American Water Works Association
AWWA C704-92
(Revision of ANSI/AWWA C704-70 [R84])
R
AWWA STANDARD
FOR
PROPELLER-TYPE METERS FOR
WATERWORKS APPLICATIONS
Effective date: Nov. 1, 1992.
First edition approved by AWWA Board of Directors July 21, 1949.
This edition approved Jan. 26, 1992.
AMERICAN WATER WORKS ASSOCIATION
6666 West Quincy Avenue, Denver, Colorado 80235
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
AWWA Standard
This document is an American Water Works Association (AWWA) standard. It is not a specification.
AWWA standards describe minimum requirements and do not contain all of the engineering and
administrative information normally contained in specifications. The AWWA standards usually contain options that must be evaluated by the user of the standard. Until each optional feature is
specified by the user, the product or service is not fully defined. AWWA publication of a standard
does not constitute endorsement of any product or product type, nor does AWWA test, certify, or
approve any product. The use of AWWA standards is entirely voluntary. AWWA standards are
intended to represent a consensus of the water supply industry that the product described will
provide satisfactory service. When AWWA revises or withdraws this standard, an official notice of
action will be placed on the first page of the classified advertising section of Journal AWWA. The
action becomes effective on the first day of the month following the month of Journal AWWA publication of the official notice.
American National Standard
An American National Standard implies a consensus of those substantially concerned with its scope
and provisions. An American National Standard is intended as a guide to aid the manufacturer, the
consumer, and the general public. The existence of an American National Standard does not in any
respect preclude anyone, whether he has approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard.
American National Standards are subject to periodic review, and users are cautioned to obtain the
latest editions. Producers of goods made in conformity with an American National Standard are
encouraged to state on their own responsibility in advertising and promotional materials or on tags
or labels that the goods are produced in conformity with particular American National Standards.
CAUTION NOTICE: The American National Standards Institute (ANSI) approval date on the front
cover of this standard indicates completion of the ANSI approval process. This American National
Standard may be revised or withdrawn at any time. ANSI procedures require that action be taken
to reaffirm, revise, or withdraw this standard no later than five years from the date of publication.
Purchasers of American National Standards may receive current information on all standards by
calling or writing the American National Standards Institute Inc., 11 West 42nd St., New York, NY
10036 (212) 642-4900.
Copyright © 1992 by American Water Works Association
Printed in USA
ii
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
Committee Personnel
The AWWA Subcommittee on Current-Type Meters had the following personnel at the time of approval:
James W. Smith, Chair
D.J. Kullmann, Vice-Chair
R.T. Huth
W.M. Kremkau
J.P. Sullivan Jr.
The AWWA Standards Committee on Water Meters, which reviewed and
approved this standard, had the following personnel at the time of approval:
Donald E. Jackson, Chair
James W. Smith, Vice-Chair
Donald J. Kullmann, Secretary
Consumer Members
G.A. Delgado, Department of Water and Power, Los Angeles, Calif.
R.C. Graff, Water Utilities Department, San Diego, Calif.
K.W. Grant, Louisville Water Company, Louisville, Ky.
B.C. Grimm, Memphis Light, Gas, and Water Division, Memphis, Tenn.
R.E. Howell, Utility Services Department, Port St. Lucie, Fla.
Ron Hyde, Fort Worth Water Department, Fort Worth, Texas
D.E. Jackson, Branford, Conn.
T.E. Kjartanson, City of Winnipeg Waterworks, Winnipeg, Man.
W.M. Kremkau, Washington Suburban Sanitary Commission,
Hyattsville, Md.
Jean-Pol Mahieu, Kansas City Water Department, Kansas City, Mo.
R.L. Miller, Arizona Water Company, Casa Grande, Ariz.
D.S. Morrow, Denver Water Department, Denver, Colo.
King Moss II, Dallas Water Utility, Dallas, Texas
L.E. Orr, Water and Wastewater Department, Phoenix, Ariz.
E.M. Poaches Jr., Philadelphia Water Department, Philadelphia, Pa.
L.M. Scott, Lincoln Water System District Shop, Lincoln, Neb.
L.E. Simmonds, East Bay Municipal Utilities District, Oakland, Calif.
J.W. Smith, Gary-Hobart Water Corporation, Gary, Ind.
R.A. Stehmeir, Milwaukee Water Works, Milwaukee, Wis.
J.P. Sullivan, Commissioners of Public Works, Charleston, S.C.
J.P. Sullivan Jr., Boston Water and Sewer Commission, Boston, Mass.
iii
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(NEWWA)
General Interest Members
E.E. Baruth,* Standards Engineer Liaison, AWWA, Denver, Colo.
A.F. Hess,* Council Liaison, Regional Water Authority,
New Haven, Conn.
K.R. Johnson, Seattle, Wash.
R.N. Koch, Roncoke Associates, Sewickley, Pa.
R.C. McPherson, Rochester, N.Y.
Richard San Giacomo, R & D Engineering & Land Surveying, P.C.,
Buffalo, N.Y.
D.A. Wheadon, Brown & Caldwell, Provo, Utah
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
Producer Members
G.D. Anderson, Sensus Technologies Inc., Uniontown, Pa.
A.N. Dellerson, Sparling Instruments Company Inc., El Monte, Calif.
P.J. Ferguson, Hays, Division of Romac Industries, Lowell, N.C.
L.W. Fleury Jr., Hersey Products Inc., Cranston, R.I.
T.H. Gerardi,† Kent Meters Inc., Ocala, Fla.
P.T. Grayson, Kent Meters Inc., Ocala, Fla.
R.T. Huth, Water Specialties Corporation, Porterville, Calif.
M.N. Kavouklis,† Hersey Products Inc., Cranston, R.I.
J.H. Kennedy,† Badger Meter Inc., Dallas, Texas
D.J. Kullmann, Schlumberger Industries, Atlanta, Ga.
W.C. Myers,† Master Meter Inc., Bullard, Texas
G.J. Nolte, Precision Meters Inc., Orlando, Fla.
Jerry Potter, Master Meter Inc., Longview, Texas
Clay Spence,† McCrometer, Division of Ketema, Hemet, Calif.
D.H. Strobel, Badger Meter Inc., Milwaukee, Wis.
Glenn Voss, McCrometer, Division of Ketema, Hemet, Calif.
*Liaison, nonvoting
†Alternate
iv
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
(AWWA)
Contents
SEC.
PAGE
SEC.
