall® is free swimming. The minimum pipe diameter is 12-inch (300-mm) for Sahara®
and 10-inch (250-mm) for SmartBall®.
6.1.6 Acoustic Monitoring for Wire Breaks in PCCP. One of the primary failure mechanisms
for PCCP is wire breakage. Real-time monitoring for ongoing wire breaks can enable a picture to be built
up over time of the rate of wire breaks and more importantly, any concentrations of breakage. These can
indicate locations where corrosion is causing rapid deterioration of the pipe and where intervention is
necessary to prevent a failure. The wire breaks can be detected acoustically. This technique can be used
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in all diameters of pipe, not just those where man entry is possible. There are four possible types of
installation and the requirements for installation will vary according to the method as listed below:
• Hydrophone Arrays: Up to 32 hydrophones can be mounted on a cable up to a mile long.
The cable and hydrophones can be inserted into an operational pipeline. One advantage of
this approach is that it is possible to have close hydrophone spacing cost-effectively. Data
are transmitted through the cable to a data acquisition center.
• Hydrophone Stations: Hydrophones are inserted into the flow at convenient stations by
making 1 inch taps under pressure. Data from each hydrophone are transmitted to a data
acquisition center.
• Surface mounted sensors: Piezoelectric sensors (accelerometers) are surface mounted on the
pipe and data are transmitted above ground to a data acquisition center.
• Fiber Optic Sensors: These consist of a long jacketed cable with internal continuous glass
fiber sensor, which is able to transmit light. As the whole of the fiber is the sensor, it is in
close proximity to any wire break. In addition, fiber optic can also be set up to monitor
pressure and temperature.
The acoustic data from these installations are collected and transmitted by wireless internet to the
company for analysis. The two companies that undertake this monitoring have variations on installations
depending on location and pipe diameter. They both have developed their own procedures and software
for analysis of data. They both claim to be able to separately identify wire break noise and its location
from other acoustic events. It may even be possible in the future to distinguish third-party damage events.
Using this data and analysis, they can estimate the state of distress of each pipe section.
6.2 Maintenance and Emergency Repair of Rehabilitation Systems
Maintenance departments at utilities have set procedures for emergency repairs offeree mains. These are
dependent on material, type of emergency (break, leak, joint leak, etc.), and location. A rehabilitated
main effectively adds to the range of material that must be potentially repaired in an emergency. There
are no set procedures for repair of rehabilitated (i.e., lined) force mains. This is an area of concern for
utilities and certainly makes them reluctant to line their mains because they do not know how to deal with
them when emergency repair becomes necessary. This further influences the choice of replacement over
rehabilitation. The onus is on the suppliers of lining technologies to develop repair procedures for their
products in force main applications and to train utilities in their application. Procedures that require the
vendors' personnel to attend and undertake specialist works will not be adequate in emergency situations
where swift action is necessary.
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7.0 GAPS BETWEEN NEEDS AND AVAILABLE TECHNOLOGIES
All of the tools for force main system rehabilitation programs are not yet in place. This section addresses
the gaps that need to be closed in order to provide utilities with the decision-making processes and the
rehabilitation technologies necessary to develop such programs. The first section will address data gaps
in terms of knowledge of the host pipe condition and the second section will address capability gaps in
terms of available renewal technologies.
7.1 Data Gaps
The data gaps between needs and available technologies are significant.
The available inspection technologies can obtain the required data concerning the condition offeree
mains, which is necessary for assessment and renewal design purposes. But these technologies cannot be
used cost-effectively or without shutdown of the main, which is generally not possible or entails major
cost. Data may be obtained either externally or internally. External data require excavation for inspection
on the pipe surface. For reasons of cost and practicality, this can only be done at a small number of
discrete locations along a pipeline. As a result, the sample size is extremely small and the confidence
level of the findings in terms of being representative of the pipeline as a whole is very low. Internal data
require the main to be shut down and dewatered for inspection. This is extremely costly due to the
service interruption, which may require by-pass pumping or honey wagons to be used to transport the
wastewater in the absence of upstream storage capacity.
As a result, little data are obtained on force main condition upon which assessment and subsequent
rehabilitation decisions can be based. Rehabilitation decision-making can only be made on the basis of
operational indicators such as power consumption, air release valve operation, or main breaks. The
alternative is to consider consequence of failure and to renew high risk lines irrespective of any
knowledge of their condition. This is inefficient and results in higher cost than either preventative
maintenance or rehabilitation intervention based on condition assessment within a risk-based framework.
The WERF report titled Inspection Guidelines for Force Mains addresses this issue (WERF, 2009). It
sets out guidelines for inspection based on material. It also covers prioritization of inspections and the
key considerations in the development of an inspection plan.
A key finding based on international experience reviewed is that utilities consider that there is benefit in
being able to make a proactive decision on whether to renew based on risk. Part of this is to know where
problems do not exist so expenditure can be deferred. The renewal decision is based on three elements:
the rate of deterioration of assets; the condition of critical locations; and whether spending can be
deferred. Risk analysis can also help indicate where the "wait and see" approach is most cost-effective.
It is also important to take into account that inspection can create liabilities. Knowledge of a defect
creates a need to do more than "wait and see."
A first step is to establish risk-based assessment methods to identify force mains with serious
consequences of failure, either in operational or environmental and public impact terms, or both. This
will drive the need to understand the likelihood of failure and will identify the characteristics offeree
mains for which this information is needed. A second step is to consider prioritization for external data
collection. A method for identifying high risk locations in terms of likelihood of failure based on
environment and operating characteristics could pinpoint high risk locations, which would be selected for
direct inspection. This would increase the chance that the small sample obtained would identify more
critical conditions than otherwise.
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There is a clear need for assessment methodologies that can work with limited data. These could
potentially be based on Bayesian belief networks. There is also a need for inspection technologies that
can provide data more cost-effectively to support these assessment methodologies. Development of clear
maintenance guidelines, and linking of O&M data, for example cathodic protection system and power
consumption data, to condition assessment is also necessary.
7.2 Capability Gaps
This section will address capability gaps in terms of rehabilitation technologies. The available
rehabilitation technologies generally meet needs well. Despite being developed either for water mains or
gravity sewers, they can readily be adapted for use in force mains. CIPP has a track record in force
mains. The emergence of new CIPP systems based on woven fiberglass and UV-curing, which provides a
much stronger liner with some hoop strength, also has applications in force mains. A gap exists in terms
of a design procedure for CIPP in pressure applications to ensure that long-term performance
requirements can be met.
The combination of tensile strain and potential chemical attack from wastewater can create strain
corrosion problems in polymeric resin-based materials. This was a major problem for the early GRP
pipes, under the name Techite, and there were several failures. The potential for strain corrosion in CIPP
materials in pressure wastewater applications needs to be understood and taken into account in the design
procedures developed.
Sliplining with PVC or HOPE also meets the needs in force mains, as does close-fit lining using either
material. Non-structural methods, such as sprayed liners for internal corrosion protection are also equally
well-adapted to force mains as they are to other pressure pipes provided that the materials used have
adequate chemical resistance to wastewater and mechanical resistance to abrasion, which is more likely in
force mains than in water mains.
The primary capability gaps are access needed to the main and the need to shut down, dewater, and clean
the main for rehabilitation. This is an inevitable feature of any internal rehabilitation technology, as it is
for inspection technologies. This also places a limitation on the use of rehabilitation in force mains. If
the cost and disruption of by-pass pumping to open the main for access approaches that of replacement,
and replacement leads to a longer remaining service life, a Net Present Value calculation may indicate
that replacement is more cost-effective.
There is also a need for emergency repair procedures for lining systems and for utilities to be trained in
their application. Lack of such procedures makes utilities reluctant to rehabilitate force mains, preferring
replacement with materials for which they have emergency repair procedures in place.
7.3 Benefits, Costs, and Challenges in Closing Gaps
Based on the information gathered in this report, Table 7-1 summarizes the technology gaps and the
potential costs and benefits associated with their closure.
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Table 7-1. Technology Gaps and Closure Costs and Benefits
Gap Close By Benefit Cost Challenge
External data collection
External data collection
Internal data collection
Risk-based assessment
Assessment with limited data
Operation and maintenance for
assessment
CIPP long-term performance in
pressure wastewater application
CIPP pressure design
Rehabilitation or replacement
decision-making
Emergency repair of
rehabilitation systems
Increase sample size
Target high risk locations
Live insertion and working
Method for determining
consequence of failure
Bayesian belief networks
Integrated approach/database
Determining susceptibility to
strain corrosion
Develop/adopt procedure/method
Knowing total rehabilitation cost
including by-pass pumping,
compared with replacement cost
Develop procedures and train
utility personnel
More reliable data
Find worst case. Prioritize
Reduced cost of data
Identify critical assets
Assessment at lower data
collection cost
More assessment data at low
cost
Long-term confidence in CIPP
rehabilitation
Long-term confidence in CIPP
rehabilitation
Improved decision-making on
rehabilitation vs. replacement
Remove reluctance of utilities
to rehabilitate force mains
High
Medium
High
Low
Medium
Low
Medium
Low
Medium
Medium
Technologies that provide wall
thickness data over a long distance from
a single point
Develop screening method - use LPR
Live insertion and retrieval of existing
tools
Transforming qualitative information
into quantitative data for decision-
making
Determining adequate level of data for
model to be robust
Obtaining and capturing relevant data
Test method to identify strain corrosion
effect over long-term
Acceptance of method developed
Data for robust cost model
Rapid procedures that can be
implemented by utility crews
00
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8.0 FINDINGS AND RECOMMENDATIONS
Partly because of the difficulty in assessing the condition of sewer force mains, leaving a lot of
owners with questions about the integrity of these critical assets, and the limited amount of
rehabilitation technologies available for renewing a deteriorated main, there has not been a significant
amount of renewal work in the past. Most of the renewal activity has been outright replacement of the
force main, either by open cut or trenchless means. As the nation's force mains age further, greater
emphasis will be placed on finding cost-effective ways to renew these critical assets. Fortunately,
new products and technologies are now emerging for carrying out a direct condition assessment on a
buried force main, as well as rehabilitation methods for those found in distress. Many of these
rehabilitation methods originated in the gravity sewer market or water market, but have been adapted
to meet the special needs of sewer force mains.
One method of assisting owners in their efforts to apply some of these emerging technologies will be
in the publication of demonstration projects and case studies. Also, setting up a decision support
system that helps a utility ask the right questions so that a viable rehabilitation solution emerges is
paramount. Utilities also need to consider implementing maintenance programs that can
demonstratively extend the useful life of their current mains, deferring the cost of renewal or
replacement to a future date.
This section reviews a number of these subjects and offers suggestions for technologies that might be
considered in some demonstration projects.
8.1 What Systems Would Benefit Most from Being Demonstrated in Field Settings?
Systems that would benefit from demonstration in field settings fall into two categories: data
collection (inspection) systems and rehabilitation systems. The scope of this review is rehabilitation
rather than inspection. Nevertheless, the demonstration of certain inspection systems was considered
to be valuable because they can provide data that drive rehabilitation decisions. Referring to Table 7-
1, the technologies for which field demonstration would yield greatest benefit would be the following:
• External data collection: Screening method to identify high risk locations. Potentially
LPR or over line potential surveys.
• Internal data collection: Live insertion and retrieval of inspection tool. Pipe Diver (PPIC,
Canada) for PCCP and See Snake for ferrous mains.
• Internal data collection: Acoustic technologies for leak detection and location of air
pockets. Sahara® (PPIC, Canada) and SmartBall® (Pure Technologies, Canada).
• Internal lining: CIPP (nonwoven felt/polyester resin and woven fiberglass/UV-cured);
sliplining (PVC and HOPE); and close-fit lining (PVC and HOPE).
• Structural spray-on lining with fast cure: polyurea-based material.
8.2 Key Parameters for Evaluation in Demonstration Projects
Table 8-1 identifies the key parameters to be evaluated in demonstration projects.
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Table 8-1. Parameters for Evaluation in Demonstration Projects
Technology Installation Parameters Performance Parameters Comments
LPR
Pipe Diver
Sahara81
SmartBall"8
CIPP, Nonwoven felt + polyester resin
CIPP, Woven fiberglass + UV-curing
Sliplining PVC
Sliplining HOPE
Close-fit lining PVC
Close-fit lining HOPE
Representative soil sample
Live insertion and retrieval
Live insertion and retrieval
Live insertion and retrieval
Size of openings. Speed of installation
Size of openings. Speed of installation
Size of openings. Speed of installation.
End fittings
Size of openings. Speed of installation.
End fittings
Size of openings. Speed of installation.
End fittings
Size of openings. Speed of installation.
End fittings
Ability to identify high risk locations for
external corrosion
Speed of operation. Impact on operation
of main. Range of data collected
Size of leak detected. Identification of
air pockets
Size of leak detected. Identification of
air pockets
Strain corrosion. Long-term performance
under pressure. Abrasion resistance
Strain corrosion. Long-term performance
under pressure. Abrasion resistance
Fatigue loading. Abrasion resistance
Fatigue loading. Abrasion resistance
Fatigue loading. Abrasion resistance
Fatigue loading. Abrasion resistance
Rate of corrosion
Cost of tapping. Saving in obviating by-
pass pumping
None.
None.
Life-cycle costs. May need accelerated
aging tests. Repair methods
Life-cycle costs. May need accelerated
aging tests. Repair methods
Life-cycle costs. Capacity effect of
cross-section loss. Repair methods
Life-cycle costs. Capacity effect of
cross-section loss. Repair methods
Life-cycle costs. Repair methods
Life-cycle costs. Repair methods
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8.3 Guidance for Establishing a Comprehensive System Rehabilitation Program
Many questions remain unanswered and Tables 7-1 and 8-1 identify the key issues and what
additional information is necessary. However, it is clear that a system rehabilitation program needs to
integrate several aspects and to have a broader vision than merely the rehabilitation technology and its
implementation.
The elements that need to be integrated, within the scope of an asset management approach, are:
inspection; assessment; maintenance; and rehabilitation. These will support a decision-making
process that ensures cost-effective maintenance of a desired service level for the force mains within a
wastewater collection and conveyance system.
When this framework is established, decisions concerning individual elements of the program can be
made. The scope of this report is rehabilitation so this section will focus on rehabilitation and not on
the bigger picture. When rehabilitation has been identified as a potential solution, three questions
must be answered in reaching a decision as to method:
(1) What is necessary? (i.e., What problem is to be solved and what performance is required
in service, including service life?)
(2) What is feasible? (i.e., What methods can achieve the performance level identified as
necessary?)
(3) What is cost-effective? (i.e., Of the feasible options, which achieves the performance
required at least cost, including alternatives such as replacement?)
When these decisions have been made, aspects such as material selection, testing, and QA can be
developed and included in individual project specifications. The specifications should require test
data or testing to be carried out to verify that the desired performance through the service life can be
met. It should also set out a QA regime to ensure that the material and its installation conform to the
specification requirements.
The type of specification used is also important. It may be prescriptive or performance-based. A
prescriptive specification identifies what must be done and also how it must be achieved. A
performance specification sets out what must be done and the required performance level, but leaves
the "how" to the contractor. A prescriptive specification places greater risk on the owner whereas a
performance specification shares risk more evenly between owner and contractor.
8.4 Guidance for Maintenance Programs
Maintenance also comes under an asset management plan and framework and contributes to cost-
effective operation offeree mains through their service life. Often poor or non-existent maintenance
is a contributory factor in the need for rehabilitation, so development and implementation of efficient
maintenance can reduce or delay the need for rehabilitation or replacement of a main, with significant
financial benefit.
The key elements offeree main maintenance are: regular cleaning; maintenance of cathodic
protection systems; and maintenance of air release valves. Operational indicators such as power
consumption and frequency and volume of air release valve operation can identify when and where
maintenance is required. Linking these indicators to a maintenance program will make it more cost-
effective. Using maintenance data can also contribute to condition assessment and decisions on
timing of rehabilitation or replacement offeree mains.
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8.5 Sound, Risk-Based, Decision-Making Process Development
This also falls into the area of asset management. Overall system risk may be defined as the risk of
failing to achieve the service level desired. Each element in the system contributes to this risk. The
likelihood offeree main failure and the consequence for the system both need to be known to assess
risk and to prioritize assessment and intervention in a cost-effective manner. If consequence of failure
is low, there is little value in knowing likelihood because it has no impact on decisions made or
actions taken. Therefore, the first step is to identify critical assets for which consequence of failure is
high. When this is done, it becomes necessary to identify the likelihood of failure for assets where the
consequence of failure is above a certain threshold. Inspection and condition assessment of the assets
support this effort. The level of likelihood of failure identified from inspection and assessment then
drives management of the asset, comprising maintenance, operation (possibly actions such as
reducing operating pressure), and rehabilitation or replacement. This management approach is
designed to maintain risk at an acceptable level as defined in an asset management plan.
8.6 Cost-Effectiveness of Decision-Making Processes
The decision-making process relies on data from inspection to assess risk levels and to decide on
necessary actions. Determining the level of data or information required to support effective
decisions is a key aspect of the process. Too little data and the wrong decisions may be made; too
much data and the cost of obtaining the data may exceed its value in the process. Neither scenario is
cost-effective.
hi general, more information leads to better decisions. But this leads to a quest for perfect
information to eliminate risk from the decisions to be made. This is not cost-effective. Decision-
making processes that can be effective with limited information are necessary. Bayesian belief
networks provide one platform for such processes. In addition, these processes need to be combined
with expertise, experience, knowledge, and engineering judgment if they are to be robust and reliable,
while also mitigating risk. For this reason, "black box" processes that can be blindly followed by
non-specialists are high risk processes with the potential for overlooking unusual conditions or
contributing factors to risk.
A key element in the decision-making process as to the method of rehabilitation chosen is the degree
of deterioration present in the force main. The differences in the design of a liner designed for a
partially deteriorated main versus a fully deteriorated main can be substantial. When insufficient data
are available to make that distinction, owners tend to err on the conservative side and chose a solution
appropriate for a fully deteriorated asset. More cost-effective solutions are eliminated from the
decision-making process as a result of such actions.
8.7 Timing for Rehabilitation Action
One element not addressed in this report is the determination of when is the most appropriate time for
a rehabilitation action to be implemented on an asset class. This report alludes to the "end of life" of
an asset as the point where rehabilitation is required. The "end of life" can be defined in several
different ways (Rose, 2009):
• End of Physical Life - pipe actually fails (collapses)
• End of Service Life - pipe no longer performs at level required by stakeholders (e.g.
customers and regulators)
• End of Economic Life - pipe in its current management and operating environment
ceases to be the lowest cost alternative to satisfy a specified level of performance or
service at an acceptable level of risk
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These limits are reached at different points in time, usually with end of service life (driven by
customer complaints) reached before physical or economic end of life is achieved. However, most
condition assessment activities are focused on the determination of the end of the physical life of the
asset, while it is the end of service life or economic life that drives reinvestment.
One of the key decisions a utility manager has to make is when to rehabilitate an asset from an
economic and service life standpoint. Answering this question is beyond the scope of this report, but
is vital to the asset management of a sewer force main system. This topic will be addressed in a later
research report, which is devoted to decision-making support systems for replacement versus
rehabilitation.
8.8 Demonstration/Verification of Pressure System Rehabilitation
The need at this stage is to demonstrate or verify elements of pressure system rehabilitation. Tables
7-1 and 8-1 set out the needs and the specific elements to verify. All of these are contributors to the
development of an integrated asset management program for the force main element of wastewater
systems. Their verification will enable methodologies and protocols for comprehensive system
rehabilitation programs to be developed that are robust, efficient, and cost-effective. A combination
of demonstration projects to verify capabilities and closing gaps in data and knowledge is essential to
support development of the necessary tools for force main rehabilitation programs. Programs that
allow an owner to reasonably predict the remaining life of a force main that has been renewed with a
liner is paramount.
