1、AWWA Standard SM Transit-Time Flowmeters in Full Closed Conduits Effective date: July 1, 2016. First edition approved by AWWA Board of Directors June 19, 2003. This edition approved Jan. 16, 2016. Approved by American National Standards Institute Feb. 17, 2016. ANSI/AWWA C750-16 (Revision of ANSI/AW
2、WA C750-10) Copyright 2016 American Water Works Association. All Rights Reserved.ii 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
3、 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 pub- lication of a standard does not constitute en
4、dorsement of any product or product type, nor does AWWA test, certify, or approve any product. The use of AWWA standards is entirely voluntary. This standard does not supersede or take precedence over or displace any applicable law, regulation, or code of any governmental authority. AWWA standards a
5、re 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 Official Notice section of Journal American Water Works A
6、ssociation. The action becomes effective on the first day of the month following the month of Journal American Water Works Association publication of the official notice. American National Standard An American National Standard implies a consensus of those substantially concerned with its scope and
7、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 that person has ap - proved the standard or not, from manufacturing, marketi
8、ng, 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 encour - aged to
9、 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 n oti Ce : The American National Standards Institute (ANSI) approval date on the front cover of this standar
10、d 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 Nati
11、onal Standards may receive current information on all standards by calling or writing the American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036; 212.642.4900; or emailing infoansi.org. ISBN-13, print: 978-1-62576-160-6 eISBN-13, electronic: 978-1-61300-380-0DOI
12、: http:/dx.doi.org/10.12999/AWWA.C750.16 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
13、 for review purposes, without the written permission of the publisher. Copyright 2016 by American Water Works Association Printed in USA hours of work by your fellow water professionals. Revenue from the sales of this AWWA material supports ongoing product development. Unauthorized distribution, eit
14、her electronic or photocopied, is illegal and hinders AWWAs mission to support the water community. This AWWA content is the product of thousands of Copyright 2016 American Water Works Association. All Rights Reserved.iii Committee Personnel The AWWA Subcommittee on Ultrasonic Devices, which develop
15、ed this standard, had the follow- ing personnel at the time: Jeff Smith, Chair J.J. Gemin, AECOM, Kitchener, Ont., Canada (AWWA) M.J. Keilty, Endress+Hauser Flowtec AG, Estes Park, Colo. (AWWA) M.D. Kyser, Professional Engineering Consultants P.A., Tulsa, Okla. (AWWA) J. Smith, Primary Flow Signal I
16、nc., Cranston, R.I. (AWWA) J.S. Trofatter, Duperon Corporation, Saginaw, Mich. (AWWA) The AWWA Committee on Rate Type Flowmeters, which reviewed and approved this standard, had the following personnel at the time: Joseph J. Gemin, Chair General Interest Members J.A. Casados, Instituto Mexicano de Te
17、cnologia del Agua, Progreso, Morelos, Mexico (AWWA) A. Dabak, Texas Instruments, Dallas, Texas (AWWA) D. Faber, Faber & Associates, Columbus, Ind. (AWWA) J.J. Gemin, AECOM, Kitchener, Ont., Canada (AWWA) A.M. Horbovetz, M.E. Simpson Company Inc., Valparaiso, Ind. (AWWA) F.S. Kurtz,* Standards Engine
18、er Liaison, AWWA, Denver, Colo. (AWWA) M.D. Kyser, Professional Engineering Consultants P.A., Tulsa, Okla. (AWWA) R.A. Richter, National Institute of Standards and Technology, Gaithersburg, Md. (AWWA) S.F. Sarrouh, T&M Associates, Dublin, Ohio (AWWA) J.S. Trofatter, Duperon Corporation, Saginaw, Mic
19、h. (AWWA) Producer Members R.A. Barillas, Badger Meter, Milwaukee, Wis. (AWWA) G.H. De Jarlais, Badger Meter, Milwaukee, Wis. (AWWA) M.J. Keilty, Endress+Hauser Flowtec AG, Estes Park, Colo. (AWWA) * Liaison, nonvoting Alternate Copyright 2016 American Water Works Association. All Rights Reserved.iv
