Water Meters - Selection, Installation, Testing, and Maintenance - Manual of Water Supply Practices, M6 (4th Edition)

134 Pages·1999·24.44 MB·English

by  Awwa

Water Meters-
Selection, Installation,
Testing, and Maintenance
MANUAL OF WATER SUPPLY PRACTICES-M6, Fourth Edition
AWWA MANUAL M6
Fourth Edition
A \
I
F 0 y 8 y 8
American Water Works Association
Copyright (C) 1999 American Water Works Association All Rights Reserved
MANUAL OF WATER SUPPLY PRACTICES-M6, Fourth Edition
Water Meters-Selection, Installation, Testing, and Maintenance
Copyright 0 1999 American Water Works Association
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any
means, electronic or mechanical, including photocopy, recording, or any information or retrieval system,
except in the form of brief excerpts or quotations for review purposes, without the written permission
of the pubiisher.
Project Manager and Editor: Sharon Pellowe
Production Editor: Michael Malgrande
Library of Congress Catalogingin-Publication Data
Water meters -- selection, installation, testing, and maintenance. -- 4th ed.
p. cm. -- (AWWA manual ; M6)
Includes bibliographical references and index.
ISBN 1-58321-017-2
1. Water-meters. I. Series. 11. American Water Works Association.
TD49LA49 no. M6 1999
[TD499]
628,1'4421--dc21
99-044930
CIP
Printed in the United States of America
American Water Works Association
6666 West Quincy Avenue
Denver. CO 80235
ISBN 1-58321417-2 Printed on recycled paper
Copyright (C) 1999 American Water Works Association All Rights Reserved
Figures
1-1 Roman adjutage, 4
1-2 Pitot tube, 7
1-3 Modified Pitot tube, 7
1-4 Improved form of the Woltman meter, 8
1-5 Cutaway of an “open or interchangeable” Woltman-type turbine meter, 8
1-6 Cutaway of a “closed” Woltman-type turbine meter with magnetic drive, 9
1-7 Original form of the Woltman meter, 9
1-8 Class I turbine meter, 10
1-9 Class I1 turbine meter, 11
1-10 Venturi tube, 11
1-11 Orifice meter and differential pressure sensing mercury manometer
instrument, 13
1-12 Original duplex-piston meter, 14
1-13 Early rotary-piston meter, 15
1-14 Displacement-type oscillating-piston meter with magnetic drive, 16
1-15 Displacement-type nutating-disc meter with magnetic drive, 17
1-16 Cutaway of a plastic-body small-disc meter, 17
1-17 Cutaway of a dry-head multi-jet meter without a “frost protection” device, 18
1-18 Cutaway of a dry-head multi-jet meter with a patented “frost protection”
device, 18
1-19 Compound meter, double-register type, 19
1-20 Compound meter, single-register type, 20
1-21 Fire-service meter, 21
1-22 Propeller meter, 22
1-23 Typical plastic-body small-disc meter, 26
4- 1 Two types of meter setters for vertical indoor piping, 41
4-2 Outdoor meter settings with integral yoke (left) and meter yoke (right), 42
4-3 Manifold of large meters, 44
4-4 Diagram of manifold of three large meters, 44
4-5 Flanged water meter setter, 45
4-6 Optimum turbine meter installation, 46
5-1 Effect of modifying change-gear combinations in typical 5/s-in. (15-mm)
meter, 48
5-2 Basic requirements for a volumetric meter-testing assembly, 64
V
Copyright (C) 1999 American Water Works Association All Rights Reserved
5-3 Rotameter rate-of-flow indicator, 65
5-4 Test benches for small meters, 66
5-5 Test bench for l'h-in. (40-mm) and 2-in. (50-mm) meters, 66
5-6 Testing of large meters, 67
5-7 Large meter testing facility, 67
5-8 Detail of calibration scale of testing tank and sectional view of tank with
outlet valve, 69
5-9 Automatic cutoff valve, 71
5-10 Large multiple-test table, 72
5-11 Field testing flanged meters, 74
5-12 Field-test apparatus for small meters, 75
5-13a Mobile meter test van, 76
5-13b Mobile test van automatic control panel, 76
6-1 Dismantling and cleaning of meters in shop, 81
6-2 Opening of disc chamber and gauging of chamber ball socket, 84
6-3 Examination and assembly of chamber and disc, 85
6-4 Inspection and gauging of oscillating piston and chamber, 87
7- 1 Cart for moving and storing meters, 95
7-2 Suggested layout for small-size repair shop, 97
7-3 Suggested layout for medium-size repair shop, 98
7-4 Suggested layout for larger-size repair shop, 99
8- 1 Meter history record, 103
8-2 Service order, 103
8-3 Report of meter test and repairs, 104
9- 1 Three versions of direct-reading remote-register systems, 110
9-2 Typical remote encoding meter-reading system, 111
vi
Copyright (C) 1999 American Water Works Association All Rights Reserved
Tables
2- 1 Types of meters for water measurement, 30