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9.0 REFERENCES
Aggarwal, S.C. and MJ. Cooper. 1984. External Pressure Testing oflnsituform Linings. Internal
Report. Coventry Polytechnic.
American Society Civil Engineers (ASCE). 2005. Pipeline Design for Installation by Horizontal
Directional Drilling, Manual & Reports on Engineering Practice No. 108, Ruston, VA.
American Water Works Association (AWWA). 2001. Rehabilitation of Water Mains, Manual of
Water Supply Practices M28, Denver, CO.
American Water Works Association Research Foundation (AWWARF). 2003. Investigation of Pipe
Cleaning Methods, Denver, CO.
U.S. Environmental Protection Agency (EPA). 2007. Innovation and Research for Water
Infrastructure for the 21st Century Research Plan. Office of Research and Development,
National Risk Management Research Laboratory. April 30.
Newman, A.E. 2000. Ferrocement & Laminated Cementitious Composites, Techno Press 3000, Ann
Arbor, MI, 372p.
Office of Water Service (OFWAT). 2005. Water & Sewerage Service Unit Costs and Relative
Efficiency, 2003-2004 Report, Jan. 2005, 114p.
Plastic Pipe Institute (PPI). 2009. "PPI PVC Range Composition Listing Of Qualified Ingredients,"
PPI TR-2/2009(a), PPI, Washington, D.C. 20009.
Simicevic, J. and R. Sterling. 2003. Survey of Bid Prices for Trenchless Methods, Report and MS
Access 2000 Database, Trenchless Technology Center, Louisiana Tech University, Ruston,
LA, 77p.
Rose, D. 2009. Private email correspondence.
Thomson J., R. Morrison, and E. Spivak. 2006. The Investigation, Assessment, and Design of a
Rehabilitation Solution, WEFTEC Conference Dallas, TX.
Water Environment Research Foundation (WERF). 2009. Guidelines for the Inspection of Force
Mains (Draft). 04-CTS-6UR. Alexandria, VA.
86
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APPENDIX A
RENEWAL TECHNOLOGIES DATASHEETS
-------
Technology/Method Spray On Lining/Polyurethane
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Conventional
Formally known as Copon Hycote 169HB by E.Wood Inc. A preceding product
Copon Hycote 169 was introduced in the UK in 1 999. A succeeding product 3M
Scotchkote Spray-in-Place Pipe 269 (which is a polyurea formulation) is slated
for introduction in the US in 2009.
Actively being used in UK and Canada. About 200 miles have been lined, the
bulk of which is in UK.
3M Scotchkote 169HB
3M Corrosion Protection Products Division
Austin, Texas
Phone:512-984-5515
Fax: 512-984-4871
Web: http://www.3m.com/
Email: gsnatwig@,mmm.com
Derrick Horsman
Alltech Solutions, Canada
Email: dhorsman(3)alltechsolutions.ca
Peter Oram
AECOM, US
Email: e.peter.oram(5),m-e. aecom.com
Copon Hycote 169HB is a two component coating specifically designed for use
in pipeline applications and is available as a grey finish. The material has a low
viscosity to allow for pumping to remote spray heads and is moisture tolerant to
provide high-build slump resistant coatings with improved adhesion
characteristics. Finished coatings are hard, glossy and free of surface tack or
greasiness. This rapid setting polymeric lining offers a semi- structural spray
lining alternative to conventional replacement technologies without the large
scale disruption generally associated with replacement.
• No large scale disruption compared to PE slip lining
• Excellent abrasion resistance.
• Long-term corrosion protection material
• Equivalent to AWWA M28 Class 3 Rehabilitation technology.
• Usually bypass service is not required.
• Approved under UK Regulation 3 1 (4)(a) of the Water Supply (Water
Quality) Regulations.
• Recommended for pipes prone to local damage and well suited for local
host pipe damage.
• Easier leakage detection on metal pipes.
• Not recommended for pipe with residual asset life less than 30 years
• Not recommended for use in PVC pipe because of failure pattern in host
pipes
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Oil, Gas and Industrial pipelines
II. Technology Parameters
Service Application
Service Connections
Structural Rating Claimed
Materials of Composition
Diameter Range, inches
Rehabilitation by spray lining
Fully -bonded along pipe thereby requires no secondary fittings
Tensile Stress at yield is 14.2 MPa
Tension Modulus is 600 MPa
Flexure Modulus is 770 MPa
* LC8 standards clearance
Polyurethane
• Base Component: White thixotropic liquid
• Activator Component: Black thixotropic liquid
• Mixed Material: Light Grey
>=4
A-l
-------
Technology/Method Spray On Lining/Polyurethane
Thickness Range, inches
Pressure Capacity, psi
Temperature Range, °C
Renewal Length, feet
Other Notes
• Film Thickness of 80 mils is recommended under NSF 61 listing.
• Practical applications of 1 20 to 200 mils are achieved.
• Actual lining thickness is at the discretion of the utility thickness.
At 3 mm coating thickness, 145 psi for 100 mm pipe diameter.
*Capacity changes with material thickness and pipe diameter
To be stored in the original sealed containers at temperatures between 0°C and
40°C. Copon Hycote 169 HB shall not be applied when substrate/water
temperatures are less than 3°C. Material temperature at the application head is
25-35°C.
575 feet
• Adhesion performance is 10.2 MPa
• Approved manufacturing facility is in North Yorkshire, UK
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation Methodology
QA/QC
NSF 61 approved
DWI approved - UK
Norwegian, Spanish, and Polish Approvals also available
Equipment needs special head and cleaning.
30+ years. Some studies suggest 40-60 years.
• Number of Coats: 1
• Maximum Thinner: None
• Cure Time: 30 minutes at 30°C
• Special Comments: Mixratio of A:B is 2.5:1. One hour flush required
prior to being placed into service.
• Linings of 1-5 mm thickness may be applied in a single pass of the
application head.
• Cleaning, drying and joint- filling are required.
• One excavation required for every 1 00-1 50m approximately.
• Same day return to service for every 1 00-1 50 m renewal length.
• Disruption for around 8 hours.
• Recommended deflection in pipe of up to 12 degrees.
• CCTV inspection of the coating may be carried out after a minimum cure
period of 10 minutes from completion of lining.
• The coating shall be allowed to cure for a minimum period of 60 minutes
after completion of lining before the commencement of disinfection and
flushing procedures.
• Principles of Water Supply Hygiene and Technical Guidance Notes
• Effective control of a BS EN ISO 9000 Quality System In- Situ Rapid
Setting Polymeric Lining Operational
• Guidelines and Code of Practice: Published by Warren Associates
(Pipelines) Ltd
• Material Safety Data Sheet
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements for
Rehabilitated Sections
Using a maximum of not more than 1 00 mg/L of free chlorine
Leakage detection tests, recoating
V. Costs
Key Cost Factors
Case Study Costs
Lesser storage space required, reduced number of pit excavations, universal item
product and does not vary for different pipe diameters, all soil to be treated as
contaminated waste, allows use of existing pipe rather than exhuming it, smaller
carbon footprint, does not affect external pipe condition, small number of
resources amounting to reduced contractor risk, lesser time for installation site,
tarmac coating required at excavation pits. Contribution to material costs
includes the lining material, equipment, and use of existing pipe.
Approximately 60 Euros in urban areas (2006)
VI. Data Sources
References
• http://solutions.3m.com/wps/portal/3M/en US/Corrosion/Protection/Product
A-2
-------
Technology/Method Spray On Lining/Polyurethane
s/Catalog/?PC 7 RJH9U52300NAF02J1MHGK22C53 nid=QF308SF96Fb
e9JQFPTCN6Zgl
• http://www.nsf.com/Certified/PwsComponents/Listings.asp?Company=0019
0&Standard=061
• Alltech Magazine article
• Pipeline Rehabilitation Worldwide: Copon Hycote 169HB Technical
Guidance Note
A-3
-------
Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating Claimed
Materials of Composition
Diameter Range, inches
Thickness Range, inches
Spray on Lining/Polyurea
I. Technology Background
Emerging
3M Water Infrastructure just introduced Scotchkote Spray-In-Place Pipe (SIPP)
269 Coating at the ASCE Pipeline 2009 conference in San Diego. The original
formulation developed by E. Wood, known as Copon Hycote 169HB was a
polyurethane and not capable of meeting the NSF 61 standard, according to 3M
representatives.
The original Copon Hycote 169HB is actively being used in the UK and Canada.
About 200 miles have been lined, bulk of which is in UK. The new Scotchkote
SIPP 269 has no known uses as of the time of this report.
Scotchkote Spray-In-Place Pipe (SIPP) 269 Coating
3M Water Infrastructure
3M Center, Building 223-02-S-24
St. Paul, MN 55 144- 1000
Phone:512-984-5515
Fax: 512-984-4871
Web: http : //www. 3 m . com/water
Email: gsnatwig(5),mmm.com
Not available
Scotchkote SIPP 269 is a two component coating specifically designed for use in
pipeline applications and is available as a grey finish. The material has low
viscosity characteristics for pumping to remote spray head locations and is
moisture tolerant to provide high build slump resistant coatings with strong
adhesion characteristics. The gel time at 68°F is 120 seconds, cure time for CCTV
inspection is 10 minutes, and ready for return to service in 60 minutes. It is made
of 100% solids and has no VOCs. Based on the material properties, all of which
are short term values, this polyurea coating will primarily be suitable as an inner
corrosion barrier or a semi- structural (Class II) liner. The low elastic modulus
means the liner will act as an interactive liner and be dependent on the host pipe to
carry the internal pressure.
• Approved to NSF/ANSI Standard 61 as certified by WQA and NSF
• Contains no VOCs per EPA method 8260
• Quick cure allows CCTV inspection immediately after application (10
minutes)
• Same day return to service, bypass service not required.
• Can be applied to pipes 4 to 50 inches in diameter
• Typically will not plug service connections
• Material property data is all based on short-term testing
• Material appears to be very flexible with low tensile strength, which will
limit its use for semi or fully structural rehabilitation.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Oil, Gas and Industrial pipelines
II. Technology Parameters
Rehabilitation by spray lining
Fully bonded along pipe thereby requires no secondary fittings
Tensile Strength: 16 MPa (2,320 psi)
Flexural Strength: 22 MPa (3,190 psi)
Flexural Modulus: 720 MPa (104,400 psi)
Polyurea
• Base Component: White thixotropic liquid
• Activator Component: Black thixotropic liquid
• Mixed Material: Light Grey
4-50 inches
• Film target thickness is 1 40 mils (3 . 5 mm).
• Practical applications of 1 20 to 200 mils are achieved.
A-4
-------
Technology/Method Spray on Lining/Polyurea
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
• Actual lining thickness is at the discretion of the utility thickness.
No information on bridging capability available.
• To be stored in the original sealed containers at temperatures between 32°F
(0°C) and 86°F (30°C).
575 feet
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation Methodology
QA/QC
NSF 61 approved
DWI approved - UK
Norwegian, Spanish, and Polish approvals also available
Equipment needs special head and cleaning.
30+ years, some studies suggest 40-60 years.
• Number of Coats: 1
• Cure Time : 1 0 minutes at 86°F (20°C)
• Special Comments: Mix ratio of A:B is 1 : 1 by volume. One hour flush
required prior to being placed into service.
• Linings of 1mm - 5 mm thickness may be applied in a single pass of the
application head.
• Cleaning, drying and joint-filling are required.
• 1 excavation required for every 100-150 m approximately.
• Same day return to service for every 1 00-1 50 m renewal length.
• Disruption for less than 8 hours.
• CCTV inspection of the coating may be carried out after a minimum cure
period of 10 minutes from completion of lining.
• The coating shall be allowed to cure for a minimum period of 60 minutes
after completion of lining before the commencement of disinfection and
flushing procedures.
1 . Principles of Water Supply Hygiene and Technical Guidance Notes
2. Effective control of a BS EN ISO 9000 Quality System In- Situ Rapid Setting
Polymeric Lining Operational
3. Guidelines and Code of Practice: Published by Warren Associates
(Pipelines) Ltd
4. Material Safety Data
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements for
Rehabilitated Sections
Using a maximum of not more than 1 00 mg/L of free chlorine
Leakage detection tests, recoating
V. Costs
Key Cost Factors
Case Study Costs
Lesser storage space required, reduced number of pit excavations, universal item
product and does not vary for different pipe diameters, all soil to be treated as
contaminated waste, allows use of existing pipe rather than exhuming it, smaller
carbon footprint, does not affect external pipe condition, small number of
resources amounting to reduced contractor risk, lesser time for installation site,
tarmac coating required at excavation pits. Contribution to material costs includes
the lining material, equipment, and use of existing pipe.
Representative coverage rate for 8 inches diameter pipe is 0.2 gallons/feet
VI. Data Sources
References
www.3M.com/water
A-5
-------
Technology/Method Close Fit/Tension Based, Symmetrical Reduction
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Conventional
Late 1980s
Over 1,000 miles (1,600 km) of Swagelining have been installed to date.
Swagelining
Suite 100
600 Bent Creek Boulevard
Mechanicsburg
PA 17050
USA
Phone: 717-724-1900
Fax:717-724-1901
Web: http ://www. Swagelining . com
Email : info . us(5)advanticagroup .com
Licensees provided on website.
• The Swagelining system uses polyethylene pipe, which has an outside
diameter slightly larger than the inside diameter of the pipe to be lined.
After sections of PE are fused together to form a continuous pipe, the PE
pipe is pulled through a reduction die, which temporarily reduces its
diameter.
• This allows the PE pipe to be pulled through the existing pipeline. After the
PE pipe has been pulled completely through the pipe, the pulling force is
removed and the PE pipe returns toward its original diameter until it presses
tightly against the inside wall of the host pipe.
• Swagelining is suitable for the rehabilitation of all types of pressure pipe.
• When the host pipe is structurally sound, the wall thickness of the liner may
be reduced.
• Since sections of PE pipe are butt fused together, there are no joints where
leaks could develop in the future.
• Compact, lightweight equipment requires very little setup time resulting in
less disruption, faster installation, and less expense.
• It is capable of installing the full range of PE pipe quickly and easily in cast
iron, ductile iron, steel, concrete and asbestos cement pipelines.
• There is no shrinkage or curing and no field chemistry or heating is required.
Polyethylene is flexible, leak tight, and highly resistant to chemical attack.
• Tension must be maintained on the string of pipe until full insertion is
completed.
• Work site requires room for a long string of butt- fused pipe sections to be
strung out before diameter reduction
Force Main Water Main Forced Sewer Other: Gas, Water Injection Lines,
Mining Slurry and any other services using metallic pipe.
II. Technology Parameters
Service Application
Service Connections
Structural Rating Claimed
Materials of Composition
Diameter Range, inches
Thickness Range, inches
Pressure Capacity, psi
Temperature Range, °F
Rehabilitation and replacement
Standard fittings are available to allow sections of PE-lined pipe to be easily and
securely reconnected to the rest of your water transmission or distribution system.
Wide variety of PE pipes and a full complement of tapping, branching, and
connection methods have been developed to provide a total renewal system.
This depends on the PE pipe rating as well as whether or not the PE is to be used
as a liner or a replacement for the existing pipe.
Polyethylene
4-44 inches
DR 1 1 to 42
This depends on the PE pipe rating as well as whether or not the PE is to be used
as a liner or a replacement for the existing pipe.
Pressure derating is required for temperatures above 80°F up to 100°F. The
manufacture to be consulted for temperatures above 100°F.
A-6
-------
Technology/Method Close Fit/Tension Based, Symmetrical Reduction
Renewal Length, feet
Other Notes
Up to 3,000 feet between excavations.
Not Available
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation Methodology
QA/QC
PE pipe is approved for potable water service in most countries, and can be
specified to withstand a wide range of internal pressures and burial depths
PE pipes used in the Swagelining process are manufactured to ISO, AGA,
ASTIVI, and API standards, so lines renewed by this process have known
physical properties and an established service life.
As per specification of PE pipe used.
As per client specifications.
As per sliplining, but the PE pipe is pulled through a die prior to being pulled
through the host pipe.
Not available
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements for
Rehabilitated Sections
Resistant to corrosion, abrasion, and ground movement.
Standard as PE pipe is used.
V. Costs
Key Cost Factors
Case Study Costs
Social & economic cost of open cut replacement versus trenchless rehabilitation
of existing pipe lines.
List of parameters or key drivers for the costs. Labor, transport, PE prices &
delivery, joints (price & delivery), mobilization, pit excavation, cleaning,
inspection, gauging, lining, testing, re-connection, site restoration.
Not available
VI. Data Sources
References
http://www.gl-group.com/en/is/8816.php
http ://www. advanticagroup. com/default. aspx?page=5 94
http://www.gl-group.com/pdf/Swagelining DS.pdf
Communication with Richard Hempson.
A-7
-------
Technology/Method Close Fit PE/Symmetrical Reduction
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Conventional
1985 introduced into the US
8,000 miles of Tite Liner installed.
Tite Liner®
United Pipeline Systems (Division of Insituform Technologies)
135 Turner Drive
Durango, CO 81 301
Phone: 970-259-0354
Fax: 970-259-0356
Web: www.insituform.com
Not available.
The liner pipe is custom sized so that the OD is larger than the ID of the host pipe.
The pipe is butt-fused together to the desired length. A roller reduction unit is
placed at the insertion end, while a winch is placed at the other. The winch pulls
the fusion welded liner through the roller reduction unit, which radially
compresses the liner OD during the insertion. Once the liner pipe is completely
through the section to be lined, the tension is released and the Tite Liner expands
radially to fit inside the host pipe.
• Resistant to many fluids
• Structural capability to bridge holes and gaps
• Minimal diameter reduction
• Low coefficient of friction
• Minimal site disruption
• Long section lengths
• Low cost
• Must be continuous installation without interruption
• HOPE liner thin wall
• Surface damage to HOPE liner during installation
• Interactive - host pipe must have sufficient structural strength to carry
internal and external loads
Force Main Gravity Sewer Laterals Manholes Appurtenances Water
Main Service Lines Other: Oil and Gas
II. Technology Parameters
Service Application
Service Connections
Structural Rating Claimed
Materials of Composition
Diameter Range, inches
Thickness Range, inches
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
Corrosion protection and abrasion resistance to steel pipes in the oil and gas,
mining, and chemical industries. Leak stoppage for water and wastewater lines.
Not available.
Class II or III, Semi- Structural
HOPE PE3408 or PE4710
2-52 inches
Not available.
Not available.
Not available.
Up to 2,600 feet
Not available.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation Methodology
QA/QC
NSF 61 Listing (for potable water applications)
Not available.
Not available.
Not available.
See above description of main features for installation process.
Not available.
A-8
-------
Technology/Method
Close Fit PE/Symmetrical Reduction
IV. Operation and Maintenance Requirements
O&M Needs
Not available.
Repair Requirements for
Rehabilitated Sections
Not available.
V. Costs
Key Cost Factors
Not available.
Case Study Costs
Not available.
VI. Data Sources
References
www. insituform .com
A-9
-------
Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating Claimed
Materials of Composition
Diameter Range, inches
Thickness Range, inches
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
III
Product Standards
Design Standards
Design Life Range
Installation Methodology
Symmetrical Reduction PE Close Fit Liner
I. Technology Background
Emerging
2001 in US
Total HOPE experience worldwide - over 8000 miles.
