McGraw Hill Piping Handbook
Trang 2PIPING HANDBOOK
ASME Fellow
The sixth edition of this Handbook was edited by
Mohindar L Nayyar, P.E.
The fifth edition of this Handbook was edited by
Reno C King, B.M.E, M.M.E., D.Sc., P.E.
Professor of Mechanical Engineering and Assistant Dean,
School of Engineering and Science, New York University
Registered Professional Engineer
The first four editions of this Handbook were edited by
Sabin Crocker, M.E.
Fellow, ASME: Registered Professional Engineer
Trang 3Library of Congress Cataloging-in-Publication Data
Copyright 1930, 1931, 1939, 1945 by McGraw-Hill, Inc All Rights Reserved Printed in the United States of America No part of this publication may be reproduced, stored in a retrieval system, or
transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher.
Copyright renewed 1973, 67, and 59 by Sabin Crocker All rights reserved.
1 2 3 4 5 6 7 8 9 0 DOC/DOC 9 0 9 8 7 6 5 4 3 2 1 0 9
ISBN 0-07-047106-1
The sponsoring editor for this book was Linda Ludewig, the editing supervisor was Peggy Lamb, and the production supervisor was Sherri Souffrance This book was set in Times Roman by the PRD Group Printed and bound by R R Donnelley & Sons Company.
Information contained in this work has been obtained by The
McGraw-Hill Companies, Inc (‘‘McGraw-Hill’’) from sources
believed to be reliable However, neither McGraw-Hill nor
its authors guarantees the accuracy or completeness of any
information published herein and neither McGraw-Hill nor
its authors shall be responsible for any errors, omissions, or
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This book is printed on acid-free paper
Trang 4Other McGraw-Hill Handbooks of Interest
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Bleier ⭈ FAN HANDBOOK
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Eckhardt ⭈ KINEMATIC DESIGN OF MACHINES AND MECHANISMS
Elliott et al. ⭈ STANDARD HANDBOOK OF POWERPLANT ENGINEERING
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Lingaiah ⭈ MACHINE DESIGN DATA HANDBOOK
Parmley ⭈ STANDARD HANDBOOK OF FASTENING AND JOINING
Rohsenow ⭈ HANDBOOK OF HEAT TRANSFER
Rosaler ⭈ STANDARD HANDBOOK OF PLANT ENGINEERING
Rothbart ⭈ MECHANICAL DESIGN HANDBOOK
Shigley & Mischke ⭈ STANDARD HANDBOOK OF MACHINE DESIGN
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For more information about McGraw-Hill materials,
call 1-800-2-MCGRAW in the United States In other
countries, call your nearest McGraw-Hill office.
Trang 5Preface xvii
Chapter A1 Introduction to Piping Mohinder L Nayyar A.1
Chapter A2 Piping Components Ervin L Geiger A.53
Chapter A3 Piping Materials James M Tanzosh A.125
Chapter A4 Piping Codes and Standards Mohinder L Nayyar A.179
Chapter A5 Manufacturing of Metallic Piping Daniel R Avery and
Alfred Lohmeier A.243
Chapter A6 Fabrication and Installation of Piping Edward F Gerwin A.261
Chapter A8 Prestressed Concrete Cylinder Pipe and Fittings
Richard E Deremiah A.397
Chapter A9 Grooved and Pressfit Piping Systems
Louis E Hayden, Jr. A.417
v
Trang 6vi CONTENTS
Chapter A10 Selection and Application of Valves Mohinder L Nayyar,
Dr Hans D Baumann A.459
Chapter B1 Hierarchy of Design Documents Sabin Crocker, Jr. B.1
Chapter B3 Piping Layout Lawrence D Lynch,
Charles A Bullinger, Alton B Cleveland, Jr. B.75
Chapter B4 Stress Analysis of Piping Dr Chakrapani Basavaraju,
Dr William Saifung Sun B.107
Chapter B5 Piping Supports Lorenzo Di Giacomo, Jr.,
Jon R Stinson B.215
Chapter B6 Heat Tracing of Piping Chet Sandberg,
Joseph T Lonsdale, J Erickson B.241
Chapter B7 Thermal Insulation of Piping Kenneth R Collier,
Kathleen Posteraro B.287
Chapter B8 Flow of Fluids Dr Tadeusz J Swierzawski B.351
Chapter B9 Cement-Mortar and Concrete Linings for Piping
Richard E Deremiah B.469
Chapter B10 Fusion Bonded Epoxy Internal Linings and External
Coatings for Pipeline Corrosion Protection Alan Kehr B.481
Chapter B11 Rubber Lined Piping Systems Richard K Lewis,
David Jentzsch B.507
Trang 7CONTENTS vii
Chapter B12 Plastic Lined Piping for Corrosion Resistance
Michael B Ferg, John M Kalnins B.533
Chapter B13 Double Containment Piping Systems
Christopher G Ziu B.569
Chapter B14 Pressure and Leak Testing of Piping Systems
Robert B Adams, Thomas J Bowling B.651
Chapter C1 Water Systems Piping Michael G Gagliardi,
Louis J Liberatore C.1
Chapter C2 Fire Protection Piping Systems Russell P Fleming,
Daniel L Arnold C.53
Chapter C3 Steam Systems Piping Daniel A Van Duyne C.83
Chapter C4 Building Services Piping Mohammed N Vohra,
Paul A Bourquin C.135
Chapter C5 Oil Systems Piping Charles L Arnold, Lucy A Gebhart C.181
Chapter C6 Gas Systems Piping Peter H O Fischer C.249
Chapter C7 Process Systems Piping Rod T Mueller C.305
Chapter C8 Cryogenic Systems Piping Dr N P Theophilos,
Norman H White, Theodore F Fisher, Robert Zawierucha,
M J Lockett, J K Howell, A R Belair, R C Cipolla,
Raymond Dale Woodward C.391
Chapter C9 Refrigeration Systems Piping William V Richards C.457
Trang 8viii CONTENTS
Chapter C10 Hazardous Piping Systems Ronald W Haupt C.533
Chapter C11 Slurry and Sludge Systems Piping Ramesh L Gandhi C.567
Chapter C12 Wastewater and Stormwater Systems Piping
Dr Ashok L Lagvankar, John P Velon C.619
Chapter C13 Plumbing Piping Systems Michael Frankel C.667
Chapter C14 Ash Handling Piping Systems Vincent C Ionita,
Joel H Aschenbrand C.727
Chapter C15 Compressed Air Piping Systems Michael Frankel C.755
Chapter C16 Compressed Gases and Vacuum Piping Systems
Michael Frankel C.801
Chapter C17 Fuel Gas Distribution Piping Systems Michael Frankel C.839
Chapter D1 Thermoplastics Piping Dr Timothy J McGrath,
Stanley A Mruk D.1
Chapter D2 Fiberglass Piping Systems Carl E Martin D.79
Appendix E1 Conversion Tables Ervin L Geiger E.1
Appendix E2 Pipe Properties (US Customary Units)
Dr Chakrapani Basavaraju E.13
Trang 9CONTENTS ix
Appendix E2M Pipe Properties (Metric) Dr Chakrapani Basavaraju E.23
Appendix E3 Tube Properties (US Customary Units) Ervin L Geiger E.31
Appendix E3M Tube Properties (Metric) Troy J Skillen E.37
Appendix E4 Friction Loss for Water in Feet per 100 Feet of Pipe E.39
