570987003
                TECHNICAL ASSISTANCE DOCUMENT:
              THE APPLICATION AND CALIBRATION OF
            PRESSURE INSTRUMENTS, FLOWMETERS,  AND
               FLOW CONTROL DEVICES  AS APPLIED
                      TO INJECTION WELLS
                         Prepared by:
              The Underground Injection Control
            Quality Assurance (UIC-QA)  Workgroup,
             U.S. Environmental Protection Agency
      Office of Drinking Water, State Programs Division
             Underground Injection Control Branch*
                                             Project Manager:

                                                Mario Salazar
                                      State Programs Division
                                               ODW  (WH-550E)
                                             EPA Headquarters
                                           401.M Street, S.W.
                                       Washington, D.C.  20460

                                     Final Technical Editing:

                                  Drew Dawn Enterprises, Inc.
                               2522 South Dakota Avenue, N.E.
                                  Washington, D.C. 20018-1634
                                               (202) 526-3577
                        September 1987
*See Acknowledgements

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                          DISCLAIMER

     This report was prepared for informational training
and technical assistance purposes.  Any references to
specific companies, trade names, or commercial products
do not constitute endorsements or recommendations of
them by the United States Environmental Protection
Agency.

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                       ACKNOWLEDGEMENTS
     The preliminary drafts of this document were prepared by
Mr. Anthony J. Vellios and Mr. John Mentz of SMC Martin
Inc., Valley Forge, Pennsylvania under EPA Contract No. 68-
01-6288.  The manual was extensively revised and completed by
the UIC-QA work group.  The authors acknowledge the valuable
input provided by Mr. Jeff Cantwell of 3D Instruments and Mr.
Jim Casey of Waco Associates.  Special mention is given to
Mr. Joe Roesler of EPA EMSL-Cincinnati as the principal re-
viewer and contributor in his role as instrumentation expert.

     The UIC-QA work group members were:

          Philip Baca*
          New Mexico Oil Conservation Division
          P.O. Box 2088
          Santa Fe, NM 87501

          Gene Coker                       .  (404) 347-3866
          U.S. EPA Region IV, GWS, WSB
          345 Courtland Street, NE
          Atlanta, GA 30365

          John Creech*
          Dupont Company
          Box 3269
          Beaumont, TX 77704

          Richard Ginn*
        .  Railroad Commission of Texas
          P.O. Drawer 12967
          Capital Station
          Austin, TX 78711

          Fred Hille                         (601) 961-5171
          Bureau of Pollution Control
          Mississippi Department of Natural Resources
          P.O. Box 10385
          Jackson, MS 39209

          Juanita Hillman                    (303) 236-5065
          U.S. EPA Region VIII, 8ES
          One Denver Place
          999 18th Street.
          Denver, CO 80295

          Linda Kirkland                     (214) 655-2217
          U.S. EPA Region VI, Office of
            Quality Assurance
        '  1445 Ross Avenue
          .Dallas, TX 75202-2733

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             ACKNOWLEDGEMENTS
               (continued)
Charles A. Koch                    (701) 224-2969
North Dakota Industrial Com.
900 East Blvd.
Bismarck, ND 58505    .

Bert Moniz*
Dupont Company
Box 3269
Beaumont, TX 77704

Bernie Orenstein*
U.S. EPA Region V, 5WD
230 South Dearborn Street
Chicago, IL 60604

Paul Osborne*
U.S. EPA Region VIII, Water Division,
   8WM-DW
1860 Lincoln Street
Denver, CO 80295

Irwin  Pomerantz*
U.S. EPA Headquarters
QAO, Office of Drinking Water  (WH-550)
401 M  Street, S.W.
Washington, B.C.  20460

Joseph Roesler**                    (513)  569-7286
U.S. EPA, EMSL
26 W.  St. Clair
Cincinnati, OH  45268

Mario  Salazar (Project Manager)     (202)  382-5561
U.S. EPA Headquarters
401 M  Street,  S.W.
Washington, D.C.  20460

Jeff van Ee                         (702)  798-2367
U.S. EPA,  EMSL-LV,  AMD,  AMW
P.O. BOX 15027
Las Vegas,  NV 89114

Ron Van Wyk (Task Leader)**        (214)  655-7160
U.S.  EPA Region VI, WSB  (6W-SG)
 1445  Ross Avenue
 Dallas,  TX 75202-2733

 * No longer in work group
 **Mainly responsible for the manual
                 iii

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                           PREFACE
     Correctly selected,  accurately installed, and properly
functioning flowmeters and pressure gauges are essential to
precisely monitor injection wells.  The type of device se-
lected must be suitable for the accuracy and precision re-
quired of the measurement.  The construction material of the
instrument must be compatible with the environment in which
the meter or gauge is placed; it must be appropriate also for
       . . .*                                  ,
the pressures, temperatures, fluid properties, and flow
ranges  that are  anticipated.  Moreover, measurement control
devices should always be  properly maintained  and calibrated;
the manufacturers'  specifications and  guidelines should
be followed,  and their  factory  services used, when appro-
priate .
      The best way to maintain the proper  functioning of  a
 gauge or meter is to regularly clean and calibrate it.   The
 time limits between recalibrations depend upon the type of .
 instruments, and type of fluids to be measured.  Gauges and
 meters can be recalibrated on site by the owner, if the right
 equipment is available;  and, if it is not, done off site by
 either  a service shop or the manufacturer.
      Finally, this  document was prepared  to  introduce the
 basic  concepts  of flow and pressure metering in injection
 wells  to EPA Regional office staffers, state regulators, and
 the  regulated community.
       The  reader will find manufacturer's  lists, and inspec-
  tion and operator checklists  at the end  of the manual.

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                      TABLE OF CONTENTS


                                                         Page

PREFACE                                                   iv
LIST OF FIGURES                                           vi
LIST OF TABLES                   .  '                      viii

INTRODUCTION                                               1

PRESSURE MEASURING DEVICES                                 3
     Pressure Gauges                                       3
        Bourdon Tubes                                      3
        Helical Coil Gauges                               10
        Gauges and Extreme Environments                   10
     Pressure Transducers                         •        15
     Downhole Pressure Recording Devices                  17
     Pressure Recording Devices            "               20
     Methods for Testing Pressure Instruments             23
        Deadweight Tester                                 23
        Portable Gauge Testers                            24
     Calibrating Pressure Gauges                          28
     "Negative" Pressure Gauges                           31
     Open Annulus Wells                                   32

FLOWMETERS                                                33
     Types of Flowmeters        .                          33
     Operational Principles                               38
        Positive-Displacement Flowmeters                  38
     .   Turbine Flowmeters                                44
        Differential 'Pressure-Producing Flowmeters        49
        Sonic Flowmeters      •                       -55
        Doppler Flowmeters                                57
        Float-Type Flowmeters                          '59
        Electromagnetic Flowmeters                        61
        Vortex-Shedding Flowmeters  ,                      63
        Other Flowmeter Designs                           63
     Testing and Calibrating Flowmeters                   65
     Flow Recording Devices                               68

CONTROL DEVICES                                           69
     Valves                                         .71
     Actuators                                            78

APPENDIX A - List of Manufacturers                        79

APPENDIX B - Glossary                                     82

APPENDIX C - Publications                                 85

REFERENCES                                                88

CHECKLISTS FOR INSPECTIONS                                89
                             v

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                       LIST OF FIGURES

Figure                      Title                      Page
   1       The Working Components of the Bourdon
             Tube Driven Pressure Gauge                 '4
   2 •      Retarded Gauge    •                           11
   3       Retard Spring and Clamp '                    .11
   4       Helical Coil Gauge                      '     12 .
   5       Diaphragm Seal  •       .                      14
   6       The Pressure Transducer (bottom) and
             the Wheatstone Bridge Strain Gauge
             (top)                                      16
   7       The Amerada RPB-4-Gauge                      18
   8       Electronic Receiver-Recorder                 21
   9       Mechanical Pressure Recorder        .         22
  10       Deadweight Tester and Portable Gauge
             Tester                                     25
  11       Portable Gauge  Tester                        27
  12       Bourdon Gauge Components                     29
  13       Bi-Rotor Oval Gear Meter                     39
  14       Rotating-Paddle Meter                        40
  15       Oscillating Piston Meter                     41
  16       Rotating Vane Meter                         ,42
  17       Major  Components  of a Turbine Meter          45
  18       Bearingless Flowmeter                        47
  19       Flow Ranges and K-Factors                    48
  20       Typical Turbine Performance  Curve            48
  21       Schematic  Diagram of a Working  Orifice       50
  22       Schematic  Diagram of a Working  Flow
             Nozzle                                     51
                            VI

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                       LIST OF FIGURES
                         (continued)

Figure                      Title         .  .           Page
  23       Plan View of a Flow Tube                     52
  24       Plan View of a Venturi Tube                  53
  25       Sonic Flowmeter                    ,          56
  26       Doppler Flowmeter                      ,58
  27       Typical Transparent Float Flowmeter          60
  28       Principles of Magnetic Flowmeters            62
  29       Cut-Away View of a Vortex-Shedding
             Flowmeter                                  64
  30       Schematic Diagram of a Piston Prover         67
  31       Block Diagram of the Working Compo-
             nents of an Electronic Recorder            70
  32       The Eccentric Plug Valve        :             74
  33       Globe Control Valve                          75
  34       Cage Plug                                    77
                           VII

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Table
                        LIST OF TABLES
                            Title                      Page
  1          Fluid Media and Appropriate Bourdon
               Tube Material                             6

  2          Different Flowmeter Specifications         34

  3          Flowmeter Material Resistance              36

  4          Applications of Various Valve Designs      72
                            Vlll

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                         INTRODUCTION

     The Underground Injection Control (UIC) program was
established by the U.S. Environmental Protection Agency to
protect underground sources of drinking water (USDWs) from
potential pollution by injection wells.  Improperly completed
or operated wells can cause ground water contamination.
     The UIC program requires that the mechanical integrity
of. all injection wells be tested before operation begins, and
at least once every five years thereafter.  For Class I wells
the annulus pressures, injection pressures, flow rates and
volumes must also be continuously monitored and recorded.
Periodic, monitoring of pressures and flow rates is required
for Class II and III wells.
     Except during well stimulation, injection pressures must
not exceed a magnitude which would initiate fractures or
propagate existing fractures in confining beds adjacent to
USDWs  (in regards to Class  II wells),  or the injection zone
in the case of Class. I and  III wells.
     An important part of the Underground Injection  Control
program involves monitoring injection  volumes and rates, and
injection and annulus pressures.  This observance requires
the availability of accurate and reliable equipment,  along
with the knowledge needed for proper application.
Flowmeters, indicators,  and recorders  are used to measure and
record volumes and injection rates; the pressures are
ascertained with gauges, transducers,  and/or various downhole

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instruments.
     Each instrument has its own operating requirements,
which must be met to assure that the device operates within
specifications.  Excessive temperatures, pressures, flows, or
vibrations will generally adversely affect the accuracy and
service life of these instruments; care must, therefore, be
taken to install and maintain these devices according to the
manufacturer's instructions.              :
     Devices that measure pressures and flows often have to
be calibrated before installation and recalibrated
periodically to assure continued accuracy.  It is the
operator's  responsibility to assure that tests and
recalibrations are conducted as required.  Inaccurate
instruments should be recalibrated, repaired, or replaced as
quickly as  feasible.
    ' This report discusses  the various devices that are used
to measure  the pressures and the flow rates of injection
wells; particularly, those  instruments that are used by
regulatory  agencies  and injection well operators for
assessing well operations.
     Some terms  are  used in this report that may be
unfamiliar  to  the  reader; these expressions are defined  in
Appendix B.
     Check  Lists are included  at the  end  of the document
which  can be used  by appropriate personnel to  determine  the
effectiveness  of flow control  devices  as  applied  to
underground injection control  programs.