Foreword
I
II
III
IV
V
History of Standard........................ vii
Acceptance....................................... vii
Information Regarding Use
of This Standard ......................... viii
Modification to Standard ................. ix
Major Revisions ................................ ix
Standard
1
General
1.1
1.2
1.3
1.4
1.5
Scope...................................................
Definitions ..........................................
References ..........................................
Affidavit of Compliance.....................
Basis for Rejection .............................
2
Materials
2.1
2.2
2.3
2.4
2.5
2.6
2.8
2.9
General ...............................................
Flow Tubes or Main Cases ...............
Register Boxes and Covers ...............
Propellers ...........................................
Propeller Shafts/Spindles..................
Propeller Shaft/Spindle Bearings
and Bushings...................................
Flow-Straightening Vanes
and Liners .......................................
External Case Closure Fasteners.....
Companion Flanges ...........................
3
General Design
3.1
3.2
3.3
Size ..................................................... 5
Capacity.............................................. 5
Length, Width, and Height............... 5
3.4
3.5
3.6
3.7
3.8
Pressure Requirement ......................
External Case Closure Fasteners ....
Accessibility .......................................
Registration Accuracy .......................
Markings ............................................
4
Detailed Design
4.1
4.2
Tubes or Cases................................... 7
Flow-Tube or Main-Case
Connections ..................................... 7
Companion Flanges........................... 7
Registers............................................. 8
Register Boxes ................................. 10
Propellers ......................................... 10
Seal-Wire Holes ............................... 10
4.3
4.4
4.5
4.6
4.7
1
1
1
3
3
PAGE
5
5
5
7
7
Appendix
2.7
3
4
4
4
4
4
4
5
5
A
Supplemental Information
A.1
Units of Measurement ................ 11
A.2
Tests
A.2.1
A.2.2
A.2.3
Capacity and Pressure-Loss
Tests............................................... 11
Pressure Tests ................................. 12
Accuracy Tests ................................. 12
A.3
Testing Equipment ...................... 12
A.4
Registration Accuracy
A.4.1
A.4.2
A.4.3
A.4.4
Excessive Wear ................................
Temperature Extremes ...................
Corrosion ..........................................
Improper Installation ......................
v
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
12
13
13
13
SEC.
A.4.5
A.4.6
PAGE
SEC.
Material in Suspension ................... 13
Entrained Air................................... 13
Tables
1
A.5
Periodic Tests ............................... 14
A.6
Meter Storage................................ 14
A.7
Placing Meter in Service............ 14
PAGE
2
3
4
5
A.1
Propeller Meters for Waterworks
Applications ..................................... 6
Propeller Meter Dimensions ............. 6
Main-Case Connections or Meter
Installation Types ........................... 8
Companion Flange Dimensions ........ 9
Maximum Indication on Initial
Dial and Minimum Register
Capacity ........................................... 9
Average Recommended Intervals
Between Meter Tests .................... 14
vi
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
Foreword
This foreword is for information only and is not a part of AWWA C704.
I. History of Standard. Current-type water meters were first developed for
measuring flowing air and water. A booklet, published in Hamburg, Germany, in
1790 by Benjamin Gottlob Hoffman, described a form of current meter developed by
Reinhard Woltman, which seems to be the first practical meter for the purpose. It
was originally developed to measure stream flow and was not considered adaptable
for use in a closed pipe. However, since then it has been changed materially in
design, construction, and use and adapted for closed pipelines.
The first effort to standardize current-type meters for customer service in the
United States resulted in the formulation of AWWA Standard Specifications for
Cold-Water Meters—Current Type, in 1923. These were revised on July 25, 1947, as
AWWA C701-47—Standard Specifications for Cold Water Meters—Current Type.
During the period between 1923 and 1947, a different version of current-type meters
was developed for use in special applications such as pump station discharge and
main line measurement. The only difference in construction features between the
two types is the original design for use in customers’ service lines contains a removable measuring cage in which a turbine operates, and the later type does not.
Instead, a propeller operates either directly within the pipeline itself or within the
main meter body. This change in design results in differences in operating ranges,
friction losses, and capacities of the two types. Due to development of the second
type, AWWA Specification for Current Type Meters—Propeller Drive, C704, was
adopted as tentative in 1949, and was made a standard in 1950.
Confusion results from having two standards for what is essentially the same
type of meter, and considerable judgment is required in the selection of one or the
other. The AWWA Meter Committee, in the 1970 revisions of AWWA C701 and
AWWA C704, attempted to make the two standards more compatible in order to
better assist the user in selection. This revision of AWWA C704 was approved by
the AWWA Board of Directors on Jan. 26, 1992. The dates of approval and numerical designations of all past editions of AWWA C704 are listed below.
Designation
Date of Approval
7M.5-T
7M.5-1950/C704-50
AWWA C704-70
AWWA C704-70(R75)
AWWA C704-70(R84)
July 21, 1949
May 25, 1950
Jan. 26, 1970
Jan. 26, 1975
Jan. 29, 1984
II. Acceptance. In May 1985, the US Environmental Protection Agency
(USEPA) entered into a cooperative agreement with a consortium led by NSF International (NSF) to develop voluntary third-party consensus standards and a certification program for all direct and indirect drinking water additives. Other members of
the consortium included the American Water Works Association Research Foundation (AWWARF), the Conference of State Health and Environmental Managers
(COSHEM), the American Water Works Association (AWWA), and the Association of
State Drinking Water Administrators (ASDWA). The consortium is responsible for
the cooperative effort of manufacturers, regulators, product users, and other interested parties that develop and maintain the NSF standards.
vii
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
In the United States, authority to regulate products for use in, or in contact
with, drinking water rests with individual states.* Local agencies may choose to
impose requirements more stringent than those required by the state. To evaluate
the health effects of products and drinking water additives from such products, state
and local agencies may use various references, including
1. An advisory program formerly administered by USEPA, Office of Drinking
Water, discontinued on Apr. 7, 1990.
2. Specific policies of the state or local agency.
3. Two standards developed under the direction of NSF, ANSI†/NSF‡ 60,
Drinking Water Treatment Chemicals—Health Effects, and ANSI/NSF 61, Drinking
Water System Components—Health Effects.
4. Other references including AWWA standards, Food Chemicals Codex,
Water Chemicals Codex§, and other standards considered appropriate by the state or
local agency.
Various certification organizations may be involved in certifying products in
accordance with ANSI/NSF 61. Individual states or local agencies have authority to
accept or accredit certification organizations within their jurisdiction. Accreditation
of certification organizations may vary from jurisdiction to jurisdiction.