Appendix E4M Friction Loss for Water in Meters per 100 Meters of Pipe Troy J Skillen E.59
Appendix E5 Acceptable Pipe, Tube and Fitting Materials per
the ASME Boiler and Pressure Vessel Code and the ASME Pressure
Appendix E6 International Piping Material Specifications
R Peter Deubler E.69
Appendix E7 Miscellaneous Fluids and Their Properties Akhil Prakash E.83
Appendix E8 Miscellaneous Materials and Their Properties
Akhil Prakash E.101
Appendix E9 Piping Related Computer Programs and Their
Appendix E10 International Standards and Specifications for Pipe, Tube, Fittings, Flanges, Bolts, Nuts, Gaskets and Valves Soami D Suri E.119
Trang 10Dr Hans D Baumann, Fisher Controls International, Inc., Portsmouth, NH 03801(CHAP A10)
A R Belair, PRAXAIR, Inc., 175 East Park Drive, P.O Box 44, Tonawanda, NY
Pitts-Sabin Crocker, Jr., P.E. 307 Claggett Drive, Rockville, MD 20851(CHAP B1)
Richard E Deremiah, P.E., Project Manager, Price Brothers Company, 367 West Second Avenue, Dayton, OH 45402(CHAPS A8 AND B9)
R Peter Deubler, P.E., Technical Director, Fronek Company, Inc., 15 Engle Street, wood, NJ 07631(APP E6)
Engle-Lorenzo DiGiacomo, Jr., Senior Engineer, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703(CHAP B5)
C J Erickson, Engineering Consultant, Retired from E I DuPont De Nemours & Co., P.O Box 6090, Newark, DE 19714-6090(CHAP B6)
xi
Trang 11xii HONORS LIST
Michael B Ferg, Marketing Engineer, Crane Resistoflex Company, One Quality Way, ion, NC 28752(CHAP B12)
Mar-Peter H O Fischer, Manager, Pipeline Operations, Bechtel Corporation, P.O Box 193965,
50 Beale Street, San Francisco, CA 94119(CHAP C6)
Theodore F Fisher, Process Engineer, PRAXAIR, Inc., 175 East Park Drive, P.O Box 44, Tonawanda, NY 14150-2053(CHAP C8)
Russell P Fleming, P.E., Vice President Engineering, National Fire Sprinkler Association, Inc., Robin Hill Corporate Park, Route 22, P O Box 1000, Patterson, NY 12563(CHAP C2)
Phillip D Flenner, P.E., Staff Engineer Welding, Consumer Energy, Palisades Nuclear Plant,
27780 Blue Star Highway, Covert, MI 49043-9530(CHAP C10)
Michael Frankel, CIPE, 56 Emerson Road, Somerset, NJ 08873(CHAPS C13, C15, C16 AND C17)
Michael G Gagliardi, Manager, Raytheon Engineers & Constructors, 160 Chubb Avenue, Lyndhurst, NJ 07071(CHAPS C1 AND APP E4)
Dr William E Gale, P.E., Bundy, Gale & Shields, 44 School Terrace, Novato, CA 94945
Trang 12HONORS LIST xiii
Alfred Lohmeier, Materials Engineer, Formerly Vice President, Stanitomo Corporation of America, 345 Park Ave., New York, NY 10154(CHAP A5)
Michael J Lockett, PRAXAIR, Inc., 175 East Park Drive, P.O Box 44, Tonawanda, NY 14150-2053(CHAP C8)
Joseph T Lonsdale, Director of Engineering, Dryden Engineering Company, Fremont, CA
Arling-Stanley A Mruk, 115 Grant Avenue, New Providence, NJ 07974(CHAP D1)
Rod T Mueller, Engineering Standards Coordinator, Exxon Research & Engineering Co.,
180 Park Avenue, Florham Park, NJ 07932(CHAP C7)
Mohinder L Nayyar, P.E., ASME Fellow, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703(CHAPS A1, A4, AND A10)
Alan D Nance, A D Nance Associates, Inc., 4545 Glenda Lane, Evans, GA 30809-3215
William V Richards, P.E., 4 Court of Fox River Valley, Lincolnshire, IL 60069(CHAP C9)
Chet Sandberg, Chief Engineer, Raychem Corporation, 300 Constitution Drive, Menlo Park,
Dr Tadeusz J Swierzawski, 50 Chandler Road, Burlington, MA 01803(CHAP B8)
James M Tanzosh, Supervisor, Materials Engineering, Babcock & Wilcox Co., 20 S Van Buren Ave., Barberton, OH 44203(CHAP A3)
N P Theophilos, Standards Manager, PRAXAIR, Inc., 175 East Park Drive, P.O Box 44, Tonawanda, NY 14150-2053(CHAP C8)
Daniel A Van Duyne, 206 Nautilus Drive, Apt No 107, New London, CT 06320
Trang 13xiv HONORS LIST
John P Velon, Vice President, Harza Engineering Company, Sears Towers, 233 South Wacker Drive, Chicago, IL 60606-6392(CHAP C11)
Harry A Ainsworth, S.P.E., Consultant, 4 Maple Avenue, Sudbury, MA 01776-344
Karen L Baker, Senior Mechanical Engineer, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Dr C Basavaraju, Senior Engineering Specialist, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Robert Burdick, Bassett Mechanical, P O Box 755, Appleton, WI 54912-0755
Richard E Chambers, Principal, Simpson, Gumpertz & Hager, Inc., 297 Broadway, ton, MA 02174
Arling-Sabin Crocker, Jr., P.E., 307 Claggett Drive, Rockville, MD 20878 Formerly Project neer, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Engi-Donald R Frikken, P.E., Engineering Fellow, Solutia, Inc 10300 Olive Boulevard, St Louis,
Evans C Goodling, Jr., P.E., Consulting Engineer, Parsons Energy & Chemical Group,
2675 Morgantown Road, Reading, PA 19607-9676
John Gruber, Senior Engineering Specialist, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Charles Henley, Engineering Supervisor, Black & Veach, 8400 Ward Parkway, P O Box
Trang 14HONORS LIST xv
Donald J Leininger, 7810 College View Court, Roanoke, VA 24019-4442
Jimmy E Meyer, Middough Association, Inc., 1910E 13th Street, Suite 300, Cleveland, OH 44114-3524
Ronald G McCutcheon, Senior Design Engineer, Mechanical Systems & Equipment ment, Ontario Hydro Nuclear, 700 University Avenue, Toronto, ON, Canada, M5G1X6
Depart-Mohinder L Nayyar, ASME Fellow, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Ann F Paine, P.E., Senior Engineering Specialist, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Soami D Suri, P.E., Senior Mechanical Engineer, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703(APP E10)
Henry R Sonderegger, P.E., Engineering Manager, Research and Development Center,
1467 Elmwood Avenue, Cranston, RI 02910
George W Spohn, III, Executive Vice President, Coleman Spohn Corporation, 1775 E 45th Street, Cleveland, OH 44103-2318
Kristi Vilminot, Engineering Supervisor, Black & Veach, 2200 Commonwealth Boulevard, Ann Arbor, MI 48105
Mahmood Naghash, Senior Engineering Specialist, Bechtel Power Corporation, 5275 view Drive, Frederick, MD 21703
West-Ralph W Rapp, Jr., Senior Staff Engineer, Shell Oil Product Company, P O Box 2099, Houston, TX 77252-2099.