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                  PRESSURE MEASURING DEVICES

     Injection pressures are measured in several ways.  One
procedure uses the pressure source to mechanically expand a
hollow tube or a coil which in turn causes a pointer to move
across a graduated dial; this method utilizes several kinds
of pressure gauges as well as downhole pressure "bombs," and
self-contained pressure recorders.  Another uses pressure
transducers that contain a strain gauge that is connected to
an exposed diaphragm.  As the diaphragm stretches under
pressure, its strain is converted into an electrical  signal
                                                  V
that is proportional to pressure.  Both pressure transducers
and pressure gauges are discussed in detail in the following
pages:
PRESSURE GAUGES
     The standard pressure gauge is a small instrument  (1"-6"
diameter) and consists  of a  dial face, a pointer, and a
driving mechanism.  It  is connected directly to  the pipe  in
which  pressure  is to be monitored.  Pressure can be instantly
read on the  dial face.  Most such gauges are inexpensive  and
compact  —  if compared  to  other measuring  devices.
Bourdon Tubes
     Most pressure  gauges  use the Bourdon  "C"  tube  as the
driving mechanism for the gauge pointer.   The  Bourdon tube is
 a hollow C-shaped tube  as shown in  Figure  1.   The  tube is
 located  inside  the gauge case and is  directly attached to a

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Figure 1.  The  Working Components of  the Bourdon Tube
           Driven Pressure Gauge.   The fluid under
           pressure flows directly  into the tube and
           causes it to expand.  This expansion pulls
           a  segment gear which  in_turn drives a
           pointer.
        POINTER
        BOURDON
         TUBE
                                               BOURDON TUBE WITH
                                               INTERNAL PRESSURE
                                                   GAUGE RIM
SEGMENT GEAR
                                       STEM
                         PRESSURIZED  FLUID

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threaded stem.  The fluid travels through the stem into the
tube.  The tube deflects in proportion to the amount of fluid
pressure.  This in turn forces a segmented gear arm to drive
the pointer gear.  The gearing can be slightly adjusted to
assure linearity and provide an accurate pressure reading.
     The tube can be made from a variety of materials, but
construction materials must be selected so as to protect the
instrument from corrosion, since the fluid is in contact with
the  inside of the tube.  Table 1 gives the appropriate
materials to be used for different fluid media.  Bourdon tube
gauges can be designed to measure pressures up to 20,000 psi.
Inaccuracies  range  from 0.25 percent to 3 percent of  full
range.   (Temperature is an important factor to be considered
in reducing error.)
     The error expected can be approximated by the  formula:
               e  =  .02 x T x P
                       Ps
 In which:
 .02 = an empirical constant
 e = error
 T = Temperature (°K)
 P = Pressure, applied
 Ps = Pressure range
 (Considine, 1974)

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                                              TABLE 1

                         FLUID MEDIA AND APPROPRIATE BOURDON TUBE MATERIAL
                               LEGEND

                                P
                                S403
                                M
                                S316
                       Bourdon Tube Material

                        Phosphor Bronze
                        403 Stainless Steel
                        K Monel
                        316 Stainless Steel
Medium

Acetone
Acetic Acid
Acetate Solvents
Acetic Anhydride
Acetylene (dry)
Alcohols
Alums
Ammonia
Ammonium Carbonate
Ammonium Chloride

Ammonium Hydroxide
Ammonium Phosphate
Ammonium Sulfate
Aluminum Chloride
Aluminum Fluoride*
Aluminum Sulfate
Amyl Chloride (dry)
Beer
Benzene
Benzol
Boric Acid
Benzyl Alcohol
Brine*
Bourdon Tube Material

  P, S403, M, S316
  S316, S403
  S403, M, S316
  M, S316
  P, S403, M, S316
  P, S403, M, S316
  S403, M, S316
  S403, S316
  S403, S316
  M

  S403, S316
  S403, S316
  M     -      .
  M
  M
  S403, M, S316
  M
  P, M, S316
  P, S403, M, S316
  P, S403, M, S316
  P, M  •
  S403, M, S316
  M
Medium

Bromine (dry)
Butane
Butanol
Butyric Acid
Calcium Chloride*
Calcium Bisulfite
Calcium Hydroxide
Carbon Dioxide (dry)
Carbon Disulfide
Carbon Tetrachloride
  (dry)
Carbonic Acid
Carbolic Acid
Chlorine (dry)
Casein
Chloroform (dry)
Chromic Acid
Chromium Fluoride*   .
Citric Acid
Coal Gas
Cottonseed Oil
Copper Sulfate
Cuprous Oxide
Ethers
Bourdon Tube Material

  M
  S403, M, S316
  P, M  :
  P    '
  P, S403, S316
  S403, S316
  P
  P, S403, M, S316
  S403, S316
  M, S316

  M, S316
  M, S316
  M, S316, S403
  P
  P, M, S316
  S403, S316
  M
  S403, M, S316
  P
  S403, M, S316
  S403, S316
  S403, M, S316
  P, S403, M, S316

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                                              TABLE 1

                                            (continued)
Medium
Ethyl Cellulose
Ethyl Acetate
Ethylene (dry)
Ethyl Chloride (dry)
Ethylene Dibromide
  (dry)
Ethylene Bichloride
  (dry)
Ethylene Glycol
Ferric Nitrate
Ferric Sulfate
Formaldehyde
Freon
Gasoline
Gelatine
Glucose
Glycerine
Hydrocyanic Acid
Hydrogen
Hydrogen Peroxide*
Hydrogen Sulfide
Kerosene
Lacquers
Lactic Acid;
Lithium Chloride*
Magnesium Chloride*
Magnesium Sulfate
Naptha
Mercury
Natural Gas
Bourdon Tube Material

  P, S403, M, S316
  P, S403, M, S316
  M
  M
  P, M

  M

  P, S403, M, S316
  S403, S316
  S403, S316
  M, S316
  P, S403, M, S316
  P,..S403, M, S316
  M, S316
  P, S403, M, S316
  P, S403, M, S316
  S403, M, S316
  P. M, S316
  S403, M, S316
  M         -   	
  P, S403, M, S316
  P, S403, M, S316
  S403, S316
  M   .
  M
  P, S403, M, S316
  P, S403, M, S316
  S403, S316
  P, S403, M, S316
Medium
Magnesium Hydroxide
Nickel Acetate
Nitrogen
Nitric Acid*
Nitrous Acid*

Nitrosyl Chloride

Oleic Acid
Oxalic Acid
Oxygen*
Paraffin
Picric Acid •
Phosphoric Acid*
Phosphorous Acid*
Photographic Solutions
Petroleum Oils
Potassium Chloride*
Potassium Hydroxide
Potassium Sulfate*
Potassium Permanganate
Propane Gas
Pyroxylin
Salicylic Acid
Steam (under 300 psi)
Steam (over 300 psi)
Sodium Bicarbonate
Sodium Bisulfate
Sodium Carbonate
Sodium Chloride*
Bourdon Tube Material

  S403, M, S316
  P, M
  P, S403, M, S316
  S316
  S316

  M

  S403, M, S316
  M
  P, S403, M, S316   .
  P, S403, M, S316
  S403, S316
  S403, S316
  S403, S316
  S403, S316
  P, S403, M, S316
  M
  M
  M
  S403, S316
  P, S403, M, S316
  M
  P, S403, M, S316
  P, S403, M, S316
  S403, S316
  M, S316
  M, S316
  M, S316
  M

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                                              TABLE 1

                                            (continued)


Medium                 Bourdon Tube Material
Sodium Cyanide           S403, S316
Sodium Fluoride*         M
Sodium Hydroxide*        M, S316
Sodium Metaphosphate     M, S316
Sodium Nitrate*          S403, M, S316
Sodium Perborate*        M, S316
Sodium Peroxide*         S403, M, S316
Sodium Phosphate         S403, M, S316
Sodium Silicate          S403, M, S316
Sodium Sulfate*          M
Sodium Sulfide           S403, M, S316
Sodium Sulf ite*          M, S316
Silver Nitrate           S403, S316
Stearic Acid             S403, M, S316
Sulfur Dioxide*          S403, S316
Sulfurous Acid*          S403, S316
Tetraethyl Lead          M
Titanium Sulfate         M
Toluene                  p, S403, M, S316
Trichloroethylene        S403, M, S316
  (dry)
* Depending upon certain conditions

           (Chilton, 1976)

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     The gauges used for injection well monitoring should
have a full scale pressure range not more than twice that of
the normal injection pressure (Chilton, 1976), otherwise the
sensitivity of the meter to measure accurately is lost.  For
example, a Bourdon gauge installed on a well where normal op-
erating pressure is. 1000 psi should have a full range of not
more than 2000 psi.  If a 10,000 psi is used, the maximum er-
ror would increase from 60 to 300 psi  (140 to 700 feet of
head).
     One advantage of Bourdon gauges is that their movements
can be  retarded.  The scale of  a retarded gauge abruptly
changes at a  certain point on the dial (see Figure  2).  Often
these gauges  have a small portion of the total scale  reading
spread  out over  90 percent of the dial.  This allows  a gauge
reader  to.observe a normal range of pressures, while  provid-
ing  a means  to read pressures far above normal.   Retarding is
achieved  by  attaching, a spring  to the  gauge movement (see
Figure  3)  and allowing the  segment  gear to  come  in contact
with the  spring only  at the  required pressure range.
      A disadvantage of the  Bourdon  tube pressure gauge is its
 inability to handle vibrations  without special equipment.
 Pulsating pressure or vibrating pipelines•can cause gear
 teeth and bearing wear; powder from these abraded parts can
 deposit on other moving parts of the gauge which can result
 in loss of calibration and operational life..
     • There are several methods to diminish the harmful ef-
 fects  of vibration.  One is to connect pulsation dampeners

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to the stem of the gauge.  For these mechanisms to work
correctly, the tube must be filled with glycerin.  The glyce-
rin slows the action of the Bourdon tube and reduces the
effect of vibration.
     One dampener design is a synthetic rubber bulb that
seals the service medium from the gauge proper; another uses
a moving pin, which works like a piston> to absorb most of
the vibration energy.  For permanently encased gauges the
casing should be filled with glycerin or silicone to directly
dampen gear movement (Dresser-Ashcroft, Bulletin OH-1).
Helical Coil Gauges
     Pressure can also be measured mechanically with a heli-
cal coil gauge  (see Figure 4).  These gauges use sensing
coils instead of tubes to move a pointer across a dial.  The
pipe fluid is directly connected to the coil which unwinds
under pressure.
     Bearings steady the coil and force the lateral movement
to translate into rotation.  The degree of unwinding is di-
rectly proportional to pressure.
     Helical coil gauges are especially suited for high vi-
bration applications, since they have few parts and no gears.
Some coil gauges can measure pressures as high as 20,000 psi
with errors that range only from 0.25 to 1.0 percent of full
range.
Gauges and Extreme  Environments
     -Some difficulties can arise with pressure gauges under
certain temperature and  chemical conditions.  Joint construc-
                              10

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Figure 2. Retarded Gaug.e.  The scale changes  at 10 psi
           (Dresser-Ashcroft, 250-1353-H).
                                        SINGLE RETARD
                                        0 to 30 psi Dial
 Figure 3.
Retard Spring  and Clamp.   The segment gear
swings downward  with pressure and requires
more force once  it strikes the spring
(Dresser-Ashcroft,  250-1353-H).
                     CLAMP
                            PILLAR SCREW
                                  SPRING
                               11

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Figure 4.   Helical Coil  Gauge.  As the  pressure increases
            inside the  stem tube, the helical coil unwinds,
            thus rotating the pointer clockwise.
                 POINTER.—
          HELICAL
           COIL
          BEARINGS
                                                   GAUGE RIM
                                        STEM
                            PRESSURIZED FLUID
                                12

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tion is an important factor in the ability of  the gauge to
operate properly at a given temperature.  Only gauges with
welded joints are rated to withstand a temperature of 750°F;
while silver brazed joints operate to 450°F and  soft soldered
joints are rated to 150°F.  Even  in gauges with  strong
joints, more delicate internal working parts may fail at high
temperatures.  Gauges also may lose accuracy with increasing
temperatures; for example, the accuracy  in- the reading of
some gauges can change 1.5 percent per 100°F.  To protect
gauges from the effects of high temperatures operators usual-
ly connect the gauge to service'lines with a piece of pipe.
Tests have shown that a foot-long, half-inch pipe can reduce
a process temperature from 200°F  to 120°F at the gauge where
ambient temperatures are  80°F  (Dresser-Ashcroft  250-1353-H).
     Pipe fluids can damage a gauge by corroding or clogging
'the measuring element (e.g., Bourdon tube) when  they come in
direct contact.  Diaphragm seals  should  be used  between the
injection or annulus fluid and the gauge (see  Figure 5) to
isolate the gauge from the process fluid.  The pressure is
then transmitted to the gauge via the glycerin that fills the
tube and stem.
     A diaphragm seal is  useful when a single  gauge is used
to monitor several injection systems at  different times.  If
a diaphragm is provided for a pipe, cross-contamination due
to switching pressure gauges is eliminated.
    • Diaphragm seals are  also useful to  prevent  extremely low
temperature fluids from entering  the gauge and causing freeze
                              13

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Figure  5 .
Diaphragm Seal.  The diaphragm transmits  pipe
pressure to the instrument without allowing
the pipe medium to  pass (ITT Hildebrandt,.
1983).
             GAUGE CR
             INSTRUMENT
             CONNECTION
         UPPER
         HOUSING
          LOWER
          HOUSING
                                  STAINLESS
                                  STEEL
                                  NAMEPLATE
                                  FOR  PRODUCT
                                  IDENTIFICATION
                                                   CONTINUOUS
                                                   DUTY FEATURE
                                                 DIAPHRAGM
             BACK-UP
             RING
                                PROCESS
                                CONNECTION
                                14

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damage; however, a diaphragm seal can affect the precision of
a gauge and its ability to withstand pressures; such a seal
can also magnify errors created by temperature increases.  A
way to remedy this is to fill the instrument with fluids that
have low thermal coefficients of expansion.  Such fluids in-
clude glycerin which can be used up to 300°F and silicone
D.L. 710 which can be employed to 700°F.  Since the total
error is dependent upon the fluid volume expansion, tempera-
ture change on each component, as well as the spring constant
of the diaphragm foil, the resultant accuracy can only be
estimated (Considine, 1974).

PRESSURE TRANSDUCERS
     Pressure transducers convert the mechanical force of
pressure in the pipe to an electrical signal.  A transducer
(see Figure 6) typically contains a pressure sensitive dia-
phragm that has four strain gauges attached to it in a con-
figuration called a Wheatstone bridge.  When there is no
pressure upon the diaphragm, the bridge stays flat and the
resistance of each strain gauge is equal.  The diaphragm
changes its shape as pressure is applied and this deflection
creates a change in resistance that is proportional to
pressure.  When the diaphragm is exposed to pressure, the
transducer behaves like a pressure gauge.
     The lack of moving parts makes the pressure transducers
ideal for employment in vibrating, corrosive, or dirty en-
vironments; they can be fitted with diaphragm seals and
dampeners for any unusual conditions.  Some transducers can
                             15

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Figure 6.  The Pressure Transducer (bottom)  and the
           Wheatstone Bridge Strain Gauge ,{top).
           Pressured fluid creates a deflection on
           the diaphragm which in turn changes  the
           resistance of the Wheatstone Bridge.   The
           change in current is proportional to the
           pressure that is applied to the diaphragm.
                           FIXED RESISTOR
          INPUT (+)
-m
          INPUT ( —)
                                          STRAIN GAUGE
                               FIXED RESISTOR


                               INSULATOR

                               DIAPHRAGM

                               BODY
                 PRESSURIZED FLUID
                     FLUID
                              16

-------
operate at temperatures of up to 450°F, although effective
operations of most are limited to 250°F.  Rated pressures can
3De as high as 25,000 psi.  Typical errors are around 0.5 per-
cent.