Appendix A, “Toxicology Review and Evaluation Procedures,” to ANSI/NSF 61
does not stipulate a maximum allowable level (MAL) of a contaminant for substances not regulated by a USEPA final maximum contaminant level (MCL). The
MALs of an unspecified list of “unregulated contaminants” are based on toxicity
testing guidelines (noncarcinogens) and risk characterization methodology (carcinogens). Use of appendix A procedures may not always be identical, depending on the
certifier.
AWWA C704-92 does not address additives requirements. Thus, users of this
standard should consult the appropriate state or local agency having jurisdiction in
order to
1. Determine additives requirements including applicable standards.
2. Determine the status of certifications by all parties offering to certify products for contact with, or treatment of, drinking water.
3. Determine current information on product certification.
III. Information Regarding Use of This Standard. When placing orders
for meters manufactured to conform to this standard, it is necessary for the purchaser to supply specific supplementary information regarding the following:
1. Standard used—that is, AWWA C704-92, Standard for Propeller-Type
Meters for Waterworks Applications.
2. An affidavit of compliance (Sec. 1.4) and certificate of testing for accuracy
and capacity (Sec. A.2.3 and Sec. A.2.1) from the supplier or manufacturer if
required.
3. Size of meter (Sec. 3.1) and quantity required.
*Persons in Canada, Mexico, and non-North American countries should contact the
appropriate authority having jurisdiction.
†American National Standards Institute Inc., 11 W. 42nd St., New York, NY 10036.
‡NSF International, 3475 Plymouth Rd., Ann Arbor, MI 48106.
§Both publications available from National Academy of Sciences, 2102 Constitution Ave.
N.W., Washington, DC 20418.
viii
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
4. Type of end connections, including threaded, flanged, plain-end, groovedend, welding-saddle, saddle-type, or fire hydrant connections (Sec. 4.2).
5. Whether companion flanges, gaskets, bolts, and nuts (Sec. 4.3 and Sec. 2.8)
are to be furnished with flanged meters.
6. Whether meters are to be furnished with open or hermetically sealed registers; with units of measure, including US gallons, cubic feet, cubic metres, or other
units (Sec. 4.4); with a center sweep-test hand (Sec. 4.4.1.5); or with an instantaneous flow-rate indicator reading in US gallons per minute, cubic feet per second,
cubic metres per hour, litres per second, or other units.
7. If seal-wire holes are to be omitted (Sec. 4.7).
8. Whether flow tube or main casing is to be cast iron or fabricated steel
(Sec. 2.2).
9. The modification of registration accuracy if test water temperature exceeds
100°F (38°C).
10. If water is highly aggressive, special materials required to resist corrosion
(Sec. A.4.3).
IV. Modification to Standard. Any modification of the provisions,
definitions, or terminology in this standard must be provided in the purchaser’s
specifications.
V. Major Revisions. The major changes to AWWA C704-70(R84) in this revision are
1. Section 1.3, References, was added.
2. Section 1.5, Basis for Rejection, added the statement that meters not complying with all requirements of this standard shall be rejected. The warranty
requirement was eliminated.
3. Section 2 contains new terminology and references to ANSI,* ASTM,† and
AWWA standards on materials for components of propeller-type meters.
4. Section 1.2, Definitions, was added.
5. The appendix was updated.
6. The title of AWWA Standard C704 was changed.
7. Soft metric units of measurement were added.
8. Deleted 5-in. (125-mm) meter size.
9. Added 42-in. (1050-mm) through 72-in. (1800-mm) meter sizes (in 6-in.
[150-mm] increments).
10. Modified dimensions of 2-in. (50-mm) through 36-in. (900-mm) size meters.
11. Added saddle-type meters.
12. Added materials of construction for propellers and flow-straightening
vanes and liners.
13. Deleted copper alloy as a material of construction for flow tubes, casings,
fasteners, and companion flanges.
14. Added general and detailed design sections.
15. Deleted requirement that 2-in. (50-mm) and 3-in. (75-mm) meters shall
have flow-straightening vanes.
16. Increased meter operating temperature to 100°F (38°C) from 80°F (27°C).
17. Added recommended procedure for placing meter in service.
*American National Standards Institute Inc., 11 W. 42nd St., New York, NY 10036.
†American Society for Testing and Materials, 1916 Race St., Philadelphia, PA 19103.
ix
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
This page intentionally blank.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
American Water Works Association
R
AWWA C704-92
Revision of ANSI/AWWA C704-70(R84)
AWWA STANDARD FOR
PROPELLER-TYPE METERS FOR
WATERWORKS APPLICATIONS
SECTION 1: GENERAL
Sec. 1.1 Scope
This standard covers the various types and classes of propeller meters in sizes
2 in. (50 mm) through 72 in. (1800 mm) for waterworks applications. These meters
register by recording the revolutions of a propeller set in motion by the force of
flowing water striking the blades.
Sec. 1.2 Definitions
In this standard, the following definitions shall apply:
1.2.1 Manufacturer: The party that manufactures, fabricates, or produces
materials or products.
1.2.2 Purchaser: The person, company, or organization that purchases any
materials or work to be performed.
1.2.3 Supplier: The party who supplies material or services. A supplier may or
may not be the manufacturer.
Sec. 1.3 References
This standard references the following documents. In their latest revisions,
they form a part of this standard to the extent specified herein. In any case of
conflict, the requirements of this standard shall prevail.
ANSI*/ASME† B1.20.1—General Purpose Pipe Threads.
*American National Standards Institute Inc., 11 W. 42nd St., New York, NY 10036.
†American Society of Mechanical Engineers, 345 E. 47th St., New York, NY 10017.
1
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
2
AWWA C704-92
ANSI/ASME B16.1—Cast-Iron Pipe Flanges and Flanged Fittings, Class 25,
125, 250, and 800.
ANSI/ASME B16.5—Pipe Flanges and Flanged Fittings.
ASTM* A48—Standard Specification for Gray Iron Castings.
ASTM A53—Standard Specification for Pipe, Steel, Black and Hot-Dipped,
Zinc-Coated Welded and Seamless.
ASTM A120—Standard Specification for Pipe, Steel, Black and Hot-Dipped
Zinc-Coated (Galvanized) Welded and Seamless, for Ordinary Uses. (Discontinued.)
ASTM A126—Standard Specification for Gray Iron Castings for Valves,
Flanges, and Pipe Fittings.
ASTM A153—Standard Specification for Zinc Coating (Hot-Dip) on Iron and
Steel Hardware.
ASTM A159—Standard Specification for Automotive Gray Iron Castings.