Gursharan Singh, Engineering Supervisor, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Walter M Stephan, Engineering Manager, Flexitallic, Inc., 1300 Route 73, Suite 311, Mt Laurel, NJ 08054
Dr Jagdish K Virmani, Senior Engineering Specialist, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Charles Webb, Application Engineer, Ameron, P O Box 878, Burkburnett, TX 76354
Horace E Wetzell, Jr., Vice President, The Smith & Oby Company, 6107 Carnegie Avenue, Cleveland, OH 44103
TECHNICAL AND ADMINISTRATIVE SUPPORT
Michelle A Clay, Project Administrator, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
Rohit Goel, Piping Engineer, Bechtel India Limited, 249A Udyog Vihar, Phase IV,
Trang 15Freder-xvi HONORS LIST
Sandeep Singh, Piping Engineer, Bechtel India Limited, 249A Udyog Vihar, Phase IV, Gurgaon-122015, Haryana, India
Troy J Skillen, Mechanical Engineer, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703
M C Stapp, Project Administrator, Bechtel Power Corporation, 5275 Westview Drive, erick, MD 21703
Fred-Soami D Suri, P.E., Senior Mechanical Engineer, Bechtel Power Corporation, 5275 Westview Drive, Frederick, MD 21703(APP E10)
James Kenyon White, Administrative Supervisor, Bechtel Power Corporation, 5275 view Drive, Frederick, MD 21703
West-Dolly Pollen, 656 Quince Orchard Road, Gaithersburg, MD 20878
Trang 16It is with great sense of gratitude and humility I take this blessed moment to offer
this Seventh Edition of Piping Handbook The challenge presented by the success
of the Sixth Edition, coupled with our objective to enhance its reference value andwiden its scope, motivated us to reach out and draw upon the recognized expertise
on piping related topics not covered in the Sixth Edition In addition, we directedour synergetic efforts to upgrade the existing contents to include the latest advancesand developments in the field of piping and related technologies
Fifteen (15) new chapters and nine (9) new appendixes have been added Theseadditions accord a unique status to this resource book as it covers piping relatedtopics not covered in any one book Inclusion of metric and/or SI units along with
US customary units is intended to accommodate the growing needs of the shrinkingworld and the realities of the international market We have maintained the familiarand easy to use format of the Sixth Edition
I consider myself fortunate to have the opportunity to associate and work withrenowned and recognized specialists and leaders whose contributions are not limited
to this Piping Handbook, but go far beyond For me it has been a rewarding and
enlightening experience I find myself humbled by depth of their knowledge, cal experience, and professional achievements These distinguished contributorshave offered the sum total of their know how in the form of guidance, cautions,prohibitions, recommendations, practical illustrations, and examples, which should
practi-be used prudently with due consideration for application requirements Thestrength, authenticity, and utility of this reference book lie in the wide spreaddiversity of their expertise and unity of their professionalism
Based upon the feedback received over the past seven years from the users ofthe Sixth Edition of this handbook, I feel honored to express my and users gratitude
to all the contributors for their commitment to their profession and their highergoal of helping others They have made the difference Their spirit of giving backhas not only continued, but has brought in new contributors to expand the scopeand enhance the utility of this handbook I feel confident that all the contributorsshall enjoy the professional satisfaction and the gratitude of users of this handbook.The selfless efforts of all the reviewers listed in the Honors List are of greatsignificance in making improvements in presentation of the subject matter Theextent of their experience, knowledge, and an insight of topics has been instrumental
in extracting the best out of contributors and upgrading the contents of thishandbook
The contributors and reviewers have earned a distinguished status I salute theircommitment; admire their efforts; respect their professionalism; and applaud theirachievements I want to recognize their perseverance, dedication, hard work andsincerity of their commitment in spite of increasing demands on their time
I am indebted to the members of the editorial team who spent countless hoursand made personal sacrifices to make this team project a reality Jill Hershey, TroySkillen, and Soami Suri did not spare any effort to not only fulfill their commitment,but went beyond to accomplish the objectives They offered constructive comments,
xvii
Trang 17xviii PREFACE
new ideas and energy to support them In addition to contributing, they assisted
me in reviewing, editing, checking and correcting the manuscript Furthermore,they provided an objective assessment of needs of progressive professionals involved
in piping related fields Their efforts reinforced my faith in bright future of ourprofession The support and assistance provided by Ervin L Geiger and SabinCrocker, Jr., as Associate Editors, is key to the successful completion of this effort.Each and every individual providing administrative, technical and automationservices, listed in Honors List, kept the entire process moving smoothly by theirsincere efforts Linda Ludewig, Peggy Lamb, and the others at McGraw-Hill couldnot be better or more cooperative in accommodating our reasonable and unreason-able requests in producing this handbook to the best of their abilities
Whenever you, the readers and users of this handbook, find it to be of help inyour mission, please thank the contributors, reviewers, technical, administrativeand automation personnel listed in the Honors List, and the editorial and productionstaff of McGraw-Hill If, at any time, this handbook falls short of your expectations,please do not hesitate to pass it on to me It will help us improve the contents andtheir utility I shall owe you my gratitude
I take pride in recognizing the active support of my daughters, Mukta andMahak; and my son, Manav; who helped me in researching and collecting data;preparing manuscript; reviewing proof pages; and performing other tasks, as needed.This time they not only allowed me to devote their share of my life to this handbook,but also dedicated a part of their life to it My wife, Prabha, provided the proverbialsupport a spouse can hope for, in doing and accomplishing what I aimed for Nowords can convey my feelings and thoughts for her contributions
Mohinder L Nayyar
Trang 18HOW TO USE THIS
HANDBOOK
As with any handbook, the user of this handbook can seek the topic covered eitherwith the help of the table of contents or the index However, an understanding ofthe organization and the format of this handbook will enhance its utility
The handbook is organized in five parts:
Part A, Piping Fundamentals: There are ten chapters in Part A, numbered
Al through A10, dealing with commonly used terminology associated with pipingunits—U.S Customary units and metric/SI units, piping components, materials,piping codes and standards, manufacturing of piping, fabrication and installation
of piping, bolted joints, prestressed concrete piping, and grooved and Pressfit pipingsystems, Each chapter is a self-contained unit The chapter numbers, figures andtables sequentially preceded For example, in the case of Chapter Al, the figuresare numbered as Fig A1.1, Fig A1.2, and so on, and tables are numbered as TableA1.1, Table A1.2, and so on Pages are numbered sequentially throughout eachpart, starting with A.1
Part B, Generic Design Considerations: The Part B consists of fourteen chapters.