DOWNHOLE PRESSURE RECORDING DEVICES
     Downhole pressure instruments are most commonly used
during formation testing.  A downhole pressure gauge is com-
monly referred to as a "bomb."  The bomb components are
either a Bourdon tube pressure gauge or a coil-spring assem-
bly, plus a strip chart recorder (see Figure 7).  The chart
can be set to record over a certain time period, and then the
whole instrument is lowered — usually by wire-line down the
casing or borehole.  After the designated time has elapsed,
the bomb must be raised to obtain the data.
     Figure 7 shows a cross section of the two areas of an
Amerada bomb.  The top part (recording section) contains
the clock, chart, and stylus; while the bottom unit (pressure
element) holds a helically-wound Bourdon tube, bellows, and a
maximum registering thermometer.  The bellows is needed to
isolate the Bourdon tube from contaminating well fluids.  The
bellows should be cleaned after each run, since it is often
exposed to corrosive environments.  It should also be rou-
tinely checked to determine whether it is operating properly.
     A common test to ascertain if the bellows has failed is
to push on it with a metal tube.  A "spongy" feel to the bel-
lows, as opposed to a solid feel, indicates a leak in the
system (again, a maximum registering thermometer should be
                             17

-------
    OUTER
    HOUSING
    CLOCK
    CLOCK
    CLUTCH

    LEAD
    SCREW-
    CHART
    HOLDER
    LIFT
CHART
HOLDER
FOR FLAT
OR
FLANGED CHART
STYLUS    	
STEEL SAPPHIRE
OR DIAMOND

  STYLUS
  ASSEMBLY
  B - III
  OR
  B - 229 ON
  RPG -3 ONLY
  CARRYING
  PLUG
                             STYLUS
                             SHAFT
                             GUARD
      STYLUS
      SHAFT
                             ELEMENT
                             HOUSING
                                              Figure 7,
                             BOURDON
                          JL ' TUBE
      SUPPORT
      ROD
The Amerada
RPB-4  Gauge.
Pressured
fluid  enters
the bellows
and the
bourdon tube
which  acti-
vates  the
stylus
(Geophysical
Research
Corp.).
      ELEMENT
    .  BASE

    BELLOWS
    «•( OPTIONAL)
       UNBELLOWS
       OR  FILTER
     OIL
     TRAP

      THERMOMETER
      WELL

      MAXIMUM
      REGISTERING
      THERMOMETER
      ( OPTIONAL)
        RECORDING
    SECTION (GAUGE)
PRESSURE
ELEMENT
                                 18

-------
provided and used since the maximum testing temperatures
should be known and because the instrument calibration will
vary with temperatures).  The recording section of the bomb
is used to generate a record of pressures encountered.
     Coil-spring recorders use a piston, that moves due to
external pressure, to push a calibrated spring.  A stylus is
provided to record pressures on the chart, and the stylus can
be driven by either a piston spring or a Bourdon tube; more-
over, it may have a steel, sapphire, or diamond point.  The
chart is generally brass and it is coated on one side with
gray paint so that the pressure curve can be seen as a con-
trast between the colors, which are usually brass and gray.
     The upper pressure limit of these instruments can be as
high as 20,000 psi with errors of 0.2 percent of full scale.
Special high temperature gauges can withstand temperatures up
to 500°F.  Clocktimes range from 3 to 360 hours.  Coil-spring
bombs may have errors of 5-10 percent of full scale.
     Several types of downhole gauges may be permanently in-
stalled.  One, made by Ball Brothers Research Corporation of
Boulder, Colorado, uses a Bourdon tube that telemeters data
to a chart/recorder at the surface; and, it uses a single
conductor cable.  Recorded pressure curves often have a
"stair-step" appearance because the information transfer be-
tween the surface and downhole is not continuous.  The gauge
is accurate to about 0.2 percent of full scale  (Matthews and
Russell, 1967).  Another gauge has a downhole transmitter
that consists of a steel cylinder with a diaphragm on one
                              19

-------
end and a taut wire that stretches from the diaphragm to the
cylinder body.  A coil and magnet surround the wire and cause
it to vibrate.  Changing pressures cause the diaphragm to de-
form; this in turn proportionally changes the frequency of
the wire vibrations, which allows the current change in the
coil to be transmitted to a receiver on the surface.  Total
error can be as low as 0.25 percent with a recording range of
1,100 to 5,900 psi (Matthews and Russell, 1967)."

PRESSURE RECORDING DEVICES
     Many instruments that measure pressure, flow, and tem-
perature (e.g., pressure transducers), can transmit electri-
cal signals to a receiver-recorder (see Figure 8).  Electro-
nic recorders write on either circular or strip charts, • and
such recorders are discussed later in this report.
     Most pressure gauges are self-contained units that me-
chanically display data with pointers.  Connecting a recorder
directly to these gauges is impossible.  Several manu-
facturers solve this problem by creating a recorder that
directly measures the deflection of a Bourdon tube that is
contained insides a recorder case  (see Figure 9).   The re-
corder resembles a 360-degree chart recorder' except that the
pen arm is driven mechanically by  a Bourdon tube, instead of
electrical signals.  The tube is directly connected to the
pressure source by a bendable hollow extension.  A recorder
offered by C. E. Invalco can measure pressures of up to
10,000 psi with errors of only 1.0 percent of full scale.
                              20

-------
Figure 8.  Electronic Receiver-Recorder  (Omega, 1984)

                              21

-------
Figure  9 .
Mechanical Pressure Recorder.  Typical recorder
made  by Combustion Engineering, Inc.   The
pressure line  is  to the right of the  chart
drive.   The line  conducts  process fluid pres-
sure  to the bourdon tube  (C), which  in turn
guides  the pen arm with a  link  (C. E.  Invalco,
1984) .
                     J A  D H  L   F B
                                                   A. PEN LIFTER
                                                   B. ADJUSTABLE STATIC
                                                     ELEMENT CONNECTION LINK.
                                                   C. STATIC. ELEMENT
                                                     MICRO - RANGE ADJUST
                                                   D. PEN ARM
                                                   .E. CHART  DRIVE
                                                   F. PEN SHAFT  ARM
                                                   S. STATIC  ELEMENT
                                                     LINEARITY ADJUST
                                                   H. PEN ZERO ADJUST
                                                   I. AIRCRAFT  HINGE
                                                   J. DOOR  STOP
                                                   K. CLOSED CELL NEOPRENE
                                                     GASKET
                                                   L. PEN BRACKET (ONE PIECE)
                                                   M. ADJUSTABLE  DOOR  LATCH
                     -K
                         INTERIOR VIEW OF MODEL 212
                                  22

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METHODS FOR TESTING PRESSURE INSTRUMENTS
     Pressure instruments should be examined regularly, al-
though the frequency depends on the environment.  Instruments
subject to high temperature and fluctuating pressures should
be checked for accuracy more than annually; and, devices
measuring pressure of highly corrosive fluids should be
checked more frequently for correctness.
     Testing frequency will also depend on the type of in-
stallation; for example, a Bourdon tube or helical coil in
which a corrosive fluid is in direct contact with the gauge
should be checked for accuracy several times per year.  If a
diaphragm separates the gauge from the corrosive substance,
less frequent testing may be required.  Testing dates should
always be recorded on a chart, along with the amount of error
found on the gauge during the test.  Corrective action, such
as recalibration, should also be included.  A history of per-
formance of the pressure instrument will give the operator
or inspector an indication of how often the gauge is to be
tested or recalibrated.
     Pressure instruments may be tested by the following
methods:
     •  use of a deadweight gauge tester
     •  use of one of many portable gauge testers that employ
        a test gauge as a standard
Deadweight Tester
     A deadweight tester uses primary weight measurements
that are based upon National Bureau of Standards' (NBS) data
for calibration to obtain about 99.9 percent accuracy over a
                             23

-------
pressure range of 15 to 10,000 psi.  Each unit is ad-
justed for standard gravity conditions, thus local gravity
situations should be taken into account during testing
(Miller, 1983).
     The apparatus consists of a hydraulic"pump that is-used
to. pressure a manifold; the manifold is connected to either a
precalibrated test gauge or a free floating piston which
holds calibrated weights and a tube which leads to the gauge
that is being tested (see Figure 10).
     In use, the hydraulic pump exerts pressure against the
piston and the weights that ride on the piston.  When the
piston and the weights spin freely, the pressure in the mani-
fold is equal to the total mass of'the piston and weights —
divided by the cross-sectional area of the piston.  The gauge
or transducer being tested should read a value equal to this
calculated pressure throughout the scale (Dresser-Ashcroft
Form No. 250-1526-A).  Tests also involve pumping the dead-
weight tester until the gauge shows its maximum reading.
Slowly releasing pressure after this test is an effective way
to scan for any sticking of the needle.
     The deadweight tester is the ideal tool for testing in-
struments in the laboratory, due to its high degree of accu-
racy throughout the testing scale.  However, the weights used
in testing should be periodically rechecked to provide assu-
rance that they conform to NBS standards.
Portable Gauge Testers
     For field applications, where portability and ease of
                             24

-------
Figure 10.
Deadweight  Tester and Portable  Gauge Tester.
The same  degree of pressure  exits both open-
ings of the manifold.  The pressure entering
the uncalibrated gauge can be compared with
weights  (deadweight tester)  or  another gauge
(portable gauge tester).
         UNCALIBRATED
            GAUGE
                    TEST GAUGE
                                                 PLATE FOR WEIGHTS
                                                      PISTON
                                                     CYLINDER
                                                     DISC SEAT
                                    PRESSURIZED MANIFOLD
                        PISTON


          •HYDRAULIC FLUID RESEVOIR
                                25

-------
use are important, several manufacturers offer portable gauge
testers.  These testers rely on less accurate means of mea-
suring pressure than the deadweights described above.  For
example, Dresser-Ashcroft makes a portable test pump that is
interchangeable with its deadweight tester but uses a test
gauge instead of weights for calibration (see Figure 10; the
test range is from 15 to 10,000 psi with an error of 0.25
percent).  Although accuracy is reduced, the whole assembly
is easier to carry into the field than a deadweight tester;
arid moreover, it does not have to be used on a level surface.
Dresser-Ashcroft also makes a portable gauge testing set that
weighs only about 12 pounds.  Portability is gained in return
for a slightly higher error of within 0.5 percent and a lower
pressure range of 0-500 psi.  These gauge testers consist of
a hydraulic test pump with two connections; one for a test
gauge and another for an uncalibrated gauge.
      Yet another type of portable gauge tester is manufac-
tured by 3D Instruments  (see Figure 11).  The unit has a
cylindrical reservoir which connects to a manifold; two pump
handles are placed underneath the manifold and opposite to
each other.  A transparent reservoir is filled with water 'and
a 1/4-inch hose 'is connected to the gauge to be tested.  The
handles are pumped manually until the test gauge reads a de-
sired pressure; the vernier knob is then used to adjust the
pressure gauge to the proper value.
                              26

-------
Figure  11.
Portable Gauge Tester.  Both a  test gauge
.and  an uncalibrated gauge can :be  attached
to the tester at  the same time  (3D Instru-
ments,  Inc. 1981).
       PRESSURE GAUGE
          (typical )
   HOSE
       VERNIER ADJUSTMENT
                HYDRAULIC
                  PUMP
                                                        PNEUMATIC
                                                          PUMP
                                                     NEEDLE
                                                     VALVES
                                27

-------
CALIBRATING PRESSURE GAUGES


     If any inaccuracies in a gauge have been found during


testing, it is important that the gauge be either cleaned or


recalibrated.  Some calibration procedures can be performed


easily and quickly, while others require special tools,
                 *

knowledge and time.


     In order to restore a gauge to efficiency, sometimes, a


complete replacement of the movement and linkage is needed.


Often, however, just cleaning the parts or calibrating the


gauge is all that is required; frequently, only a pointer ad-


justment is needed which is called "rezeroing" (Dresser-


Ashcroft Form No. 250-1526-A).


     There are many ways to adjust pointers in gauges (some


gauges have adjustable gears or. friction bushings, while


others have a cam adjustment which rotates the entire move-


ment) .  If the pointer is nonadjustable, it is necessary to


•loosen the-pointer and retighten it at another position.  In


C-type (Bourdon) tubes (see Figure 12) hairsprings should be


tightened with a tweezer to maintain sufficient torque


throughout the gauge range.


     Pressure gauge manufacturers have a variety of ways to


change the pivot radius and they should always be contacted


if such change is needed; the same is true when linearity


adjustments are necessary.  When calibrating liquid-filled


gauges, the liquid must be initially drained (Dresser-


Ashcroft Form No. 250-1526-A).
                             28

-------
Figure 12
Bourdon Gauge Components  (Dresser-Ashcroft,
250-1353-H).
           POINTER
           BUSHING
           POINTER
           SPRING
         ROTARY  MOVEMENT
         SHOWN.
                             BOURDON TUBE

                             SEGMENT

                             BOURDON TUBE TIP

                             ANGLE OF  PULL

                             CONN.;LINK

                             SLIDING  PIVOT TYPE
                             SPAN ADJUSTMENT
                             SHOWN
                             SEGMENT  PIVOT
                             RADIUS
                                   29

-------
     Pointer adjustments required under certain circum-
stances are summarized below:
     Pointer Behavior            .   Corrective Action
1.   Pointer behaves in uniform     1.  Adjust span
     manner except above or be-
     low maximum scale at maximum
     pressure.                               <              .
2.   Pointer travels too far        2.  Increase pivot radius
3.   Pointer does not travel far    3.  Decrease pivot radius
     enough
     The above calibration procedures' do not apply to gauges
with helical, coils because the tube designs are relatively
simple; all that is generally necessary for recalibration is
either a pointer adjustment with'a screw or a replacement of
the coil.
     While pressure transducers can be rezeroed at the re-
ceiver, linearity cannot be so adjusted.  A loss of linearity
indicates that the transducer must be replaced.
     Pressure "bombs can be calibrated with a deadweight tes-
ter; first, the recording element should be checked by in-
stalling a protractor on the element and a pointer on the
stylus shaft.  If the movement is smooth and complete under
pressure, the test may begin.  To calibrate — simply apply
five or ten known pressures, starting from the maximum and
going to the minimum; then spin the chart:holder to have it
read the corresponding pressures and then set.  Again, if
nonlinearity results, the element should be replaced.
    • Since most downhole pressure recorders are of unique de-
signs, the manufacturers should be consulted for calibration
                              30

-------
procedures.