ASTM A167—Standard Specification for Stainless and Heat-Resisting Chromium–Nickel Steel Plate, Sheet, and Strip.
ASTM A276—Standard Specification for Stainless and Heat-Resisting Steel
Bars and Shapes.
ASTM A283—Standard Specification for Low and Intermediate Tensile
Strength Carbon Steel Plates, Shapes, and Bars.
ASTM A307—Standard Specification for Carbon Steel Bolts and Studs, 60,000
PSI Tensile Strength.
ASTM A493—Standard Specification for Stainless and Heat-Resisting Steel for
Cold Heading and Cold Forging Bar and Wire.
ASTM A530—Standard Specification for General Requirements for Specialized
Carbon and Alloy Steel Pipe.
ASTM A536—Standard Specification for Ductile-Iron Castings.
ASTM A570—Standard Specification for Hot-Rolled Carbon Steel Sheet and
Strip, Structural Quality.
ASTM A582—Standard Specification for Free-Machining Stainless and HeatResisting Steel Bars, Hot-Rolled or Cold-Finished.
ASTM B26—Standard Specification for Aluminum-Alloy Sand Castings.
ASTM B85—Standard Specification for Aluminum-Alloy Die Castings.
ASTM B164—Standard Specification for Nickel–Copper Alloy Rod, Bar, and
Wire.
ASTM B167—Standard Specification for Nickel–Chromium–Iron Alloys Seamless Pipe and Tube.
ANSI/ASTM B176—Standard Specification for Copper–Alloy Die Castings.
ASTM B564—Standard Specification for Nickel Alloy Forgings.
ASTM B584—Standard Specification for Copper Alloy Sand Castings for General Applications.
ASTM D1248—Standard Specification for Polyethylene Plastics Molding and
Extrusion Materials.
ASTM D1788—Standard Specification for Rigid Acrylonitrile–Butadiene–
Styrene (ABS) Plastics.
ASTM D2135—Standard Classification of Hard Rubbers. (Discontinued.)
ASTM D3935—Standard Specification for Polycarbonate (PC) Unfilled and
Reinforced Material.
*American Society for Testing and Materials, 1916 Race St., Philadelphia, PA 19103.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
PROPELLER-TYPE METERS
3
ANSI/ASTM D4066—Standard Specification for Nylon Injection and Extrusion
Materials (PA).
ASTM D4067—Standard Specification for Reinforced and Filled Polyphenylene
Sulfide Injection Molding and Extrusion Materials.
ASTM D4101—Standard Specification for Propylene Plastic Injection and
Extrusion Materials.
ASTM D4181—Standard Specification for Acetal (POM) Molding and Extrusion Materials.
ANSI/AWWA C110/A21.10—American National Standard for Ductile-Iron and
Gray-Iron Fittings, 3 In. Through 48 In., for Water and Other Liquids.
ANSI/AWWA C200—Steel Water Pipe, 6 In. and Larger.
ANSI/AWWA C207—Steel Pipe Flanges for Waterworks Service—Sizes 4 In.
Through 144 In.
ANSI/AWWA C210—Liquid Epoxy Coating Systems for the Interior and Exterior of Steel Water Pipelines.
ANSI/AWWA C213—Fusion-Bonded Epoxy Coating for the Interior and Exterior of Steel Water Pipelines.
Sec. 1.4 Affidavit of Compliance
The purchaser may require an affidavit from the manufacturer or supplier that
meters furnished comply with all applicable requirements of this standard.
Sec. 1.5 Basis for Rejection
Meters not complying with all requirements of this standard and the purchaser’s specifications shall be rejected. The manufacturer shall bear the expense of
replacing or satisfactorily correcting all meters rejected for failure to comply with
this standard.
SECTION 2: MATERIALS
Sec. 2.1 General
The composition of all alloys in this section is subject to commercially accepted
tolerances.* Section 2.2 through Sec. 2.9 do not require any one specific material,
but list materials typically used in the construction of water meters. The listings are
not intended to be considered all inclusive and should not be used to limit the use of
other materials. When reference is made to ANSI, ASTM, AWWA, or other standards, it shall be understood that the latest revision thereof shall apply unless the
date of the standard is also specifically listed.
2.1.1 Materials shall be selected for their strength and resistance to corrosion
and shall not impart to the water objectionable taste, odor, or toxic substances in
normalized concentrations exceeding the maximum contaminant levels (MCLs) as
defined by the US Environmental Protection Agency (USEPA).
*The 1986 amendments to the US Safe Drinking Water Act (SDWA) limit materials used
for wetted pipe fittings to a maximum 8 percent lead.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
4
AWWA C704-92
Sec. 2.2 Flow Tubes or Main Cases
Flow tubes or main cases may be made of cast iron as listed in ASTM A126,
ASTM A159, or ASTM A536; or fabricated steel such as ASTM A53, ASTM A120,
and ANSI/AWWA C200, protected by a corrosion-resistant coating or other
anticorrosion treatment such as ASTM A153, ANSI/AWWA C210, and
ANSI/AWWA C213.
Sec. 2.3 Register Boxes and Covers
Register boxes and covers shall be made of a copper alloy containing not less
than 57 percent copper such as UNS C85800 as listed in ANSI/ASTM B176 or
ASTM B584; cast iron such as those included in ASTM A48, ASTM A126, and
ASTM A159; aluminum such as UNS A03190 per ASTM B26 or ASTM B85; or a
suitable engineering plastic such as polycarbonate (PC) per ASTM D3935, nylon (N)
per ANSI/ASTM D4066, propylene per ASTM D4101, or acetal per ASTM D4181.
Register boxes and covers made of cast iron shall be protected with a corrosion-resistant coating.
Sec. 2.4 Propellers
Propellers shall be made of suitable molded or cast material having sufficient
rigidity and strength to operate at maximum rated capacity of the meter. Propellers
shall have a specific gravity as close as possible to that of water. They shall be of
sufficient dimensional stability to retain operating clearance and not warp or deform
when exposed to operating temperatures of 100°F (38°C). Representative materials
include engineering plastics such as polyethylene per ASTM D1248, propylene per
ASTM D4101, nylon (N) per ANSI/ASTM D4066, polyphenylene oxide (PPO) per
ASTM D4067, or acrylonitrile–butadiene–styrene (ABS) per ASTM D1788; or vulcanized rubber per ASTM D2135.