The topics covered deal with generic design considerations, which may be applicable
to any piping system irrespective of the fluid or the mixture carried by the piping.The generic topics are design documents, design bases, piping layout, stress analysis,piping supports, heat tracing, thermal insulation, and flow of fluids In addition, thelined piping systems: cement, rubber, epoxy and plastic lined piping systems areincluded to provide guidance when corrosion is a concern A chapter on doublecontainment piping systems provides needed guidance to handle hazardous fluids.The last chapter in Part B deals with pressure testing of piping systems The chapter,page, figure, and table numbering scheme is similar to that described for Part A
Part C, Piping Systems: There are 17 chapters in Part C, each dealing with a
specific type of piping system or systems involving application of specific tions The piping systems covered include water, fire protection, steam, buildingservices, oil, gas, chemical and refinery (process piping), cryogenic, refrigeration,toxic and hazardous wastes, slurry and sludge, stormwater and wastewater, plumb-ing, ash handling, compressed air and vacuum, fuel gas and laboratory pipingsystems The numbering approach for Part C is similar to Part A
considera-Part D, Nonmetallic Piping: considera-Part D has two chapters, Dl and D2 Chapter Dl
addresses thermoplastics piping, and Chapter D2 covers fiberglass piping systems.The numbering scheme for pages, figures, and tables is similar to the one followedfor Part A
Part E, Appendixes: Part E of the handbook contains reference technical data
and information that could be very handy and useful to the users It consists of 10appendixes, El through E10 They include conversion tables, pipe and tube proper-ties, pressure drop tables, ASTM and international piping materials, fluid properties,piping related computer programs, and an exhaustive list of international standards.Depending upon the need, level of piping knowledge, and requirements, the
xix
Trang 19xx HOW TO USE THIS HANDBOOK
user of this handbook may find it very convenient to locate the desired information
by focusing on a specific part of the handbook
Last but not least, the Seventh Edition of Piping Handbook includes metric/SI
units in parentheses The values stated in each system are not exact equivalents;therefore, each system must be used independently of the other At times, unitequivalents are rounded off while at places they are approximated to provide ameasure of equivalency Different approaches have been followed depending uponthe practices prevalent in a segment of the piping industry We regret the variationsand expect the users to understand the state of the art in regard to use of units.The users are cautioned to check and verify units prior to making calculations withthe help of equations included in the handbook or elsewhere
Trang 20P ● A ● R ● T ● A
PIPING FUNDAMENTALS
Trang 21CHAPTER A1 INTRODUCTION TO PIPING
Mohinder L Nayyar, P E.
ASME Fellow Bechtel Power Corporation
The fire protection piping networks in residential, commercial, industrial, andother buildings carry fire suppression fluids, such as water, gases, and chemicals toprovide protection of life and property The piping systems in thermal power plantsconvey high-pressure and high-temperature steam to generate electricity Otherpiping systems in a power plant transport high- and low-pressure water, chemicals,low-pressure steam, and condensate Sophisticated piping systems are used to pro-cess and carry hazardous and toxic substances The storm and wastewater pipingsystems transport large quantities of water away from towns, cities, and industrialand similar establishments to safeguard life, property, and essential facilities
In health facilities, piping systems are used to transport gases and fluids formedical purposes The piping systems in laboratories carry gases, chemicals, vapors,and other fluids that are critical for conducting research and development In short,the piping systems are an essential and integral part of our modern civilization just
as arteries and veins are essential to the human body
The design, construction, operation, and maintenance of various piping systemsinvolve understanding of piping fundamentals, materials, generic and specific designconsiderations, fabrication and installation, examinations, and testing and inspectionrequirements, in addition to the local, state and federal regulations
A.3
Trang 22A.4 PIPING FUNDAMENTALS
PIPING
Piping includes pipe, flanges, fittings, bolting, gaskets, valves, and the containing portions of other piping components It also includes pipe hangers andsupports and other items necessary to prevent overpressurization and overstressing
pressure-of the pressure-containing components It is evident that pipe is one element or apart of piping Therefore, pipe sections when joined with fittings, valves, and othermechanical equipment and properly supported by hangers and supports, are
called piping.
Pipe
Pipe is a tube with round cross section conforming to the dimensional ments of
Pipe Size
Initially a system known as iron pipe size (IPS) was established to designate the
pipe size The size represented the approximate inside diameter of the pipe ininches An IPS 6 pipe is one whose inside diameter is approximately 6 inches (in).Users started to call the pipe as 2-in, 4-in, 6-in pipe and so on To begin, each pipe
size was produced to have one thickness, which later was termed as standard (STD)
or standard weight (STD WT.) The outside diameter of the pipe was standardized.
As the industrial requirements demanded the handling of higher-pressure fluids,
pipes were produced having thicker walls, which came to be known as extra strong (XS) or extra heavy (XH) The higher pressure requirements increased further, requiring thicker wall pipes Accordingly, pipes were manufactured with double extra strong (XXS) or double extra heavy (XXH) walls while the standardized
outside diameters are unchanged
With the development of stronger and corrosion-resistant piping materials, theneed for thinner wall pipe resulted in a new method of specifying pipe size and
wall thickness The designation known as nominal pipe size (NPS) replaced IPS, and the term schedule (SCH) was invented to specify the nominal wall thickness
of pipe
Nominal pipe size (NPS) is a dimensionless designator of pipe size It indicates
standard pipe size when followed by the specific size designation number without
an inch symbol For example, NPS 2 indicates a pipe whose outside diameter is2.375 in The NPS 12 and smaller pipe has outside diameter greater than the sizedesignator (say, 2, 4, 6, ) However, the outside diameter of NPS 14 and largerpipe is the same as the size designator in inches For example, NPS 14 pipe has anoutside diameter equal to 14 in The inside diameter will depend upon the pipewall thickness specified by the schedule number Refer to ASME B36.10M orASME B36.19M Refer to App E2 or E2M
Diameter nominal (DN) is also a dimensionless designator of pipe size in the
metric unit system, developed by the International Standards Organization (ISO)
It indicates standard pipe size when followed by the specific size designation number
Trang 23INTRODUCTION TO PIPING A.5
TABLE A1.1 Pipe Size Designators: NPS and DN
Pipe Wall Thickness
Schedule is expressed in numbers (5, 5S, 10, 10S, 20, 20S, 30, 40, 40S, 60, 80, 80S,
100, 120, 140, 160) A schedule number indicates the approximate value of the
expression 1000 P/S, where P is the service pressure and S is the allowable stress,
both expressed in pounds per square inch (psi) The higher the schedule number,the thicker the pipe is The outside diameter of each pipe size is standardized.Therefore, a particular nominal pipe size will have a different inside diameterdepending upon the schedule number specified
Note that the original pipe wall thickness designations of STD, XS, and XXShave been retained; however, they correspond to a certain schedule number de-pending upon the nominal pipe size The nominal wall thickness of NPS 10 andsmaller schedule 40 pipe is same as that of STD WT pipe Also, NPS 8 and smallerschedule 80 pipe has the same wall thickness as XS pipe
The schedule numbers followed by the letter S are per ASME B36.19M, andthey are primarily intended for use with stainless steel pipe The pipe wall thicknessspecified by a schedule number followed by the letter S may or may not be thesame as that specified by a schedule number without the letter S Refer to ASMEB36.19M and ASME B36.10M.10,11
ASME B36.19M does not cover all pipe sizes Therefore, the dimensional ments of ASME B36.10M apply to stainless steel pipe of the sizes and schedulesnot covered by ASME B36.19M
require-PIPING CLASSIFICATION
It is usual industry practice to classify the pipe in accordance with the temperature rating system used for classifying flanges However, it is not essential
Trang 24pressure-A.6 PIPING FUNDAMENTALS
TABLE A1.2 Piping Class Ratings Based on ASME B16.5 and Corresponding PN Designators
con-2 For pressure-temperature ratings, refer to tables in ASME B16.5, or ASME B16.34.
