1、Quarter- Turn Valves: Head Loss, Torque, and Cavitation Analysis Third Edition M49 Incorporates errata dated May 1, 2017Printed on recycled paper Printed in the United States of America American Water Works Association 6666 West Quincy Avenue Denver, CO 80235-3098 awwa.org hours of work by your fell
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3、r Supply PracticesM49, Third Edition Quarter-Turn Valves: Torque, Head Loss, and Cavitation Analysis Copyright 2001, 2012, 2017, 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, i
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5、f the content or any consequences of its use. In no event will AWWA be liable for direct, indirect, special, incidental, or consequential damages arising out of the use of information presented in this book. In particular, AWWA will not be responsible for any costs, including, but not limited to, th
6、ose incurred as a result of lost revenue. In no event shall AWWAs liability exceed the amount paid for the purchase of this book. Project Manager: Melissa Valentine Production: Studio Text Cover Design: Melanie Yamamoto Manuals Specialist: Sue Bach Library of Congress Cataloging-in-Publication Data
7、Names: Bosserman, Bayard E., II, author. | Holstrom, John R., author. |American Water Works Association, editor. Title: M49, quarter-turn valves : head loss, torque, and cavitation analysis/ by B.E. Bosserman and John R. Holstrom. Other titles: Quarter-turn valves Description: Third edition. | Denve
8、r, CO : American Water Works Association,2017 | Series: Manual M49 | Includes bibliographical references andindex. Identifiers: LCCN 2017001678 | ISBN 9781625762061 Subjects: LCSH: Water-pipes-Valves. Classification: LCC TD491 .B67 2017 | DDC 628.1/5-dc23 LC record available at https:/lccn.loc .gov/
9、2017001678 ISBN-13 978-1-62576-206-1 eISBN-13 978-1-61300-406-7iii AWWA Manual M49 Contents List of Figures, v List of Tables, vii Preface, ix Acknowledgments, xi Chapter 1 Introduction 1 Scope, 2 New Defi nitions, MRST and AST, 2 Diameter Assumptions, 3 Quarter-Turn Valve Design, 4 System Condition
10、s, 9 Defi nitions, 11 References, 13 Chapter 2 Valve Head Loss and Equivalent Resistance System Model 15 Discussion of Head Loss, Choking, and Cavitation, 15 Defi nitions, 16 Head Loss Calculations, 20 Reducer Installations, 23 Inherent and Installed Control Valve Flow Characteristics, 25 Equivalent
11、 Resistance System Model, 26 Variable Head Source Methodology, 31 Energy Calculations, 32 References, 35 Chapter 3 Valve Torque 37 Discussion of Torque Calculations, 37 Defi nitions, 39 Combining Torque Components, 42 Seating and Unseating Torque, 46 Packing and Hub Torque, 50 Bearing Torque, 51 Cen
12、ter of Gravity Torque, 55 Hydrostatic Torque, 56 Dynamic Torque, 58 Shaft Off set or Eccentricity Torque, 60 Other Components of Torque, 65 System Characteristics, 72 References, 76 Chapter 4 Valve Cavitation 77 Defi nitions, 77 Predicting Cavitation, 79 Cavitation Calculation Methodology Example, 8
13、2 Methods of Reducing Cavitation, 84 References, 84iv QUARTER-TURN VALVES: HEAD LOSS, TORQUE, AND CAVITATION ANALYSIS AWWA Manual M49 Chapter 5 Valve Testing 85 Uncertainty, 85 Testing Requirements, 86 Test Procedure, 87 Seating/Unseating Test Procedure, 93 References, 95 Chapter 6 Valve Application
14、s 97 Actuator Sizing, 97 Extended Bonnet Installation, 100 Effects of Pipe Installations, 101 Typical Range of Some Coefficients, 111 Cautions, 113 Summary, 114 References, 115 Appendix A, 117 Appendix B, 119 Appendix C, 121 Index, 129 List of Manuals, 133v AWWA Manual M49 Figures 1-1 Valve disc, po
15、rt, and pipe diameters, 4 1-2 Typical ball valve construction, 6 1-3 Typical butt erfl y valve construction, 7 1-4 Typical plug valve construction, 8 1-5 Typical rotary cone valve construction, 9 1-6 Butt erfl y valve off set designs, 10 1-7 Free discharge and reservoir inlet installations of BFVs,
16、11 2-1 Typical quarter-turn valve fl ow, diff erential pressure, cavitation, and choking graphical explanation, 17 2-2 Smaller-than-line-sized butt erfl y valve installation, 22 2-3 Reducer geometry, 23 2-4 Typical inherent valve characteristics, 26 2-5 Installed valve characteristics, 26 2-6 Equiva
17、lent resistance system model, 27 2-7 Example equivalent resistance system model diagram, 30 2-8 Graphical relationship between head loss and velocity, 31 2-9 Comparative operating costs by valve type, 34 3-1 Basic closure member design geometries, 40 3-2 Horizontal valve shaft in a horizontal pipe,
18、41 3-3 Seat-side, reverse, and shaft-side direct fl ow direction orientations, 42 3-4 Active torque sign convention; positive values tend to close the valve, 42 3-5 Dynamic torque (T d ) and bearing torque (T b ) during valve closure, 45 3-6 One-, two-, and three-pump system operating curves, 45 3-7
19、 Multiple-pump installation; example shown with butt erfl y valves, 46 3-8 Butt erfl y valve seating torque, 46 3-9 Plug valve seat perimeter and port area, 48 3-10 Butt erfl y valve packing and hub seal torque (T p ), 50 3-11 Bearing friction torque (T b ), 52 3-12 Center of gravity torque (T cg ),