Sec. 2.5 Propeller Shafts/Spindles
Propeller shafts/spindles shall be made of stainless steel such as ASTM A276
type 316 or 303, ASTM A530 grade CF8M, or ASTM A167 type 316; monel such as
UNS NO4400 per ASTM B164 or UNS NO4400 per ASTM B167; or tungsten carbide (88 percent WCA, 12 percent Ni). If the spindle also functions as a bearing
member, it should be coated or sleeved with a suitable material such as high-alumina ceramic or chrome oxide.
Sec. 2.6 Propeller Shaft/Spindle Bearings and Bushings
Propeller shaft/spindle thrust bearings shall be of jewel, ball, or other suitable
type made of corrosion-resistant material such as tungsten carbide (88 percent
WCA, 12 percent Ni) or stainless steel per ASTM A276 type 440C or ASTM A167
type 316. Propeller shaft/spindle radial bushings or bearings shall be made of durable materials such as high-alumina ceramic or graphite.
Sec. 2.7 Flow-Straightening Vanes and Liners
Flow-straightening vanes (and liners when furnished) shall be of corrosion-resistant material such as suitable engineering plastic, including polycarbonate (PC)
per ASTM D3935, polyphenylene oxide (PPO) per ASTM D4067; or stainless steel
per ASTM A167 type 304; or other materials such as steel per ASTM A570 grade A
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
PROPELLER-TYPE METERS
5
protected by corrosion-resistant treatment such as fusion-bonded epoxy per
ANSI/AWWA C213.
Sec. 2.8 External Case Closure Fasteners
Meterhead/casing bolts, nuts, capscrews, studs, and washers shall be made of
stainless steel per ASTM A582 type 303, ASTM A167 type 302, 304, and 316; ASTM
A276; ASTM A493; or, if approved by the purchaser, steel treated to resist corrosion
such as galvanized carbon steel per ASTM A307 grade B. Fasteners for nonpressure
assemblies may be made of the above listed materials or of a suitable engineering
plastic such as acetal per ASTM D4181, polycarbonate (PC) per ASTM D3935, nylon
(N) per ANSI/ASTM D4066, or propylene per ASTM D4101.
Sec. 2.9 Companion Flanges
Companion flanges when furnished shall be made of cast iron, including ASTM
A126 grade B, ASTM A48, and ASTM A159; or of steel, including ASTM A283,
ASTM A53, and ASTM A120.
SECTION 3: GENERAL DESIGN
Sec. 3.1 Size
The meter sizes indicated in Table 1 shall be the same as the nominal sizes of
the flow tube/casing connections.
Sec. 3.2 Capacity*
The nominal capacity rating and the related pressure-loss limits shall be the
same as those listed in Table 1 for the intermittent maximum flow.
Sec. 3.3 Length, Width, and Height
Maximum overall length of the meter face-to-face dimension of plain ends or
flanges shall not be greater than those listed in Table 2. Meter width and height
shall not exceed those listed in Table 2.
Sec. 3.4 Pressure Requirement
Meters supplied under this standard shall operate without leakage or damage
to any part at a working pressure of 150 psi (1050 kPa).
Sec. 3.5 External Case Closure Fasteners
All external meterhead/case bolts, nuts, capscrews, studs, and washers shall be
designed for easy removal after long service.
Sec. 3.6 Accessibility
The operating assembly from propeller to output shaft shall be easily removable as a complete unit from the meter case or body or from the pipe if a saddle type
is used. Propeller shafts shall revolve in removable corrosion-resistant ball or roller
bearings, or in bushings of durable materials. Meters shall be designed for easy
*See Section A.2.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
6
AWWA C704-92
Table 1 Propeller Meters for Waterworks Applications
Meter Size
in.
(mm)
Maximum Head Loss
at Intermittent
Maximum Flow*
psi
(kPa)
Intermittent
Maximum Flow*
gpm
(m3/h)
Normal Flow Limits
gpm
(m3/h)
2
3
4
6
8
(50)
(75)
(100)
(150)
(200)
35–100
40–250
50–500
90–1200
100–1500
(8–23)
(9–57)
(11–110)
(20–270)
(23–340)
120
300
600
1350
1800
(27)
(68)
(135)
(300)
(405)
5
5
2
1
0.5
(34)
(34)
(14)
(7)
(3.5)
10
12
14
16
18
(250)
(300)
(350)
(400)
(450)
125–2000
150–2800
250–3750
350–4750
450–5625
(28–450)
(34–640)
(57–850)
(79–1080)
(102–1280)
2400
3375
4500
5700
6750
(545)
(765)
(1020)
(1295)
(1530)
0.5
0.5
0.5
0.5
0.25
(3.5)
(3.5)
(3.5)
(3.5)
(1.7)
20
24
30
36
42
(500)
(600)
(750)
(900)
(1050)
550–6875
800–10,000
1200–15,000
1500–20,000
2000–28,000
(125–1560)
(180–2270)
(270–3400)
(340–4540)
(450–6360)
8250
12,000
18,000
24,000
40,000
(1875)
(2725)
(4090)
(5450)
(9090)
0.25
0.25
0.25
0.25
0.10
(1.7)
(1.7)
(1.7)
(1.7)
(0.7)
48
54
60
66
72
(1200)
(1350)
(1500)
(1650)
(1800)
2500–35,000
3200–45,000
4000–60,000
4750–75,000
5500–90,000
(570–7950)
(725–10,200)
(910–13,600)
(1080–17,000)
(1250–20,400)
50,000
55,000
80,000
95,000
115,000
(11,350)
(12,500)
(18,180)
(21,590)
(26,100)
0.10
0.10
0.10
0.10
0.10
(0.7)
(0.7)
(0.7)
(0.7)
(0.7)
*As shown for use 10 percent to 15 percent of total time meter is operating.
Table 2 Propeller Meter Dimensions
Maximum Dimensions
Length
Meter Size*
in. (mm)
2
3
4
6
8
(50)
(75)
(100)
(150)
(200)
10
12
14
16
18
(250)
(300)
(350)
(400)
(450)
20 (500)
24 (600)
30 (750)
36 (900)
42 (1050)
48 (1200)
Screw
in. (mm)
14
16
20
22
(356)
(406)
(508)
(560)
Flanged Tube
in.
(mm)
Plain End
in.
(mm)
in.
Width
(mm)
in.