Insitu Guard™ Flexed HDPE
Insituform Technologies, Inc
17999 Edison Avenue
Chesterfield, MO 63005
Phone: 800-234-2992
Fax:636-519-8744
Web: http://www.insituform.com/
Not available
Inserted into a new or existing pipeline, the polyethylene liner is continuous, and
installed with a close-fit against the inner wall of the host pipe. The polyethylene
liner isolates the flow stream from the host pipe wall, eliminating internal
corrosion. InsituGuard stops leaks, and can provide a fully structural solution in
some cases.
• Rapid installation
• Drinking water approved
• Negotiates long radius (sweep) bends
• Utilizes high-performance PE 1 00 (47 1 0)
• Minimizes disruption
• Cannot do factory bends (20% diameter reduction to facilitate introduction)
• Bypass required
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Rehabilitation
Service Connections have to be excavated. Fused fittings used to reinstate.
Class 3 or 4 depending upon diameter, pressure and host pipe condition.
4710(PE100)
6 to 48 inches
DR 17 or thinner
Pressure rating to 1 50+ psi for Class 3 . Class 4 dependent upon DR.
140°F
2000+ feet depending on winching capacity.
Pipes may be cleaned, as needed, with high-pressure water jet cleaners,
mechanically powered equipment, and winch cable attached devices or fluid-
propelled pig devices.
. Technology Design, Installation, and QA/QC Information
HDPE is certified as complying with ANSI NSF Standard 61.
Class 4 design based on AWWA/PPI design standards.
Class 3 interactive design based on industry accepted design methodology.
50 years
1 . Excavations are required for installation and to remove any existing fittings.
2. The PE pipe selected for the project is welded into lengths suitable for
installation; this can be the entire length, or shorter segments to accommodate
available work space. If shorter segments are used, they will be fused together
prior to entering the roller reduction machine.
3 . The welded pipe is pushed through the roller box, which alters the shape of the
pipe, resulting in a diameter reduction of up to 20% of the cross-sectional area.
4. The liner is inserted into the host pipe.
5. Once the liner is in place, it is cut to length, end fittings are attached and the
liner is pressurized to snap the bands.
6. Intermediate fittings are installed, service connections are excavated and
A-10
-------
Technology/Method Symmetrical Reduction PE Close Fit Liner
QA/QC
reconnected, and the completed line is pressure tested, disinfected and returned
to service. Access points are backfilled and reinstated.
• Prior to installation of InsituGuard, CCTV inspection of the main is needed to
locate any obstructions, protrusion, changes in diameter or in-line valves that
could affect the InsituGuard.
• After installation, InsituGuard is inspected again visually with CCTV, and any
abnormalities are noted.
• For the post-installation pressure test, InsituGuard is subjected to an internal
pressure equal to twice the known operating pressure, or operating pressure
plus 50 psi, whichever is less.
• After a stabilization period, the test period is one hour. Limit on make-up
water to maintain pressure is 20 gallons per inch diameter per mile of pipe per
day.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements for
Rehabilitated Sections
Before returning the InsituGuard to service, for potable water, the system shall be
disinfected in accordance with local standards.
Excavate, remove the damaged portion of InsituGuard and host pipe (if necessary),
install end couplers and bridge the previously damaged location with new pipe and
couplers as required.
V. Costs
Key Cost Factors
Case Study Costs
The most costly material is the pipe.
Not available
VI. Data Sources
References
http ://www. insituform. com/default, aspx
http://www.insituform.com/content/309/insituguard-pressure-pipe.aspx
http ://www. insituform. com/content/3 1 2/poly flex installation. aspx
A-ll
-------
Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating Claimed
Materials of Composition
Diameter Range, inches
Thickness Range, inches
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
III
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation Methodology
Rolldown/Close Fit PE Liner Symmetrical Reduction
I. Technology Background
Emerging
Not available.
Not available.
Rolldown
Subterra
Daniels Contractors Ltd
Lyncastle Way
Appleton Thorn
Warrington WA4 4ST
UK
Phone: +44 (0)1925 860666
Email: info(g),subterra.co.uk
Web: www.subterra.co.uk
Not available.
Rolldown is a close fit polyethylene lining. Standard grade (PESO) PE is pushed
through a series of concentric rollers reducing the diameter to facilitate placement
inside a deteriorated host pipe. After insertion, the liner is pressurized with water
at ambient temperature to revert to its original size.
• Negotiate bends up to 11 .25°
• Designed to be fully structural (full pressure) or just a thin wall liner that
bridges over holes and gaps
• PE holds its reduced diameter indefinitely prior to reversion, allows
stop/start internal corrosion
• Minimal loss of cross-sectional area and therefore capacity
• Custom extruded PE with OD to match host pipe ID
Force Main Gravity Sewer Laterals Manholes Appurtenances Water
Main Service Lines Other: Gas transmission and distribution
II. Technology Parameters
Water Supply and Distribution, Sewer Pumping Mains
Reinstate via excavation
Fully structural (IV) or Semi- Structural (II)
PESO
4-20 inches (100-500mm)
Not available.
232 psi (16 bar)
73°F (pressure derating required at higher temperatures)
5,000 feet (1,500 meters) in one insertion
Not available.
Technology Design, Installation, and QA/QC Information
NSF 61 Certified (for potable water applications)
Not available.
50 years
Not available.
PE pipe is custom extruded with OD matching ID of host pipe. The host pipe is
cleaned, removing any internal corrosion or deposits. The integrity of the host
pipe should be checked via CCTV. At site, the string of PE pipe is butt- fused
together and then pushed through a series of concentric rollers, which reduces the
diameter of the liner pipe allowing it to be pulled through the host pipe. Insertion
lengths of up to 5,000 feet are possible. The reduced diameter PE pipe maintains
its diameter until subjected to internal water pressure. The internal pressure
reverts the pipe back to its original diameter and in close contact with the host
pipe. The string of PE pipes can be pulled through a bend of up to 1 1 .25°.
Standard couplings are then attached to the end of the exposed pipe sections and
make-up pieces are inserted to reconnect the pipe to the existing main.
A-12
-------
Technology/Method
QA/QC
Rolldown/Close Fit PE Liner Symmetrical Reduction
CCTV the line, after cleaning, to make sure there are no impediments to prevent
insertion and reversion of the PE liner.
IV. Operation and Maintenance Requirements
O&M Needs
Not available.
Repair Requirements for
Rehabilitated Sections
Not available.
V. Costs
Key Cost Factors
Not available.
Case Study Costs
Not available.
VI. Data Sources
References
www.subterra.co.uk, Rolldown flyer
A-13
-------
Technology/Method Subcoil/Close Fit PE Liner Fold and Form
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Emerging
Not available.
Not available.
Subcoil
Subterra
Daniels Contractors Ltd
Lyncastle Way
Appleton Thorn
Warrington WA4 4ST
UK
Phone: +44 (0)1925 860666
Email: infofgjsubterra. co.uk
Web: www.subterra.co.uk
Not available.
Subcoil is a close fit polyethylene lining that is factory folded and held in a "C"
shape. Subcoil arrives on a large spool. After insertion, the liner is pressurized
with water at ambient temperature breaking the temporary bands and reverting the
pipe back to its original dimensions and forming a close fit with the host pipe.
• Negotiate bends up to 22.5°
• Designed to be a thin wall liner that bridges over holes and gaps preventing
leakage
• Stops internal corrosion
• Minimal lost of cross-sectional area and therefore capacity
• Custom extruded PE with OD to match host pipe ID
• Proprietary end fittings needed to join the liner up to the existing main
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Gas transmission and distribution
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of Composition
Diameter Range, inches
Thickness Range, inches
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
Water Supply and Distribution, Sewer Pumping Mains
Reinstate via excavation using proprietary fittings
Semi- Structural (II)
PESO
4-12 inches (95-300mm)
Not available.
Depends on size of hole being bridged
73°F (pressure derating required at higher temperatures)
3,500 feet (1,000 meters) in one insertion
Not available.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation Methodology
NSF 61 Certified (for potable water applications)
Not available.
50 years
Not available.
PE pipe is custom extruded with OD matching ID of host pipe. The host pipe is
cleaned, removing any internal corrosion or deposits. The integrity of the host
pipe should be checked via CCTV. The spool of PE is pulled through the host
pipe. Insertion lengths of up to 3,500 feet are possible. The reduced cross-section
PE pipe maintains its shape until subjected to internal water pressure. The
internal pressure breaks the restraining straps and reverts the pipe back to its
original diameter and in close contact with the host pipe. The string of PE pipes
can be pulled through a bend of up to 22.5°. Proprietary couplings are then
attached to the end of the exposed pipe sections and make-up pieces are inserted
to reconnect the pipe to the existing main.
A-14
-------
Technology/Method Subcoil/Close Fit PE Liner Fold and Form
QA/QC
CCTV the line (after cleaning) to make sure there are no impediments to prevent
insertion and reversion of the PE liner. Pressure test after insertion.
IV. Operation and
O&M Needs
Repair Requirements for
Rehabilitated Sections
Maintenance Requirements
Not available.
Not available.
V. Costs
Key Cost Factors
Case Study Costs
Not available.
Not available.
VI.
References
Data Sources
www. sub terra .co.uk
A-15
-------
Technology/Method PE Liner/ Cement Mortar Bonded Interactive Composite Liner
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Innovative
UK market in 1 999 and US market in 2006
MainSaver is a new product technology with approximately 5,000 feet installed in
the US. Annual installations are expected to increase from about 5,000 feet per
year to 20,000+ feet per year.
MainSaver"
MainSaver
1819 Denver West Drive, Suite 100
Golden, CO 80401
Phone: 303-277-8603
Fax: 303-277-0042
Web: www. mainsaverworld .com
Email: info(5),mainsaverworld.com
MainSaver has been installed in several municipal water systems in the Rocky
Mountain region, including several high profile linings (two under Interstate 25,
approximately 3,300 feet in neighborhoods, and a school fire line restoration) for
the City of Thornton, Colorado.
City of Thornton
12450 Washington Street
Thornton, CO 80241-2405
Contact:
Mr. Jason Pierce, P.E.
720-977-6274
MainSaver is a flexible MDPE tube with integral grout key hooks on the outside
surface, which is inserted into the main, then a pre-determined quantity of
proprietary cement grout is placed between the outside of the tube and the inside
of the host pipe. Air pressure is used to move a rounding swab along the length of
the liner, which progressively expands the tube and distributes the grout against
the interior surface of the host pipe, physically filling all pipe defects. MainSaver
is used to renew pipes with holes, displaced joints, leaking joints, offsets of no
more than 1 2.5% of each joint and maximum 22° long radius elbows. It is NSF 61
certified for use with potable water.
• Simple system, easy to install
• Low installation cost
• Suitable for use with all types of pipes, particularly ferrous, asbestos-
cement, reinforced concrete, and pre-stressed concrete cylinder pipe.
• Cement provides active corrosion protection (ferrous mains) and the PE tube
ensures water quality
• Prevents leakage
• Service connections can be reinstated robotically to reduce excavation
requirements.
• Ideal installation temperature range is between 40°F and 80°F, although
MainSaver has specific hot and cold weather installation procedures.
• Designed for pressure pipes only.
• Unsuitable for lining through diameter changes
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Potable water, raw water and force mains
MainSaver uses its RoboTap™ method for remote robotic service connection
reinstatement after the MainSaver composite has been installed. This eliminates
the need to excavate the main to reinstate service connections.
Class III, Interactive and Semi- Structural Liner
Medium density polyethylene, cement mortar (Masterflow181 1515 PipeSaver)
A-16
-------
Technology/Method PE Liner/ Cement Mortar Bonded Interactive Composite Liner
Composition
Diameter Range, inches
Thickness Range, inches
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
4 inches to 12 inches
Approximately 3/16 inches (3.0 mm). However, grout will often be thicker where
it is filling pipe defects.
Max. hole size of 2.4 inches or gap of 0.4 inches with pressure up to 294 psi (20
bar)
Min. 37°F during installation
Approximately 500 feet
All installed materials are ANSI/NSF 61 certified for contact with potable water.
Cathodic protection can be restored to ferrous pipes to retard external corrosion.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation Methodology
QA/QC
NSF 61 listed
None cited.
If properly installed, a 50+ year design life for the liner would be reasonable.
None cited.
Main must be thoroughly cleaned and CCTV inspected. Robotically plug any
open service connections where unwanted grout may migrate. Tube liner is
winched into main. At end where grout is to be introduced, fit grout injection
fitting to main. Trim other end of liner and install tensioning and anti-twist
assembly. Grout slug is pumped into the grout fitting and the rounding swab is
advanced down length of lining run to distribute the mortar around the outside of
the liner. The liner is held under very low air pressure in order to allow the grout
to hydrate for up to 16 hours. Once the grout is hydrated, the lining is inspected
using CCTV and infrared thermography. MainSaver's RoboTap is used to
remotely, robotically reinstate the service connections, and PE end seals are
installed to protect the new liner as it is returned to service. The pipe is
disinfected (if potable water).
MainSaver/W.S.U.'s Quality Management System is certified to ISO 9001:2000
for the Custom Manufacture of NSF Standard 61 Extruded Tape and In-situ
Remediation of Potable Water Lines. The host main is cleaned and CCTV
inspected prior to lining, and post-lining the installation is CCTV and IRTV
(infrared) inspected to verify grout distribution behind the liner.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements for
Rehabilitated Sections
No special maintenance needs. PE liner is smooth and should maintain low
frictional resistance.
If a lined section needs to be repaired, the MainSaver composite liner can be cut
out with the damaged pipe section and conventionally patched with a spool piece.
V. Costs
Key Cost Factors
Case Study Costs
Set up costs (key cost drivers) are generally dependent upon mobilization
logistics, traffic control requirements, trench backfilling requirements, and asphalt
and concrete replacement. Material costs are constant. The main variable is the
amount of material required.
MainSaver's installation costs are competitive with cement mortar lining, less
expensive than CIPP rehabilitation, and less expensive than conventional pipeline
replacement.
VI. Data Sources
References
MainSaver Web site and brochure. MainSaver will provide third party test data
and results to interested parties upon request.
A-17
-------
Technology/Method Subline/Close Fit PE Liner Fold and Form
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Emerging
Not available.
Not available.
Subline
Subterra
Daniels Contractors Ltd
Lyncastle Way
Appleton Thorn
Warrington WA4 4ST
UK
Phone: +44 (0)1925 860666
Email: info(g),subterra.co.uk
Web: www.subterra.co.uk
Consolidated Edison, Inc.
Bronx and Manhattan
1 200 feet of 30 inches and 600 feet of 36 inches cast iron lined with Subline.
760mm Subline had an SDR of 32.5 and the 910 mm Subline an SDR of 60.
Subline is a close fit polyethylene lining. Pre- welded standard grade PE (PESO) is
pushed through a former that folds it into a "C" shape that is temporarily
maintained by restraining bands. After insertion, the liner is pressurized with
water at ambient temperature breaking the temporary bands and reverting the pipe
back to its original dimensions.
• Negotiate bends up to 45°
• Designed to be a thin wall liner that bridges over holes and gaps preventing
leakage
• Stops internal corrosion
• Minimal lost of cross-sectional area and therefore capacity
• Custom extruded PE with OD to match host pipe ID
• Proprietary couplings needed to join the liner up to the existing main
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Gas transmission and distribution
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range, inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
Water Supply and Distribution, Sewer Pumping Mains
Reinstate via excavation using proprietary fittings
Semi-Structural (II)
PESO
3-60 inches (75-1,600 mm)
0.12-0.80 inches (3-20 mm)
Depends on size of hole being bridged
73°F (pressure derating required at higher temperatures)
3,500 feet (1,000 m) in one insertion
Include specific notes here such as water quality, I/I control, other
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
NSF 61 Certified (for potable water applications)
Not available.
50 years
Not available.
PE pipe is custom extruded with OD matching ID of host pipe. The host pipe is
cleaned, removing any internal corrosion or deposits. The integrity of the host
pipe should be checked via CCTV. At site, the string of PE pipe is butt- fused
together and then pushed through a former that folds the pipe into a "C" shape
allowing it to be pulled through the host pipe. The pipe is temporarily strapped to
A-18
-------
Technology/Method Subline/Close Fit PE Liner Fold and Form
QA/QC
maintain the reduced shape through insertion. Insertion lengths of up to 3,500 feet
are possible. The reduced cross-section PE pipe maintains its shape until
subjected to internal water pressure. The internal pressure breaks the restraining
straps and reverts the pipe back to its original diameter and in close contact with
the host pipe. The string of PE pipes can be pulled through a bend of up to 45°.
Proprietary couplings are then attached to the end of the exposed pipe sections and
make-up pieces are inserted to reconnect the pipe to the existing main.
CCTV the line, after cleaning, to make sure there are no impediments to prevent
insertion and reversion of the PE liner. Pressure test after insertion.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Not available.
Not available.
V. Costs
Key Cost Factors
Case Study Costs
Not available.
Not available.
VI. Data Sources
References
www.subterra.co.uk, Subline fiver
A-19
-------
Technology/Method Fold and Form PE Close Fit Liner
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits Claimed
Main Limitations Cited
Applicability
(Underline those that
apply)
Emerging
2001 in US
Total HOPE experience worldwide - over 8,000 miles.
Folded HOPE worldwide experience - approximately 6 miles.
InsituGuard'M Folded HDPE
Insituform Technologies, Inc
17999 Edison Avenue
Chesterfield, MO 63005
Phone: 800-234-2992
Fax:636-519-8744
Web: http://www.insituform.com/
1,000 feet of 19-24 inches
Steven Tusler
City of Colorado Springs
121 S. Tejon
Colorado Springs, CO 80947
719-668-8537
19,000 feet of 30 inches
Mr. Dick Fett
IMC Agrico Company
Mulberry, Florida
863-648-9990
3, 700 feet of 36 inches
Mr. Howard Wellspring
City of Baytown, TX
2 123 Market St
Baytown, TX 77522
713-424-5508
Inserted into a new or existing pipeline, the polyethylene liner is continuous, and
installed with a close- fit against the inner wall of the host pipe. The polyethylene
liner isolates the flow stream from the host pipe wall, eliminating internal
corrosion. InsituGuard stops leaks, and can provide a fully structural solution in
some cases.
• Rapid installation - 40% reduction in diameter
• Drinking water approved
• Negotiates long radius (sweep) bends
• Utilizes high-performance PE 1 00 (471 0)
• Cannot do factory bends
• Bypass required
• Wall thickness limitation dependent upon diameter.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range, inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range, °F
Rehabilitation
Service Connections have to be excavated. Fused fittings used to reinstate.
Class 3 or 4 depending upon diameter, pressure and host pipe condition.
4710(PE100)
12-48 inches
DR 1 7 or thinner
Pressure rating to 1 50+ psi for Class 3 . Class 4 dependent upon DR.
Temperature derating required for temperatures over 80°F. Max temp is 140°F
A-20
-------
Technology/Method Fold and Form PE Close Fit Liner
Renewal Length, feet
Other Notes
2,000+ feet depending on winching capacity.
Pipes may be cleaned, as needed, with high-pressure water jet cleaners,
mechanically powered equipment, and winch cable attached devices or fluid-
propelled pig devices.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation
Methodology
QA/QC
HOPE is certified as complying with ANSI NSF Standard 61 .
Class 4 design based on AWWA/PPI design standards. Class 3 interactive design
based on industry accepted design methodology.
50 years
1 . Excavations are required for installation and to remove any existing fittings.
2. The PE pipe selected for the project is welded into lengths suitable for
installation; this can be the entire length, or shorter segments to accommodate
available work space. If shorter segments are used, they will be fused together
prior to entering the folding machine.
3 . The welded pipe is pushed through the folding machine, which alters the shape
of the pipe, resulting in a diameter reduction of up to 40% of the cross-sectional
area. The shape is maintained by banding the folded pipe.