20、 55 3-13 Hydrostatic torque (T h ), 57 3-14 Dynamic torque (T d ) for a symmetrical disc butt erfl y valve, 59 3-15 Dynamic torque coeffi cient (C t ) graph for butt erfl y valves with symmetrical and off set closure members, 60 3-16 Dynamic torque (T d ) for a butt erfl y valve with symmetric and o
21、ff set discs, 61 3-17 Total opening torque (T to ) for a 20-in. to 30-in. butt erfl y valve with symmetric and off set discs (in both fl ow directions), 61vi QUARTER-TURN VALVES: HEAD LOSS, TORQUE, AND CAVITATION ANALYSIS AWWA Manual M49 3-18 Total opening torque (T to ) for a 78-in. to 96-in. butte
22、rfly valve with symmetric and offset discs (in both flow directions), 62 3-19 Total closing torque (T tc ) for a 20-in. to 30-in. butterfly valve with symmetric and offset discs, 62 3-20 Total closing torque (T tc ) for a 78-in. to 96-in. butterfly valve with symmetric and offset discs, 63 3-21 Shaf
23、t offset or eccentricity torque (T ecc ), 63 3-22 Bearing torque caused by closure member and shaft(s) weight orientation angles, 66 3-23 Center of gravity torque pipe angle definition, 68 3-24 Valve shaft and pipe orientation from vertical axis for center of gravity torque, 68 3-25 Valve shaft and
24、pipe orientation from vertical axis for hydrostatic and bearing torque, 70 3-26 Example torque calculation summary graph, 75 4-1 Cavitation zones downstream of a butterfly valve disc, 78 4-2 Typical cavitation index levels and acceleration readings, 80 4-3 Flow rate and acceleration readings, 80 4-4
25、 Typical cavitation index values for a 6-in. (150-mm) butterfly valve (Reference upstream pressure from laboratory test = P ut= 70 psi, vapor pressure from laboratory test = P vt= 12 psi), 81 4-5 Example cavitation analysis summary graph, 83 5-1 Basic flow test system, 87 5-2 Butterfly valve test in
26、stallation, 88 6-1 Typical actuator torque characteristics, 99 6-2 Typical ball valve construction, 99 6-3 Scotch yoke traveling nut actuator cutaway, 99 6-4 Link-and-lever traveling nut actuator cutaway, 100 6-5 Actuator sizing characteristics graph, 101 6-6 Typical extended bonnet construction, 10
27、2 6-7 Vertical elbow upstream of a butterfly or other quarter-turn valve preferred installation orientation, 104 6-8 Upstream expansion orientation preferences, 105 6-9 Upstream orifice orientation preferences, 106 6-10 Upstream reducer orientation preferences, 107 6-11 Upstream check valve preferre
28、d installation orientation, 107 6-12 Series-mounted valve preferred installation orientation, 108 6-13 Combined improper orientations, 108 6-14 Plug valve preferred installation orientation for suspended solids applications, 111 B-1 Seating torque free body diagram, 119vii AWWA Manual M49 Tables 2-1
29、 Reducer and Increaser Calculations, 25 2-2 Valve Reducer, and Increaser Assembly Adjusted Flow Coeffi cients, 25 2-3 Head Loss Calculation Data for Constant Head Source Example, 30 2-4 Annual Pumping Cost Example Calculation, 33 3-1 Torque Component Category, 38 3-2 Torque Calculation Data for Cons
30、tant Head Source Example, 75 4-1 Cavitation Calculation Data for Constant Head Source Example, 83 6-1 Typical Bearing Friction Coeffi cients, 112 6-2 Typical Packing Coeffi cients, 112 6-3 Typical Seating Coeffi cients, 112 6-4 Typical Full-Open Flow Coeffi cients, 113 C-1 Nomenclature, terms, and s
31、ymbols, 121 C-2 Conversion of units, 128 C-3 Abbreviations, 128This page intentionally blank.ix AWWA Manual M49 Preface The purpose of this manual is to present a recommended method for calculating operating torque, head loss, and cavitation for quarter-turn valves typically used in water works ser-
32、 vice. It is a discussion of recommended practice, not an American Water Works Association (AWWA) standard. The text provides guidance on generally available methods for using quarter-turn valves as well as their cavitation, fl ow, and torque characteristics. Questions about specifi c situations or
33、applicability of specifi c valves and values should be directed to the manufacturers or suppliers. Information in this manual is useful for technicians and engineers who want a basic understanding of the calculations associated with the use and specifi cation of quarter-turn valves. The valve torque
34、, fl ow, and cavitation coeffi cients given are typical but generic values covering a variety of products. Actual fl ow, cavitation, or torque coeffi cients for a particular manufacturers valve should be used in calculations for a specifi c valve and application to obtain the highest calculation acc
35、uracy. The history of this manual is related to that of American National Standards Institute ANSI/AWWA C504, Standard for Rubber-Seated Butt erfl y Valves. Until the 1994 edition, ANSI/AWWA C504 included Appendix A, which described a recommended method of calculating torques for butt erfl y valves.