Height
(mm)
14
18
20
22
24
(356)
(457)
(508)
(560)
(610)
(432)
(432)
(533)
(584)
6
9
9
11
13 1⁄2
(152)
(229)
(229)
(279)
(343)
11
12
15
16
18
3⁄4
17
17
21
23
26
28
42
48
54
(660)
(710)
(1070)
(1220)
(1370)
25
27
41
47
53
(635)
(685)
(1040)
(1190)
(1350)
16
19
21
23 1⁄2
25
(406)
(483)
(533)
(597)
(635)
21
24
25
28
29
3⁄4
(1500)
(1800)
(2110)
(2410)
(2720)
(3020)
1⁄2
27
(699)
32
(813)
38 3⁄4 (984)
46
(1170)
53
(1350)
59 1⁄2 (1510)
32
36
41
49
57
62
1⁄2
60
72
84
96
108
120
(1525)
(1830)
(2130)
(2440)
(2740)
(3050)
59
71
83
95
107
119
*Meter sizes 54 in. to 72 in. (1350 mm to 1800 mm) not applicable.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
1⁄2
1⁄4
1⁄4
1⁄2
1⁄4
1⁄4
1⁄2
1⁄4
3⁄4
3⁄4
1⁄2
1⁄2
(298)
(318)
(387)
(413)
(470)
(552)
(616)
(641)
(724)
(743)
(826)
(933)
(1060)
(1260)
(1450)
(1590)
PROPELLER-TYPE METERS
7
removal of all interior parts with the exception of straightening vanes without disturbing the connections to the pipeline.
Sec. 3.7 Registration Accuracy
The meter shall meet the following requirements for accuracy with test water
at a temperature less than 100°F (38°C).
3.7.1 Normal flow rate. At any rate of flow within the normal flow limits set
forth in Table 1, the meter shall register not less than 98 percent nor more than
102 percent of the water actually passed through the meter.
Sec. 3.8 Markings
The meter size and serial number shall be permanently indicated on the meter
head. The direction of flow shall be permanently indicated on the meter tube and
meter head.
3.8.1 Register-box markings. The name of the manufacturer shall be cast and
the serial number of the meter shall be imprinted on the cover of the register box. If
the meter is not equipped with a cover, the markings shall be cast and imprinted on
the register box assembly.
SECTION 4: DETAILED DESIGN
Sec. 4.1 Tubes or Cases
All meters shall have an outer case or tube, or shall be mounted on an existing
pipe. Castings shall not be repaired in any manner. The inlet and outlet shall have
a common axis. Flanges shall be parallel.
4.1.1 Flow-straightening vanes. All 4-in. (100-mm) and larger meters shall
have flow-straightening vanes or vanes shall be available as separate components
that can be welded or bolted into the pipeline.
Sec. 4.2 Flow-Tube or Main-Case Connections
4.2.1 Meter connections. Methods of connecting a meter to a pipeline include
attaching a flow tube or main case to the pipe using threaded spuds, flanged ends,
grooved ends, or plain ends, or mounting the metering mechanism directly on the
exterior surface of the pipe wall by means of a welding saddle, clamp-on saddle, or
strap-on saddle.
The available main-case connection installation types for each size of meter are
listed in Table 3.
4.2.2 Threaded spuds. Meter spuds shall be tapped 2 in. (50 mm) or 3 in.
(75 mm). Threads shall conform to ANSI/ASME B1.20.1 for internal taper pipe
threads.
4.2.3 Casing flanges. Meter casing flanges shall be of the round type, faced
and drilled, and shall conform to ANSI/ASME B16.1 for cast-iron pipe flange, Class
125 (see Table 4) for diameter and drilling or ANSI/AWWA C207, steel flat face
flange, Class D.
Sec. 4.3 Companion Flanges
Companion flanges, gaskets, bolts, and nuts shall be provided if required by
the purchaser’s specifications. Companion flanges shall be of the round type, faced,
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
8
AWWA C704-92
Table 3 Main-Case Connections or Meter Installation Types
Meter Size
in.
(mm)
Threaded
Spud
X
X
Flanged
Plain
End
Welding
Saddle
Clamp-on
Saddle
Strap-on
Saddle
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
2
3
4
6
8
(50)
(75)
(100)
(150)
(200)
10
12
14
16
18
(250)
(300)
(350)
(400)
(450)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
20
24
30
36
42
(500)
(600)
(750)
(900)
(1050)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
48
54
60
66
72
(1200)
(1350)
(1500)
(1650)
(1800)
X
X
X
X
X
X
X
NOTE: The availability of connections for a given meter size vary by manufacturer.
drilled, and tapped with ANSI/ASME B1.20.1 internal pipe thread if a threaded
flange is used. Companion flanges shall conform to ANSI/ASME B16.1 for cast-iron
pipe flange, Class 125 (see Table 4) for diameter and drilling or ANSI/AWWA C207,
steel flat-face flange, Class D.
Sec. 4.4 Registers
Registers shall be straight reading, either hermetically sealed by the manufacturer or open, and shall read in US gallons, cubic feet, cubic metres, or other units,
as specified by the purchaser. The register mechanism shall not be in contact with
the water being measured.
4.4.1 Register odometers. The numerals on the odometer wheels shall not be
less than 3⁄16 in. (4.8 mm) in height and should be readable at a 45° angle from
vertical.
4.4.1.1 The register lock and side gears shall be fastened securely to the
odometer wheel discs and hubs. The tumbler pinions shall mesh accurately at the
turnover points with the lock and side gears of the adjacent odometer wheels. Both
main and pinion shafts shall be secured in the register frame, register plates, or
both, so that they cannot get out of position. The pinion shaft shall be so designed
that there is no possibility of its bending and allowing the pinion to skip at the
turnover point.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
PROPELLER-TYPE METERS
Table 4 Companion Flange Dimensions
Minimum Thickness
Meter Size*
in.
(mm)
Diameter Bolt
Hole Circle
in.
(mm)
2
3
4
6
8
(50)
(75)
(100)
(150)
(200)
4
6
7
9
11
3⁄4
10
12
14
16
18
(250)
(300)
(350)
(400)
(450)
14
17
18
21
22
1⁄4
20
24
30
36
42
48
(500)
(600)
(750)
(900)
(1050)
(1200)
Number of
Bolt Holes
(121)
(152)
(190)
(241)
(298)
4
4
8
8
8
(362)
(432)
(476)
(540)
(578)
25
(635)
29 1⁄2 (749)
36
(914)
42 3⁄4 (1085)
49 1⁄2 (1260)
56
(1420)
1⁄2
1⁄2
3⁄4
3⁄4
1⁄4
3⁄4
Diameter
Bolt Holes
in. (mm)
3⁄4
At Bolt Hole
in.