that piping be classified as Class 150, 300, 400, 600, 900, 1500, and 2500 The piping rating must be governed by the pressure-temperature rating of the weakest pressure- containing item in the piping The weakest item in a piping system may be a fitting
made of weaker material or rated lower due to design and other considerations.Table A1.2 lists the standard pipe class ratings based on ASME B16.5 along with
corresponding pression nominal (PN) rating designators Pression nominal is the
French equivalent of pressure nominal
In addition, the piping may be classified by class ratings covered by other ASMEstandards, such as ASME B16.1, B16.3, B16.24, and B16.42 A piping system may
be rated for a unique set of pressures and temperatures not covered by any standard
Pression nominal (PN) is the rating designator followed by a designation number, which indicates the approximate pressure rating in bars The bar is the unit of
pressure, and 1 bar is equal to 14.5 psi or 100 kilopascals (kPa) Table A1.2 provides
a cross-reference of the ASME class ratings to PN rating designators It is evidentthat the PN ratings do not provide a proportional relationship between different
PN numbers, whereas the class numbers do Therefore, it is recommended thatclass numbers be used to designate the ratings Refer to Chap B2 for a moredetailed discussion of class rating of piping systems
OTHER PIPE RATINGS
Manufacturer’s Rating
Based upon a unique or proprietary design of a pipe, fitting, or joint, the turer may assign a pressure-temperature rating that may form the design basis forthe piping system Examples include Victaulic couplings and the Pressfit systemdiscussed in Chap A9
In no case shall the manufacturer’s rating be exceeded In addition, the turer may impose limitations which must be adhered to
manufac-NFPA Ratings
The piping systems within the jurisdiction of the National Fire Protection tion (NFPA) requirements are required to be designed and tested to certain requiredpressures These systems are usually rated for 175 psi (1207.5 kPa), 200 psi (1380kPa), or as specified
Trang 25Associa-INTRODUCTION TO PIPING A.7
AWWA Ratings
The American Water Works Association (AWWA) publishes standards and fications, which are used to design and install water pipelines and distribution systempiping The ratings used may be in accordance with the flange ratings of AWWAC207, Steel Pipe Flanges; or the rating could be based upon the rating of the jointsused in the piping
speci-Specific or Unique Rating
When the design pressure and temperature conditions of a piping system do notfall within the pressure-temperature ratings of above-described rating systems, thedesigner may assign a specific rating to the piping system Examples of such applica-tions include main steam or hot reheat piping of a power plant, whose designpressure and design temperature may exceed the pressure-temperature rating ofASME B16.5 Class 2500 flanges It is normal to assign a specific rating to the piping.This rating must be equal to or higher than the design conditions The rating of allpressure-containing components in the piping system must meet or exceed thespecific rating assigned by the designer
Dual Ratings
Sometimes a piping system may be subjected to full-vacuum conditions or merged in water and thus experience external pressure, in addition to withstandingthe internal pressure of the flow medium Such piping systems must be rated forboth internal and external pressures at the given temperatures In addition, a pipingsystem may handle more than one flow medium during its different modes ofoperation Therefore, such a piping system may be assigned a dual rating for twodifferent flow media For example, a piping system may have condensate flowingthrough it at some lower temperature during one mode of operation while steammay flow through it at some higher temperature during another mode of operation
sub-It may be assigned two pressure ratings at two different temperatures
GENERAL DEFINITIONS
Absolute Viscosity. Absolute viscosity or the coefficient of absolute viscosity is
a measure of the internal resistance In the centimeter, gram, second (cgs) or metricsystem, the unit of absolute viscosity is the poise (abbreviated P), which is equal
to 100 centipoise (cP) The English units used to measure or express viscosity areslugs per foot-second or pound force seconds per square foot Sometimes, theEnglish units are also expressed as pound mass per foot-second or poundal secondsper square foot Refer to Chap B8 of this handbook
Adhesive Joint. A joint made in plastic piping by the use of an adhesive substancewhich forms a continuous bond between the mating surfaces without dissolvingeither one of them Refer to Part D of this handbook
Air-Hardened Steel. A steel that hardens during cooling in air from a temperatureabove its transformation range.1
Trang 26A.8 PIPING FUNDAMENTALS
Alloy Steel. A steel which owes its distinctive properties to elements other thancarbon Steel is considered to be alloy steel when the maximum of the range givenfor the content of alloying elements exceeds one or more of the following limits2:
or a definite range or a definite minimum quantity of any of the following elements
is specified or required within the limits of the recognized field of constructionalalloy steels:
or any other alloying element added to obtain a desired alloying effect
Small quantities of certain elements are unavoidably present in alloy steels Inmany applications, these are not considered to be important and are not specified
or required When not specified or required, they should not exceed the ing amounts:
Ambient Temperature. The temperature of the surrounding medium, usually used
to refer to the temperature of the air in which a structure is situated or a device erates
op-Anchor. A rigid restraint providing substantially full fixation, permitting neithertranslatory nor rotational displacement of the pipe
Annealing. Heating a metal to a temperature above a critical temperature andholding above that range for a proper period of time, followed by cooling at asuitable rate to below that range for such purposes as reducing hardness, improvingmachinability, facilitating cold working, producing a desired microstructure, orobtaining desired mechanical, physical, or other properties.3(A softening treatment
is often carried out just below the critical range which is referred to as a cal annealing.)
subcriti-Arc Cutting. A group of cutting processes in which the severing or removing ofmetals is effected by melting with the heat of an arc between an electrode and thebase metal (includes carbon, metal, gas metal, gas tungsten, plasma, and air carbon
arc cutting) See also Oxygen Cutting.
Arc Welding. A group of welding processes in which coalescence is produced byheating with an electric arc or arcs, with or without the application of pressure andwith or without the use of filler metal.3,4
Trang 27INTRODUCTION TO PIPING A.9
Assembly. The joining together of two or more piping components by bolting,welding, caulking, brazing, soldering, cementing, or threading into their installedlocation as specified by the engineering design
Automatic Welding. Welding with equipment which performs the entire weldingoperation without constant observation and adjustment of the controls by an opera-tor The equipment may or may not perform the loading and unloading of the work.3,5
Backing Ring. Backing in the form of a ring that can be used in the welding ofpiping to prevent weld spatter from entering a pipe and to ensure full penetration
of the weld to the inside of the pipe wall
Ball Joint. A component which permits universal rotational movement in a ing system.5
pip-Base Metal. The metal to be welded, brazed, soldered, or cut It is also referred
to as parent metal.
Bell-Welded Pipe. Furnace-welded pipe produced in individual lengths from length skelp, having its longitudinal butt joint forge-welded by the mechanicalpressure developed in drawing the furnace-heating skelp through a cone-shaped
cut-die (commonly known as a welding bell), which serves as a combined forming and
welding die
Bevel. A type of edge or end preparation
Bevel Angle. The angle formed between the prepared edge of a member and aplane perpendicular to the surface of the member See Fig A1.1
Blank Flange. A flange that is not drilled but is otherwise complete
Blind Flange. A flange used to close the end of a pipe It produces a blind end
which is also known as a dead end.
Bond. The junction of the weld metal and the base metal, or the junction of thebase metal parts when weld metal is not present See Fig A1.2
Branch Connection. The attachment of a branch pipe to the run of a main pipewith or without the use of fittings
Braze Welding. A method of welding whereby a groove, fillet, plug, or slot weld
is made using a nonferrous filler metal having a melting point below that of the
FIGURE A1.2 Bond between base metal and
Trang 28A.10 PIPING FUNDAMENTALS
base metals, but above 800⬚F The filler metal is not distributed in the joint bycapillary action.5(Bronze welding, the term formerly used, is a misnomer.)