4. The liner is inserted into the host pipe.
5. Once the liner is in place, it is cut to length, end fittings are attached and liner is
pressurized to snap the bands.
6. Intermediate fittings are installed, service connections are excavated and
reconnected, and the completed line is pressure tested, disinfected and returned to
service. Access points are backfilled and reinstated.
• Prior to installation of InsituGuard, CCTV inspection of the main is needed to
locate any obstructions, protrusion, changes in diameter or in-line valves that
could affect the InsituGuard.
• After installation, InsituGuard is inspected again visually with CCTV, and
any abnormalities are noted.
• For the post-installation pressure test, InsituGuard is subjected to an internal
pressure equal to twice the known operating pressure, or operating pressure
plus 50 psi, whichever is less. After a stabilization period, the test period is
one hour. Limit on make-up water to maintain pressure is 20 gallons per inch
diameter per mile of pipe per day.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Before returning the InsituGuard to service, for potable water, the system shall be
disinfected in accordance with local standards.
Excavate, remove the damaged portion of InsituGuard and host pipe (if
necessary), install end couplers and bridge the previously damaged location with
new pipe and couplers as required.
V. Costs
Key Cost Factors
Case Study Costs
The most costly material is the pipe.
Not available
VI. Data Sources
References
http://www.insituform.com/default.aspx
A-21
-------
Technology/Method Fold and Form/Thermoformed
I. Technology Background
Status
Conventional
Date of Introduction
1994
Utilization Rates
Over 4.5 million feet installed since 1994. Split fairly evenly between 4 to 16
inche and 18 to 30 inches pipeliner installations. As of 2008, PVC Alloy
Pipeliner has been installed in 36 states, and 2 international countries, with over
$20 million dollars worth of PVC Alloy Pipeliner contracts completed annually.
Listed for use by at least 30 State DOT's.
Vendor Name(s)
Ultraliner PVC Alloy Pipeliner™
Ultraliner, Inc.
201 Snow Street/PO Drawer 3630
Oxford, AL 36203
Phone:256-831-5515
Fax:256-831-5575
Website: www.ultraliner.com
Email: info(gjultraliner.com
Practitioner(s)
Georgia Department of Transportation (GDOT) - District One
Ken Reed, District Bridge Maintenance Manager
2505 Athens Hwy SE
P.O. Box 1057
Gainesville, Georgia 30503-1057
City of Los Angeles, California
Keith Hanks
650 S. Spring St., Room 1000
Los Angeles, CA 90014
Phone:213-847-8770
Jacksonville Naval Air Station [1]
Bill Myer, the Navy's airfield facility manager for bothNAS Jacksonville and the
Outlying Field [OLF] of the White House
Phone: 904- 542-3176
Email: bill.meyer(gjnavy.mil
Description of Main
Features
Ultraliner PVC Alloy Pipeliner is a solid wall PVC pipe manufactured from
virgin PVC homopolymer resin with no fillers, which is modified with special
additives to improve ductility and toughness. The pipeliner is collapsed flat and
coiled on a reel in continuous, jointless lengths. Small diameters, 12 inches and
less, are folded in the field prior to insertion, while large diameters, 15 inches and
above, are deflected to a smaller profile (approx. 50%) at the manufacturing
facility.
Main Benefits Claimed
Conforms to size transitions, tight bends, offset joints and other
irregularities.
Does not shift/shrink longitudinally or radially after installation (memory
reset by heat and stretching to new dimensions); consistently achieves a tight
fit.
Able to withstand significant shallow impact loads.
Reliable flanged and gasketed end seals in pressure applications and
hydrophilic gasket end seals in gravity applications.
The solid wall PVC alloy cuts and polishes smoothly and quickly without
jagged edges at lateral reconnections.
Very high abrasion resistance and ductility.
PVC alloys are chemically compatible with any sewerage application where
a traditional direct burial PVC pipe would be appropriate.
Factory controlled consistency of design properties including modulus, wall
thickness, and corrosion resistance enhances long-term asset manageability
[2], [3].
Low mobilization, shipping, and set-up costs make for exceptional
competitiveness in rural, DOT, and smaller scale projects.
A-22
-------
Technology/Method Fold and Form/Thermoformed
Main Limitations
Cited
Applicability
(Underline those that
apply)
• Relatively small job site footprint. Most equipment can be parked away
from the insertion access if necessary.
• Materials are NSF 61 approved, but system has yet to be listed for use in
potable water lines; listing is planned to be pursued in the future.
• Limited long-term pressure test data to support independent use as a fully
structural liner in pressure applications; available data supplemented by 10
years of practical field application.
• Requires access at both ends of the pipe for installation.
• Requires excavation for a pressure seal at branch connections.
• All tight-fitting liners require additional technologies (grout packing, lateral
lining, or other) to provide a seal at internal branch connections.
• Elevated temperatures lower the modulus of thermoplastics like PVC alloys,
thus modulus adjustments should be considered within the structural
equations when the application is significantly above routine wastewater
flow temperatures.
• Construction network is small scale which limits available economies of
scale and influences potential competitiveness on larger scale projects
(particularly 30,000 linear feet +).
• Not currently available in most major metros. This is subject to change with
coverage expansion.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Culverts, Industrial, Water Intake
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
Wastewater, storm water, raw water, industrial, power
Laterals remotely reinstated with robots. Down time 5 hours plus time to
reinstate laterals. Sewer main flow typically disrupted for 3 to 4 hours.
Fully structural, independent liner. Flexural modulus available as 145,000 psi
(F1871) or 280,000 psi (F1504), and flexural strength as 4,100 psi (F1871) or
5,000 psi (Fl 504). Design is determined by industry standard equations with
material properties adjusted for long-term performance under load.
Virgin PVC alloy compound (impact modified, no fillers, NSF approved)
4 to 30 inches - F1504 only to 16 inches
4 inches -DR 32.5, 6, 8, 9 inches -DR 32.5 to 35, 10, 12, 15, 16 inches -DR
32.5 to 41 , 1 8 inches - DR 35 to 50, 21 , 24, 30 inches - generally designated by
wall thickness up to 0.65 inches
Currently available for low pressure, under 80 psi (only available up to 1 5 inches
diameter pipe). Design methodologies are still being researched, with no
available standards. Have completed one "experimental" 150 psi project.
1 00°F (continuous) for Fl 871 ; 1 20°F for Fl 504; intermittent and diluted flows at
higher temps may be acceptable. Under sustained elevated temperatures, the
design modulus needs to be adjusted for structural calculations.
Up to 600 feet typical; 1 ,000 feet for 8 to 12 inches has been achieved, and up to
650 feet for 21 inches and 24 inches, up to 500 feet for 30 inches
Minimal to no loss of flow capacity expected; flow velocity increases can be
significant. No noxious or toxic chemicals (NSF potable water and FDA food
contact safe materials). Safe for use in environmentally sensitive applications.
Has evidenced comparable I/I control to competitive alternatives in field
applications.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
ASTM F-1871 Standard Specification for Folded/Formed Poly (Vinyl Chloride)
Pipe Type A for Existing Sewer and Conduit Rehabilitation
ASTM F-1504 Standard Specification for Folded Poly (Vinyl Chloride) (PVC)
Pipe for Existing Sewer and Conduit Rehabilitation
Appendix within ASTM installation standard F1867 and F1947 is the same as
that within ASTM F1216 for CIPP products.
A-23
-------
Technology/Method Fold and Form/Thermoformed
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
100 year claimed [4], [5], but not field-demonstrated; long-term material data
testing and creep strain analysis offered as evidence of claim.
ASTMF1867
ASTMF1947
The Ultraliner PVC Alloy pipeliner is pulled into the cleaned host pipe, usually
through a manhole. Access is required at both ends. Once in place, the ends are
plugged and the pipeliner expanded with steam and air pressure (thermoformed)
to reset the PVC Alloy's "memory" to the new size and shape. Installation and
processing of the liner takes 4 to 5 hours, excluding the time to reinstate laterals
and some street operations set-up and tear down time.
Design material properties are quality assured at the manufacturing facility per
ASTM product standards (F1871 or F1504) using industry standard QA/QC
protocols common to the manufacture of all PVC pipes. Specification
compliance is confirmed prior to installation. Standard industry post-construction
QA/QC tests are available for further verification.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
No special maintenance training is required. Any cleaning or de-rooting
procedure routinely practiced by maintenance personnel within PVC pipes is safe
for use within PVC Alloy pipeliners. The host pipe can easily be removed
(hammer a rigid host pipe to shatter it) without damaging the pipeliner, if new
connections or repairs need to be made in the future. Standard fittings, couplings,
and saddles are readily adaptable for use with PVC Alloy Pipeliners.
PVC Alloy pipeliners are capable of structurally lining and conforming to
crushed sections of pipe and severe off-sets. Repair decisions are therefore
generally driven by system performance and long-term O&M requirements rather
than constructability limitations.
V. Costs
Key Cost Factors
Case Study Costs
PVC Alloy Pipeliners have relatively low set-up, mobilization, and shipping &
handling costs. Materials are shelf-stable (do not have to be temperature
controlled) and can be affordably shipped one reel at a time or in bulk
(thereby enabling payment for stored materials where appropriate).
• Extensive cleaning of the host pipe, above and beyond what is considered a
routine pipe maintenance cleaning project, is required for all tight- fitting
liners.
• On gravity pipes, no excavation is required, providing significant savings.
Access can be achieved through a manhole ring on one end and at least a
clean-out on the other end. Laterals are robotically reinstated internally.
• Pressure pipes frequently require excavation at the ends (and in the middle
where maximum lengths have been exceeded), at valves and hydrants, and at
connections. This can significantly impact cost-competitiveness against
alternative technologies that can avoid excavation.
• De- watering is not required for quality assurance, as water exposure cannot
alter design property compliance of a solid wall PVC Alloy Pipeliner, but it
may be utilized for risk control, as appropriate, since excessive groundwater
can narrow the window of installability.
• The material cost is all inclusive (and includes manufacturing QA/QC) with
no additional on-site mixing of chemicals, nor "finishing" labor
requirements prior to installation.
• End seals, when specified, are routinely included in the unit price for the
pipeliner.
• Lateral reinstatements are generally a separate cost because the numbers of
connections vary.
• PVC Alloy pipeliners tend to be more competitive on small scale (short
lengths, small diameter) projects given low mobilization and set up costs
compared to other trenchless rehab methodologies.
GDOT- seven deteriorated culverts, ranging in diameter from 15 inches to 30
inches and 40 to 80 feet in length were lined for a total cost of $43,288. This was
34% less than the bid price of $65,674 to dig-and -replace. Generally speaking,
A-24
-------
Technology/Method
Fold and Form/Thermoformed
large scale (25,000 feet +) 8 inches PVC Alloy pipeline! projects can receive bids
in the $22 per feet range, whereas smaller scale 8 inches projects with significant
mobilization requirements or especially challenging conditions can receive prices
up into the approximately $40 per feet range.
VI. Data Sources
References
Ultraliner PVC Alloy Pipeliner™ brochure
Private correspondence with Grant Whittle, VP of Ultraliner.
[1] Whittle L. G. (2008). Takes Off at Naval Air Station in Jacksonville, Fla.
Trenchless Technology Magazine, November, 2008.
[2] Whittle L. G. and W. Zhao (2009). The Need for and Benefits of a Minimum
Wall Thickness Requirement for Pipeliners. No Dig International 2009, Toronto,
Canada, March 29 - April 3. Paper Accepted.
[3] Zhao W. and L. G. Whittle (2009). An Asset Management Definition of Pipe
Rehabilitation Success or Failure. ASCE Pipeline International 2009, San Diego,
CA, Aug 16-19. Abstract Accepted.
[4] Zhao W. and L. G. Whittle (2008). Long-term Performance life Prediction
Using Critical Buckling Strain. NASTT No-dig 2008, Dallas, TX, April 27-May
2.
[5] Zhao W. and L. G. Whittle (2008). Plastic Pipeliner Long-term Design: How
to Accommodate Creep? ASCE Pipeline International 2008, Atlanta, GA, July
22-27.
A-25
-------
Technology/Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Fold and Form PVC/ Thermoformed
I. Technology Background
Conventional
1999
200 miles in the past 10 years.
EX Pipe
Miller Pipeline
P.O. Box 34141
Indianapolis, IN 46234
Phone: 800-428-3742
Email: info(3)millerpipeline.com
City of Piano - Over 200,000 LF Installed
Steve Spencer
P.O. Box 860358
Piano, Texas 75086
972-769-4140
Anne Arundel Co, MD - Over 130,000 LF Installed
Lew Addison
504 Baltimore Annapolis Blvd.
Severna Park, MD 21 146
410-647-2727
Collier County, FL - Over 100,000 LF Installed
Steve Nagy
6027 Shirley St.
Naples, FL 34109
239-591-0186
EX Pipe is a high strength, un-plasticized PVC manufactured in a factory
environment, meeting ASTM Fl 504. The EX Pipe material is softened with heat
and continuously inserted into the host pipe via manholes or other access points.
After insertion, the pipe is then expanded approximately 1 0% to fit tightly within
the host pipe.
• Resistant to chemicals and abrasion
• Stops water infiltration and exfiltration, root intrusion and soil loss
• Smooth pipe finish improves flow characteristics
• Cost to install EX Pipe is much less than conventional trenching techniques
• No styrene odors
• Low coefficient of thermal expansion means service cut-outs will not move
• Can be installed in lines with 90° bends and small diameter changes
• Only available in diameters 6 to 1 5 inches
• Installation by Miller Pipeline only
• Minimal reduction in cross-section
• No long-term pressure or tensile testing to substantiate a hydrostatic design
basis for pressure use
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Not available.
Sewer laterals reinstated with robotic cutter and CCTV. No information on use
of EX Pipe for low pressure applications.
Not available.
EX Pipe is made from a base PVC, conforming to ASTM D1784, cell
classification 12334B. The following are physical properties of EX Pipe:
Test Method Value
Flexural Modulus, psi ASTM D790 340,000
Flexural Strength, psi ASTM D790 9,000
A-26
-------
Technology/Method Fold and Form PVC/ Thermoformed
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range, °F
Renewal Length, feet
Other Notes
Tensile Strength, psi ASTM D638 6,000
Coeff Of Thermal Expansion, in/in/°F 3.0 x 10"5
Long-term reduction of flexural modulus for creep 50%
6-15 inches
0.20-0.43 inches
Not available
HOT
6 inches - 600 feet, 8 inches - 580 feet, 10 inches - 425 feet, 12 inches - 425
feet, 15 inches - 350 feet
No NSF 61 listing so not approved for potable water.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
ASTM Fl 504
ASTM F1947, Appendix XI (same as F1216)
50 year
ASTM Fl 947
Existing pipe is first cleaned and CCTV. Protruding service connections are
removed, and partially collapsed sections repaired (open cut). The EX Pipe is
heated in the pipe warmer trailer to soften the PVC. Once softened, the EX Pipe
is winched through the host pipe. Once in place, steam and pressure are applied
to expand the PVC tightly against the host pipe. Steam is then replaced with air,
while maintaining a constant pressure and the PVC is cooled to 100°F. After
cooling, the PVC is trimmed at each pipe end. If for gravity sewer, house service
connections are reopened using robotic cutting devices combined with a CCTV.
The line undergoes CCTV after installation. A section of pipe ("coupon") is
removed from each run of pipe for independent testing. Testing should include
flexural and tensile properties, as a minimum.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Same as PVC Pipe
Same as PVC Pipe
V. Costs
Key Cost Factors
Case Study Costs
• Avg. length of line per setup
• Number of laterals to be reconnected
• On 12-15 inches by-pass pumping can become a cost factor
• Heavy cleaning or protruding tap removal
• Limited easement access
• Point repairs of collapsed or partially collapsed pipe
$20-$45/feet depending on size and quantities
VI. Data Sources
References
www. millerpipeline. com
A-27
-------
Technology/Method Fold and Form PVC/ Thermoformed
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Conventional
1992
Over 100 miles for gravity sewer, no force mains
AM-Liner II®
American Pipe & Plastics, Inc.
PO Box 577
Binghamton, NY 13902
Phone: 607-775-4340
Email: ampipe(g)ampipe.com
Website: www.amliner.com
Not available.
AM-Liner II is manufactured from PVC specially formulated for pipeline
rehabilitation. The AM-Liner II is pulled into the host pipe and thermoformed
creating a seamless, jointless, solid wall PVC pipe that tightly conforms to the
interior contours of the original host pipe.
• Installation can be done in under 4 hours - minimizes by-pass pumping and
traffic control
• Liner is manufactured in a controlled environment, not in the field.
• Installed only by trained licensed contractors.
• PVC is resistant to all chemicals normally found in a sewer.
• Smooth interior - low friction factor
• No experience with pressure applications
• Not cost competitive with CIPP in diameters over 1 2 inches
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Culverts
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Gravity wastewater and storm water
Laterals reinstated robotically. No pressure connections.
Fully structural for gravity sewer. Not actively marketed for force mains.
PVC compound conforming to ASTM D 1784 Cell Classification 12111. The
installed liner has the following minimum physical properties:
Test Method Value
Tensile Strength, psi ASTMD638 3,600
Tensile Modulus, psi ASTM D638 1 55,000
Flexural Strength, psi ASTM D7 90 4,100
Flexural Modulus, psi ASTMD790 145,000
A 25% reduction used for long-term modulus.
6-12 inches
0.0185 inches (SDR 32.5) to 0.462 inches (SDR 26)
Unknown.
Unknown.
1000 feet.
Not available.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
ASTM F1871, Standard Specification of Folded/Formed Poly (Vinyl Chloride)
Pipe Type A for Existing Sewer and Conduit Rehabilitation
ASTM F1867, Appendix XI (same as F1216)
Not available.
ASTM F1867, Standard Practice for Installation of Folded/Formed Poly (Vinyl
Chloride) (PVC) Pipe Type A for Existing Sewer and Conduit Rehabilitation
A-28
-------
Technology/Method Fold and Form PVC/ Thermoformed
Installation
Methodology
QA/QC
High pressure water jet and CCTV inspect the line before installing liner. Heat
the coil of folded flat AM-Liner II in the trailer until it is flexible enough to
uncoil and pull through the shaping device and into the host pipe. Shaping
device located at entrance to host pipe, or alternatively on back of heating trailer.
High pressure water hose from cleaning truck is connected to the water spray
nozzle assembly on the shaping device. The liner is pulled from the reel, the end
(3 feet) folded over, and holes drilled for attachment of the pulling cable. The
liner is then winched through the shaping device, after flow of water to the spray
nozzles is started. The liner is pulled until it arrives at the downstream pit
(manhole) and is brought to street level. The liner is cut at street level at both
ends, leaving several feet of extra liner for stress relief. Steam is applied to the
liner from the upstream free end. The pressure in the liner is controlled with the
release of steam at the downstream end. A temperature of 200°F is maintained
for the predetermined length of time. The cooling process is begun by switching
from steam to compressed air. The pressure is maintained for 30 minutes after
the liner has cooled to 80°F. The pressure is released and the ends trimmed. The
liner is CCTV inspected and service connections reinstated robotically.
Field samples collected per ASTMF 1867, Section 7. 3. Leakage test after cool
down, and before reinstatement of connections.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
None identified.
None identified.
V. Costs
Key Cost Factors
Case Study Costs
Not available.
Not cost competitive with CIPP above 12"
VI. Data Sources
References
AM-Liner Data Sheet, AM-Liner II General Specification (Aug. 16, 2005), AM-
Liner Installation Procedure (10/05)
A-29
-------
Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
II
Product Standards
Design Standards
Design Life Range
Close Fit Lining/Expandable PVC
I. Technology Background
Conventional
Not available
Not available
Duraliner™ expandable PVC pipe
Underground Solutions, Inc.