"NEGATIVE" PRESSURE GAUGES          -
     In cases in which a well injects into an underpressur-
ized formation, pressure at the well-head could be lower than
the atmospheric pressure.  In these cases, accurate injection
pressure readings can only be attained with a gauge that mea-
sures absolute pressure.  The primary measuring elements in
these gauges would have to be isolated from the atmosphere
and the instrument would have to be more 'sophisticated than
regular pressure gauges.  Pressure gauge systems that contain
one absolute and one "positive" gauge are commonly known as
compound gauges.  Several manufacturers produce absolute and/
or compound gauges.  A complete list was not available at the
printing of this document (see the list of Manufacturers of
standard pressure instrumentation at the end of the docu-
ment).  Prices for these gauges and recording devices range
from around $15, to several thousand dollars for very accu-
rate gauges with recording devices.
     "Negative" pressure gauges can have ah application in
measuring less than atmospheric conditions in injection
wells.  These measurements can be used in determining pres-
sure vs. injection rate trends which can be analyzed to
determine the mechanical integrity of the tubular goods;
this is because any significant departure from the trend
can signal changes in the injection conditions.  However,
if the well has an isolated annulus, a more sensitive mech-
anical integrity tracking system would consist of monitoring

                             31           :

-------
changes in the annulus pressure, especially if it is higher
than the infection pressure.

OPEN ANNULUS WELLS
     Open annulus (also known as fluid seal) wells can be of
two designs, static and dynamic.  Static systems are by far
the more common; it is for this reason, only static systems
will be discussed here.  The difference in the two is whether
the liquid in the annulus is contained there or comingled
with the injection fluid at the bottom of the well.  A static
open annulus well uses .two "immiscible" fluids that interface
in the bottom of the annulus and isolate it from the
injection fluid.
   •  The annulus fluid level is' monitored to estimate the lo-
cation of its interface with the injection fluid.  This esti-
mate allows the operator to infer the mechanical integrity of
the casing and tubing.  One such monitoring assembly consists
of a graduated holding tank that is connected to the annulus;
the tank is used to keep a positive pressure on the annulus.
The annulus is filled usually with a noncorrosive fluid to a
reference level on the holding tank.  A significant casing
leak is generally indicated by a drop in fluid level as it
drains into the formation adjacent to the point of leakage.
If tubing pressure exceeds annulus pressure, a leak in the
tubing can result in a rise in the fluid level.
     A way to continuously record the annulus fluid level is
to use one of two models of Stevens recorders (types A or F).
Each of these recorders uses a float, which rises and falls

                             32

-------
with the fluid level.  The float is connected to a pulley by
a cable.  On the Type F recorder, the pulley rotates a drum
that is marked with a steady moving pen.  On a Type A record-
er, the pulley moves the pen as the water level changes.
Both record fluid levels versus time on the charts.

                          FLOWMETERS
TYPES OF FLOWMETERS
     Flowmeters can be classified into distinct groups; that
is, positive displacement meters and inference type meters.
Positive displacement meters measure flow directly by sepa-
rating the flow stream into segments of known volumes and
counting them  (Reason, 1983), while inference meters infer a
flow rate by measuring a certain dynamic property of the flow
stream that is proportional to the flow rate.  Below is a
listing of seven of the most used inference flowmeters:
            •  Turbine
            •  Differential Pressure Producing
            •  Sonic
            •  Doppler
            •  Float Type
            •  Electromagnetic
            •  Vortex Shedder- Meters
     Table 2 lists the most common types of flowmeters along
with their approximate accuracies, pressure limits, and other
important parameters.  All of these values are general and
may vary among manufacturers  and between the separate models
offered by a single manufacturer.  Table 3 lists construction
materials which should be used in flowmeters for various
chemical exposures.
     The following section contains some basic calibration
                              33

-------
             TABLE 2
DIFFERENT FIOWMETHR SPECIFICATIONS
FUmmeter
Oscillating
Piston
Hut ut Ing
Paddle
Oval Gear
Rotating
Vane
Pi at on
Bearing-
less
TUrbine
Single
Inpeller
TUrbine
Orifice
Typical
Application
Slurries,
acids
solutions
Wide variety
of liquids
Wide variety
of substances
Wide variety
of ] 1 quids
Non corrosive
Highly corro-
sive
Clean fluids
Water
Clean fluids
Maximum
Pressure
150
1,440
275
1.440
275
300
500
150
600
Maximum
Tenperatura*
300°F
450°F
200°F
200°F
.180°F
266°F
850°F
150°F
700°F
Maxinun
Flow rate/
Velocity**
35 gpm
. 1,250 gpm
150 gpm
8,750 gpm
20 gpm
320 gpm
50,000 gpm
2,250 gpm
25,000 gpm
Advantage
Magnetic pickoff,
no contact with
gears
low pressure loss,
wide range of vis-
cosities
Wide application,
viscous liquids
Low pressure
drop, wide range
of viscosities
Low flow, counter
Handles corro-
sives
Out be more accu-
rate than rating,
precise
Inexpensive, high
flow
Inexpensive, high
flow
Drawback
Vulnerable to
extremes
Fluids with
solids
Fluids with
solids
Liquids with
solids
Liquids with
solids
Liquids with
solids
Liquids with
solids
Narrow appli-
cation
High head
loss, inac-
curate during
low flow
Error
0.5%
0.2%
0.5%
0.5%
0.5%
2.0%
0.5%
2.0%
1.0 -
3.0%
Manu-
facturers
Badger
Uquid
Controls
Smith
Snlth
Tbkhelm
C.E. Invalco
C,E. Invalco
Snlth, Flow
Technology
Badger
Badger,
Anetek,
Daniels
General Price***
f 2.000 for 2-inch
$ 2,000 for 2-inch
$ 4,130 for 2-inch
$20,000; $3,600
for 2-lnch with
counter
f 830 for 1-inch
with counter
$ 1,240 for 2-inch
$ 6.500
? 1,100
$ 150+ with flange
$530

-------
cn
TABLE 2
(continued)
Flowneter
Nozzle
Flow Tube
Venturi
Tube
Sonic
Doppler
Float
Electro-
magnetic
Strain
Gage
Nutating
Disc
Vortex
~ Shedding
Typical
Application
Clean fluids
Sludge, oils
acids, water
Sludge, oils
acids, water
Clean liquids,
any type
Suspended
solids
Clean liquids
Sewage, other
conductive
liquids
Liquids, dirty
corrosives
Clean corro-
sives solvents
Wide variety
of liquids
Maximum
Pressure
4,000
500
4,000
3,000
Exterior
8,960
300
5,000
150
1,500
Maximum
Temperature*
800°F
800°F
800°F
300°F
140°F
752°F
356°F
700°F
250°F
580°F
Maximum
Flow rate/
Velocity**
25,000 gpm
25,000 gpm
25,000 gpm
lOft/sec
48-inch
pipe
35ft/sec
660 gpn
30ft/sec
40ft/sec
20 gprn
2,850 gpm
Advantage
High flow, high
pressure
low head loss,
high flow
Low head loss,
high flow
Piggable, large
diameter pipe
Piggable, good
for dirty fluids
Simple, inexpen-
sive
Piggable, only
3-5 diameter pipe
lead needed
. Simple, with-
stands extremes
lew flow, counter
Simple, durable
Drawback
High head
loss, inac-
curate during
low flow
Inaccurate
during low
flow
Inaccurate
during low
flow
Liquids with
solids
Clean liquids
Liquids with
solids
Noneonduct ive
liquids
High head loss
for anall pipes
Vulnerable to
extremes
Not piggable,
affected on
overrange
Error
1.0 -
3.0%
1.0%
0.8%'
2.0%
2.0%
1.0%
1.0%
0.5%
2.0%
1.25%
Manu-
facturers
Badger
BIF, Badger
BIF, Badger
Mapco
Mapco
Krone,
Ametek
Krone
Ramapo
Tokheim
Fischer &
Porter
Yokogowa
Ibxboro
General Price***
$ 2,000+
$ 3,000
$ 3,300
$ 2,500
$ 1,400
$ 400 for
$ 3,500
$ 2,500
$ 656 for





2- inch

1-inch
$ 1,250 for 2-inch
installed cost
competitive with
orifice plate
                                                                                                                                                   meters
                  * Depending upon materials and size.
                 ** Percent of flow rate.  The accuracy is stated by the manufacturer and is not specific to any viscosity or temperature.
                *** 8-inch pipe except when otherwise stated.  1985 prices  (•*• Plus $1,000 for transmitters)

-------
                                  TABLE 3

                       FLOWMETER MATERIAL .RESISTANCE  .

                            (Smith Meters, 1980)
Material Used
for Flowneter

Aluminum
Bronze
Cast Iron
Tungsten Carbide
Carbon Steel
Austenitic Stainless
Steels
Buna-N
Viton A
Ethylenes, Propylenes
Teflon*  '
Resistant To

Organic acids, amines, sol-
vents, alcohols, ketones
Solvents, acetates, esters,
alcohols, ketones, petro-
leum solvents, glycols,
aromatic hydrocarbons,
water

93-95% sulfuric acids, alka-
lis, hydroxides, ammonia,
amines, solvents, alcohols,
ethers, ketones, petroleum
solvents

Dilute and concentrated
sulfuric and hydrochloric
acids, brine
High resistance to petroleum
products

Organic acids, amines, hy-
droxides, food products,
fatty acids, anilines, sol-
vents, alcohols, ethers,
ketones

Petroleum products, water,
ethylene glycol fluids
Aromatic hydrocarbons, acids,
halogenated hydrocarbons

Ketones, alcohols, •water,
steam

Most chemicals
Not Resistant To '

Hydroxides, acids,
acid salts, alka-
lis

Mineral acids,
amines, alkalis,
hydroxides
Organic acids,
dilute acids
Oxidizing acids
(nitric), organic
acids (lactic and
citric)

Acids, water
Mineral acids,
concentrated acid
salts
Ketones, acids,
halogenated hydro-
carbons

Ketones, amines
Petroleum products
Hydrofluoric acid
                                      36

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                                  TABLE 3

                                (continued)


Material Used
for ELowneter      .•      Resistant To                       Not Resistant To

Ryton**                 '  Most chemicals                     Most oxidizing
                                                             acids

Carbon Pure-Bon***        Ifost chemicals                     Strong oxidizing
                                                             acids
  * Trademark E. I. DuPont
 *-* Trademark Phillips Petroleum Company
*** Trademark Pure Carbon Company
                                      37

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adjustment information for most flowraeters; however, specific
procedures vary for each type and make of meter.  The manu-
facturers should therefore be consulted if detailed calibra-
tion procedures are needed (see Appendix A).

OPERATIONAL PRINCIPLES
Positive-Displacement Flowmeters
     Positive-displacement meters measure volumetric flow di-
rectly by continuously separating a flow stream into discrete
volumetric segments and then counting them.  Several types of
positive-displacement meters are illustrated in Figures 13
through 16.  Although the specific method of flow segregation
varies, common characteristics of all positive-displacement
meters include:
     • Can be used on lines ranging from 1/4-inch to 16
       inches                             '
     • Can handle pressures up to 1,440 psi although most
       are made to withstand much lower pressures
       Can be designed to measure almost any flow rate
       Can be accurate to within 0.2 percent of full scale
       Can operate better at lower pressure
       Can not be cleaned through the use of a "pig"
       Can use the energy of flow to drive the counter
       through a gear train               .
       Can not be used with fluids that contain solids or
       grains.
In the Bi-Rotor oval gear meter (see Figure 13) two rotors
are geared together and each revolves about a shaft.  Water
entering the meter causes the rotors to revolve, but only the
water trapped in the measuring chamber (hatched section)
passes through the meter.  Two volumes of measured water pass
for each single rotation of a rotor.  The rotor revolves
freely around a non-rotating shaft which is hollow and houses
a second rotation shaft in its center.  The rotation of the
                             38

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Figure  13 .
Bi-Rotor Oval Gear  Meter.  The two rotors
(bottom)  move with  the flow  (Smith Meters,
1977}.                                 .      '
                    DRIVING  MAGNET
                    ( Kynar Coated )
                                       BEARING
                                  NON  ROTATING
                                  SHAFT
             BEARING
                                                 DRIVEN
                                                 MAGNET
                                    ROTOR
                                 39

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Figure 14.  Ro-tating-Paddle Meter.  Exterior gears on
            each  paddle move the upper main paddle,
            which records data.
                       CROSS  SECTION
                                ROTATING PADDLES
                               40

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Figure 15.
Oscillating  Piston Meter.  Fluid enters  the
intake/ bounces  off the barrier, and  al-
ternatively  pushes (solid) and pulls  (dotted)
the piston vertically.
          PISTON
          AXLE
                                               PISTON
                                                      FLOW
                     OUTLET-
                      '-FLUID INTAKE