Brazing. A metal joining process in which coalescence is produced by use of anonferrous filler metal having a melting point above 800⬚F but lower than that ofthe base metals joined The filler metal is distributed between the closely fittedsurfaces of the joint by capillary action.5
Butt Joint. A joint between two members lying approximately in the same plane.5
Butt Weld. Weld along a seam that is
butted edge to edge See Fig A1.3
Bypass. A small passage around a
large valve for warming up a line An
emergency connection around a
butt-ing valve, trap, etc., to use in case it is
Cast Iron. A generic term for the family of high carbon-silicon-iron casting alloysincluding gray, white, malleable, and ductile iron
Centrifugally Cast Pipe. Pipe formed from the solidification of molten metal in
a rotating mold Both metal and sand molds are used After casting, if requiredthe pipe is machined, to sound metal, on the internal and external diameters tothe surface roughness and dimensional requirements of the applicable material spec-ification
Certificate of Compliance. A written statement that the materials, equipment, orservices are in accordance with the specified requirements It may have to besupported by documented evidence.6
Certified Material Test Report (CMTR ). A document attesting that the material
is in accordance with specified requirements, including the actual results of allrequired chemical analyses, tests, and examinations.6
Chamfering. The preparation of a contour, other than for a square groove weld,
on the edge of a member for welding
Cold Bending. The bending of pipe to a predetermined radius at any temperaturebelow some specified phase change or transformation temperature but especially
at or near room temperature Frequently, pipe is bent to a radius of 5 times thenominal pipe diameter
Trang 29INTRODUCTION TO PIPING A.11
Cold Working. Deformation of a metal plastically Although ordinarily done atroom temperature, cold working may be done at the temperature and rate atwhich strain hardening occurs Bending of steel piping at 1300⬚F (704⬚C) would beconsidered a cold-working operation
Companion Flange. A pipe flange suited to connect with another flange or with
a flanged valve or fitting A loose flange which is attached to a pipe by threading,van stoning, welding, or similar method as distinguished from a flange which is castintegrally with a fitting or pipe
Consumable Insert. Preplaced filler
metal which is completely fused into the
root of the joint and becomes part of the
weld.1See Fig A1.4
Continuous-Welded Pipe.
Furnace-welded pipe produced in continuous
lengths from coiled skelp and
subse-quently cut into individual lengths,
hav-ing its longitudinal butt joint
forge-welded by the mechanical pressure
de-veloped in rolling the hot-formed skelp
through a set of round pass welding
rolls.3
Contractor. The entity responsible for FIGURE A1.4 Consumable insert ring furnishing materials and services for fab- serted in pipe joint eccentrically for welding inrication and installation of piping and horizontal position.
Corner Joint. A joint between two
members located approximately at right
angles to each other in the form of an
L See Fig A1.5
Coupling. A threaded sleeve used to
connect two pipes Commercial
cou-FIGURE A1.5 Corner joint.
plings have internal threads to fit
exter-nal threads on pipe
Covered Electrode. A filler metal electrode, used in arc welding, consisting of ametal core wire with a relatively thick covering which provides protection for themolten metal from the atmosphere, improves the properties of the weld metal, and
Trang 30A.12 PIPING FUNDAMENTALS
stabilizes the arc Covered electrodes are extensively used in shop fabrication andfield erection of piping of carbon, alloy, and stainless steels
Crack. A fracture-type imperfection characterized by a sharp tip and high ratio
of length and depth to opening displacement
Creep or Plastic Flow of Metals. At sufficiently high temperatures, all metalsflow under stress The higher the temperature and stress, the greater the tendency
to plastic flow for any given metal
Cutting Torch. A device used in oxygen, air, or powder cutting for controllingand directing the gases used for preheating and the oxygen or powder used forcutting the metal
Defect. A flaw or an imperfection of such size, shape, orientation, location, orproperties as to be rejectable per the applicable minimum acceptance standards.7
Density. The density of a substance is the mass of the substance per unit volume
It may be expressed in a variety of units
Deposited Metal. Filler metal that has been added during a welding operation.8
Depth of Fusion. The distance that
fu-sion extends into the base metal from
the surface melted during welding See
Fig A1.6
FIGURE A1.6 Depth of fusion.
Designer. Responsible for ensuring
that the engineering design of piping
complies with the requirements of the applicable code and standard and any tional requirements established by the owner
addi-Dew Point. The temperature at which the vapor condenses when it is cooled atconstant pressure
Dilatant Liquid. If the viscosity of a liquid increases as agitation is increased at
constant temperature, the liquid is termed dilatant Examples are clay slurries and
pro-is produced by heating with an electric arc or arcs between the bare metal electrode
or electrodes and the work The welding is shielded by a blanket of granular, fusiblematerial on the work Pressure is not used, and filler metal for the inside and outsidewelds is obtained from the electrode or electrodes
Ductile Iron. A cast ferrous material in which the free graphite is in a spheroidalform rather than a fluke form The desirable properties of ductile iron are achieved
by means of chemistry and a ferritizing heat treatment of the castings
Trang 31INTRODUCTION TO PIPING A.13
Eddy Current Testing. This is a nondestructive testing method in which eddycurrent flow is induced in the test object Changes in the flow caused by variations
in the object are reflected into a nearby coil or coils for subsequent analysis bysuitable instrumentation and techniques
Edge Joint. A joint between the edges of two or more parallel or nearly lel members
paral-Edge Preparation. The contour
pre-pared on the edge of a member for
weld-ing See Fig A1.7
Electric Flash-Welded Pipe. Pipe
hav-ing a longitudinal butt joint in which
co-alescence is produced simultaneously FIGURE A1.7 Edge preparation.
over the entire area of abutting surfaces
by the heat obtained from resistance to
the flow of electric current between the two surfaces and by the application ofpressure after heating is substantially completed Flashing and upsetting are accom-panied by expulsion of metal from the joint.4
Electric Fusion-Welded Pipe. Pipe having a longitudinal or spiral butt joint inwhich coalescence is produced in the preformed tube by manual or automaticelectric arc welding The weld may be single or double and may be made with orwithout the use of filler metal.4
Electric Resistance-Welded Pipe. Pipe produced in individual lengths or in uous lengths from coiled skelp and subsequently cut into individual lengths having
contin-a longitudincontin-al butt joint in which cocontin-alescence is produced by the hecontin-at obtcontin-ainedfrom resistance of the pipe to the flow of electric current in a circuit of which thepipe is a part and by the application of pressure.3
Electrode. See Covered Electrode.