229 Howes Run Road
Sarver, PA 16055
Phone: 724-353-3000
Fax: 724-353-3020
Email: info(g)undergroundsolutions.com
Web: www.undergroundsolutions.com
Not available
Duraliner™ is a patented, fully structural pipe rehabilitation system. The piping
system can handle a wide range of system operating pressures and restore or
improve the flow capacity of the host pipe. Duraliner™ PVC provides a design-
life of 100+ years. The end result is a brand new pipe within the existing pipe.
• It meets system operating pressures.
• Fully structural "stand alone" system.
• It is resistant to water disinfectant induced oxidation and resistant to
hydrocarbon permeation.
Not available
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Fire protection systems , Industrial water
lines
II. Technology Parameters
Rehabilitation and Replacement
• Duraliner™ is tapped with standard fittings and procedures.
• Duraliner™ easily connects with standard fittings and valves.
• Most common applications have Duraliner™ expanded to ductile iron (DI)
outside diameters (OD), making standard PVC gasketed fittings compatible.
• Duraliner™ may be tapped with the same tapping saddles used on
conventional PVC.
• When tapping Duraliner™ one should refer to the Uni-Bell PVC Pipe
Association's guidance for tapping PVC.
Not available
PVC
4-16 inches
Not available
150psi+
Not available
Not available
The improved coefficient of friction offsets the reduction in internal area to
maintain or improve flow.
.. Technology Design, Installation, and QA/QC Information
NSF 61 Certified
Products meet all of the same current performance standards and health/safety
issues as AWWA C900 and C905 PVC pipe
It conforms to cell classification 12454 as defined in ASTM D1784, meets
ANSI/AWWA C900 or ANSI/AWWA C905
100 Year Design Life
A-30
-------
Technology/Method Close Fit Lining/Expandable PVC
Installation Standards
Installation
Methodology
QA/QC
Not Available
• Minimal excavations are performed.
• Duraliner™ is fused to length for the project.
• Duraliner™ is expanded tightly against the interior walls of the host pipe.
• Exposed ends of the Duraliner™ are expanded to standard fitting sizes.
• The new Duraliner is cut to length and reconnected to system.
• Fused Duraliner™ is inserted into cleaned, inspected host pipe.
Not available
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
As Duraliner™ is expanded molecular reorientation increases its hydrostatic
design basis. This works toward offsetting the DR increase from expansion in
the pressure rating.
Not available
V. Costs
Key Cost Factors
Case Study Costs
Not available
Not available
VI. Data Sources
References
Website for Underground Solutions Inc.
A-31
-------
Technology/Method CIPP/Pull In Place or Inversion
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Conventional
1986
9 million feet installed from inception.
Miner® CIPP
Inliner Technologies, LLC (a Layne Christensen company and subsidiary of
Reynolds Inliner, LLC)
1468 West Hospital Rd.
Paoli, Indiana 47454
Phone: 812-723-0704
Email: gyothersfgjinliner.net
Web: www.inliner.net
Gwinnet County Storm Sewer Improvements
25,000 feet of CIPP, diameters 15 to 72 inches
Gwinnet County Watershed Manager
684 Winder Highway
Lawrenceville, GA 30045
Phone: 678-376-7068
Frank Matticola
White Creek Project - Nashville, TN
90,000 feet of CIPP, 800 service lateral renewals - 41% I&I reduction
CTE Engineers
220 Athens Way, Suite 200
Nashville, TN 37228
Phone:615-244-8864
Charlie Brown
Resin impregnated felt tube that can be either installed by the inversion method
or pulled into place. The felt tube is made by Inliner Products, Inc (subsidiary)
and sized to fit the host pipe, taking any bends and diameter transitions into
consideration. Resin impregnation is usually done off-site in a controlled
environment. The catalyzed resin impregnated tube can be stored for up to two
weeks in a refrigerated environment. Isophthalic polyester, vinylester and epoxy
resin systems can be accommodated. Inliner CIPP incorporates two patented
features: StretchGuard™ and ResinGuard™
• No dig or limited excavation renewal
• 40% to 50% less costly than traditional open cut replacement
• Minimum 50 year service life
• No long-term pressure regression or tensile testing has been done
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Gravity and Low Pressure Wastewater
Small diameter laterals opened by remote cutter, large diameter by man entry.
Pressure connections not accommodated.
Class II, III, or IV
Inliner Technologies uses both isophthalic polyester resin, epoxy vinyl ester and
"enhanced" polyesters. The enhanced resin is a filled isophthalic polyester.
Inliner fills their isophthalic polyester resin with a variety of materials based on
the application. The non- woven needled felt tube is made of polyester fibers. An
outer layer of impermeable thermoplastic material (polyethylene or
polyurethane) is used to protect the resin from water and contaminants. If using
the pulled in place installation method, an inner calibration hose or removable
bladder is used. The calibration hose is constructed of thin dry felt coated with
an impermeable plastic membrane. The felt is saturated with excess resin in the
A-32
-------
Technology/Method CIPP/Pull In Place or Inversion
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
pulled in place liner and becomes part of the finished liner. The removable
bladder, a thermoplastic membrane, is used in short laterals and point repairs,
where it is preferred to not cut the ends of the installed CIPP liner.
The properties of the Inliner CIPP product are listed below depending on the
type of resin used:
Isophthalic Enhanced
Flexural Modulus, psi 250,000-380,000 400,000-450,000
Flexural Strength, psi 4,500-6,600 4,500-7,000
Tensile Modulus, psi 290,000-360,000 290,000-400,000
Tensile Strength, psi 3,000-6,000 3,000-5,000
Tensile Elongation, % 1-3 2-4
4-120 inches
0.12-2.4 inches (3-60mm)
Recommended < 60 psi operating pressure
Recommended for 140°F or less
Lengths from 5 feet to 2400 feet have been installed
Inliner is not NSF 61 listed so not appropriate for potable water.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
ASTMD5813
ASTM F1216, Appendix XI (Design Considerations)
50 year design life
ASTM F1216 for inversion, ASTM F 1743 for pull in place
The CIPP tube is inserted by either inversion using water or air, or pulled into
place. For inversion the tube is inflated by either water or air pressure. If using
the pull in place method, a calibration hose or removable bladder is inverted
inside the felt tube after the tube is pulled in to position. Curing is by either hot
water or hot air (steam) in either case.
Prior to lining, the line should be cleaned and CCTV used to locate laterals,
connections, offsets, diameter transitions, etc. After lining, CCTV is used again
to locate any anomalies or defects (bulges, wrinkles, etc.) in the liner. Either
restrained samples, or specially made flat plate samples, using the same resin and
felt fabric, are made and tested for conformance to minimum flexural properties.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Standard CCTV inspection and water cleaning
CIPP Short Sectional point repairs readily available from several contracting
firms
V. Costs
Key Cost Factors
Case Study Costs
Mobilization affects cost when contract contains minimal segments of CIPP
lining. Generally speaking, a project of 3,000 linear feet or more will offset any
effect of mobilization on cost. Diversion or by -pass pumping requirements can
have a significant impact on cost. For materials, recent fluctuations in the cost of
the resin and fuel have impacted costs of the installed CIPP
Not available.
VI. Data Sources
References
Inliner Design Guide (March 2008), Inliner Technical Brochure (no date)
A-33
-------
Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
CIPP/Inversion with Hot Water Cured
I. Technology Background
Emerging
1995
44 miles since 1 995
Insituform PPL® (Pressure Pipe Liner)
Insituform Technologies, Inc.
17999 Edison Ave., Chesterfield, MO 63005
Phone: 636-530-8000
Fax:636-519-8744
Web: www.insituform.com
14,000 feet of 16 to 30 inches Fire Water Piping
Alyeska Marine Terminal
Valdez, AK
Mr. Kent Peterson
Alyeska Pipeline
907-834-7357
750 feet of 1 8 inches Sewage Force Main
Lake Waukomis, MO
Mr. Charles Raab
Sr. Technical Advisor
TREKK Design Group, LLC
1441 East 104th St., Suite 105
Kansas City, MO 641 31
816-874-4662
crabb @trekkllc .com
125 feet of 47 inches Cooling Water Piping
Citgo Petroleum Corporation
Lake Charles, LA
Mr. Ronnie Nichols
Planner
Citgo Petroleum Corporation
Clifton Ridge Road
Lake Charles, LA 70633
318-708-8580
Insituform PPL is a custom engineered CIPP product designed to eliminate leaks
and prevent internal corrosion and/or erosion in structurally sound pressure
pipes. It is an interactive liner that will span small holes, pits or open joints in
the host pipe. The CIPP tube has a similar construction to standard Insituform
CIPP tubes, with special glass reinforcement included to handle pressure
applications. Resins used are either vinyl ester or epoxy (special epoxy for
potable water applications).
• Spans over small holes, gaps or open joints.
• Extends life of a deteriorated or leaking pressure pipe.
• Minimal disruption as installed inside existing main, trenchlessly.
• Smooth interior surface.
• Stops internal corrosion.
• Can be installed in line with bends up to 90°.
• Interior must be very clean, with no protrusions.
• Shut down system or by-pass pump during insertion and cure.
• Not fully structural so host pipe must continue to carry internal pressure and
external load.
• Designed to resist external pressures due to groundwater when the host pipe
is empty.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Process Lines
A-34
-------
Technology/Method CIPP/Inversion with Hot Water Cured
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Water (potable), Gravity and Low Pressure Wastewater, Industrial - cooling
water, fire water, and process lines
Liner stops and starts at connections, which must be reinstated via open cut.
Class III - Semi- Structural, capable of bridging holes, gaps and joints while the
host pipe carries the full internal pressure
Vinyl ester or epoxy resins (special epoxy for potable water), standard Insituform
CIPP non-woven felt tube but with special glass reinforcement included.
Minimum Physical Properties (25°C)
Property ASTM Method Value
Initial Flexural Modulus of Elasticity D790 250,000 psi
Initial Flexural Strength D790 6,500 psi
Initial Tensile Strength D638 5,000 psi
Initial Tensile Modulus D638 300,000 psi
For design of spanning over small holes, the flexural strength is reduced to l/3r
of the initial value for long-term performance. In addition, a factor of safety of 2
is utilized.
8-60 inches
0.3-0.7 inches (8-1 8 mm)
Up to 200 psi
120°F
200 to 1,000 feet
All terminations must be fitted with mechanical end seals.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
Special epoxy used for potable water applications - NSF 61 listed
ASTMF1216, Appendix XI. 3.1
50 years
F1216
Pipeline is to be cleaned and all debris removed from the interior. CCTV should
be performed before lining. All obstructions, including reducers, line valves and
protruding connections to be removed. The reinforced Insituform felt tube is
resin saturated either in the factory or on site and prepared for installation. On
site, the tube is positioned in the pipeline using water pressure to turn the tube
inside out (inversion). The water pressure forces the tube to a close fit with the
host pipe. After positioned, the resin is cured by circulating hot water through
the tube. Once cured, the pipe is cooled to a maximum of 90°F. The ends are cut
and sealed. Expansion type end seals with expandable stainless steel bands and
elastomeric seals are used for this purpose. The pipe may be returned to service
after CCTV inspection and pressure testing.
• Prior to insertion of tube, CCTV inspection of main needed to locate any
obstructions, protrusion, changes in diameter or in-line valves that could
affect liner.
• After insertion and cure, liner inspected again visually with CCTV, and any
abnormalities are noted.
• For each inversion length, one liner sample, suitable in size to yield 5
specimens, is collected either from a section of the cured pipe lining
(usually at termination point) or a flat plate sample and subjected to flexural
and tensile testing. Average values should exceed minimums used for
design.
• Pressure testing to be carried out after liner has reached original ambient
ground temperature. The liner and host pipe subjected to a hydrostatic
internal pressure equal to twice the known operating pressure, or operating
pressure plus 50 psi, whichever is less. After stabilization period of 2-3
hours, test period is one hour. Limit on make-up water to maintain pressure
A-35
-------
Technology/Method CIPP/Inversion with Hot Water Cured
is 20 gallons per inch diameter per mile of pipe per day.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Minimal. Inspect pipe in accordance with the owner's asset management plan.
Excavate, remove damaged portion of PPL and host pipe (if necessary), install
end seals and bridge previously damaged location with new pipe and couplers as
required.
V. Costs
Key Cost Factors
Case Study Costs
By-pass requirements, host pipe cleaning, pipe diameter and length, tube
thickness, number of appurtenances (valves, fittings, fire hydrants, air release
valves, etc), excavation requirements. In order, most costly materials are resin,
tube, and end seals.
Not available.
VI. Data Sources
References
www. insituform. com
A-36
-------
Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
II
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
CIPP/Direct Inversion/Pull in Place/Hot Water and Steam Cured
I. Technology Background
Conventional
1995
Install approx. 200 miles of liner per year. Have only started pressure pipe
installations in past several years.
National Liner®
National EnviroTech Group
12707 North Freeway, Suite 490
Houston, TX 77060
Phone:281-874-0111
Email: inf ofgjnationalliner. com
Web: www.nationalliner.com
Not available.
National Liner is a CIPP product made of a non- woven, needled, polyester felt
that is shop or site impregnated with a thermosetting polyester resin. Vinylester
resins are used for pressure applications. A new composite structure,
incorporating glass fiber reinforcement, is being developed for pressure
applications.
• No-dig (or minimum excavation) renovation.
• Excess resin mechanically locks tube to host pipe by filling in cracks.
• Smooth interior surface for improved flow characteristics.
• 7 licensed and trained installation contractors covering US market.
• No ASTM product standard for CIPP pressure pipe liners.
• No long-term tensile or pressure regression data for pressure applications.
• Limited experience with pressure (force main) projects.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Storm Sewers
II. Technology Parameters
Gravity and Low Pressure Wastewater
Reinstate gravity laterals remotely. No provisions for reinstating pressure
connections.
Class IMII - Semi Structural for felt, Class IV - Structural for glass
Non- woven polyester felt material (from Applied Felts) which is saturated with
either an isophthalic or vinylester polyester resin, depending on application.
Force mains use vinylester. A new composite structure that incorporates glass
fiber for higher pressure is being developed.
6-120 inches
4.5 mm to 33.5 mm with felt tube are typical, but greater thickness are possible
50 psi with polyester felt tube, higher with glass fiber composite
w/PE resin up to 205°F; w/VE resins up to 248°F
Small diameters up to 800 feet; Large diameters up to 2000 feet in one
installation
BOH Brothers and Visu-Sewer Clean & Seal both have reported doing sewer
force mains.
. Technology Design, Installation, and QA/QC Information
ASTM D5813 (Gravity Sewer) - none for pressure applications
ASTM F1216, Appendix XI, WRc, and standard engineering design using
resources such as RERAU report R4A2-18
50 years
ASTM F 1 2 1 6, ASTM F 1 743
All mains to be cleaned and CCT V inspected before start of lining. The resin
saturated tube is inverted into the main using a column of water or pressurized
A-37
-------
Technology/Method CIPP/Direct Inversion/Pull in Place/Hot Water and Steam Cured
QA/QC
air. The pressure required to properly expand the tube to the host pipe is given
by the tube manufacturer. Once in place the liner is cured by heating the water
or air up to the temperature required to initiate polymerization of the resin
system.
The host pipe is cleaned and CCTV used prior to installation of the liner. Any
changes in dimensions or offsets can be accommodated in the design of the liner
so best if this is done well in advance of the planned installation. Samples of the
cured liner are taken per 8. 1.1 or8.1.2of ASTM F 1 2 1 6 . In addition to
dimensional checks of the liner samples (outside diameter, wall thickness),
flexural properties (ASTM D790) and tensile properties (ASTM D638) are also
determined.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
The condition of the CIPP should be monitored and maintained on a routine
basis consistent with that of other piping in the system. The conditions should be
coded per a standardized methodology. Should a defect appear requiring repairs;
those repairs should be as warranted by the type of defect discovered using the
techniques available for those type of repairs.
For restoration of water-tightness to the CIPP wall where damage has occurred
or a defect identified; install a part-liner.
Where delamination of the PU coating occurs (quite rare); mill off the detached
portion of the coating.
V. Costs
Key Cost Factors
Case Study Costs
CIPP costs are driven by length of reaches that can be done in a single
installation, diameter and thickness of the liners to be installed (material costs),
and contractor efficiency. Regarding contractor efficiency, there are two
components to consider; mobilization costs and project management skills.
Not available.
VI. Data Sources
References
www.nationalliner.com; Email correspondence withR. Pavlic
A-38
-------
Technology/Method CIPP/ Inversion and Hot Water or Steam Cured
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Emerging
October 2007
Approximately 10,000 feet of potable water lined in first year
Paraliner PW and Paraliner FM
NOVOC Performance Resins, LLC
3687 Enterprise Dr.
Sheboygan, WI 53083
Phone:877803-1700
Fax: 920 803-0695
Website: www. NOVOC.com
Placer County Water- Auburn, CA (News release Feb. 2009)
Paraliner PW or FM is a resin-impregnated flexible fiberglass/felt tube
manufactured by NOVOC Performance Resins. The tube is impregnated by the
installation contractor with a 100% solids NOVOC vinyl ester resin. The tube is
installed either by the inversion method using a head of water or pulled into place
by a winch and inflated with air. The resin is cured by either circulating hot
water or steam. Once installed, the liner shall extend from start to end in a
continuous tight fitting watertight liner.
• Trenchless installation with minimal interruption.
• Liner can be cured using hot water or steam.
• Short cure times - resins contain no styrene, curing time reduced 30%-50%
over other CIPP liners.
• Minimal shrinkage to ensure tight fit to host pipe- 100% solids.
• Green solution - patented NOVOC resin are environmentally responsible
with no styrene and no EPA reportable components
• NSF 61 listed - okay for potable water
• Utilizes licensees to install potable water product
• Patent pending service connection fittings
• By-pass required during lining and cure.
• Main must be well cleaned with mechanical scrappers or power boring.
• No long-term pressure regression or tensile testing to confirm a hydrostatic
design basis for 50 year design life.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Water - potable and raw water, Wastewater - force mains, gravity sewer
Reinstate after curing. Can be done robotically from within for corporation
connections. Larger connections must be excavated and reinstated mechanically.
Class IV - Structural, designed to carry full internal and external loads
The tube consists of one or more layers of absorbent non- woven felt fabric.
Fiberglass is also included. The outside layer of the tube is coated with an
impermeable, flexible membrane that contains the resin and allows monitoring of
the impregnation (wet out) process. The resin is NOVOC 4900 PW (for potable
water) and is a 100% solids, zero HAP, vinyl ester resin. The resin system emits
less than 1% VOCs. It has a glass transition temperature of 591°F. Mean
physical properties of the reinforced resin (initial) as follows:
Property Test Method Value
Flexural Strength, psi ASTM D790 16,000 psi
Flexural Modulus, psi ASTM D790 940,000 psi
Tensile Strength, psi ASTMD638 16,000 psi
Tensile Modulus, psi ASTM D638 900,000 psi
Water Aging - 0.4%
6-96 inches and larger
A-39
-------
Technology/Method CIPP/ Inversion and Hot Water or Steam Cured
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
0.18 inches (4.5 mm) to 2.07 inches (52.5 mm)
230 psi Burst Pressure (Based on 8 inches dia. x 6 mm thick)
220°F
Approx. 1 ,000 feet depending on diameter
Include specific notes here such as Water Quality, I/I control, other
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
No product standards, NSF 61 listing (for potable water applications) from
Underwriters Laboratories
ASTM F1216, Appendix X.I
50 years
ASTM F1216, Section 7 and/or ASTM F1743, Section 6
• The main is first CCTV inspected and cleaned.