3-1 Elevation above supply main-elevation head, 34
3-2 Comparison of computed water flow friction losses for service line,psilft, 35
3-3 Computed pressure losses for service components, psi, 36
3-4 Discharge from fixtures and faucets at various operating pressures, 37
4- 1 Large meter installation guides for compound meters and class I and I1 turbine
meters, 43
5- 1 Required accuracy limits for compliance with guidelines, 49
5-2 State public service commission regulations for periodic testing of water
meters as of Nov. 30, 1994, 53
5-3 Test requirements for new, rebuilt, and repaired cold-water meters, 54
5-4 Percentage re7! 'stration tables for test quantities other than 10, 100, or
1,000 gal or ft , 58
5-5 1989 sample test meters test results-set date, 61
5-6 1989 sample test meters test results-purchase date, 62
5-7 1989 sample test meters test results-consumption, 63
8- 1 Meter information system-basic data requirements, 102
vii
Copyright (C) 1999 American Water Works Association All Rights Reserved
Foreword
This manual is a guide to selecting, installing, testing, and maintaining water
meters. The manual discusses recommended practices; it is not an AWWA standard
calling for compliance with certain specifications. It is intended for use by new and
existing utilities of all sizes, either as a textbook for those not fully familiar with
meters or as a reference manual. Water utilities may use this manual as a tool to
obtain the best revenue for their investment in meters and maintenance facilities.
Design engineers and consultants may use this manual in laying out new meter
installations or repair shops.
Most readers will first use this manual for assistance on an individual prob-
lem; however, for adequate knowledge of the field of water meter usage, the entire
manual should be studied. This manual references applicable AWWA standards for
the various types of meters. Copies of these standards may be purchased from the
AWWA Customer Service Department.
The AWWA manual on water meters was first published in a series of articles
in the June, July, August, and September 1959 Journal AWWA and was issued as a
separate reprint in 1962. A second edition of the manual was published in 1973, as
a complete revision, updating and substantially enlarging the 1962 serial edition.
The third edition was published in 1986 and included substantial updates to the
text and photographs. The fourth edition contains current information from the lat-
est meter standard revisions. Since 1986, much has changed in meter reading tech-
nology, and the future holds even greater promise. Although current at time of
publication, the rate of advancement in the area of meter reading virtually assures
an early obsolescence of this edition.
ix
Copyright (C) 1999 American Water Works Association All Rights Reserved
Contents
List of Figures, v
List of Tables, vii
Foreword, ix
Acknowledgments, xi
Chapter 1 History of Water Measurement and Development of
Water Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Introduction, 1
Water Supply in Ancient Times, 1
Measuring Devices of More Recent Times, 6
Acceptance of Meters by Water Utilities, 23
Standardization, 23
Remote-Reading Devices, 25
Plastic Parts and Components, 27
Chapter 2 Selecting Meter Types . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Introduction, 29
Small Flows, 30
Medium Flows, 30
Large Flows, 31
Chapter 3 Effects of Water-Flow Friction, Increased Usage, and
Pressure Losses on Service Adequacy . . . . . . . . . . . . . . . . . . . . 33
Introduction, 33
Factors to Consider in Sizing Mains, 33
Friction-Loss Data, 35
Sample Service Installation Calculation, 36
Chapter 4 Meter Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
,
Introduction, 39
Indoor Versus Outdoor Settings, 39
Meter Installation, 40
Chapter 5 Testing of Meters-Test Procedures and Equipment . . . . . . 47
Introduction, 47
Accuracy Limits, 48
Testing New Meters, 51
Field Testing, 72
Chapter6 MaintenanceandRepairofDisplacementMeters . . . . . . . . 79
Introduction, 79
Meter Replacement, 80
Meter Maintenance and Repair, 80
Disassembling, 82
Disc Meters With Three-Part Chambers, 86
...
111
Copyright (C) 1999 American Water Works Association All Rights Reserved
Oscillating-Piston Meters, 86
Mechanical-Drive Meter Reassembly, 88
Repair of Magnetic-Drive Meters, 89
Conclusion, 90
Chapter 7 Maintenance Shop Layout and Equipment
Introduction, 91
Meter Shop Equipment, 92
Shop Layout, 94
Chapter 8 Meter Records . . . . . . . . .