                   L—BARRIER
                                41

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Figure  16.
Rotating Vane Meter.   The cam  forces the
blades  to extend  and  then contain a dis-
crete volume of fluid (Smith Meters,
1977) .
                              CAM
                                      MEASURING
                                        CHAMBER
                3 LAOS
                PATH OF
                BLADES

                FLOWING
                 LIQUID
                             METER
                             HOUSING

                             BLADE'
                             SEARING
                             ROTOR
                                 42

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rotors is magnetically coupled to the second shaft forcing it
to rotate in proportion to the amount of liquid passing
through the meter; this rotation is then metered.
     The other rotating meters (see Figures 14-16) operate on
similar principles.  A complete discussion;of positive-dis-
placement meters may be found in the Handbook on Process
Instruments by Douglas Considine.
     Positive-displacement meters generally have a calibra-
tor that fine tunes the output of the counter in 0.05 per-
cent increments, usually over a 5.0 percent total adjustment
range.  Because 'differing viscosities alter calibration,  a
positive-displacement meter  should be calibrated after  its
installation.  Positive-displacement meters are considered  to
be  the  best  flowmeters for higher viscosity fluids  (fuel  or
crude oil),  which tend to cause inaccuracies with other types
of  meters  (Reason, 1983).  Positive-displacement meters sel-
dom have tp  be  recalibrated  when used with low--viscosity,
clean liquids,  such as water (Ginesi, Greby,  1985).   On the
other hand,  frequent recalibration may  be necessary if  the
meter is used to measure volumes  of heavy .oils or fluids
 that contain solids.   Fluids that contain solids cause  ex-
 cessive wear of parts through mechanical friction which can
 degrade.the accuracy of the meter.   Meters that are used with
 liquids such as heavy oils should be recalibrated at least
 once a year; however, past meter performances will dictate
 better the frequency of recalibrations needed.
                              43

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Turbine Flowmeters
     Turbine meters infer flow rate by measuring the rate of
the revolutions of a bladed rotor.  To obtain a volumetric
flow rate it.is necessary to assume that the flow rate is
proportional to the stream velocity, and that the stream
velocity is proportional to the rotor angular velocity.  A
turbine meter usually has three basic sub-assemblies  (see
Figure 17) which.are the body, the rotors ^(turbines), and the
pickup (Miller, 1983).  The turbine meters  that contain the
sub-assemblies, can come in almost any  size, flow,  and pres-
sure rating.  A wide variety of materials are available  (see
Table  3).  The most important  part of the meter is
the bladed rotor  which  is  suspended  in  the  flowing  stream  on
the platform bearing  and rotor shaft.   The  rotor  should  have
regularly spaced  paramagnetic  material  to  allow for the  de-
tector 's pickup  coil  to monitor revolutions of the  rotor.
Turbine  meters,  which can  be  accurate to within  0.5 percent
 of flow rate or  better, have  been constructed to  withstand
 flow rates to 50,000  gpm and pressures to  500 psi.
      Of interest is the fact that one form of turbines uses
 only a single impeller.  It is frequently classified-as a
 "water meter" because it is often used on water mains.  The
 meter contains a single,  long impeller (instead of a rotor
 assembly) which is connected, by way of bearings, to either a
 geared shaft or a cable.  This assembly leads to a magnetic
 pickup housing (Badger Meter, DMR-110).  Impeller meters are
 less accurate, about 2 percent error full  range, than stan-
                               44

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Figure 17.   Major Components  of a Turbine Meter (C. E
             Invalco, 1984).           .
                 BODY
MAGNETIC
PICKUP
                                              FLOW
                                              DIRECTION
                                  ROTOR
                                SUPPORT
                               45

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dard turbine meters because of the impeller design.
     Another turbine meter incorporates two rotors which are
connected by a vertical shaft (see Figure 18).  When fluid-
flow begins, the rotors are floated above their seat as the
stream flows between them.  The rotors spin without the need
for shafts  or bearings; bearing wear and friction  are there-
fore eliminated.  These bearingless flowmeters are especially
useful for  highly corrosive liquids; but, they are only ac-
curate to within 2.0 percent of the flow rate.
     The best method for  judging  the performance of a turbine
meter is by the repeatability of  its K-factor  (pulses per
gallon) under identical conditions and by its  accuracy
throughout  a flow range.   Figure  19, shows  a  sample chart
which lists the K-factor  for certain size meters.  The  small-
er the meter, the higher  the K-factor.  Figure 20, is a typi-
cal turbine flowmeter  performance curve which depicts the
K-factor  variation  which  must be  considered when extreme
accuracy  is desired.
      A  common method to measure meter  accuracy is to  run two
meters  in series  and compare  their readings (Smith Meters,
 1977).   A highly accurate, portable turbine meter kit is
 available to test and calibrate turbine meters on-site.  The
 kit contains several flowmeters,  each made for a certain vis-
 cosity range,  with accuracy ranges to within 0.25 percent and
 a precision rating to within 0.05 percent.
     •Turbine meters are made for fluids without particles.
 Obstructions and solids can seriously affect the  accuracy of
                              46

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the meter;  thus,  a removable mesh  strainer should be install-

ed ahead of the flowmeter for protection.  As a rule-of-

thumb, a meter should have 10 diameters  length of

straight pipe upstream and downstream and the mesh  strainer

should also be installed at this distance from the  meter.

Turbine flowmeters should not be located near electric- mo-

tors, transformers, sparking devices, or high-voltage  lines.
Figure 18.  Bearingless Flow Meter.   The shaft and  rotors
      •  .    float during flow.•  A magnetic pickup records
            their spin (C. E. Invalco,  1984).
         SHAFT AND
         UPPER ROTOR
         ASSEMBLY
-Ot
 LOWER ROTOR
     LOWER HOVER  DISC
MAGNETIC PICKUP



      XP ADAPTER


         UPPER COVER

        - BODY
                                                   LOWER COVER
              LOWER
              RETAINING PLATE
                              47

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Figure  19
Flow  Ranges and
1984).
'K"  Factors  (C. E.  Invalcof
Bodv
Si/.e
V*~
1"
\<2"
Rep«alable
Flow Ranee
Min.
.8
4.7
13
25
45
Max.
16
77
209
400
700
Linear
Flow Range
Si in.
1.4
6.6
17.6
33.7
60.0
Max.
14
66
176
.137
600
*Pulses Per
Gallon
K-Factor
4330
910
340
178
51
               'Data based on water calibration ai 20° C.
 Figure 20.
Typical Turbine performance Curve.
Factor versus  flow rate percentage
 (Smith Meters,  1977).
                      IO-
              METER
              "K"FACTOR
              PULSES/BBL
                                                    LINEARITY
                                           REPEATABILITY
                                ZS'i      50%      •n=-a
                             METER FLOW RATE  -  % MAXIMUM
                                 48

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 Differential Pressure-Producing Flowmeters
      Differential pressure-producing flowmeters use a flow
 restrictor, usually called a primary element, to decrease
 the cross sectional area of a pipe.  As a .fluid passes
 through the restricted area, its velocity increases.  A re-
 sulting drop in pressure occurs due to the conservation of
• energy as described by the Bernoulli equation.  Pressure
 sensors are located at either side of the restricted area to
 measure the pressure differential that is the result of flow.
 The differential pressure is proportional to the square of
 the flow rate, so the square root of the differential pres-
 sure  is used to determine flow volumes.
       A variety of'primary elements exist on the market.  They
 either fit  inside a section of pipe, or are placed between
 two sections.  In order  for the  element to' work correctly, up
 to 30 diameters of.straight pipe must be run before,  and 15
 diameters  after,  the  element.  Some  of the more common  types
 of primary elements are  orifice  plates .(see  Figure 21), flow
 nozzles  (see  Figure 22), flow  tubes  (see  Figure  23),  and ven-
 turi  tubes (see Figure  24); the  latter two are useful for
 fluids  that contain solids, such as  sewage,  and  high flows  of
 up to 25,000  gpm  because of their relatively low pressure
  losses.   Flow nozzles and orifice plates  should  not be used
  for fluids containing solids  because deposits tend to accumu-
  late, and their accuracy is affected.   Flow nozzles work well
  with high pressure steam and  fluids under pressures up to
  4,000 psi.  Primary elements,  especially orifice plates,
                                 49

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Figure 21.
Schematic Diagram of  a Working Orifice Plate.
Pressure decreases as the fluid velocity
increases through the plate.
    HIGH PRESSURE
       TAP
                                         LOW PRESSURE
                                           TAP
                       ORIFACE PLATE
                     50

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Figure 22.   Schematic Diagram  of  a Working Flow Nozzle.
                 HIGH PRESSURE
                    TAP
LOW PRESSURE
   TAP
                                    FLOW NOZZLE
                                  51

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Figure 23.  plan View of  a Flow Tube (Badger Meter,  Inc.,
             1981).
 TYPICAL
 HIGH PRESSURE
 CONNECTION
TYPICAL
LOW PRESSURE
CONNECTION
                              ANNULAR  CHAMBER
                                    52

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   Figure  24.   plan View of  a Venturi Tube  (Badger Meter,
                 Inc.,  1962).
LINE SIZE
                                                   REMOVABLE  COVER FOR
                                                   CLEANING  8  INSPECTION
                                          - LOW PRESSURE CONNECTION;:
                                           3/4"NPT
                      HIGH PRESSURE;CONNECTION
                      3 /4" NPT
                                       53

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cause pressure losses and are not piggable.
     The accuracy of a primary element can be checked by
placing a manometer in the pressure sensor opening without
having to shut down the flow (Halmi, 1976).  To maintain the
calibration when using fluids that contain solids, the inte-
rior surfaces should be finished with a deposit-resistant
material;' a primary element also should be easily accessible
through a large opening to facilitate checking and cleaning
of any deposits.  Some factors that determine the adequacy of
instruments using orifices as the primary measuring devices
are:
        Tolerance of meter tube bore
        Uniformity of flow profile           •
        Fabrication of the orifice plate
        Installation of the orifice plate
        Wear of the orifice plate and metering tube
     An important aspect of differential pressure flowmeters
is the manner in which the differential'pressure, and there-
fore flow rate, is determined.  These systems, when first de-
veloped, used two piezometer standpipes.  Tubes ran from the
pressure sensor holes to two standpipes that were filled with
the pipe fluid.  The fluid levels in the standpipes changed
with the flow velocity.  A more common measuring technique
is to use a bellows transmitter (differential pressure
transmitter) with both tubes running from the meter to each
side of a bellows.
     The position of the bellows varies with differential
pressure which changes the signal that is emitted from the
transmitter.  Other transmitters use the pressure from the
                               54

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tubes to push mercury within a manometer to move a core
within an induction coil to produce a voltage which
can be recorded electronically.  Due to the toxic charac-
teristics of mercury, other liquids are now used.
     With some brines or other particle-laden fluids, pres-
sure lines can clog even when equipped with elaborate flush-
ing systems.  To solve this problem, some current differen-
tial pressure flowmeters use a liquid-filled probe with a
diaphragm set flush to the inside of the primary element.  A
small motor inside the probe applies an equalizing pressure
to the dry side of the diaphragm.  The differential pressure
is recorded by a transmitter.
     Electronic transducers are more susceptible to fouling
than differential pressure transmitter systems; therefore,
most operators use the simple pressure transducer, especial-,
ly for fluids that do not precipitate.  The accuracy of all
probes can be checked with a manometer without shutting down
the system,
Sonic Flowmeters                          ,          .
     Sonic flowmeters use the speed of sound to estimate the
speed of fluids in a pipe to extrapolate their flow rate.
Most types use two transducers pointed at each other and set
at a 45 degree angle to, or inside the pipe  (see Figure 25).
One transducer emits ultrasonic waves while the other re-
ceives them.  The moving fluid affects the speed of the
ultrasonic waves in proportion to the flow rate.  Sonic
flowmeters can measure any moving liquid; however, the
                                55

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Figure 25.
Sonic Flowmeter.  The speed  of  sound from
Transducer A to B is substracted  by the
speed from B to A.  The difference in the
speed of sound measured from A , to B and
transducers B to A is proportional to the
flow rate (Mapco, 1984).
                                 B
                 FLOW

                 III
               DIRECTION
                                56

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performance of meters that are clamped to the exterior of the

pipe can be greatly affected by the pipe material, especially

with fiberglass and cast iron pipes.  Sonic flowmeters should

not be used for metering liquids with large amounts of solid

particles; even a few gas bubbles can cause problems.  Sonic
                 •
flowmeters can handle flows up to 10 ft/sec in pipes as large

as 48-inch and pressures as high as 3,000 psi.

     Zeroing sonic flowmeters can be accomplished in the

field, while rescaling requires special instructions or a re-

turn to the dealer/manufacturer.  A sonic flowmeter has the

advantages'of being piggable, and able to deal with large

volumes, high pressures, and to handle corrosive fluids.

Doppler Flowmeters

     Doppler ultrasonic flowmeters utilize the Doppler Effect

to estimate the speed of a liquid traveling through a pipe.

The fluid must contain either solids or bubbles for the meter

to work correctly.  A transducer transmits a  sonic wave which

reflects off particles in the -fluid onto a receiving

transducer  (see Figure 26).  The difference in frequencies of

these two  sonic waves serves to calculate the fluid velocity.