• The installation contractor impregnates the tube with the NOVOC vinyl
ester resin. The liner is then inserted into the main either by direct
inversion using water head or pulled in by a winch. The use of a lubricant
is recommended. The liner can be installed through a 45° elbow. The
pressure head or steam/air pressure needs to fall within NO VOC's
recommended guidelines to insure a proper finished thickness and that the
liner fits snug to the existing pipe wall, producing dimples at service
connections and flared ends at the entrance and exit points.
• After inflation, the liner is cured using either circulating hot water or
steam. Thermocouples are placed between the liner and the invert of the
manhole or end of the host pipe and used to monitor the temperature and
time of the exothermic reaction.
• Once cured, the liner is cooled down to a temperature of 100°F before
relieving the pressure.
• The liner is cut to appropriate length to allow fitting of end seals (Miller
Pipe "Weko-Seals" or equal) or Full-Circle Pressure Clamps or MJ
Fittings.
CCTV main after cleaning, log location of service connections. Likewise, CCTV
line after temperature cools to under 1 00°F to make sure liner was properly
installed. Pressure test the line after CCTV inspection, and before reinstating
connections, to a minimum of 120% of the normal operating pressure. Line to be
CCTV inspected again after service connections are reinstated.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
None identified.
Paraliner products can be relined and or point repaired.
V. Costs
Key Cost Factors
Case Study Costs
• To determine whether or not a CIPP application is more cost-effective than
other alternatives such as slip-lining or dig-and-replace
• If there are environmental sensitivities
• Determining the reduction of flow capacity vs. other alternatives
• The structural integrity of the existing host pipe
• Service downtime
No cost case studies available.
VI. Data Sources
References References upon request
A-40
-------
Technology/Method CIPP/Inversion with Hot Water Cured
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
Emerging
1998
19 miles since 1998
Insituform RPP™ (Reinforced Pressure Pipe)
Insituform Technologies, Inc.
17999 Edison Ave.
Chesterfield, MO 63005
Phone: 636-530-8000
Fax:636-519-8744
Web: www.insituform.com
1 ) Zone 7 Water Agency- Alameda County Flood Control and Water
Conservation District
5,400 feet of 12 inches RPP on an old cast iron pipe - December 2008
Key Contact:
Steven J. Ellis
Assistant Engineer
Zone 7 Water Agency
1 00 North Canyons Parkway
Livermore, CA 945541
925-454-5037 (direct)
925-454-5726 (fax)
sellis@zone7water.com
2) CityofMuscatine, I A
Sewer force main - 1 ,700 feet of 24 inches - December 2007
Key Contact:
Gary Kleve
Sulzberger Excavating
563-263-1697
3) Gainesville Regional Utilities
Sewer force main - 330 feet of 16 inches - 2007
Key Contact:
John Gifford
Gainesville Regional Utilities
352-317-1837
Insituform RPP is a custom engineered CIPP product designed to restore the
structural integrity to distressed pressure pipes and prevent internal corrosion
and/or erosion. It is a structural renewal product that does not rely upon the host
pipe. The CIPP tube has a similar construction to standard Insituform CIPP
tubes, with special glass reinforcement included to handle pressure applications.
Resin used is vinyl ester.
• Provides a structural renewal.
• Spans over small holes, gaps or open joints.
• Extends life of a deteriorated or leaking pressure pipe.
• Minimal disruption as installed inside existing main, trenchlessly.
• Smooth interior surface.
• Stops internal corrosion.
• Can be installed in line with bends up to 45°.
• Interior must be very clean, with no protrusions.
• Shut down system or by-pass pump during insertion and cure.
• Incomplete long-term pressure regression tests on cured RPP liner available
for confirmation of design values recommended for long-term tensile
strength in pressure design (Did not achieve the correct number of bursts
during the log time frames to meet the ASTM data requirement).
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Industrial Pressure
A-41
-------
Technology/Method CIPP/Inversion with Hot Water Cured
apply)
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Wastewater, Industrial Cooling Water.
Liner stops and starts at connections, which must be reinstated via open cut.
Class IV -Structural - handle all external and internal loading. No bonding to
the original host pipe wall assumed.
A sewn tube consisting of two or more layers of absorbent non- woven synthetic
fiber combined with glass fiber reinforcement. The outside layer of the tube is
plastic coated with a translucent flexible material for visual inspection during
resin impregnation. A vinyl ester resin, compatible with the inversion and curing
process, is used.
Minimum Physical Properties (25°C)
Property ASTM Method Value
Initial Flexural Modulus of Elasticity D790 250,000 psi
Initial Flexural Strength D790 7,000 psi
Initial Tensile Strength D638 6,000 psi
For internal pressure design, a long-term tensile strength equal to l/3r of the
initial design value is used. In addition, a factor of safety of 2 is utilized.
8-72 inches
5-26 mm
Up to 80 psi, diameter dependent.
120°F
200 to 1,000 feet
All terminations must be fitted with mechanical end seals.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
Not suitable for potable water.
ASTM F1216, Appendix XI .3.2 for the Fully Deteriorated Pressure Pipe
condition.
50 years
ASTMF1216
Pipeline is to be cleaned and all debris removed from the interior. The line is to
be CCTV inspected before lining. All obstructions, including reducers, line
valves and protruding connections to be removed. The reinforced Insituform felt
tube is resin saturated either in the factory or on site and prepared for installation.
On site, the tube is positioned in the pipeline using water pressure to turn the tube
inside out (inversion). The water pressure forces the tube to a close fit with the
host pipe. After positioned, the resin is cured by circulating hot water through
the tube. Once cured, the pipe is cooled to a maximum of 90°F. The ends are cut
and sealed. Expansion type end seals with expandable stainless steel bands and
elastomeric seals are used for this purpose. The pipe may be returned to service
after CCTV inspection and pressure testing.
• Prior to insertion of tube, CCTV inspection of main needed to locate any
obstructions, protrusion, changes in diameter or in-line valves that could
affect liner.
• After insertion and cure, liner inspected again visually with CCTV, and any
abnormalities are noted.
• For each inversion length, one liner sample, suitable in size to yield 5
specimens, is collected either from a section of the cured pipe lining
(usually at termination point) or a flat plate sample and subjected to flexural
and tensile testing. Average values should exceed minimums used for
design.
• Pressure testing to be carried out after liner has reached original ambient
ground temperature. The liner and host pipe subjected to a hydrostatic
A-42
-------
Technology/Method CIPP/Inversion with Hot Water Cured
internal pressure equal to twice the known operating pressure, or operating
pressure plus 50 psi, whichever is less. After stabilization period of 2-3
hours, test period is one hour. Limit on make-up water to maintain pressure
is 20 gallons per inch diameter per mile of pipe per day.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Minimal. Inspect pipe in accordance with the owner's asset management plan.
Excavate, remove damaged portion of RPP and host pipe (if necessary), install
end seals and bridge previously damaged location with new pipe and couplers as
required.
V. Costs
Key Cost Factors
Case Study Costs
By-pass requirements, host pipe cleaning, pipe diameter and length, tube
thickness, number of appurtenances (valves, fittings, fire hydrants, air release
valves, etc), excavation requirements. In order, most costly materials are resin,
tube and end seals.
Not available.
VI. Data Sources
References
www. insituform .com
A-43
-------
Technology/Method CIPP/Glass Fiber Reinforced
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Innovative
2002 in Sweden, 2004 in Hong Kong and Canada
1 2 miles/year
Nordipipe™
Norditube Technologies (a Sekisui-CPT Company)
501 N. El Camino Real, Suite 224
San Clemente, CA 92672
Phone: 714-267-1030
Web: www.cpt-usa.com/info
Mr. Jean Lemire, Eng.
City of Cornwall
1225 Ontario Street
Cornwall (Ontario) Canada
K6H 5T9
Tel. (613)930-2787
Email i elemirefgjcornwall . ca
Mr. Tony Di Fruscia, Eng. P. Eng.
City of Montreal
13301, Sherbrooke Street East
Suite 209
Montreal (Quebec) Canada
H1A1C2
Tel. (514)872-6678
Email tonvdifruscia(g)ville.montreal.qc.ca
Ms. Annie Fortier, Eng.
City ofDorval
60 Martin Avenue
Dorval (Quebec) Canada
H9S 3R4
Tel. (514)633-4244
Email afortier(S)ville.dorval.qc.ca
Norditube is a CIPP system that incorporates a glass fiber reinforced layer
between two felt layers, impregnated with epoxy or vinylester resin. A PE
coating is on the interior. Resin impregnation is done by the installation
contractor, either at his facility or onsite.
• Fully Structural - no support of the host pipe required for internal or
external loads
• NSF 61 listing (cold water, up to 78°F) and BNQ approval for potable
• High pressure resistance
• Negotiate bends up to 45 degrees
water
• 48 inches maximum diameter
• No US installations
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
Pressure water and wastewater
Internal cut and external re-instatement by excavation
Type 4 - Fully structural
Polyethylene coating in contact with potable water, non- woven felt and glass
fiber chopped mat, with epoxy or vinyl ester resin. Epoxy is used for potable
water projects (NSF listing), and vinyl ester for other applications. Vinyl ester
resin is half the cost of the epoxy.
5-48 inches
A-44
-------
Technology/Method CIPP/Glass Fiber Reinforced
inches
Thickness Range,
inches
Pressure Capacity, psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
0.18-0.94 inches (4.6-24 mm)
6 inches to 250 psi and 48 inches to 60 psi
100°F with Epoxy and 160°F with vinyl ester
500-600 feet
12 inches force main installation in Hamburg, Germany using vinylester and 16
inches force main in the UK using epoxy resin
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
No product standards, NSF 61 listing (cold water, up to 78°F)
ASTM F1216 Appendix XI
50- Year Design
ASTMF1216
Air inversion with air/steam cure, or water column inversion with circulated
water cure; service reinstatement by internal robotics or external with saddles.
Resin impregnation is usually done at the contractor's facility, but onsite is also
possible.
Resin yield check for impregnation; pressure gauges for air inversion;
temperature monitoring during cure; hydrostatic pressure test and post installation
video for acceptance
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Protection of the PE coating during inspection or cleaning
Install a spool piece with mechanical adapter; Link-Pipe ring repair
V. Costs
Key Cost Factors
Case Study Costs
Set-up costs - pit excavation (civil work), mobilization, pipe cleaning/de watering,
site restoration, traffic control, temporary by-pass including road crossings and
disinfection, hydrostatic testing, valves, hydrants, tee's (mechanical work),
installation and cure, video inspection
Material costs - liner, resin, spool pieces, new valves, tee's and hydrants
Not available.
VI. Data Sources
References
Email correspondence with Steve Leffler; Norditube brochure
A-45
-------
Technology/Method CIPP/Pull in Place/UV Cured
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Emerging
1 997; first usage in Europe, outside Europe since 2001
2008: 660,000 feet (200,000 m)
Berolina Liner
BKP Berolina Polyester GmbH (a division of Greiffenberger AG)
Am. Zeppelinpark, 27
D-l 3591 Berlin
Germany
Phone: +49 30 3647 1400
Email: info @bkp . berolina . de
Web: www.bkp-berolina.de
Berliner Wasserbetriebe, 1 0864 Berlin, Germany
Mr. Bernhard Czikkus, bernhard.czikkus(5)bwb.de or Mr. Andreas Rademacher,
andreas . rademacher (gjbwb . de
Phone: +49 30 864 44160
PipeFlo Contr. Corp., Mr. Bruce Noble, bruce@pipeflo.ca;
180 Chatham Street, Hamilton, Ontario L8P 2B6, Canada; phone: 19055727767
Arkil Inpipe GmbH, Mr. Werner Manske, Werner.manske(g)arkil.de; Lohweg
46E, 30559 Hannover, Germany; phone: +4951 19599536
Tuboseal c.c.; Mr. Jean-Louis Frey, ilf(5),tuboseal.co.za; P.O. Box 2513; Somerset
West, 2 Cape Town, 7129 South Africa; phone: +27824528129
The Berolina-Liner is composed of glass-fiber and/or polyester webs impregnated
with polyester or vinylester resin. The layers are overlapped and staggered giving
the tube variable stretching capability. The liner is UV cured. The glass-fiber
layer provides sufficient axial strength for pulling the liner into place.
BKP produces the Berolina-Liner with a protective inner film and a UV resistant
outer film. The inner film is removed after installation. The outer film also
prevents resin from migrating into laterals. The liner is delivered pre wet-out and
ready for installation. The liner can be stored for up to 6 months without cooling.
• UV cured resulting in less CO2 emission and reliable curing results - neither
influenced by ground water, temperature and storage time.
• For same stiffness, thickness less than a polyester felt product.
• Inflation by compressed air (7.5 psig) allows CCTV inspection of liner prior
to UV cure.
• Suitable for circular and oval profiles.
• Designed with ring stiffness classes SN1 250- 10000 (MPa), which is similar
to GRP pipe for direct burial.
• Can bridge over profile or cross-section changes.
• Highest rating in IKT water impermeability tests.
• BKP production is located in Berlin, Germany.
• Not certified for use with potable water.
• No long-term pressure regression or tensile testing to substantiate a full
structural (Class IV) design.*
• No strain corrosion testing as per ASTM D5813 (6.4.2)*
• * Tests have been done and certified according to European and Japanese
standards. ASTM test will follow.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Culverts
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Gravity and low pressure wastewater, storm water
Laterals are optically located (with CCTV) after curing and reinstated with
robotic cutters. No provisions for pressure connections.
No claim made in literature, but with stiffness class SN10000 through 20 inches
A-46
-------
Technology/Method CIPP/Pull in Place/UV Cured
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
(500MM), liner suitable for fully deteriorated gravity host pipe.
The Berolina-Liner is made of up to 5 layers of glass-fiber and/or polyester web
that is impregnated with a UV-light curing polyester resin. BKP uses only ISO
NPG resin of the type 1 140 according to DIN 16946/2. The resin is qualified for
Group 3 in accordance to DIN 1 8820/1 . For demanding requirements, a vinylester
resin is used. The inner protective film and outer UV resistant film are flexible,
water impenetrable and equipped with a styrene barrier. Minimum initial ring
flexural modulus claimed is 1 .45 x 106 psi, and the approximate initial tensile
modulus 2. 03 x 106 psi.
6-40 inches (other sizes available upon request)
0.08-0.47 inches (2-12 mm), depending on diameter
New Berolina-LP-Liner (low pressure) currently in test phase with pressure
capacity up to 45 psi.
Polyester resin up to 1 22°F; Vinylester resin up to 1 58°F
1,200 feet (400m)
Licensed CIPP Corp (Hudson, IA) to be sole nationwide US provider in Nov.
2008.
Local contractors acceptable
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation
Standards
Installation
Methodology
QA/QC
According to EN 13566-4/DRAFT INTERNATIONAL STANDARD ISO/DIS
1 1296-4; ASTM not applicable, new ASTM standard in preparation
ATV-M 127-2; ASTM Fl 21 6, Appendix X.I
Minimum 50 years
New ASTM standard in preparation; WRc certified installation manual available
• The host pipe is first thoroughly cleaned and CCTV inspected. A protective
film sleeve, covering the lower half of the host pipe, is next drawn into the
pipe to be rehabilitated by a winch. The Berolina-Liner is then winched into
place and both ends are closed off with end cans. The tube is calibrated
using compressed air (7.5 psig), which presses the liner against the host
pipe's inner wall.
• The outer UV resistant tube prevents migration of the resin and styrene into
the soil and groundwater, and also prevents resin from penetrating the
laterals.
• After expansion of the liner, a special UV light is "fired" and pulled through
the liner at a defined speed. A CCTV camera can monitor the liner during
the passage of the light train.
• With the tube ends sealed, the curing occurs free of any emissions.
• After curing, the inner film is removed leaving a smooth inner surface.
• Laterals are easily identified (outward expansion of liner) and reinstated
using conventional robotic cutters.
BKP controls the quality of the liner with testing of the liner and components at
their plant, as well as during and after curing in the field.
Qualification testing of the liner has included:
• high pressure water jet cleaning (Hamburg Model) - 60 passes
• 1 0,000 hrs fatigue (creep) tests
• leakage tests (CP308)( water impermeability)
• Darmstadt tilted drain experiment (abrasion test)
• burning test
The more important QA (factory) requirements are:
• reactivity tests of resin
• impermeability tests (DIN/EN 1610)
• wall thickness measurement
A-47
-------
Technology/Method CIPP/Pull in Place/UV Cured
• measurement of initial ring stiffness
• 3-point bending test (flexural modulus and strength)
• barcol hardness
• residual styrene content
During installation, the more important QC requirements are:
• installation pressure diagram
• curing speed diagram
• number of UV-light used
• temperature diagram
After installation, the more important QC requirements are:
• impermeability test
• wall thickness
• measurement of the initial ring stiffness
• 3-point bending test
• measurement of the resin content (loss on ignition)
• Residual styrene content
• CCT V of liner for visual defects
IV. Operation and Maintenance Requirements
O&M Needs
None
Repair Requirements
for Rehabilitated
Sections
Use standard methods for GRP-polyester pipes/products
V. Costs
Key Cost Factors
Totally trenchless method, no pits needed up to installation of 36 inches
(depending on manhole cover size). Costs mainly driven by wall thickness
(according to static needs) and diameter of pipe. By-pass pumping time and cost
is limited due to fast installation procedure. Mobilization and site setup reduced
because of small footprint, liner is shipped to site ready for use, and customized
equipment, opening of lateral completely possible directly after installation.
Case Study Costs
No project costs available from BKP.
VI. Data Sources
References
www.bkp-berolina.de, BKP-Berolina brochure (no date), IKT Liner Report 2007
A-48
-------
Technology/Method CIPP/UV Light Cure
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Emerging
Developed by Brandenburger in Germany. Introduced by Reline America into US
in 2007.
5 million feet installed in 24 countries.
Blue-Tek™
Reline America, Inc.
116 Battleground Ave.
Saltville, VA 24370
Phone: 866-998-0808
Fax: 276-496-4265
Email : mburkhard(3)relineamerica. com
Web: www.relineamerica.com
Amarillo, TX
Glass fiber reinforced CIPP liner that is UV cured. The liner strength stems from
a seamless, spirally wound glass fiber tube. Polyester, vinylester or ortho resins
can be used. All wet out is performed in the factory. The seamless liner has both
an interior and exterior film, with the exterior film blocking UV light.
• Glass fiber reinforce wall thickness for higher strength and stiffness
• Thinner wall than ordinary felt reinforced liners
• Good flow characteristics
• Fast curing times for both small and large diameters (250 to 750 feet per
hour)
• Passed the APS Standard Porosity Test with score of 1 00%
• Quality-Tracker™ System for tracking entire curing process (7 steps) with a
data logger and retrieval system.
• Reduced styrene emission during curing
• Not NSF 61 listed - not suitable for potable water
• No long-term pressure regression tests for establishing HDB for pressure
pipe design - Class III for pressure applications only
• 48 inches diameter is upper limited
• Limited licensee contractor base in US at the moment
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length,
feet
Other Notes
Wastewater, storm water and raw water
Remote reinstatement of lateral connections similar to other CIPP products.
Lateral Hat™ for connection to sewer laterals
Class III or IV, Semi or Fully Structural
Advantex® EC-R glass fiber from Owens Corning and polyester, vinylester or
ortho resin depending on application.
6 to 48 inches, circular, oval, egg-shaped and square pipes (60 inches in future)
>0.14 inches (3.5 mm)
Short-term flexural modulus - 1.1 x 106 (up to 2.16 x 106 possible)
Long-term flexural modulus - 660,000 (1 .6 reduction factor)
Short-term tensile strength - 20,000 to 26,000
Not available.