20、 J.F. Panek Jr., McCrometer Inc., Rowley, Iowa (AWWA) J. Smith, Primary Flow Signal Inc., Cranston, R.I. (AWWA) D.C. Wyatt, Wyatt Engineering, Lincoln, R.I. (AWWA) User Members S. Carpenter, San Diego County Water Authority, Escondido, Calif. (AWWA) W.F. Dunnill, Consolidated Utility District of Rut
21、herford County, Murfreesboro, Tenn. (AWWA) P.A. Hayes, Mammoth Community Water District, Mammoth Lakes, Calif. (AWWA) A. Land, Dallas Water Utilities, Dallas, Texas (AWWA) S.U. Mills-Wright,* Standards Council Liaison, City of Arlington, Arlington, Texas (AWWA) S.Y. Tung, City of Houston, Houston, T
22、exas (AWWA) K. Whitaker, San Diego County Water Authority, San Diego, Calif. (AWWA) * Liaison, nonvoting Alternate Copyright 2016 American Water Works Association. All Rights Reserved.v Contents All AWWA standards follow the general format indicated subsequently. Some variations from this format may
23、 be found in a particular standard. SEC. PAGE SEC. PAGE Foreword I Introduction vii I.A Background . vii I.B History vii I.C Acceptance . viii II Special Issues ix II.A Chlorine and Chloramine Degradation of Elastomers . ix III Use of This Standard . x III.A Purchaser Options and Alternatives . x II
24、I.B Modification to Standard x IV Major Revisions . x V Comments x Standard 1 General 1.1 Scope 1 1.2 Purpose . 1 1.3 Application 1 2 References 2 3 Definitions . 2 4 Requirements 4.1 Materials . 3 4.2 Principles of Operation 3 4.3 Flowmeter Components 4 4.4 Acoustic Paths . 5 4.5 Performance Issues
25、 6 4.6 Impacts on Performance 8 5 Verification 5.1 Calibration Methods . 11 5.2 Field-Verification Techniques . 13 5.3 Calibration of Transducers and Electronic Components . 14 5.4 Calibration Traceability . 15 6 Delivery 6.1 Markings . 15 6.2 Packaging and Shipping 15 6.3 Affidavit of Compliance 15
26、 Appendixes A Purchaser Options . 17 B Transit-Time Formulas 19 Figures 1 Transit-Time Flowmeter 4 2 Wetted and Nonwetted Transducers . 5 3 Single-Path and Multipath Meters . 6 Tables 1 Transit-Time Ultrasonic Flowmeter Performance Criteria 7 A.1 Items to Consider in Selecting Transit-Time Flowmeter
27、s 17 Copyright 2016 American Water Works Association. All Rights Reserved.This page intentionally blank. Copyright 2016 American Water Works Association. All Rights Reserved.vii Foreword This foreword is for information only and is not a part of ANSI*/AWWA C710. I. Introduction. I.A. Background. The
28、 first water meter that was produced in the United States is thought to be a positive displacement meter that was fabricated in 1857. Since then, a number of other technologies and designs have been introduced to the water industry, each with its special characteristics. The ultrasonic flowmeter is
29、one of the latest additions to the industry. The use of ultrasonic flowmeters has received wide commercial acceptance since the 1970s. There are currently two distinct types of ultrasonic flowmeters available: Doppler-effect and transit-time. While the Doppler- effect meter is used extensively for w
30、ater and other liquids containing solid particles, the transit-time ultrasonic flowmeter is receiving increased acceptance in the water industry. I.B. History. In 1 985, the American Society of Mechanical Engineers (ASME) published the first standard for the transit-time ultrasonic (transit-time) fl
31、owmeters. The needs of the water industry differ, in some respects, from other industries, therefore necessitating the development of an AWWA standard for transit-time flowmeters. In 1990, the AWWA Standards Committee on Rate Type Flowmeters was formed to develop standards for transit-time meters. T
32、he Subcommittee on Ultrasonic Meters was later developed for this purpose. The subcommittee prepared a first draft of the transit-time flowmeter standard in 1992. The first draft was reviewed and commented on by the subcommittee members as well as members of the Rate Type Flowmeter Committee. Subseq
33、uent drafts were sent out to a number of transit-time flowmeter manufacturers in 1994 for their review and comments. A 1995 draft addressed these comments, where possible, and was distributed to all who had previously commented on the drafts. A revised draft was presented to the subcommittee in 1995