End Preparation. The contour prepared on the end of a pipe, fitting, or nozzlefor welding The particular preparation is prescribed by the governing code Refer
to Chap A6 of this handbook
Engineering Design. The detailed design developed from process requirementsand conforming to established design criteria, including all necessary drawings andspecifications, governing a piping installation.5
Equipment Connection. An integral part of such equipment as pressure vessels,heat exchangers, pumps, etc., designed for attachment of pipe or piping components.8
Erection. The complete installation of a piping system, including any field bly, fabrication, testing, and inspection of the system.5
assem-Erosion. Destruction of materials by the abrasive action of moving fluids, usuallyaccelerated by the presence of solid particles.9
Examination. The procedures for all visual observation and nondestructivetesting.5
Trang 32A.14 PIPING FUNDAMENTALS
Expansion Joint. A flexible piping component which absorbs thermal and/orterminal movement.5
Extruded Nozzles. The forming of nozzle (tee) outlets in pipe by pulling spherically or conically shaped dies through a circular hole from the inside of thepipe Although some cold extruding is done, it is generally performed on steel afterthe area to be shaped has been heated to temperatures between 2000 and 1600⬚F(1093 and 871⬚C)
hemi-Extruded Pipe. Pipe produced from hollow or solid round forgings, usually in ahydraulic extrusion press In this process the forging is contained in a cylindricaldie Initially a punch at the end of the extrusion plunger pierces the forging Theextrusion plunger then forces the contained billet between the cylindrical die andthe punch to form the pipe, the latter acting as a mandrel
One variation of this process utilizes autofrettage (hydraulic expansion) andheat treatment, above the recrystallization temperature of the material, to produce
a wrought structure
Fabrication. Primarily, the joining of piping components into integral pieces readyfor assembly It includes bending, forming, threading, welding, or other operationsupon these components, if not part of assembly It may be done in a shop or inthe field.5
Face of Weld. The exposed surface of a weld on the side from which the weldingwas done.5,8
Filler Metal. Metal to be added in welding, soldering, brazing, or braze welding.8
Fillet Weld. A weld of an approximately triangular cross section joining twosurfaces approximately at right angles to each other in a lap joint, tee joint, cornerjoint, or socket weld.5See Fig A1.8
Fire Hazard. Situation in which a material of more than average combustibility
or explodibility exists in the presence of a potential ignition source.5
Flat-Land Bevel. A square extended root face preparation extensively used ininert-gas, root-pass welding of piping See Fig A1.9
Trang 33INTRODUCTION TO PIPING A.15
FIGURE A1.10 Welding in the flat position.
Flat Position. The position of welding which is performed from the upper side
of the joint, while the face of the weld is approximately horizontal See Fig A1.10
Flaw. An imperfection of unintentional discontinuity which is detectable by anondestructive examination.7
Flux. Material used to dissolve, prevent accumulation of, or facilitate removal ofoxides and other undesirable substances during welding, brazing, or soldering
Flux-Cored Arc Welding (FCAW ). An arc welding process that employs a uous tubular filler metal (consumable) electrode having a core of flux for shielding.Adding shielding may or may not be obtained from an externally supplied gas orgas mixture
contin-Forge Weld. A method of manufacture similar to hammer welding The term
forge welded is applied more particularly to headers and large drums, while hammer welded usually refers to pipe.
Forged and Bored Pipe. Pipe produced by boring or trepanning of a forged billet
Full-Fillet Weld. A fillet weld whose size is equal to the thickness of the thinnermember joined.8
Fusion. The melting together of filler and base metal, or of base metal only, whichresults in coalescence.8
Fusion Zone. The area of base metal
melted as determined on the cross
sec-tion of a weld See Fig A1.11
Galvanizing. A process by which the FIGURE A1.11 Fusion zone is the section ofsurface of iron or steel is covered with the parent metal which melts during the weld-
Gas Metal Arc Welding (GMAW ). An arc welding process that employs a uous solid filler metal (consumable) electrode Shielding is obtained entirely from
contin-an externally supplied gas or gas mixture.4,8(Some methods of this process have
been called MIG or CO2welding.)
Gas Tungsten Arc Welding (GTAW ). An arc welding process that employs atungsten (nonconsumable) electrode Shielding is obtained from a gas or gas mix-
Trang 34A.16 PIPING FUNDAMENTALS
ture Pressure may or may not be used, and filler metal may or may not be used
(This process has sometimes been called TIG welding.) When shielding is obtained
by the use of an inert gas such as helium or argon, this process is called inert-gas tungsten arc welding.8
Gas Welding. Welding process in which coalescence is produced by heating with
a gas flame or flames, with or without the application of pressure and with orwithout the use of filler metal.4
Groove. The opening provided for a groove weld
Groove Angle. The total included angle of the groove between parts to be joined
by a groove weld See Fig A1.12
FIGURE A1.12 The groove angle is twice the
FIGURE A1.13 A groove face.
bevel angle.
Groove Face. That surface of a member included in the groove See Fig A1.13
Groove Radius. The radius of a J or U groove See Fig A1.14
Groove Weld. A weld made in the groove between two members to be joined.The standard type of groove welds are square, single-V, single-bevel, single-U,single-J, double-V, double-U, double-bevel, double-J, and flat-land single, and dou-ble-V groove welds See Fig A1.15 for a typical groove weld
FIGURE A1.14 A groove radius.
Hammer Weld. Method of manufacturing large pipe (usually NPS 20 or DN 500and larger) by bending a plate into circular form, heating the overlapped edges to
a welding temperature, and welding the longitudinal seam with a power hammerapplied to the outside of the weld while the inner side is supported on an over-hung anvil
Hangers and Supports. Hangers and supports include elements which transfer theload from the pipe or structural attachment to the supporting structure or equipment.They include hanging-type fixtures such as hanger rods, spring hangers, sway braces,counterweights, turnbuckles, struts, chains, guides, and anchors and bearing-typefixtures such as saddles, bases, rollers, brackets, and sliding supports.5Refer toChap B5 of this handbook
Trang 35INTRODUCTION TO PIPING A.17
Header. A pipe or fitting to which a number of branch pipes are connected
Heat-Affected Zone. That portion of the base metal which has not been meltedbut whose mechanical properties or microstructure has been altered by the heat
of welding or cutting.8See Fig A1.16
FIGURE A1.17 Horizontal position fillet
Heat Fusion Joint. A joint made in thermoplastic piping by heating the partssufficiently to permit fusion of the materials when the parts are pressed together
Horizontal Fixed Position. In pipe welding, the position of a pipe joint in whichthe axis of the pipe is approximately horizontal and the pipe is not rotated duringthe operation
Horizontal-Position Fillet Weld. Welding is performed on the upper side of anapproximately horizontal surface and against an approximately vertical surface SeeFig A1.17
Horizontal-Position Groove Weld. The position of welding in which the weldaxis lies in an approximately horizontal plane and the face of the weld lies in anapproximately vertical plane See Fig A1.18
FIGURE A1.18 Horizontal position groove
Horizontal Rolled Position. The position of a pipe joint in which welding isperformed in the flat position by rotating the pipe See Fig A1.19
Hot Bending. Bending of piping to a predetermined radius after heating to asuitably high temperature for hot working On many pipe sizes, the pipe is firmlypacked with sand to avoid wrinkling and excessive out-of-roundness
Hot Taps. Branch piping connections made to operating pipelines, mains, or otherfacilities while they are in operation
Trang 36A.18 PIPING FUNDAMENTALS
Hot Working. The plastic deformation of metal at such a temperature and ratethat strain hardening does not occur Extruding or swaging of chrome-moly piping
at temperatures between 2000 and 1600⬚F (1093 and 871⬚C) would be consideredhot-forming or hot-working operations
Hydraulic Radius. The ratio of area of flowing fluid to the wetted perimeter
Impact Test. A test to determine the behavior of materials when subjected tohigh rates of loading, usually in bending, tension, or torsion The quantity measured
is the energy absorbed in breaking the specimen by a single blow, as in Charpy orIzod tests
Imperfection. A condition of being imperfect; a departure of a quality tic from its intended condition.5
characteris-Incomplete Fusion. Fusion which is less than complete and which does not result
in melting completely through the thickness of the joint
Indication. The response or evidence from the application of a nondestructive amination.5
ex-Induction Heating. Heat treatment of completed welds in piping by means ofplacing induction coils around the piping This type of heating is usually performedduring field erection in those cases where stress relief of carbon- and alloy-steelfield welds is required by the applicable code
Inspection. Activities performed by an authorized inspector to verify whether anitem or activity conforms to specified requirements
Instrument Piping. All piping, valves, and fittings used to connect instruments tomain piping, to other instruments and apparatus, or to measuring equipment.2
Interpass Temperature. In a multiple-pass weld, the minimum or maximum perature of the deposited weld metal before the next pass is started
tem-Interrupted Welding. Interruption of welding and preheat by allowing the weldarea to cool to room temperature as generally permitted on carbon-steel and onchrome-moly alloy-steel piping after sufficient weld passes equal to at least one-third of the pipe wall thickness or two weld layers, whichever is greater, havebeen deposited
Joint. A connection between two lengths of pipe or between a length of pipe and
a fitting
Joint Penetration. The minimum
depth a groove weld extends from its
face into a joint, exclusive of
reinforce-ment.5See Fig A1.20
Kinematic Viscosity. The ratio of the
absolute viscosity to the mass density FIGURE A1.20 Weld joint penetration.