1000 feet
Not NSF 61 listed yet. May be in the future.
III. Technology Design, Installation, and QA/QC Information
A-49
-------
Technology/Method CIPP/UV Light Cure
Product Standards
Design Standards
Design Life Range
Installation
Standards
Installation
Methodology
QA/QC
ASTMF 201 9-03
Not available.
50 year
Not available.
The liner is shipped in special containers and UV protected foil and can be stored
for up to 6 months without refrigeration. Sewage flow needs to be either plugged
or by-passed. After sewer is cleaned and CCTV inspected, the Blue-Tek liner is
winched into the existing pipe, inflated with air (6 to 8 psi) and then cured using a
UV light train that is pulled through the pipe. Special care is needed to ensure
that the exterior film is not damaged during installation. After curing the inner
film is removed and discarded and the liner post CCTV inspected.
• Verification of UV lamp intensity and number (wattage)
• CCTV inspection of entire line before curing
• Record of liners inner air pressure during curing
• Documentation of curing speed (feet/min)
• Resin reaction temperatures (infrared sensors)
• CCTV documentation of curing process
• Physical property tests on specimens from the liner, including water-
tightness porosity test
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Not available.
Not available.
V. Costs
Key Cost Factors
Case Study Costs
Not available.
Not available.
VI. Data Sources
References
www.relineamerica.com
A-50
-------
Technology/Method CIPP/Glass Reinforcement
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Emerging
US - 2009
Not available
InsituMain™
Insituform Technologies, Inc
17999 Edison Avenue
Chesterfield, MO 63005
Phone: 636-530-8000
Fax:636-519-8744
Web: http://www.insituform.com
Not Available
• An AWWA Class IV fully structural pressure rated cured in place technology.
• The InsituMain™ system is an ideal solution for the renewal of both
distribution and transmission water.
• No risk of disrupting or damaging nearby utilities or other underground
infrastructure systems.
• The system has a polyethylene layer on the inside pipe surface which
increases the pipe's smoothness, reduces the surface friction and provides an
additional corrosion barrier for the pipe.
• It can withstand internal pressure and external load requirements.
• Eliminates leakage and corrosion.
• Adheres to the existing host pipe.
• No need for specialty fittings.
Bypass required
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Industrial Pressure, Fire
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Rehabilitation
No specialty fittings required. In 6 inches and larger pipes service connections
can be made by robotic remote access using mechanical sealing apparatus.
Exceeds ASTM F1216 and ASTM F1743 standards
Epoxy composite layer which is reinforced with glass and polyester fiber
materials
Nominal diameter range from 6 to 36 inches
Not available
1 50 psi+ applications
120°F
Not available
Suitable for Cast/Ductile Iron, Steel, Asbestos cement, RCP and Thermoplastic.
Can do bends up to 45 degrees.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
Certified to ANSI/NSF 61 standards
Not available
50 years Design Life
In accordance with manufacturer's operation manual.
1 . The composite materials are saturated with a thermosetting epoxy resin
system either on the job-site or in an authorized Insituform wet out facility.
2. Using water or air pressure, the tube is then inserted into the host pipe by
either a pull-in or inversion method.
A-51
-------
Technology/Method CIPP/Glass Reinforcement
QA/QC
3. Following installation, hot water or steam is used to cure the thermosetting
resin.
4. The pipe is cooled, the ends are cut and the pipe is returned to service. Lined
sections are re-established to the existing system using standard pipe fittings.
Inspection of main prior to installation.
Followed by post-installation inspection, pressure testing (at twice the operating
pressure).
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Disinfection of system before pressing it in to service.
Excavate, remove the damaged portion of the pipe, install end couplers and bridge
the previously damaged location with new pipe and couplers.
V. Costs
Key Cost Factors
Case Study Costs
Not available
Not available
VI. Data Sources
References
http://www.insituform.com/mm/files/InsituMain%20Brochure.pdf
A-52
-------
Technology/Method
CIPP with Carbon Fiber/Manually Applied
I. Technology Background
Status
Conventional
Date of Introduction
US Patent 5931198 - Introduced in 1988 in the US market
Utilization Rates
Not available
Vendor Name(s)
FibrWrap
The FibrWrap Company
Fyfe Co. LLC
Nancy Ridge Technology Center
6310 Nancy Ridge Drive, Suite 103
San Diego, CA 92121-3209
Phone: 858-642-0694, 858-642-0947
Email: info(5).fvfeco.com
Web: http://www.fyfeco.com
Practitioner(s)
Gary Schult
Project Sponsor
Kiewit Western Company
For 60 inches through 96 inches PCCP pipes
Phone: 602-437-7841
John Galleher
Senior Engineer
San Diego County Water Authority
For Pipeline 5: 2 sections of 24 feet for 96 inches pipe
610 W 5th Avenue
Escondido, CA 92025
Phone:760-488-1991
Cell: 760-233-3206
Don Lieu and Robert Diaz
Chief and Engineering Project Manager
Utility Design Division
Department of Public Works
Bureau of Engineering
Howard County, MD
Cell for Mr. Lieu: 410-313-6121
Cell for Mr. Diaz: 410-313-6125
Description of Main
Features
The Tyfo® Fibrwrap® Pipe Rehabilitation System is a Fiber-Reinforced Polymer
(FRP) method, utilizing carbon fiber, for the repair, strengthening and retrofit of
corrosion-damaged and distressed large diameter PCCP, RCCP, and steel pressure
pipelines used in municipal, industrial and other applications. It's main use has
been for PCCP water and force mains that have broken prestressed wires.
Main Benefits
Claimed
Restoration of pipelines structural integrity to original load bearing
capability (pressure and external)
Can be designed to increase pipeline strength over and above original design
Non-metallic material ensures that corrosion-related damages do not recur in
rehabilitated pipe segments
NSF 61 certified system for potable water
Thin liner minimizes any loss of flow capacity
Main Limitations
Cited
Limited to sectional repairs as cost can be high
Requires highly trained and experienced technicians to work in confined
space with volatile chemicals
Surface preparation for good bond extremely important
Joint termination is an evolving technology
No standardized design approach
Applicability
(Underline those that
apply)
Force Main Gravity Sewer Laterals
Water Main Service Lines Other: Tunnel
Manholes Appurtenances
A-53
-------
Technology/Method CIPP with Carbon Fiber/Manually Applied
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Water and wastewater
No method established for service connections. Only suitable for pipe sections
with no fittings.
Fully structural rehabilitation of only distressed pipe segments -Class 4
Layers of FRPs (carbon fibers and glass fibers for electrical isolation from steel),
epoxy
30 through 201 inches and above
0.08 to 1 inches
50 psi to 3 50 Psi
220°F
16 to 20 feet pipe sections - 5 to 1 5 sections per project typical
Care should be taken during installation to prepare the surface for bonding and the
humidity must be controlled. Water blasting surface down to aggregate is
recommended. Long term durability has not yet been qualified, but should be
similar to other reinforce plastic pipes (i.e. fiberglass pipe). Negligible loss of
pipe capacity.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
ANSI/NSF 61 certified
There are no design standards covering the application of carbon fiber composite
as a liner to strengthen PCCP pipe. Some design methods determine required
composite thickness based on limiting stress in steel cylinder assuming 100% loss
of prestress wire. Limit is usually 75-85% of steel's yield strength. Ultimate
design tensile strength of the carbon composite is 120,000 psi.
• ASTM G 53 , Biological Growth Support Potential Test (BGSP) cleared
• Long Term Durability Testing by Metropolitan Water District of Southern
California.
• External loading from soils should be considered and accommodated in the
design accordingly.
• ACI 503R-93, ACI 546R-96, ASTM D 3039-93 and ASTM D 695-02a.
Minimum 50-year service life
No consensus standards. ICC Pmg Report and Fyfe Co. QA/QC
Internal surface of PCCP is first hydroblasted to aggregate. Any cracks in the
core are repaired with an epoxy. Line is then dehumidified. An epoxy tack coat is
first applied to the substrate to increase adhesion of the carbon laminate. The
carbon fiber fabric is impregnated with the epoxy resin and hand applied to the
inner wall. Fibrwrap uses Tyfo 2X which has two plies of carbon textile bonded
together. The composite is placed circumferentially such that the carbon fiber is
oriented in the hoop direction. One ply in the axial direction is often used too.
When necessary, protective coatings can be applied for aggressive chemical or
environmental exposures. Fibrwrap also places a topcoat of anNSF 61 certified
epoxy over the underlying composite.
It generally take a 3 man crew one day to repair a section of pipe.
As per manufacturer provided manual, which includes responsibility sharing on
site and in lab, manufacturing specifications, installation controls, storage, testing,
certifications, calibrations, complaints and inspection.
Two test panels, 12 inches x 12 inches each, are created each day of the materials
used in that days construction. One panel is then later cut into coupons and tensile
and flexural tested to confirm design properties. Results are reported back to the
owner within 3 weeks. Second panel is held as a referee panel in case the samples
A-54
-------
Technology/Method CIPP with Carbon Fiber/Manually Applied
fail to meet the minimum design criteria.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Indicated and provided by manufacturer.
Periodic visual inspections every two years would be ideal.
Top coat renewal feasible if abrasive environment.
Any debonded composite to be removed and new laminate applied.
V. Costs
Key Cost Factors
Case Study Costs
Exact pricing will depend on:
1) Distance from repair location to surface access.
2) Quantity of lineal feet contracted
3) Lead time for crews mobilization
4) Allotted time for onsite completion of project
5) Project service life of repair
The cost for the carbon fiber application is about $75 to $90 per layer and per feet2
of surface area. Typically, a 54 inches pipe operating at 1 50 psi with 1 2 feet of
cover would be $3,000/feet.
VI. Data Sources
References
http ://www. fibrwrapconstruction. com/pipe .htm
http://www.fibrwrapconstruction.com/pipe/pipebrochure.pdf
www. fvfeco . com
Correspondence via E-mail and a binder provided by Mr. Heath Carr.
A-55
-------
Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
I
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
CIPP with Carbon Fiber, Manually Applied
I. Technology Background
Emerging
Invented and introduced in 1 989 at The Arizona State University. Developed and
largely used in the South- Western states.
Over 100,000 linear feet have been wrapped by the CarbonWrap family of
products across the country
CarbonWrap
CarbonWrap™ Solutions LLC
3843 N. Oracle Rd.
Tucson, Arizona 85705 USA
Fax: (520) 408-5274
Toll Free: (866) 380-1269
Phone:(520)292-3109
E-mail: info(3)carbonwrapsolutions.com
Web: http://www.carbonwrapsolutions.com
Not available
Application of carbon fiber composite to interior surface of pipe. Carbon Wrap™
is used to strengthening buried pipes, especially PCCP with broken wires.
Concrete and steel pipes can be strengthened to take pressures even greater than
that of their original design.
• Requires no excavation.
• Increases pipe strength to even higher than its original pressure rating.
• Requires no heavy equipment for installation. Access thru 24 inches
manways.
• Cannot be used if the temperature is above 200°F
• Cost for application can be high versus post-tensioning with steel tendons.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Repair
This repair technique is only good for the pipe barrel, and no fittings or
connections.
Structural material
Epoxy resin and carbon fiber
Man entry (36 inches) and larger
0.125 inches and larger
Equal or greater than original pipe, if desired.
Application in humid temperature is not recommended.
Typically repair is confined to one pipe section at a time, without bridging over
joints.
Not available
[I. Technology Design, Installation, and QA/QC Information
NSF 61 compliant
ACI 440 (design standard for externally bonded FRP systems for concrete
structures)
Minimum 25 years
As per manufacturer guidelines.
In the case of 36 inches and larger diameter pipes, simple access is made through
the manholes and all operations are conducted internally. If the pipe can be
accessed from the outside, the wrapping can be performed on the outside face of
A-56
-------
Technology/Method CIPP with Carbon Fiber, Manually Applied
QA/QC
the pipe; resulting in the same benefits. It is generally applied in the following
format: Epoxy-fiber-epoxy-fiber.
Not available
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Regular cleaning is not required. Maintenance strategies should include condition
assessment measures every few years.
Re-lining may be done.
V. Costs
Key Cost Factors
Case Study Costs
The composite material is generally the key governing cost in the contracts.
may vary from job to job depending on site accessibility and pipe condition.
It
Material cost at $10-$15/square feet per layer
VI. Data Sources
References
http://www.carbonwrapsolutions.com/PDFinfo/Brochure.pdf
Phone correspondence with Dr. Hamid Saadatmanesh.
Email correspondence with Faro Mehr.
A-57
-------
Technology/Method Woven Hose Lining/Epoxy Adhesive
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Conventional
Not Available
Not Available
Starline HPL-W
Starline Trenchless Technology, LLC
1700 South Mount Prospect Road
Des Plaines, IL
60018-1804
USA
Phone: 847-768-0889
Mail: edward.iohnston@,gastechnologv.org
Czech Republic
For use in rehabilitation of drinking water mains
Not available
Not available
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Rehabilitation
Need to be addressed separately. Can be identified externally via digging or
internally via robot.
430 psi (30 bar) per DVGW
Polyester woven liner, adhesive and epoxy coatings
3 to 24 inches
Not available
Up to 430 psi
Recommended for use up to 78°F
Not available
Not available
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
All requirements for the technology's application in drinking water pipes in
Germany, the KTW recommendations for application of plastics in drinking water
pipes and the DVGW W270 Recommended Practice (German Association of Gas
and Water), have been complied with. The relevant U.S. certificate, NSF 61
(National Sanitation Foundation), has been applied for and is expected in 2010.
Not available
50 years per DVGW certification
Not available
The liner has to be pressed through calibrated rollers before it is pushed into the
pipe. Liner is then wound on a pressure drum and bolted into an inversion cone
attached to the host pipe. The liner is inverted inside the host pipe and the process
ends when the liner reaches the catch basket.
Not available
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
Not available
Not available
A-58
-------
for Rehabilitated
Sections
V. Costs
Key Cost Factors
Case Study Costs
Not available
Not available
VI. Data Sources
References
http://www.starlinett.com/index.htm
A-59
-------
Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Woven Hose Lining/Adhesive
I. Technology Background
Innovative
2000 in Canada and 2005 in USA
With the help of its licensees, over 800,000 feet (250,000 meters) of Aqua-Pipe
have been installed over the past eight years throughout Eastern Canada and the
United States.
Aqua-Pipe"
Sanexen Environmental Services Inc.
1471 Lionel-Boulet boulevard
Suite 32
Varennes (Quebec)
Canada
J3X 1P7
Phone: 800-263-0787
Web: http ://www.aqua-pipe.com
Email: aqua-pipe(3)sanexen.com
John Vose
City of Naperville
630-420-6741
1200WOgden
Naperville, IL 60563
USA
Kevin Bainbridge
City of Hamilton
905-546-2424 x 5677
320-77 James Street North,
Hamilton, ON L8R 2K3
Canada
Kamran Sarrami
City of Toronto
416-395-6370
North York Civic Center, 2nd Floor
Toronto Ontario M2N 5V7
Canada
Sanexen, in collaboration with the National Research Council Canada (NRC)
developed a new structural liner for the structural rehabilitation of drinking water
mains. Aqua-Pipe is an economical and viable alternative to the water main
problems where, in the past, dig and replace was the only choice. Aqua-Pipe is a
class IV structural liner that is designed and manufactured with mechanical
properties exceeding all specifications and meeting drinking water requirements.
• Rapid installation of ± 2,500 feet (800 meters) per week and negotiates bends
less than 90°.
• Added life for water main because of corrosion resistance and no effect on
water quality.
• Economic considerations include low carbon footprint.
Cannot negotiate 90° bends
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Rehabilitation and Replacement
The service connections are reinstated from within using a remote controlled
mechanical robot. A CCTV system is used for monitoring the operation. Water
tightness is preserved by the resin that surrounds the threaded cavities of the
service connections and ensures a tight bond with Aqua-Pipe.
A-60
-------
Technology/Method Woven Hose Lining/Adhesive
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Class IV (AWWA M28 Manual) fully structural independent liner
• Composite of woven seamless textile jacket with resin and polymeric
membrane
• Aqua-Pipe is composed of two concentric, tubular, plain woven polyester
jackets with a polymeric membrane bonded to the interior to ensure water
tightness.
• The liner is impregnated with a specific thermoset epoxy resin that allows a
tight bond between the liner and the host pipe.
6 to 1 2 inches
3 to 6 mm
Maximum operating pressures up to 1 50 psi
35°FtolOO°F
Up to 500 feet (150 meters) between access pits.
The distance between access pits determines the length of the segment.
Hazen- Williams coefficient > 1 20
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
Aqua-Pipe is certified by NSF to NSF/ANSI 61 and under BNQ Standard 3660-
950.
The mechanical properties of Aqua-Pipe exceed ASTM F1216 and ASTM F1743
recommendations.
50+ years
Aqua-Pipe is precisely aligned with the host pipe's point of entry and pulled
through to the exit point.
The shaping of Aqua-Pipe is achieved by pushing a pig through the hose using
water pressure. Circulating hot water ensures the curing process. Pulled-in-Place
Piping (PIPP) method.
This product requires the following cure time, temperature, and flush:
• Day 1 : Cure 1.5 hours at 65°C and 25 psi water pressure, then cure for
12 hours at ambient temperature and 50 psi water pressure
• Day 2: Flush at 2.8 liters per minute for 24 hours at ambient temperature
• Day 3 : Cure for 24 hours at ambient temperature
Requires a 1 hour flush with potable water prior to being placed into service.
No special procedures beyond standard manufacturer's recommendations
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
No particular maintenance needs; Pressure or dry taps for future service
connections can be easily carried out with no special equipment
Typically need to cut out defective pipe section and replace with new pipe.
V. Costs
Key Cost Factors
Case Study Costs
List of parameters or key drivers for the costs.
Set-up cost: mobilization, temporary by-pass installation, pit excavation &
backfill, pipe cleaning & inspection, service plugging & reinstatement, lining,
testing, disinfection & site restoration
Material costs: liner, resin, new pipe & fittings including valves and hydrants
Hamilton = $133/feet (35% savings); Toronto = $137/feet (50% savings);
Naperville = $186/feet (see case study)
VI. Data Sources
References
http://www.sanexen.com/en/aquapipe/index.htm
http://www.sanexen.com/en/aquapipe/tech info product.htm
Communication with Valerie Belisle, Michael Davison and Joseph Loiacono
A-61
-------
Technology/Method Saertex Liner® /CIPP
I. Technology Background
Status
Emerging
Date of Introduction
Europe in 1996 /US since 2007
Utilization Rates
2008: about 100 miles
Vendor Name(s)
Saertex-Liner®
Saertex multiCom® GmbH
Brochterbecker Damm 52
D-48365 Saerbeck
Germany
Phone: +49 2574 902-400
Fax: +49 2574 902-422
Email: multicom(g),saertex.com
Web: www.saertex-multicom.de
SAERTEX multiCom LP
12249 Mead Way
Littleton, CO 80125
Phone: 1 866921-5186
E-Mail: multicom(g)saertex.com
www. saertex-multicom.de
Practitioner(s)
DIRINGER & SCHEIDEL Rohrsanierung GmbH & Co. KG
Branch Oldenburg/Mr. Richard Mohr
Donnerschweer StraBe 82
26123 Oldenburg
Phone: +49 441 2096410
C&L Water Solutions Inc.
Mr. Larry Larsson
12249 Mead Way
Littleton, CO 80125
Phone: +1 303 7912521
Kleen GmbH Umwelt & Kanaltechnik
Mr. Uwe Rieken
BottcherstraBe 4
26506 Norden
Phone:+49 4931 97207-0
Description of Main
Features
The structural portion of the liner is made of several layers of Advantex® (ECR
glass) glass fiber reinforcement that is manufactured by SAERTEX multiCom.