The accuracy of the flow rate measured by a Doppler flowmeter

is affected by the accuracy of the measured internal diameter,

since this measurement is used to calculate the volume of the

fluid in the pipe.  Concrete, certain heterogeneous media, or

pipes less  than one inch in diameter cannot be monitored by

Doppler meters.  However, the big advantages  of Doppler flow-

meters are  that they are portable, do not interfere with
                                57

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Figure 26.  Doppler Flowmeter.  The pitch of the sound
            from a passing car changes  and 'is explained
            by  the Doppler effect.  It  also  affects the
            reflection of. sound from  particles inside
            the pipe.   The particles  accelerate the
            sound waves that emanate  from a  transmitting
            element (Mapco, 1981) .
                      TRANSMITTING  RECEIVING
                        ELEMENT    ELEMENT
                                          TRANSDUCER
                                          ADHESIVE
    DIRECTION OF FLOW
                                 58

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flow, and because they are mounted on the pipe's exterior can
handle any pressures.
     Like other sonic type flowmeters, zeroing Doppler flow-
meters is simple but rescaling is usually difficult.  Opera-
tors often must consult the manufacturer for help.
Float-Type Flowmeters
     Float-type flowmeters (sometimes called rotameters, or
variable area meters) operate on the float principle and have
an upright conical metering tube made of glass, metal, or
plastic.  Inside the tube is a float  (see Figure 27) which
moves up as the" fluid enters through the bottom of the meter.
The  float rises proportionally to the flow rate.  Transparent
flowmeters have a scale set on the meter which shows the flow
rate per height of the float,  Flowmeters with a plastic or
metal metering cone magnetically transmit 'the value of the
flow rate.  While most see-through, glass-float meters cannot
withstand.high pressures, Krohne makes a metal-float meter
that can withstand pressures of almost 9,000 psi.  Fischer
and  Porter also make a heavy-duty model that withstands  3,000
psi. Flow rates are generally limited to. less than 700  gpm
with this type  of meter.
     While float-style flowmeters can be used  for fluids of
different viscosities, they  should not be used with fluids
that contain  solids.  Deposits could  change the weight  and
flow properties of  the float which would severely retard its
accuracy.  Float-type flowmeters  should never  have  to be re-
calibrated if kept  clean.
                                59

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Figure 2,7.
Typical Transparent  Float Flowmeter.  The
incoming fluid  lifts the float to -a height
that is proportional to the rate (Ramapo
Instrument Co.).
              INLET
                                         ROTAMETER
                                          TUBE
                                 60

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Electromagnetic Flowmeters
     Electromagnetic flowmeters, sometimes called magnetic
induction flowmeters, create a magnetic field which sur-
rounds the fluid passing through the pipe.  The field coils
of the meters are energized by a pulsed B.C. current or by
line alternating current.  When the fluid flows through the
magnetic field, a voltage proportional to flow velocity is
induced.  The current produced is monitored after passing
through the electrodes which are at right angles to the
field coils (see Figure 28).  Fluid electrical conductivity
level should be at least 0.05 us/cm (Microsiemens/centi-
meter) to 20 ]is/cm for these meters to operate.  The conduc-
tivity of drinking water is generally 500 jis/cm; therefore,
magnetic flowmeters  have many applications for metering con-
ductive fluids such  as water and sewage.
     Advantages of the electromagnetic flowmeter are:
     •  No pressure  loss occurs and the system is pig-
        gable if the proper size meter is used
     •  The pipe liner and possibly the electrodes are
        in contact with the fluid
     •  Measurements are independent of the flow profile
        and other properties of the fluid
     •  They measure flows up to 15,000 gpm with accuracies
        that range from within  98  to 99.5 percent
     However, the pressure limits  are rarely more than  600
psi.  Direct-current meters have the advantages of continual
and  automatic zero-point correction that  occurs between each
pulse,  and reliable  suppression of interference voltages.
Alternating-current  meters can  be  rezeroed by  the operator,
                                61

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Figure 28.  Principles of Magnetic Flowmeters.  The medium
            flows at a certain velocity (V) inside a pipe
            of a certain diameter (D) and passes through
            the magnetic field (B) and the electrodes pick
            up the induced voltage (U) (Krohne, Product
            Guide 3).
                                62

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but special equipment is often required.



Vortex-Shedding Flowmeters



     The principle of operation of a vortex-shedding flow-



meter is to generate turbulence which is then used to monitor



flow.  A narrow vertical bar, called'a vortex shedder (see
                                          i


Figure 29), produces eddies that pulse from alternating sides



of the bar during flow.  A torque tube twists with these



pulsing vortices, whose frequencies are proportional to the



flow rate.  Strain gauges sense the tube movement and trans-



late that movement into a flow rate.      ;



     The advantages of vortex-shedding flowmeters are their



accuracy, linearity over a wide range, physical strength, and



the fact 'that deposits normally do not form on them.  Since



the sensor rests outside the meter, the pulses from the



strain gauge can be related to a full scale flow value and



therefore can be "calibrated" without having to shut off



flow.  Vortex-shedding flowmeters, however, are not piggable.



     The vortex-shedding flowmeters are available in dia-



meters up to 8 inches and can handle flow rates up to 3,000



gpm.  They are accurate to within 0.5 percent of the flow



rate, although their full scale rating is usually over 1.0



percent.



Other Flowmeter Designs



     Flow can be measured by a variety of means, especially



when the rate is inferred.  One design uses an object of



known area which is placed inside a  flow stream and connected



to  a strain gauge.  The stress on the object is proportional
                                63

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Figure 29.
Cut-away View of a Vortex-shedding  Flowmeter.
The fluid  strikes the shedder bar and vortices
alternately  push the two sides of the sensing
vane  (Fischer and Porter, 1983).
                  METER BODY
                                                 SENSOR
                                                 LINK
                                              TORQUE TUBE
                                              ( CUTAWAY)
                                                 SENSING
                                                 VANE
                                 VORTEX
                                 SHEODER BAR
                                 64

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to the flow velocity.  Calibration can be performed by ap-
plying a known force to the object.  Strain-gauge flowmeters
are accurate to within 0.5 to 2.0 percent of full range and
can withstand pressures as high as 5,000 psi.  Another design
has a vertical axle that supports a flat-lying disc; when the
plane of the disc is tilted at a low angle, the disc nutates
about the axle as fluid is passing, which gives the meter the
names, "wobble meter" or "nutating-disc meter."  With a 2-3
percent error, the wobble meter is not as accurate as posi-
tive-displacement or turbine meters, but it is less expen-
sive.
     A variety of other flowmeter variations exist on the
market.  However, they are not nearly as common as the seven
major forms of inference meters discussed above.
TESTING AND CALIBRATING FLOWMETERS
     While all flowmeters are calibrated in the factory, re-
calibration may be necessary upon emplacement.  This is done
because viscosities, pressures, and temperatures can vary
from the laboratory conditions where the meter was originally
tested (Halmi, 1976).  Flowmeters eventually wear, corrode,
or accumulate deposits, and they require recalibrations.
Operators should follow the manufacturer's recommendations on
procedures and frequencies of calibration.
     Venturi tubes and other differential-pressure devices
can be checked by placing manometers on the pressure open-
ings.  Most powered meters can have their frequency or vol-
tage output checked by an electronic test indicator.  Some

                               65.

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meters such as D.C. pulse or ultrasonic may require elec-
tronic calibration.  These procedures would not be accurate
if either deposition or corrosion changed the internal areas
of the meters.  Test results may also vary depending upon
line pressures, viscosities-and temperatures.  The most as-
sured way of checking flowmeter accuracy and calibration is
to perform direct volumetric tests with a prover.
     Provers may be used for any type of f lowmeter,, but they
are limited by pressure, temperature and type of fluid being
measured.  The most common and inexpensive prover is the vol-
umetric prover tank.  It is a tank, ranging from a five-
gallon portable to a 1,000 gallon laboratory model, that is
marked off with precise fractions of gallons (the tank should
adhere to determinations by the National Bureau of Stan-
dards).  The liquid from the flowmeter should be timed as it
is allowed to flow into the tank.
     Piston or ball-type provers are more convenient than
tanks  (see Figure 30).  They use a piston or ball which is
pushed along within a smooth bore tube by pressurized gas.
The piston or ball in turn displaces a known volume of fluid.
Electrodes on the displacer (piston or ball) generate pulses
as it passes two fixed points that define a specific volume
in the tube.  The electrical pulses are counted and timed.
Some provers generate a continuous train of electrical pulses
for more precise measurement (Cook and Strongman, 1984).  The
prover may be sensitive to solids, dirt, etc., which inter-
fere with mechanical actions.  However, the prover is
                                66

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Figure 30.
Schematic Diagram of  a  Piston Prover.  The
piston travels to the other sensor (dashed
position) while pushing a  standardized
volume of fluid out of  the prover.  The
valves reverse to return the piston.
        PISTON
       OISPLACER
                                      CONTROL VALVE (S)
                          .STANDARDIZED
                              VOLUME
                                67

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unaffected by the fluid viscosity and density in determining
the volumetric flow that goes through a flowmeter.
     Differential pressure flowmeters are not volume measur-
ing devices.  They should be calibrated for each fluid which
is metered depending on its viscosity and specific gravity.

FLOW RECORDING DEVICES
     Many flowmeters require transmitters or signal conver-
ters to send the signals (mV, V, or mA) that a recorder can
accept.  Others such as magnetic or turbine meters do not re-
quire transmitters or signal converters since the signal can
be accepted directly by the recorders.
     Others, like positive-displacement meters, use geared
counters to measure flow and need a pulse transmitter.  Pulse
transmitters attach themselves to the exterior of counters,
and then they convert the geared movements into signals.
     An electronic recorder can be one of two standard de-
signs;  the circular chart recorder and the strip-chart
recorder.  The circular recorder (see Figure 8) rotates a
chart on an axle.  A pen is provided to record pressure
or flow rate on the chart.  The pressure or flow rate scale
lies along the chart radius and the time axis is the chart
circumference.  Strip recorders consist of a rotating
cylinder which rolls a strip chart with time. . The variable
axis lies perpendicular to the rolling direction.
     The internal working parts of most electronic recorders
are generally the same.  The major components are:  the
electronic amplifier, the two-phase servo motor, the gear train,
                               68

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and the feedback element (see Figure. 31).
     An electronic signal from a flowmeter, transducer, or
other device is amplified to a power level high enough to
drive the servo motor.  The servo motor is often a two-phase
reversible type that runs at speeds proportional to input,
and in the established phase direction.  Through gearing, the
servo motor positions the pen and the feedback element; the
latter then generates a voltage which is fed back to the
servo motor.                       .       '
     Strip recorders have accuracies to within 0.5 percent of
full scale, whereas circular chart recorders usually have
accuracies to within only 1.0 percent.  The recorder should
be calibrated while it is connected to the measuring system.
Occasionally the chart speed should be checked during the
test by writing the time on the chart and comparing it with
the time elapsed.  Most circular recorders use charts that
are interchangeable with those of other manufacturers.

                       CONTROL DEVICES

     Flowmeters and pressure measuring instruments are often
accompanied by valves which are placed downstream to reduce
shock.  Elaborate systems can be designed to automatically
shut down flow when pressure, flow, or temperature exceeds
specified limits.  An automatic shut-off device, called an
actuator can be connected to a valve and set to operate only
when an instrument transmitter sends a signal at a special
frequency.

                               69         ;

-------
Figure 31.
Block Diagram of the Working  Components
of an Electronic Recorder  (BIF,  1975).
                                                    POINTER
        INPUT
                   DIFFERENTIAL
                    AMPLIFIER
                                 70

-------
     Valves are also used frequently to protect gauges and
flowmeters from freezing or corroding by separating the in-
strument from the system.  An operator may have separate
lines that contain the measuring devices.  A gauge or meter
may 'be taken off of the line and kept indoors until testing
is required.  Both valves and actuators are discussed brief.ly
in the following pages.

VALVES
     Valves are devices that control fluid flow through
pipes.  As with other instruments, valve designs vary for
differing applications.  Flow control can be executed by a
simple on-off switch or a gradual throttling device.  Some
valves are exclusively used for diversional purposes.  The
most common designs are:  the ball valve, butterfly valve,
plug valve, globe control valve, knife gate valve, and the
pinch valve.  Table 4 lists many functions of several of the
valve designs.
     The ball valve is often a hollow sphere, or half sphere
that is tightly fitted inside a valve body.  The sphere can
be turned with the poles perpendicular to the flow direction.
The flow is gradually reduced as the valve opening is re-
stricted by the sphere surface.  Some balls have a V-shaped
opening to provide smooth throttling throughout the quarter
turn that is necessary to close the valve.  Ball valves can
fit pipes as large as 48 inches in diameter and they can be
designed to withstand pressures of up to 800 psi.  These
valves are often used for throttling because of their

                               71

-------
-4
N)
Function
 On-Off
 Throttling
 Diversion

Media
 Liquids (clean)
 Liquids (dirty)
 Liquids (viscous)
 Liquids (corrosive)
 Slurries (sludge)
 Slurries (abrasive)
 Slurries (fibrous)
 High Pressure Steam
 low Pressure Steam
 Oases (clean)
 Gases (dirty)
 Gases (corrosive)
 Cry Materials
 K>od Service

Valve Characteristics
 High now Capacity
 High Pressure Drop
   Throttling
 Low Head Loss
   (wide open)
 Low Torque/Thrust
 High Tenjperature
 Cryogenic
 Erosion Resistance
Globe Control

Cage
Guided
A
A
D
A
D
D
A
D
D
D
A
A
A
C
A
D
D
A
A
E
A
B
B
D
Top 8t
Bottom
Guided
A
A
D
A
A
A
A
B
B
D
A
B
A
A
A
D
n
A
A
E
A
A
C
B

Top
Guided
A
A
D
A
A
A
A
A
B
D
B
A
A
A
A
0
D
A
B
E
C
A
A
B
                                                                               TABLE 4
                                                                APPLICATIONS OF VARIOUS VALVE DESIGNS
                                                                            (DeZurik, 1964)

                                                                                             Butterfly

                                                               Split                   Ball     High.       Rubber               3-Way  Gate     Pinch
                                                               Body   Angle   3-Way   Valves   Pressure   Sealed   Eccentric   4-Way  Valves   Valves
                                                                 A
                                                                 A
                                                                 D
                                                                  A
                                                                  A
                                                                  A
                                                                  A
                                                                  A
                                                                  B
                                                                  D
                                                                  B
                                                                  A
                                                                  A
                                                                  A
                                                                  A
                                                                  D
                                                                  D
                                                                  E
                                                                  C
                                                                  C
                                                                  B
                                                                  B
A
A
D
A
A
A
A
A
A
D
A
A
A
A
A
D
D
E
B
A
D
A
D
A
A
A
B
A
A
C
D
D
B
A
A
B
A
D
D
E
B
C
D
C
B
A
D
A
A
A
A
A
C
A
C
A
A
A
A
D
D
A
A
B
D
C
A
A
C
A
D
B
A
C
D
B
B
A
A
C
A
D
C
A
A
D
D
D
A
A
C
A
B
A
B
B
C
B
D
D
A
B
B
B
B
A
B
D
D
C
A
A
D
D
A
A
A
C
D
A
A
B
A
A
A
A
A
A
B
D
C
A
A
A
B
B
A
A
A
A
A
B
A
D
C
A
A
A
•" D
D
A
A
A
C
A
A
A
D
D
A
A
A
A
C
A
- A
A
A
A
A
' A
' D
C
A
A
A
A
C
A
B
C
D
A
A
A
D
D
C
A
B
A
D
A
A
C
D
D
A
             Key:
                  A - Typical Application
                  B - toy Be Used
                  C • Limited Application
                  D " Not Used
                  E - Not Applicable

-------
stability in high pressure situations and their resistance

to cavitation; however, they generally tend to cavitate more

at lower pressure drops than other valves (e.g., globe

valves).