36、 This appendix was deleted from the 1994 and subsequent editions of the standard for several reasons. The AWWA Standards Council directed that standards documents should not contain appendixes; appendix text should either be moved to the main body of the standard or be made into a separate, stand-al
37、one document. Members of the committ ee for ANSI/AWWA C504 at the time were concerned that the existing text of Appendix A no longer represented the cur- rent state of knowledge concerning methods for calculating torques for butt erfl y valves. In 1993, a subcommitt ee was established to rewrite App
38、endix A as a separate manual incorporating the state-of-the-art theory for calculating torque and head loss values for butt erfl y valves. The second edition of the manual expanded the introduction and some equations, added torque sign conventions, added double-off set disc design variables and calc
39、ulations, added equations for eccentricity torque, added metric units and equiva- lents, consolidated the nomenclature, and corrected some errors. This third edition man- ual broadens the application of these methods to include other quarter-turn valves such as ball, plug, and rotary cone valves. Ma
40、nual M49 refers to AWWA standards available for purchase from the AWWA Bookstore. Manufacturers graciously provided valve illustrations and other documenta- tion. AWWA does not endorse any manufacturers products, and the names of the manu- facturers have been removed from the material provided. This
41、 page intentionally blank.xi AWWA Manual M49 Acknowledgments The AWWA Standards Council Committ ee for Butt erfl y Valves developed this manual with input from the Ball & Plug Valve Committ ees. The members listed below served on the Butt erfl y Valve Committ ee at the time the manual was approved.
42、. M. MacConnell, Chair, Metro Vancouver, Canada User Members S. Carpenter, San Diego County Water Authority, Escondido, Calif. D.W. Coppes, Massachusett s Water Resources Authority, Chelsea, Mass. S. Hatt an, Tarrant Regional Water Dist., Ft. Worth, Texas V.Q. Le, Los Angeles Water & Power, Los Ange
43、les, Calif. M. MacConnell, Metro Vancouver, Burnaby, BC, Canada P.J. Ries, Denver Water, Denver, Colo. S.Y. Tung, City of Houston, Houston, Texas General Interest Members A. Ali, ADA Consulting Ltd., Surrey, B.C. M.D. Bennett , MWH, Cleveland, Ohio B.E. Bosserman, Mission Viejo, Calif. J. W. Green,*
44、 Lockwood, Andrews & Newnam, Inc., Oakbrook Terrace, Ill. J. Hebenstreit, UL LLC, Northbrook, Ill. F.L. Hinker, Santa Rosa, N.M. M.C. Johnson, Utah State University, Water Research Lab, Logan, Utah T. Jordan, HDR Inc., Denver, Colo. T.J. McCandless, American Water Works Association, Denver, Colo. D.
45、 Middleton,* AECOM, Wakefi eld, Mass. J.N. Nakashima, Lockwood, Andrews & Newnam, Inc., Oakbrook Terrace, Ill. W. Rahmeyer,* Utah State University, Water Research Lab, Logan, Utah U. Sant, AECOM, Dallas, Texas R.A. Ward, Tighe & Bond, Westfi eld, Mass. Producer Members A. Abouelleil, Henry Pratt Com
46、pany, Aurora, Ill. S. Allen, Bray Valves, Jonesboro, Ariz. J.V. Ballun, Val-Matic Valve & Manufacturing Corp., Elmhurst, Ill. K.R. Grae ,* Rodney Hunt Company, Orange, Mass. T.A. Hartman, Hartman Valve Corp., St. Louis, Mo. * Alternate Liaisonxii QUARTER-TURN VALVES: HEAD LOSS, TORQUE, AND CAVITATIO
47、N ANALYSIS AWWA Manual M49 H. Herold, V AG, Mannheim, Germany J.R. Holstrom,* Sub-committee chair, Val-Matic Valve & Manufacturing Corp., Elmhurst, Ill. K. Johnson, M&H Valve Company, Anniston, Ala. A.W. Libke, DeZURIK, Sartell, Minn. R. Tschida,* DeZURIK, Sartell, Minn. J.H. Wilber, American AVK, L
48、ittleton, Colo. D. Woollums,* Mueller Group, Chattanooga, Tenn. The AWWA Standards Council Subcommittee for Addition of Ball and Plug Valves assisted in the development of this manual. The members listed below served on the subcommittee at the time the manual was approved. John R. Holstrom , Subcommittee Chair , Elmhurst , Ill. A. Abouelleil, Henry