An inner film (styrene tight) serves as an aid to installation and is removed
immediately following the curing process. An external styrene tight film is
outside the structural layer complex, followed by an opaque film that protects
against UV exposure and damage during insertion. The liner is winched in, after
placement of a sliding film, along the invert of the host pipe. Two types of resins
can be used: a polyester resin or a vinylester resin for industrial sewage. The liner
can be either UV cured or steam cured (catalyst is included for steam curing
option).
Main Benefits
Claimed
High tensile strength in both radial and axial directions due to glass fiber
reinforcement. Handle winching forces.
Excellent material data, like an e-modulus of 1.740 x 10 psi = static needs
are achieved with thin wall thickness.
1/10 the thermal shrinkage of an ordinary polyester felt reinforced liner
resulting in annular gap normally less than 0.5%.
Higher long-term modulus than felt liners.
Cure with either UV or steam.
Liner can be placed into service directly after completion of curing process
and re-opening of the laterals.
Circular, egg-shaped or box sections can be accommodated.
Main Limitations
Cited
More expensive than polyester felt material
Hose liners produced in Germany and shipped to the US warehouse
A-62
-------
Technology/Method Saertex Liner® /CIPP
Applicability
(Underline those that
apply)
Force Main (potential) Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Storm Water Pipes
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Gravity sewer, storm water pipes
Service connections reinstated same as conventional CIPP liners.
Semi structural to fully structural. The Saertex- S-Liner and Saertex-M-Liner have
the following short-term flexural properties:
Saertex- S Saertex-M
Flexural Strength, psi 36,250 29,000
Flexural Modulus, psi 1.740 x 106 1.015 x 106
The S-Liner has a diminution factor of 1 .35 for calculating the long-term flexural
modulus.
Advantex® (ECR glass) glass fiber from Owens Corning. Polyester resin from
DSM and Scott Bader. Vinylester resin from NRC.
6 to 48 inches (1 50 to 1 ,200 mm)
0.1 18 to 0.472 inches (3 to 12 mm)
Not available.
Not available.
Hose liners up to 1,640 feet (500 m)
Not available.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
EN 13 566, Part 4
ATV-M127,Part2,NSF14
70 years based on 20,000 hour stress rupture testing
DIN EN 1610
Sewer lines need to be cleaned and TV-inspected before start of work. A sliding
film is inserted along the invert and packing heads installed at the ends of the
liner. The liner is drawn into the existing pipe and then inflated using compressed
air. The liner is then cured with either UV light or steam, depending on resin
type. The curing process is computer-controlled. After curing the packing heads
are removed and the inner film removed, tightness testing can be made at this
point. A pproximately 4 hours after curing, laterals or service connections can be
reinstated using conventional methods and the line returned to service.
Host pipe is CCTV inspected prior to lining. After lining, another CCTV
inspection is necessary to confirm that there are no wrinkles, delamination or
foreign objects (defects) in the liner. Samples, per ASTM F1743 should be
obtained and tested for wall thickness, flexural and tensile properties. Exfiltration
tests for gravity pipes, with a maximum limit of 50 gal/inch diameter/mile/day,
and pressure testing to either twice the working pressure or working pressure plus
50 psi, whichever is less, is recommended in ASTM F 1743. Allowable leakage
for pressure test is 20 gal/inch diameter/mile/day.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
Not available.
Not available.
V. Costs
Key Cost Factors
Case Study Costs
Not available.
e.g. for 8 inches = approx. $14/feet material, chemicals, foil, glass fiber and
approx. $12/feet installation, cleaning, mobilization
VI. Data Sources
References Trenchless Technology International, Pumper & Cleaner Magazine
A-63
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Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Hose Liner/Pulled in Place
I. Technology Background
Emerging
2001 in Germany
Between 20 and 30 km per year through 2008
Primus Line®
Raedlinger Primus Line GmbH
Kammerdorfer Strasse, 1 6
ChamD93413
Germany
Phone: +49 9971 4003-100
Email: primusline (gjraedlinger .com
Homepage: www.primusline.com
Double-inverted siphon under Lake Bigge. Two 12" drinking water lines, 650
feet long each, 232 psi working pressure.
Client: Kreiswasserwerke Olpe
Engineer: Bieske & Partner, Lohmar
Rising pressure pipe, 20 inches diameter, 363 psi working pressure, 1,350 feet
long with 4 - 45° bends. Pipeline located on a 76% slope.
Client: Stahlwerke Thuringen AG
Seamless woven aramid (Kevlar®) fiber in single or double-layer design
embedded in a high performance plastic. The folded pipe is pulled into the
existing pipe from a reel. No curing required. Pressure inflates the liner which is
then self supporting. Inner liner coating is either PE for water and sewer
applications, or TPU for oil and gas.
• Light weight, 1 .6 to 9. 1 kg/m depending on diameter and number of layers
of fabric.
• High strength - burst pressure of 2,580 psi (178 bar) for 6 inches diameter.
• Delivered rolled up to 5 miles on one drum.
• Easy to install - up to 6,000 feet in a single line.
• Could be used for a temporary pressure by-pass line.
• Can navigate through a 30° bend.
• Requires a special coupling device (Primus Line connectors) for jointing up
to steel, PE or other pipe materials for pressure rates higher than 16 bars.
Alternative standard PE or GRP couplings are being tested.
• Cannot accept connections so need special connectors (for high pressure) to
adapt to fittings.
• Would be imported from Germany as no US production.
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Gas and Oil
II. Technology Parameters
Pressure - water, wastewater, oil and gas
No service connections directly to the liner. A special connector (for high
pressure applications) is needed at end to join liner, via a flange or weld, to steel
pipe or fitting.
Class IV, but relies upon host pipe to carry external loads.
The Primus Line is made of a low weight fibre woven hose. The hose is
constructed of seamless interweaving of Kevlar fibre with an inner and outer
coating. The inner coating is a thermoplastic which is smooth and resistant to
many media. For water and sewer applications the inner coating is PE, for oil and
gas applications the coating is TPU. The outer coating is wear-resistant PE.
Kevlar fibre has a tensile strength of 2,920 N/mm , or 8 times that of steel.
6-20 inches (1 50-500 mm)
0.24 inches (6.5 mm)
A-64
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Technology /Method Hose Liner/Pulled in Place
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
493 psi for 6 inches (150 mm), 218 psi for 20 inches (500 mm) for single layer of
woven fabric; higher with double layer of woven fabric
60°C
Up to 6,000 feet (3,000 feet more common)
Certified for drinking water in Germany, but not in North America.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
KTW and W270 for drinking water in Europe, Deutsche Vereiniging des Gas und
Wasserfaches (DVGW) Testing Basis VP 643, June 2004
None. Raedlinger's rated pressure of the Primus Liner provides a short-term factor
of safety of 2.5 against the burst pressure. Raedlinger's literature states that long-
term creep pressure tests are conducted, in accordance to DIN 16887 and ISO
9080, with a safety coefficient of 2.0 applied to the extrapolated 50 year strength.
Minimum service life of 50 years
None
The existing pipe is first CCTV inspected. The inspection device is fitted with
tools suitable for grinding off sharp edges at pipe transitions or welded seams.
The pipe is then cleaned using a mechanical pig. Sharp edges can damage the
outer PE coating so a special fitting is needed to guide the liner into the host pipe.
The Primus Line is pulled from a reel into the pipeline that has been prepared. A
special pulling head is fitted to the end of the Primus Line for attaching the cable
for pulling. Rate of installation of up to 1 200 feet per hour possible. The
maximum pulling force is 1 00 kN. A load cell with recorder is required to
monitor and document the pulling force. With the Primus Line in final position,
special connectors are fitted on the ends and after curing of the injected resin
(Scotchcast™ Cable Resin No. 1471), the connector is used to join the Primus
Line via a welded or flanged connection to the original pipe or an adapter.
The host pipe is CCTV inspected for anomalies. The inspection device is fitted
with a grinding tool for removal of any sharp edges which could damage the
Primus Liner during insertion or operation. After the liner has been completely
installed and connecters fitted to the end, the line is hydro statically pressure tested
to ensure leak tightness. Raedlinger recommends a test pressure of 1 . 1 times
working pressure, or a minimum of 30 psi (2 bar) over working pressure.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
None identified.
Raedlinger did not state what procedures need to be followed to repair a section
that has been lined with Primus Line. It would appear that a damaged section
would have to be removed and two new special couplings used to install a
replacement section.
V. Costs
Key Cost Factors
Case Study Costs
• Time and cost savings
• Only coarse cleaning of the old pipe is necessary; no bonding of the Primus
Liner is required
• Fast installation process and fast restart of pipeline operation
• Savings through minimum construction costs
• Reduction of excavation work to a minimum; minimal disruption of public
life, no destruction of vegetation, no disturbance of road, rail and shipping
traffic
The cost for the installation was reported to be about a 70% cost savings versus
conventional replacement construction.
VI. Data Sources
References
Primus Line brochure "Innovative High-Pressure Pipelines for Trenchless Pipe
Renewal"; Reference data sheets (8 selected projects)
Pressure Rates; Scope of delivery; Installation manual (December 2008);
Installation manual connectors
A-65
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Technology/Method Glass Reinforced Thermoplastic Liner/Thermoformed
I. Technology Background
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Emerging
2008 - development trials in Europe
Limited -still in development stage
Aqualiner
Aqualiner Ltd
Unit 10, Charnwood Business Park, North Road, Loughborough, Leicestershire,
LEU 1QJ, United Kingdom
Phone: +44 (0) 1509 210027
Email: info(g)aqualiner.co.uk
Website: www.aqualiner.co.uk
Three field trials undertaken by Wessex Water. Contact Julian Britton, Manager -
Critical Sewers Team, Kingston Seymour STW, Back Lane, Kingston Seymour,
ClevedonUK BS21 6UY Tel (44) 01275 875157
Aqualiner involves inserting a glass fiber reinforced polypropylene sock into a
deteriorated pipe. Once the composite sock has been inserted into the host pipe, a
silicone rubber inflation tube pushes a heated pig through the composite melting
the thermoplastic sock against the pipe. The inversion bag presses the molten
thermoplastic composite sock against the pipe wall where it cools to form a solid
glass reinforced thermoplastic liner.
• No mixing of chemicals - long shelf life
• Environmentally safe - no releases
• Structural - capable of withstanding internal and external pressure
• Thin liner - minimizes any loss of capacity with a liner
• Trenchless method of installation- minimizes excavation and disruptions
• Still in incubation - not commercially released yet
• NSF 6 1 listing and UK approvals in process (DWI Regulation 31).
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other:
II. Technology Parameters
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Temperature Range,
°F
Renewal Length, feet
Other Notes
Water distribution, sewer force mains
Open cut or robotically reinstate. Fusion couplings under development
Fully structural (Class IV). Aqualiner will conform to the strain corrosion
requirements for a GRP sewer pipe as contained in Table 6 of EN 13566-4:2002
(similar to those in ASTM D3262).
Chopped glass fiber and polypropylene.
6-12 inches
3-6 mm
145 psi (10 bar)
-5°C to 40°C
500 feet of 12 inches
Not available.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
None at this time. Closest applicable standard might be EN ISO 1 5874 -
Polypropylene for hot and cold water installations
None at this time. Closes applicable standard might be EN 1 3566-4:2002, Plastic
piping systems for renovation of underground sewerage networks (CIPP).
50-75 years
None at this time.
The host pipe is first cleaned and then CCT V inspected for location of laterals and
fittings. The liner can be installed through a bend of up to 45 degrees. A pig is
A-66
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Technology/Method Glass Reinforced Thermoplastic Liner/Thermoformed
QA/QC
inserted into the thermoplastic composite sock. The pig heats the polypropylene
until it melts. An inversion drum deploys a silicone rubber inflation tube which
pushes the pig through the pipe. Application rate is 0.5 m/min. The inversion bag
also presses the molten thermoplastic composite sock against the pipe wall where
it cools to form a solid homogeneous thermoplastic composite liner. Pressure in
the inversion bag is kept at 45 psi (3 bar). The inversion bag is deflated and
removed after the liner cools.
After installation, CCTV inspection should be performed on the liner. The
internal surface is to be smooth, clean and free from scoring, cavities, wrinkling,
and other surface defects. Samples of the formed liner should be checked for
thickness, short-term flexural modulus and tensile strength, but as yet no design
values have been provided.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
None identified yet.
Remove host pipe and Aqualiner. Replace with new pipe section and tie back to
existing host pipe with repair clamps.
V. Costs
Key Cost Factors
Case Study Costs
• Mobilization - one fully equipped installation truck, compressor and
generator.
• Pipe cleaning as for close fit lining.
• Principal costs include liner tube, installation labor, crew size (3-4), and
power usage.
• Service lateral reinstatement by open cut or remote robotics as per close fit
lining.
Estimated Cost ~ $35-$40/feet
VI. Data Sources
References
Aqualiner Product Specification Issue 3 (Aug. 12, 2007)
A-67
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Technology /Method
Status
Date of Introduction
Utilization Rates
Vendor Name(s)
Practitioner(s)
Description of Main
Features
Main Benefits
Claimed
Main Limitations
Cited
Applicability
(Underline those that
apply)
Service Application
Service Connections
Structural Rating
Claimed
Materials of
Composition
Diameter Range,
inches
Thickness Range,
inches
Pressure Capacity,
psi
Sliplining/HDD/Pipe Bursting/Direct Bury
I. Technology Background
Emerging
Introduced November 2003. First commercial installation January 2004
Over 2 million linear feet installed since 2004
Fusible C-900®/Fusible C-905®/FPVC™
Underground Solutions, Inc. (UGSI)
13135 Danielson Street- Suite 201
Poway, CA 92064
Phone: 858-679-9551
Email: info(g)undergroundsolutions.com
Web: www.undergroundsolutions.com
Over 700 projects with municipal and industrial users in 43 out of 50 states,
Canada and Mexico. Primarily used for pressurized potable water, reclaim, and
wastewater lines
Fusible PVC™ pipe is extruded from a specific formulation of PVC resin, which
allows the joints to be butt fused together using UGSI's fusion process. Industry
standard butt fusion equipment is used with some minor modifications. The
resin/compound meets the PVC formulation in PPI Technical Report #2. With the
proprietary formulation, the fused joint strength is (minimum 95%) as strong as
the pipe wall. The fusible pipe is made in DIPS and IPS OD series, as well as
schedule and sewer sizes. The Fusible C-900 ®, Fusible C-905®, and FPVC™
pipes are NSF 61 certified for potable water.
• AWWA C900 and C905 PVC pipe
• Corrosion resistant, abrasion resistant, high "C" factor at 1 50
• Fully restrained joint - Fusible PVC™ joints allow long lengths of pipe to be
used for HDD, pipe bursting and sliplining applications.
• NSF 61 certified for potable water
• Use standard fittings and service saddles
• Higher strength enables longer pulls and larger inside diameters
• Fusion time for joint is 1 . 5 to 2 minutes per diameter inch
• PVC fusion technicians need to be trained and qualified by UGSI.
Qualification only lasts one year.
• PVC is impacted by cyclic (fatigue) pressure loadings, which are typically
experienced in a force main application.
• As a stiff, strong thermoplastic, PVC has specific guidelines for bending
radius
Force Main Gravity Sewer Laterals Manholes Appurtenances
Water Main Service Lines Other: Culverts
II. Technology Parameters
Sliplining, HDD, pipe bursting, direct bury
Reinstate with excavation. Tapping procedure per Uni-bell standards. No direct
tapping. Connect to MJ or flanged fittings.
Fully structural (Class IV) - carry full internal pressure and external loads
independent of the host pipe's remaining strength.
Fusible PVC™ is extruded with a unique patent pending formulation that meets
PPI TR-2 range of composition of qualified PVC ingredients. Meets ASTM cell
classification 12454.
4-12 inches for Fusible C-900® (potable water)
14-36 inches for Fusible C-905® (potable water)
4-36 inches for FPVC™ (potable water in other than C900/C905 dimensions and
non-potable applications)
Fusible C-900: DR 14, 18, 25
Fusible C-905: DR 14, 18, 21, 25, 32.5, 41, 51
FPVC: DR 14, 18, 21, 25, 26, 32.5, 41, 51, Sch40, Sch 80
D3034 and F679 Sewer sizes through 36 inches
165 psi - 305 psi under C900; 80 psi - 235 psi under C905
A-68
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Technology/Method Sliplining/HDD/Pipe Bursting/Direct Bury
Temperature Range,
°F
Renewal Length, feet
Other Notes
Limited to 140°F and below. Above 73°F standard internal pressure de-rating
factors apply for long-term elevated temperature exposure
Standard guidance of 300-500 feet for pipe bursting with length of >1,000 feet
completed in a single burst. Slipline length of 3,500 feet in a single pull have
been completed. HDD lengths of over 5,100 feet in a single length.
Not available.
III. Technology Design, Installation, and QA/QC Information
Product Standards
Design Standards
Design Life Range
Installation Standards
Installation
Methodology
QA/QC
AWWA C900, AWWA C905, NSF 61 Certified (for potable water applications),
ASTM D2241, D3034, F679, D1785
AWWA C900, AWWA C905
100+ years
ASCE "Pipe Bursting Projects" - ASCE Manual and Report on Engineering
Practice #112. AWWA installation standard is in development.
For sliplining, host pipe is cleaned and CCTV inspected. Depending on site
logistics, the Fusible PVC™ pipes can be strung out and the joints butt fused
above grade prior to insertion, or butt fused in the ditch. For pipe bursting, the
pipe normally is butt fused in a single length. Static burst methods only are used.
The fused PVC pipe is either winched into the host pipe for sliplining, or pulled in
behind the expansion head for pipe bursting. A non-rigid connection from the
pipe to the expansion head is used. In all installation methods the maximum
recommended pull force and the minimum recommended bend radius must be
followed.
The stock pipe is subjected to all of the normal QC requirements in AWWA
C900/C905, including dimensional conformance, flattening, acetone immersion,
hydrostatic, and burst tests. UGSI includes impact, heat reversion, and axial
tensile testing as well. In addition 3rd party labs are used to confirm extrusion
results on key tests prior to shipment. The fusion process parameters of pressure
and the time are recorded for each joint using a datalogger. Additional parameters
such as the heat plate temperature are also recorded.
IV. Operation and Maintenance Requirements
O&M Needs
Repair Requirements
for Rehabilitated
Sections
No special O&M needs.
Cut out and replace with AWWA PVC of the same OD, using repair clamps and
all standard PVC and DI water works fittings.
V. Costs
Key Cost Factors
Case Study Costs
Benefits: Due to the high tensile strength of PVC (compared to softer
thermoplastic rehab materials), Fusible PVC™ allows longer lengths of cased and
uncased pulls, which can reduce the number and cost of pit excavations required.
Reduced wall thickness for a given pressure maximizes inner diameter (ID) for a
given outer diameter (OD) either maximizing flow in an OD constrained
environment or minimizing cost of pipe material and installation as well as risk
for a given ID and pressure requirement. Additional ease and reduced cost of
reconnections using standard water works fittings.
Limitations: Due to limitations of bending radius, Fusible PVC™ may require
longer insertion pits over softer thermoplastics.
Fusible PVC™ pipe was used for a 5,120 feet directional drill crossing under the
Beaufort River for the Beaufort Jasper Water & Sewer Authority in June of 2007
and was compared in costs to both steel and HOPE pipe. The overall project cost
$1.7 million and the customer estimated savings of $400,000 (materials and
installation) by selecting Fusible PVC™ pipe over other materials for the drill
portion.
VI. Data Sources
References www.undergroundsolutions.com
A-69
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