     The butterfly valve is a circular plate that is as wide

as the inner diameter of the pipe.  The valve closes by ro-

tating the plate along a central axis, until it is perpendi-

cular to the flow direction.  Most butterfly valves are made

to withstand pressures of approximately 150 psi, and they

rest on a rubber or metal seal when closed.  Some that are

designed for pressures of 700 psi are unable to handle abra-

sives; of interest is that butterfly valves can be as large
          i'
as 96 inches in diameter.

     The plug valve uses a cylindrical plug that functions

like the sphere in ball valves, in that the valve closes on a

quarter turn.  One form of plug valve uses an eccentric ac-

tion to help prevent seat scraping and wear.  Figure 32 shows

how the valve face moves forward into the rubber seat as it

closes.  Plug valves can perform like ball valves at less

cost, although they cannot throttle under high pressures.

     Globe-control and knife-gate valves differ from other

valve designs in that they close with a straight downward

motion instead of a quarter turn.

     The globe-control valve  (see Figure 33) controls flow

between an upper and lower chamber, with a cylindrical or

conical stopper.  The conical stoppers are tapered to allow

for smooth throttling while the cylindrical stoppers are
                               73

-------
Figure 3 2.
The Eccentric Plug Valve. . The plug moves
forward into its seat as it is closing
(DeZurik, 1974).
                           CLOSED
                               74

-------
Figure 33.
.Globe Control Valve.  Fluid passes  through
 the  valve ,as the plug is raised  (C.  E.
 Invalco,  1984).
           FLOW
                                     DIAPHRAGM
                                 PLUG
                                75

-------
designed for quick on-off switching.  Some globe'-control
valves use what is called a cage.  Cages are hollow cylinders
(see Figure 134) that allow fluids to pass through slots as
the cage is raised.  Some slots are shaped for a certain
throttle characteristic.  Globe-control valves are rarely
made for pipes with a diameter of more than 16 inches.  Be-
cause of their simple designs, globe-control valves can
handle extreme temperatures and pressures.   However, they
create high head losses even when wide open and they cannot
be used with solids or fibrous slurries.
     The knife-gate valve is simply a gate door type that de-
scends from the top of the pipe and fits tightly into the
lower inside edge during closing.  The valve is inexpensive
and therefore suitable for on-off applications, even though
it is a rather poor throttle.  The knife-gate valve is manu-
factured for pipes with diameters of up to 72 inches.
     The pinch valve contains two .gates which squeeze togeth-
er from each side of the valve body to shut off flow.  The
valve is noted for its ruggedness and its straight unob-
structed flow path, both of which give the valve a wide ap-
plicability.  However, pinch valves need, more than a quar-
ter-turn, and then considerable torque in order to be
closed.
     In order to divert fluids, three-way and four-way valves
are used.  Three-way valves utilize either a rotating plug or
an angled globe-control stopper to divert flow from one chan-
nel to another.  Four-way valves place a spinning barrier at
                               76

-------
Figure 34.  Cage Plug  (C. E. Invalco, 1984).
                                77

-------
an intersection of pipes in order to exchange flow.

     Cayitation is a phenomenon that can occur when fluids •

suddenly encounter a section of pipe that has a reduced

cross-sectional area, such as a venturi tube or a closing

valve.  The pressure is lowest at the thinnest point and it

sometimes drops below the vapor pressure of the liquid

(which is a function of temperature); this condition causes

vapor bubbles which often collapse with great force down-

stream and can cause severe valve and/or pipe damage.

Because cavitation is dependent upon several factors, such as

flow velocity, valve shape,'and pipe diameter, the manufac-.

turer should be consulted for specific instructions and the

known cavitation.coefficients.


ACTUATORS

   .  Most valves can be equipped with automatic control

devices, called actuators, which can be either pneumatically
                                          i
or electrically powered.  Pneumatically powered actuators use

air pressure to force a valve to work with either a piston

traveling inside of a cylinder or a spring-loaded diaphragm.

Other actuators use electric motors.  For those valves that

required a quarter-turn, the actuator is connected via levers

or a rack and pinion set-up.

     Actuators can be fine-tuned to allow for throttling —

even though most are built to simply open and close valves.

Some globe-control valves are spring-loaded to open automati-

cally at specific line pressures.
                                78

-------
                          APPENDIX A
                    LIST OF MANUFACTURERS

     (This is neither an endorsement of these particular man-
ufacturers nor is it an all-inclusive list of manufacturers of
flowmeters, pressure gauges, and flow control devices.
Manufacturers listed here are those who'responded to the
authors' inquiries.)
Manufacturer

Ametek
U.S. Gauge Division
P.O. Box 152
Sellersville, PA 18960
(215) 257-6531

Badger Meter Mfg. Company
6116 East 15th Street
Tulsa, OK 74112
(918) 836-8411

Basic In Flow (BIF)
1600 Division Road
West Warwick, RI 02893
(215) 839-3551

Brooks Instruments Division
Emerson Electric Company
407 West Vine Street
Hatfield, PA 19440
(215) 362-3500

C. E. Invalco
Combustion Engineering, Inc.
Tulsa, Oklahoma
(918) 834-5671

DeZurik
Sartell, MN 56377
(612) 251-0221

Dresser
Instrument Division
250 East Main Street
Stratford, CT 06497
(203) 378-8281

Fischer and Porter
County Line Road
Warminster, PA 18974
(215) 674-6000
 Instrument/Device

 Pressure Gauges
 Compound Gauges
 Others
 Flowmeters
 Recorders
 Flowmeters
 Flowmeters
 Flowmeters
 Pressure Recorders
 Valves
 Valves
 Pressure Gauges
 Flowmeters
 Deadweight  Testers
.Portable Gauge Cali-
   brators

 Flowmeters
                               79

-------
                           APPENDIX A
                           (continued)
Flow Technology, Inc. .
4250 East Broadway Road
Phoeniz, AZ 85040
(602) 437-1315

Geophysical Research Corporation
6540 East Apache
P.O. Box 15968
Tulsa, OK 74158  •
(918) 834-9600

Hildebrandt Engineering Co., Inc.
7707 Pinemont Drive
Houston, TX 77040
(713) 462-5341

ISCO, Inc... Environmental Division
P.O. Box 82531
Lincoln, NE 68501
(800) 228-4373

Kent Meters
Ocala, FL 32678
(904) 732-4670

Krohne America Inc. Ltd.
11 Dearborn Road
Peabody, MA 01960
(617) 535-6060

Liquid Controls
Wacker Park
North Chicago, IL-60064
(312) 689-2400

Nusonics, Inc.  (formerly Mapco)
1800 South Baltimore Avenue
Tulsa, OK 74119
(918) 438-1010

Omega Engineering, Inc.
Box  4047
Stamford, CT 06907
(203) 359-1660
Flowmeters
Piston Provers
Pressure Bombs
Diaphragm Seals
Flowmeters
Samples
Flowmeters
Flowmeters
Flowmeters
Flowmeters
Pressure Trans-
  ducers
Electronic Recorders
                               80

-------
                           APPENDIX A
                           (continued)
Paine Instrument, Inc.
2401 South Bayview Street
Seattle, WA 98144
(206) 273-1705

Polysonics
P.O. Box 22432
Houston, TX 77227
(713) 623-2134

Ramapo Instrument Co., Inc,
2 Mars Court
P.O. Box 428
Montville, NJ 07045
(201) 263-8800

Smith Meters
1602 Wagner Avenue
Erie, PA 16512
(814) 899-0661

3D Instruments Inc.
15542 Chemical Lane
Huntington Beach, LA 92649
(714) 894-5351

Tokheim Corporation
Box 260
Fort Wayne, IN 46801
(219) 493-2554
Differential Pressure
Transducers
Flowmeters
Flowmeters
Flowmeters
Gauges
Portable Gauge
  Calibrators,
Flowmeters
                               81

-------
                          APPENDIX B
                           GLOSSARY
Actuator.  A device that operates a valve.

Annulus.  The space between the injection tubing and the well
  casing.       -            .

Bomb.  A down-hole pressure recording instrument.

Calibration.  The process of setting an instrument into
  agreement with an established standard. .

Class I Wells.
  1.  A well used, by a generator of hazardous waste or an
      owner or operator of a hazardous waste management faci-
      lity, to inject hazardous waste beneath the lowermost
      formation containing, within one-quarter mile of the well
      bore, an underground source of drinking water.
  2.  Another industrial and municipal disposal well which
      injects fluids beneath the lowermost formation contain-
      ing, within one-quarter mile of the well bore, an
      underground source of drinking water.

Class II Wells.  A well that is used to inject fluids:
  1 ..  Which are brought to the surface in connection with
      conventional oil or natural gas production and may be
      comingled with waste waters .from gas plants which are
      classified as a hazardous waste at the time of injection.
  2.  For enhanced, recovery of oil or natural gas; and
  3.  For storage of hydrocarbons which are liquids  at
      standard temperatures and pressures.

Class III Wells.  A well that is employed :to inject fluids for
  extraction of minerals including:
  1.  Mining of sulfur by the Frasch process.
  2.  In-situ production of uranium or other metals; this
      category includes only in-situ production from ore bodies
      which have not been conventionally mined.  Solution mining
      of conventional mines such as stopes leaching is included
      in Class V.
  3.  Solution mining of salts or potash.

Class IV Wells.
  1.  A well used by a generator of hazardous waste or of
      radioactive waste, by an owner or operator of a hazardous
      waste management facility; or by an owner or operator of a
      radioactive waste disposal site to dispose of hazardous
      waste or radioactive waste into a formation which is
     ' within one-quarter mile of the well and it contains an
      underground source of drinking water.
                               82

-------
  2.  Wells used by generators of hazardous waste or of
      radioactive waste, by an owner or operator of a hazardous
      waste management facility; or by an owner or operator of a
      radioactive waste disposal site to dispose of hazardous
      waste or radioactive waste above a formation which within
      one-quarter mile of the well contains an underground
      source of drinking water.                        f
  3.  Wells used by a generator of hazardous waste or an
      owner or operator of hazardous waste management facility
      to dispose of hazardous waste, which cannot otherwise be
      classified as Class I or IV (e.g., wells used to dispose
      of hazardous waste into or above a formation which
      contains an aquifer which has been exempted pursuant to
      (§146.04).     .

Class V Wells.  An injection well not included in Classes I,
  II, III, or IV.

Cryogenics.  Pertaining to very low temperatures.

Injection Zone.  A geological "formation," groups of forma-
  tions, or part of a formation receiving fluids through a
  "well."

K^Factor.  The number of pulses of a meter per gallons of
  fluid measured.

Linearity.  The closeness of a calibration curve to a speci-
  fied straight line.

Manometer.  An instrument for determining the pressure of
  gases, vapors,.or liquids.

NBS.  National Bureau of Standards, Department of Commerce.

Nutating Meter.  A flowmeter that operates on the principle of
  the positive displacement of fluid by the wobbling motion of a
  piston or disk.

Null.  A condition, such as a balance, which results in a
  minimum absolute value of output.

Piggable.  Able to be cleaned internally with a pig, which is
  a scrubber that is guided by cables or water pressures.

Pressure Drop, Loss of Head.  The difference in pressure be-
  tween the inlet and outlet of a hydraulic device during flow.

PSI (Pounds per Square Inch).  The gauge reading of contained
  liquids and gases.  Sometimes written as PSIG for gauge
  pressure alone, or PSIA for gauge plus atmospheric pressure.

Rescaling.  Altering an instrument so that it can measure
  different ranges or substances.


                               83

-------
Throttling.  The process of turning a valve to produce a
  specific flow rate.