(mm)
5⁄8
7⁄8
(19)
(19)
(19)
(22)
(22)
1
1 1⁄8
12
12
12
16
16
1
1
1 1⁄8
1 1⁄8
1 1⁄4
(25)
(25)
(29)
(29)
(32)
1
1
1
1
1
20
20
28
32
36
44
1
1
1
1
1
1
1⁄4
(32)
(35)
(35)
(41)
(44)
(44)
3⁄4
3⁄4
7⁄8
3⁄8
3⁄8
5⁄8
3⁄4
3⁄4
At Hub
in.
(mm)
7⁄8
(19)
(19)
(24)
(25)
(29)
1
1
1
1
3⁄4
(22)
(30)
(33)
(40)
(44)
9⁄16
(30)
(32)
(35)
(37)
(40)
1 15⁄16
2 3⁄16
2 1⁄4
2 1⁄2
2 11⁄16
(49)
(56)
(57)
(64)
(68)
1 11⁄16
1 7⁄8
2 1⁄8
2 3⁄8
(43)
(48)
(54)
(60)
2
3
3
3
7⁄8
(73)
(83)
(89)
(95)
3⁄4
15⁄16
3⁄16
1⁄4
3⁄8
7⁄16
3⁄16
5⁄16
9⁄16
1⁄4
1⁄2
3⁄4
*Meter sizes 54 in. to 72 in. (1350 mm to 1800 mm) not applicable.
Table 5 Maximum Indication on Initial Dial and Minimum Register Capacity
Meter Size
in.
(mm)
Maximum Allowable
Indication on Initial Dial
ft3
gal
m3
Minimum Allowable Capacity
of Register (millions)
ft3
gal
m3
2
3
4
6
8
(50)
(75)
(100)
(150)
(200)
10
10
100
100
100
100
100
1000
1000
1000
1
1
1
1
10
10
10
100
100
100
100
100
1000
1000
1000
1
1
1
1
10
10
12
14
16
18
(250)
(300)
(350)
(400)
(450)
100
1000
1000
1000
1000
1000
1000
1000
1000
10,000
10
10
10
10
10
100
1000
1000
1000
1000
1000
1000
1000
1000
10,000
10
10
10
10
10
20
24
30
36
42
(500)
(600)
(750)
(900)
(1050)
1000
1000
1000
1000
10,000
10,000
10,000
10,000
10,000
10,000
10
100
100
100
100
1000
1000
1000
1000
10,000
10,000
10,000
10,000
10,000
10,000
10
100
100
100
100
48
54
60
66
72
(1200)
(1350)
(1500)
(1650)
(1800)
10,000
10,000
10,000
10,000
10,000
100,000
100,000
100,000
100,000
100,000
100
1000
1000
1000
1000
10,000
10,000
10,000
10,000
10,000
100,000
100,000
100,000
100,000
100,000
100
1000
1000
1000
1000
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
9
10
AWWA C704-92
4.4.1.2 If the register is hermetically sealed, gears and pinions shall run free
on fixed shafts or shall be fixed on shafts that run free in the register frame, register plates, or both, and shall be constructed so that they cannot become unmeshed.
Pinions may operate between odometer wheels mounted in partition plates.
4.4.1.3 The maximum indication of digits appearing on the first odometer
wheel and the minimum capacity of the register shall conform to the requirements
set forth in Table 5.
4.4.1.4 Registers furnished with a test index circle shall be divided into
10 equal parts. The hand or pointer shall taper to a sharp point and shall be accurately set and securely held in place.
4.4.1.5 If registers are furnished with center-sweep hands, then there shall be
an index circle located near the periphery of the register graduated in 100 equal
parts, with each tenth graduation numbered. The quantities indicated by a single
revolution of the test hand shall be those shown in Table 5 for the initial dial.
Sec. 4.5 Register Boxes
The cover shall be recessed and overlap the register box to protect the lens.
The lens shall be securely held in place. All register-box compartments of meters
having a stuffing box exposed to the atmosphere shall be provided with a drain hole
1⁄8 in. (3 mm) in diameter.
Sec. 4.6 Propellers
Measuring propellers shall be mounted on, or shall rotate on, metal
shafts/spindles or be supported by bearings. Propellers mounted on shafts/spindles
shall revolve in ball or roller bearings or in bushings.
Sec. 4.7 Seal-Wire Holes
Register box screws shall be drilled with seal-wire holes sufficiently large to
accommodate standard seal wire.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
APPENDIX A
Supplemental Information
This appendix is for information only and is not a part of AWWA C704.
SECTION A.1: UNITS OF MEASUREMENT
The majority of water meters presently in service in the United States register
in either US gallons or cubic feet. Propeller meters are available in which the totalizer dial reads in US gallons, cubic feet, cubic metres, or other standard liquid
measuring units such as acre-feet. Instantaneous flow-rate indicators reading in US
gallons per minute, cubic feet per second, litres per second, cubic metres per hour,
or other units are generally available. The user should determine the most suitable
unit of measure.
SECTION A.2: TESTS
Sec. A.2.1 Capacity and Pressure-Loss Tests
Capacity tests are tests of the design of a meter. Once a meter of each size of a
given design has been tested for pressure loss at safe maximum operating capacity,
it should not be necessary to test others of the same design.
The pressure loss should be determined using two identical piezometer rings of
the same diameter as the nominal size of the meter being tested. The piezometer
rings must be free of any burrs where the holes are drilled through the wall of the
ring. No fewer than four holes should be provided, drilled in pairs on diameters at
right angles to each other. The inlet ring should be set close to the meter at a
distance of eight diameters or more below the nearest upstream stop valve or fitting.
The outlet ring should be placed at a distance of between 8 and 10 diameters from
the outlet of the meter. The diameter of the inlet and outlet pipe should be the same
as the nominal size of the meter to be tested. The rings are to be connected preferably to a suitable differential-pressure (DP) cell or manometer with measurement
capability of 0.1 psi (0.7 kPa). If a manometer is used, provisions should be made for
the complete removal of air from the apparatus; and the installation should be such
that air will rise to the air outlets. Provisions must be made for traps to prevent
accidental expulsion of mercury into the test lines when using mercury manometers.
If measurements of U-tube manometers are to be made at relatively high flow rates,
then it is necessary to read both sides of the mercury column simultaneously to
avoid errors due to fluctuations. (Other appropriate types of manometers may be
used.) The pressure loss of inlet and outlet piping from meter to piezometer rings
shall be deducted in determining the meter pressure loss.