34、. The sub- committee met in January 1996 to finalize the standard. However, the subcommittee decided that leaving the draft open to the general public for review and comment, prior to finalizing the standard, would produce a more thorough standard. Journal AWWA was considered a suitable medium for r
35、eaching the water industry. The subcommittee changed the format of the standard into a Journal AWWA article that was published in the July 1997 edition of Journal AWWA as a Committee Report. The article encouraged * American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York,
36、NY 10036. American Society of Mechanical Engineers, 2 Park Avenue, New York, NY 10016-5990. Copyright 2016 American Water Works Association. All Rights Reserved.viii the public to comment on the contents of the Committee Report. A few written com- ments were received and were addressed in developing
37、 the final draft of the standard. On Jan. 19, 2003, the standard was approved by the AWWA Board of Directors. The second edition of ANSI/AWWA C750 was approved on Jan. 17, 2010, and this edition of the standard was approved on Jan. 16, 2016. I.C. Acceptance. In May 1985, the US Environmental Protect
38、ion 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 direct and indirect drinking water additives. Other members of the original consortium included the Water Rese
39、arch Foundation (formerly AwwaRF) and the Conference of State Health and Environmental Managers (COSHEM). The American Water Works Association (AWWA) and the Association of State Drinking Water Administrators (ASDWA) joined later. In the United States, authority to regulate products for use in, or i
40、n 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 referen
41、ces, 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 : NSF/ANSI 60, Drinking Water Treatment ChemicalsHealth Effects, and
42、NSF/ANSI 61, Drinking Water System ComponentsHealth 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
43、 in accor- dance with NSF/ANSI 61. Individual states or local agencies have authority to accept or accredit certification organizations within their jurisdictions. Accreditation of certi- fication organizations may vary from jurisdiction to jurisdiction. * Persons outside the United States should co
44、ntact the appropriate authority having jurisdiction. NSF International, 789 North Dixboro Road, Ann Arbor, MI 48105. American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036. Both publications available from National Academy of Sciences, 500 Fifth Street, NW, Wash
45、ington, DC 20001. Copyright 2016 American Water Works Association. All Rights Reserved.ix Annex A, “Toxicology Review and Evaluation Procedures,” to NSF/ANSI 61 does not stipulate a maximum allowable level (MAL) of a contaminant for substances not regulated by a USEPA final maximum contaminant level
46、 (MCL). The MALs of an unspecified list of “unregulated contaminants” are based on toxicity testing guidelines (noncarcinogens) and risk characterization methodology (carcinogens). Use of Annex A procedures may not always be identical, depending on the certifier. In an alternative approach to inadve
47、rtent drinking water additives, some jurisdic- tions (including California, Louisiana, Maryland, and Vermont, for example) have called for reduced lead limits for materials in contact with potable water. Various third- party certifiers have been assessing products against these lead content criteria
48、, and a new ANSI-approved national standard, NSF/ANSI 372, Drinking Water System ComponentsLead Content, was published in 2010. On Jan. 4, 2011, legislation was signed revising the definition for “lead free” within the Safe Drinking Water Act (SDWA) as it pertains to “pipe, pipe fittings, plumbing f
49、ittings, and fixtures.” The changes went into effect on Jan. 4, 2014. In brief, the new provisions to the SDWA require that these products meet a weighted average lead con- tent of not more than 0.25 percent. ANSI/AWWA C750 does not address additives requirements. Users of this stan- dard 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 parties offering to certify products for contact with, or trea