Introduction, 101
Elements of a Good Record System, 101
Paper Meter Records, 105
Summary, 105
Chapter 9 Remote Registration . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Introduction, 107
Advantages of Remote Registration, 107
Factors Affecting Remote Registration, 108
Direct-Reading, Remote-Register System, 108
Encoder-Type, Remote-Register System, 109
Future of Remote Registration, 112
Appendix A Bibliography
Index, 117
Copyright (C) 1999 American Water Works Association All Rights Reserved
History of Water
Measurement and
Development of
Water Meters
I NTRO D UC TI 0N
Accurate water measurement is the means by which water utilities produce revenue
to cover expenses, charge each customer equitably, prevent waste of water, and mini-
mize the load on wastewater facilities. This concept is universally accepted today, but
it took thousands of years for the science of water supply and distribution to reach its
present state.
WATER SUPPLY IN ANCIENT TIMES
Early developments in water supply were described by the late Charles G. Richardson
in his article, “The Measurement of Flowing Water.”* The following excerpts describe
water measurement in ancient Roman times.
A 1953 article in German, entitled “Hundert Jahre Wassermessung,” by engineer
Martin Schaack of Karlsruhe, described in detail the early attempts to measure water.
Of interest are the following paragraphs:
*The Measurement of Flowing Water, Water and Sewage Works, 102:379 (1955).
1
Copyright (C) 1999 American Water Works Association All Rights Reserved
2 WATER METERS-SELECTION, INSTALLATION, TESTING, AND MAINTENANCE
If one will take an extensive view of the progress of the technique of water
meters, one will not overlook antiquity.
A water meter which has been operating for 3,000 years, in the Oases
Gadames in North Africa, divides into equal parts the quantity of water
served from the spring to the inhabitants of the farms. The procedure is as
follows: A man pulls a pot of water on a cord from the spring ground. The
pot has a hole, from which the water runs out again, a procedure which
lasts 3 min. Each land proprietor gets water from the spring until the
number of full pots. . . that the water commission allows him [is reached].
The man at the spring knows the irrigation program, and when the turn
for the next land proprietor comes, he throws a piece of straw in the drain.
When the piece of straw arrives at the piece of land, which . . . should be
irrigated, the owner opens a sluice gate that lets the water flow to his field
and stops, by means of another sluice gate, the flow to the . . . irrigated plot
of land. In this way, a fair division is given to all.
Exhaustive research on the jurisdiction of ancient water supplies has given
us a composite picture of this technique, before which we stand in
admiration.
Babylon, a two-stream land, was the first of the ancient granaries that had
an irrigation program. The water of the Euphrates and the Tigris led
alternately from one stream to the other-that is, the water flowed in a
standard difference, one time from the Tigris to the Euphrates, and
another time from the Euphrates to the Tigris, over and over again. It is
not out of the question that the Tower of Babel, besides its well-known
meaning as a temple, was also a signal station from which this water
distribution was assessed. It was a technique which, in today’s regulation
of water supply of the Ruhr and in Holland, has a very similar parallel.
Chinese and Egyptian well builders have produced significant results
(wells up to 500 meters deep). The British were astonished, after having
conquered the Indians, to find power catchments of 80,000,000 cubic meter
capacity; dam length, 20 kilometers; dam height, 6 meters; which compare
favorably with dams of today. These arrangements were made, of course,
without today’s technical knowledge.
Roman Adjutages
For nearly half a century, until 313 B.C., the citizens of Rome were content to draw their
water supply from the Tiber River, wells, and springs. As in our own times, such sources
became entirely inadequate to meet the needs of a rapidly growing city, and the first
of the great aqueducts, the Appian, was constructed. This was followed 40 years later
by the Anio Vetus and during the next three centuries by seven other aqueducts.
All of these aqueducts are described in meticulous detail by Water Commissioner
Frontinus in his two books ofDeAquis Urbis Romae (translated into English by Clem-
ens Herschel under the title The Water Supply ofthe City of Rome).
The contributions made by Frontinus cannot be overstated. The office of water
commissioner (approximately 35 to 104 AD.) was held, from ancient times, by the
most distinguished citizens. Frontinus set an example for all future water commis-
sioners to follow in his honest devotion to duty, thoroughness of accomplishment, and
sterling character. Those who read his voluminous report today can still profit and are
Copyright (C) 1999 American Water Works Association All Rights Reserved