11
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
12
AWWA C704-92
Sec. A.2.2 Pressure Tests
A pressure test should be made on each size of a particular design of meter
furnished. The test pressure should be 300-psi (2100-kPa) static, which may be produced by use of a hand pump or other available device. The meter should be tested
for accuracy before and after it has been pressure-tested to determine whether there
has been any distortion that could affect the registration. If satisfactory results are
obtained, it is unnecessary to make more than one pressure test on each size of a
given design of meter.
Sec. A.2.3 Accuracy Tests
All meters should be tested for accuracy of registration at flow rates and test
flow quantities in accordance with AWWA Manual M6—Water Meters—Selection,
Installation, Testing, and Maintenance. If the purchaser does not have suitable
means for testing, then the manufacturer should be required to furnish a certificate
showing that each meter has been tested for accuracy of registration and complies
with accuracy and capacity requirements of AWWA C704 when tested in accordance
with AWWA Manual M6.
SECTION A.3: TESTING EQUIPMENT
The measuring device used to determine the amount of water discharged in
testing should be designed to provide measuring accuracy to within 0.25 percent of
the actual quantity. Tanks and scales should be tested and recalibrated quarterly or
at least semiannually and records kept of such tests and calibrations.
SECTION A.4: REGISTRATION ACCURACY
In a propeller meter, the motion of the propeller is transmitted by a system of
gearing to the register, which records the flow in convenient units of measurement.
The gearing translates the motion of the propeller into the unit of measure indicated
by the register. The registration is thus directly dependent on the number of revolutions of the propeller. The registration is the measure of flow only when the meter
has been properly calibrated. After proper calibration, the meter will continue to
register correctly only if the propeller continues to make the proper number of cycles
for each unit of quantity passed through the meter. If any condition should develop
whereby the propeller is compelled to make fewer than the proper number of cycles
per unit of quantity passed through it, the meter will underregister. If the propeller
is compelled to make more than the proper number of cycles, the meter will overregister. Under ordinary working conditions, a number of factors may cause inaccurate
registration after comparatively short intervals. The more important of these are
excessive wear, extreme temperatures, corrosion, material in suspension, and the
presence of entrapped air in the lines.
Sec. A.4.1 Excessive Wear
Excessive wear of the moving parts of the meter may be caused by improper
setting, overspeeding, or the selection of a meter too small for the water demands.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
PROPELLER-TYPE METERS
13
The effects of excessive wear of the propeller are slippage and underregistration.
Excessive wear of the gear train may cause the gears to slip or bind. In either case,
if the meter does not stop entirely, underregistration will result. To avoid excessive
wear, meters should not be run at destructive speeds. The intermittent maximum
flow capacities given for meters in Table 1 of AWWA C704 are the maximum rates
of flow at which water should be passed through the meters for short periods of time
and at infrequent intervals. Maximum flow could be destructive if continuous. For
continuous 24-hour service, this type of propeller meter should not be operated at
flows greater than those shown for normal flow limits in Table 1 of AWWA C704.
Sec. A.4.2 Temperature Extremes
Cold-water meters are not affected by temperatures up to about 100°F (38°C).
Meters with slightly larger clearances than usual should be used, and the accuracy
limits of AWWA C704 may have to be modified for higher temperatures. High temperatures can cause expansion of the propeller in its setting. The result is slippage
and underregistration or complete stoppage of the meter. Lower temperatures have
no noticeable effect on the working parts of the meter unless the water freezes, in
which case damage may occur to the meter. To avoid problems caused by temperature extremes, meters should be located where they will be protected from heat and
freezing.
Sec. A.4.3 Corrosion
All the metals used in the construction of a meter are affected by the corrosive
action of water, although the action is very slow with most potable waters. It should
be recognized, however, that when meters are used in highly aggressive waters, it
may be necessary to use materials that are more resistant to corrosion. The solution
to corrosion problems requires a high degree of experience and knowledge, and the
manufacturer should be consulted for assistance.
Sec. A.4.4 Improper Installation
Propeller-meter registration accuracy can be assured only when the meter has
been properly installed and calibrated according to the manufacturer’s recommendations. Accuracy of registration and longevity of propeller meters depends on a
swirl-free, uniform flow-velocity profile both upstream and downstream of the meter.
Sec. A.4.5 Material in Suspension
Foreign material carried in suspension has a tendency to fill the space between
the propeller vanes and cause overregistration. Such overregistration is not limited
to propeller-type meters. Foreign material may also affect bearing operation causing
underregistration. Meter installations provided with strainers will retain the larger
particles in suspension, but the strainer will soon become clogged if the water is not
kept reasonably free from suspended matter. A partially clogged strainer causes
uneven flow distribution through the meter, resulting in registration error.
Sec. A.4.6 Entrained Air
All water meters will record the presence of entrained air in the lines as inaccurate registration. This inaccuracy may result in a substantial overregistration
under certain circumstances.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
14
AWWA C704-92
Table A.1 Average Recommended Intervals Between Meter Tests
Meter Size
in.
(mm)
Years Between
Tests*
2
(50)
3
(75)
4
(100)
6
(150)
and larger
4
3
2
1
*Years between tests based on normal use and conditions. Section A.5 and AWWA Manual M6 should be reviewed
completely before establishing a test-year interval for the individual utility.
SECTION A.5: PERIODIC TESTS
Meters properly selected as to size and type will give satisfactory service over a
long period of time without attention only if operated under ideal conditions. Under
ordinary conditions, meters must be given attention if they are to function properly.
In most cases, it is impossible to ascertain, without actual test, whether a meter in
service is registering with the required degree of accuracy. Consequently, to ensure
reliable meter measurements, it is essential that all meters be periodically tested.
The interval between tests and the method of conducting them must be governed
largely by local conditions. Many state regulatory commissions specify intervals
between tests on both a time and quantity basis. Under average conditions,
however, the intervals between tests should not exceed the limits set forth in Table A.1.
SECTION A.6: METER STORAGE
Meters should be stored in a location not subject to unduly high or low temperatures. If meters are to be stored outdoors for an extended period of time, they
should be covered to protect them from direct sunlight.
SECTION A.7: PLACING METER IN SERVICE
After the line has been thoroughly flushed and the meter installation completed, the service line and meter should be filled with water by slowly opening the
inlet valves and allowing trapped air to be released slowly at the highest point
available. Rapid expulsion of large slugs of entrained air should be avoided because
of possible damage to the meter’s internal measuring mechanism.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
This page intentionally blank.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
This page intentionally blank.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
This page intentionally blank.
Copyright (C) 1998 American Water Works Association, All Rights Reserved.
2P-3.5C-43704-7/98-MG
Printed on recycled paper.
Copyright © 1998 American Water Works Association, All Rights Reserved.