Torque.  The force required to turn a valve or work a
  mechanical flowmeter.
                                84

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                          APPENDIX C
                         PUBLICATIONS
     Equipment manufacturers publish technical and promotional
materials for their specific flowmeters, pressure instruments
and flow control devices.  These publications are generally
available from the equipment manufacturers; their names and
addresses are found in Appendix A.  The author of this manual
used manufacturers' literature extensively in preparing this
document.  A list of some publications used are as-follows:
Manufacturer
            Publication
Badger Meter Manufacturing Co.-Orifice Plates, Bulletin P-400
                              -Flow Nozzles, Bulletin A-401
                              -Low Loss Flow Tubes, Bulletin
                                 P-405
                              -Model MLFT, DMR 110 Z-8977
Basic In Flow
C. E. Invalco
DeZurik
Dresser-Ashcroft
•Electronic  Receivers  -  Speci-
   fication  Data  257-01.201-1,
   1975  •
-Reproduction  of  Pressure
   Differentials  as  Sensed at
   Piezometer  Openings

•  Instruction  Manual - Wand, WCC ~
    Series Turbine Flowmeter:
    Issue 7  November,  1983
-  Industrial W-Series  Flowmeter
    Installation  Instructions
    September,  1979
-IVC 251-A2, 1980
-IVC 290-A1, 1984

-Valve Selection  Guide Bulletin
   12.00-1,  January, 1984
-Series  100  Eccentric  Valves
   Bulletin  1200-1,  October, 1974

-Engineering Data Ashcroft -
   Gauges:   Form  1250-1353-H
-Installation  and Maintenance
   Manual for  Ashcroft Type 1305
   Dual  Range  Deadweight Tester
   and Type  1327  Portable  Test
   Pump:  Form Number  250-1526-A
-Pressure, Temperature,  Control
   Instrument  Ordering Handbook,
   Bulletin  OH-1
                               85

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Manufacturer
            Publication
Dresser-Roots

Fischer and Porter


Flow Technology Inc.


Geophysical Research Corp.
Hildebrandt Engineering Co.,
  Inc.
Krohne America Ind. Ltd,
Liquid Controls
Mapco
Omega Engineering, Inc.


Paine Instruments, Inc.


Ramapo Instrument Co., Inc,

Smith Meters
-Meters:  Bulletin MR-781

-Technical Information, 10LV-6,
   May, 1983

-Flow Transfer .Kit Model FT -
   AFT-4-CF Bulletin FTK 744

-Amerada RPG-3 and RPG-4 Gauge
   Operator's Manual, 1983

-Diaphragm Seal Protectors -
   Description, Operation, and
   Application, 1983
-Turbine Water Meters, Bulletin
   No:  IND-476
-Installation Instructions:
   INS-6004
-Positive Displacement Water
   Meters:  Bulletin  No. IND-376
-Installation/Start-up Instruc-
   tions:  INS-0001-DOC

-Krohne Float Type Flowmeters
   Product Guide 1
-Autoflux Magnetic - Inductive
   Flowmeters Product Guide 3

-Meters and Accessories, Cata-
   log 102 C, 1983

-Instruction Manual, Model 9000
   Nusonics Flowmeter, Publica-
   tion #ESD-611, June, 1979
-Instruction Manual, Model 1181
   Doppler Flowmeter; Publication
   #ESD-623, December, 1981

-Pressure and Strain Measure-
   ment Handbook, 1984

-Brochure EPC-83-1:  Price
   Schedule EPP-84-1

-Form GP-3, April, 1983

-Technical Paper 101A, 1977
-Technical Paper 103A, 1977
-Compatibility Manual Bulletin
   1822
                               86

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Manufacturer
            Publication
3D Instruments, Inc.

Tokheim Meters
-Form No. 3D-2001, 1981

-Advanced Design Customized
   Metering Systems:  Bulletin No.
   2610-AR
                                87

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                          REFERENCES
Chilton's Co.  Chilton's Instruments and Control Systems.
Volume 49, Radnor, PA.,  December, 1976.

Considine, D.M.  Process Instruments Controls' Handbook.  2nd
edition.  McGraw Hill Book Co., New York, NY., 1974.

Cook, R.R. and Strongman, John R.  "New Displacer Piston Sensing
System Promises More Accurate Meter Proving."  Oil and Gas
Journal.  Volume 81, p.p. 55-8, November 21, 1984.

Ginesi, D. and Greby, G.  "A Comparison of Performance Features
vs. Economic Costs."  Proceedings of the ISA 85 International
Conference.  Volume 40,  Part 2, October, 1985.

Halliday, David and Resnick, Robert.  The Fundamentals of
Physics.  John Wiley and Sons, New York, NY., 1981.

Halmi, D.  "Practical Guide to the Evaluation of the Metering
Performance of Differential Procedures."  Mechanical Society of
Mechanical Engineers.  Paper 72-WA/FM-2, 1976.

Matthews, L.S. and Russell, D.G.  Pressure Buildup and Flow
Tests in Wells.  Monograph Series.  Society of Petroleum Eng-
ineers of AIME.  Dallas, TX., 1967.

Miller, R.W.  Flow Measurement Handbook.  McGraw Hill Co., New
York, NY. , 1983.            .                    .       •   •

Reason, J,  "Special Purpose Flowmeters Offer Better Accuracy,
Range, Linearity."  Power,, March, 1983.

Welge, E.A.  Testing Oil and Gas Wells for Water Shutoff with a
Formation Tester.  California Division of Oil and Gas,
Sacramento, CA., 1981.
                               88

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          CHECKLIST FOR FLOW MEASUREMENT INSPECTION
Prepared By:
Facility:

A. General

Yes  No  N/A

Yes  No  N/A
Yes  No  N/A
Yes  No  N/A
Yes  No  N/A

Yes  No  N/A
Yes  No  N/A
Yes  No  N/A   3,


Yes  No  N/A   4,

Yes  No  N/A   5,



Yes  No  N/A   6,
                   Date:
                   Wellf:
(a)  Is primary flow measuring device pro-
    perly installed and maintained?
(b)  Is there a straight length of pipe be-
    fore and after the flowmeter of at least
    5 to 20 diameters?  This depends on the
    type of flowmeter and the ratio of pipe
    diameter to throat diameter.  Also, the.
    introduction of straightening vanes may
    reduce this requirement.
(c)  If a magnetic flowmeter is used, check
    for electric noise (interference) in its
    proximity and that the unit is properly
    grounded.*
(d)  Is the full pipe requirement met?

Flow records are properly kept.
(a)  Are records of flow measurement re-
    corded in a bound numbered log book?
(b)  Are all charts maintained in a file?
(c)  Are all calibration data entered in
    the log book? .

Are sharp drops or increases in flow
values accounted for?

Is actual flow measured?

Are secondary instruments (totalizers,
recorders, etc.) properly operated and
maintained?

Are appropriate spare parts stocked or is
service available?
*Electrical noise can sometimes be detected by erratic opera-
tion of the flowmeter's output.  Another indication is the
flowmeter location in the proximity of large motors, power
lines, welding machines, and other high electrical field
generating devices.
                               89

-------
B.  Flowmeter
               1.  Type of flowmeter used:
               2.  Show on the back a "diagram of flowmeter
                   placement in the system.  Indicate the
                   direction of.flow, the vertical height
                   relationship of the source, outfall, and
                   measuring .meter.  Give all dimensions in pipe
                   diameters.

               3.  Is meter installed correctly?
                   (a) If magnetic flowmeter is used, it
                       should be installed in an ascending
                       column, to reduce air bubbles and assure
                       full pipe flow.
                   (b) If a differential pressure meter such as
                       venturi is used, it should be installed
                       in a horizontal plane so that high
                       pressure tap is on the inlet of flow and
                       taps are horizontal sloping slightly
                       downward with facilities for cleaning
                       taps.

               4.  Flow range to be measured:	
Yes  No  N/A   5.  Is flow measurement equipment adequate to
                   handle expected ranges of flow values?

               6.  What are the most common problems that the
                   operator has had with the flowmeter?  De-
                   scribe:  	.    	


               .7.  Flowmeter flow rate: 	 mgd; totali-
                   zer flow rate:	 mgd; error: 	%

               8.  Permit projected rate of injection: 	
                   gal./day

Yes  No  N/A   9.  Is flow totalizer properly calibrated?

               10.  Frequency of routine inspection by trained
                   operator:	 / month

               11.  Frequency of maintenance inspections by
                   facility personnel: 	 / year

               12.  Frequency of flowmeter calibration: 	
               13.   Indicator  of correct  operation:   redundant
                    flowmeters	 auxiliary flowmeters	
                    pressure readings          other_	
                    power  usage of pumps
                                90

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              14.  Indicators of proper Quality Assurance:
                   redundant flowmeters	 frequent recal-
                   ibrations      other	


             PRESSURE GAUGE INSPECTION CHECKLIST

Pressure Gauges

Yes  No  N/A   1..  Is Bourdon tube gauge protected from cor-
                   rosion and freezing?

Yes  No  N/A   2.  Is pressure reading relatively constant?
                   (i.e., absence of rapid pointer movement due
                   to pulsating pressure or pipeline vibration)

Yes  No  N/A   3.  Are gauge materials suitable for the media
                   monitored?

Yes  No  N/A   4.  Is a pressure transducer properly install-
                   ed?

               5.  Date gauge last calibrated: 	;	

               6.  Method of calibration:
Yes  No  N/A   7.  Is the measuring range twice the operating
                   range or less?

Yes  No  N/A   8.  Is the gauge retarded?


Pressure Recorders

Yes  No  N/A   1.  Are pressure recorders properly installed?
                   (e.g., chart protected from weather, etc.)

Yes  No  N/A   2.  Are pressure recorders operational?  (e.g.
                   ink, charts moving, etc.)

Yes  No  N/A   3.  Is back-up gauge provided?

Yes  No  N/A   4.  Do back-up gauge pressure and recorded
                   pressure agree?

Yes  No  N/A   5.  Is the measuring range twice the operating
                   range or less?
                                91

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       CHECKLIST FOR FLOW MEASUREMENT, OPERATOR'S FORM
Prepared By:
Facility:

A. General
Yes  No  N/A
Yes  No  N/A

Yes' No  N/A


Yes  No  N/A

Yes  No  N/A
Yes  No  N/A


Yes  No  N/A


Yes  No  N/A


Yes  No . N/A



Yes  No  N/A
                       Date:
                       Well#:
1. (a) Type of primary flow measurement de-
       vice.
   (b) .Is there a straight length of pipe be-
       fore and after the flowmeter of at least 5
       to 20 diameters?  This depends on the type
       of flowmeter and the ratio of pipe
       diameter to throat diameter.  (Also, the
       introduction of straightening vanes may
       reduce this requirement.)
   (c) If a magnetic flowmeter is used, is the
       unit properly grounded?*
   (d) Is the pipe flowing free?

2. Flow records.
   (a) Are records of flow measurement record-
       ed in a bound numbered log book?
   (b) Are all charts maintained in a file?
   (c) Are all calibration data entered in the'
       log book?

3. Are sharp drops or increases in flow values
   accounted for?
4. Is actual flow measured?
   factor.  Other?  	._
                         If not indicate
    Are secondary instruments (totalizers,
    recorders , etc . ) properly operated and main-
    tained?
Are appropriate spare parts stocked?
list.
a. _ ,
b.
c.
d. _ ^_
e. _
f.               _ • _ ^
                                          Please
*Electrical noise can sometimes be detected by erratic ope-
ration of the flowmeterfs output.  Another indication is the
flowmeter location in the proximity of large motors, power  •
lines, welding machines, and other high electrical  field
generating devices.
                                92

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B. Flowmeter

               1.  Type of flowmeter used:
               2.  Note on diagram flowmeter placement in the
                   system; observe the direction of flow, the
                   vertical height relationship of the source,
                  'outfall, and measuring meter.  Give all
                   dimensions in pipe diameters.

Yes  No  N/A   3.  Is meter installed correctly?
                   (a) If a magnetic 'flowmeter is used, it
                       should be installed in an ascending
                       column to reduce air bubbles and assure
                       full pipe flow.           '•
                   (b) If a differential pressure meter such as
                       venturi is used, it should be installed
                       in a horizontal plane so that high
                       pressure tap is on the inlet of flow and
                       taps are horizontal sloping slightly
                       downward with facilities for cleaning
                       taps.

               4.  Flow range to be measured: 	
                   Indicate criteria for selecting flow range.
               6.  What are the most common problems with the
                   flowmeter?             ;
               7.  Flowmeter flow rate:   •    mgd; totalizer
                   flow rate: 	 mgd; error	%

               8.  -Permit projected rate of inspection: 	
Yes  No  N/A   9.  Is flow totalizer properly calibrated?
                   gal./day

              10.  Frequency of routine inspection by trained
                   Operator:   ,	 / Month
                               93

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                PRESSURE GAUGE OPERATOR'S CHECKLIST.
   Pressure Gauges

   Yes  No  N/A   1.   Is Bourdon tube gauge protected from cor-
                      rosion and freezing?  Describe briefly


   Yes •  No  N/A   2.   Is pressure reading relatively constant
                      (i.e., absence of rapid pointer movement due
                      to pulsating pressure or pipeline vibration)?

   Yes  No  N/A   3.   Are gauge materials suitable for the media
                      monitored?

"'* Yes  No  N/A   4.   Is a pressure transducer properly install-
                      ed?

                  5.   Date gauge last calibrated: 	

                  6.   Method of calibration:	
   Yes  No  N/A   7.  Is the measuring range twice the operating
                      range or less?

   Yes  No  N/A   8.  Is the gauge retarded?
   Pressure Recorders              '                   •'

   Yes  No  N/A   1.  Are pressure recorders properly installed
                      (e.g., chart protected from weather, etc.)?
                      Indicate how	

   Yes  No  N/A   2.  Are pressure recorders operational (e.g.,-
                      ink, charts moving, etc.)?

   Yes  No  N/A   3.  Is a back-up gauge provided?

   Yes  No  N/A   4.  Do back-up gauge pressure and recorded
                      pressure agree?

   Yes  No  N/A   5.  Is the measuring range twice the operating
                      range or less?
                                  94

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