In the metric system, kinematic viscosity
is measured in strokes or square centimeters per second Refer to Chap B8 ofthis handbook
Trang 37INTRODUCTION TO PIPING A.19
Laminar Flow. Fluid flow in a pipe is usually considered laminar if the Reynoldsnumber is less than 2000 Depending upon many possible varying conditions, theflow may be laminar at a Reynolds number as low as 1200 or as high as 40,000;however, such conditions are not experienced in normal practice
Lap Weld. Weld along a longitudinal seam in which one part is overlapped bythe other A term used to designate pipe made by this process
Lapped Joint. A type of pipe joint made by using loose flanges on lengths of pipewhose ends are lapped over to give a bearing surface for a gasket or metal-to-metal joint
Liquid Penetrant Examination or Inspection. This is a nondestructive tion method for finding discontinuities that are open to the surface of solid andessentially nonporous materials This method is based on capillary action or capillaryattraction by which the surface of a liquid in contact with a solid is elevated ordepressed A liquid penetrant, usually a red dye, is applied to the clean surface ofthe specimen Time is allowed for the penetrant to seep into the opening Theexcess penetrant is removed from the surface A developer, normally white, isapplied to aid in drawing the penetrant up or out to the surface The red penetrant
examina-is drawn out of the dexamina-iscontinuity, which examina-is located by the contrast and dexamina-istinctappearance of the red penetrant against the white background of the developer
Local Preheating. Preheating of a specific portion of a structure
Local Stress-Relief Heat Treatment. Stress-relief heat treatment of a specificportion of a weldment This is done extensively with induction coils, resistancecoils, or propane torches in the field erection of steel piping
Machine Welding. Welding with equipment which performs the welding operationunder the observation and control of an operator The equipment may or may notperform the loading and unloading of the work
Magnetic Particle Examination or Inspection. This is a nondestructive tion method to locate surface and subsurface discontinuities in ferromagnetic materi-als The presence of discontinuities is detected by the use of finely divided ferromag-netic particles applied over the surface Some of these magnetic particles aregathered and held by the magnetic leakage field created by the discontinuity Theparticles gathered at the surface form an outline of the discontinuity and generallyindicate its location, size, shape, and extent
examina-Malleable Iron. Cast iron which has been heat-treated in an oven to relieve itsbrittleness The process somewhat improves the tensile strength and enables thematerial to stretch to a limited extent without breaking
Manual Welding. Welding wherein the entire welding operation is performedand controlled by hand.5
Mean Velocity of Flow. Under steady state of flow, the mean velocity of flow at
a given cross section of pipe is equal to the rate of flow Q divided by the area of cross section A It is expressed in feet per second or meters per second.
Trang 38A.20 PIPING FUNDAMENTALS
where v⫽ mean velocity of flow, in feet per second, ft/s (meters per second, m/s)
Q⫽ rate of flow, in cubic feet per second, ft3/s (cubic meters per second,
m3/s)
A⫽ area of cross section, in square feet, ft2(square meters, m2)
Mechanical Joint. A joint for the purpose of mechanical strength or leak resistance
or both, where the mechanical strength is developed by threaded, grooved, rolled,flared, or flanged pipe ends or by bolts, pins, and compounds, gaskets, rolled ends,caulking, or machined and mated surfaces These joints have particular applicationwhere ease of disassembly is desired.5
Mill Length. Also known as random length The usual run-of-mill pipe is 16 to
20 ft (5 to 6 m) in length Line pipe and pipe for power plant use are sometimesmade in double lengths of 30 to 35 ft (10 to 12 m)
Miter. Two or more straight sections of pipe matched and joined on a line bisectingthe angle of junction so as to produce a change in direction.4
Newtonian Liquid. A liquid is called newtonian if its viscosity is unaffected bythe kind and magnitude of motion or agitation to which it may be subjected, aslong as the temperature remains constant Water and mineral oil are examples ofnewtonian liquids
Nipple. A piece of pipe less than 12 in (0.3 m) long that may be threaded onboth ends or on one end and provided with ends suitable for welding or a mechanicaljoint Pipe over 12 in (0.3 m) long is regarded as cut pipe Common types of nipplesare close nipple, about twice the length of a standard pipe thread and without anyshoulder; shoulder nipple, of any length and having a shoulder between the pipethreads; short nipple, a shoulder nipple slightly longer than a close nipple and of
a definite length for each pipe size which conforms to manufacturer’ standard; longnipple, a shoulder nipple longer than a short nipple which is cut to a specific length
Nominal Diameter (DN ). A dimensionless designator of pipe in metric system
It indicates standard pipe size when followed by the specific size designation numberwithout the millimeter symbol (for example, DN 40, DN 300)
Nominal Pipe Size (NPS ). A dimensionless designator of pipe It indicates dard pipe size when followed by the specific size designation number without aninch symbol (for example, NPS 1¹⁄₂, NPS 12).2
stan-Nominal Thickness. The thickness given in the product material specification orstandard to which manufacturing tolerances are applied.5
Nondestructive Examination or Inspection. Inspection by methods that do notdestroy the item, part, or component to determine its suitability for use
Normalizing. A process in which a ferrous metal is heated to a suitable ture above the transformation range and is subsequently cooled in still air atroom temperature.5
Trang 39tempera-INTRODUCTION TO PIPING A.21
Nozzle. As applied to piping, this term usually refers to a flanged connection on
a boiler, tank, or manifold consisting of a pipe flange, a short neck, and a weldedattachment to the boiler or other vessel A short length of pipe, one end of which
is welded to the vessel with the other end chamfered for butt welding, is alsoreferred to as a welding nozzle
Overhead Position. The position of welding performed from the underside ofthe joint
Oxidizing Flame. An oxyfuel gas flame having an oxidizing effect caused byexcess oxygen
Oxyacetylene Cutting. An oxygen-cutting process in which metals are severed bythe chemical reaction of oxygen with the base metal at elevated temperatures Thenecessary temperature is maintained by means of gas flames obtained from thecombustion of acetylene with oxygen
Oxyacetylene Welding. A gas welding process in which coalescence is produced
by heating with a gas flame or flames obtained from the combustion of acetylenewith oxygen, with or without the addition of filler metal
Oxyfuel Gas Welding (OFGW ). A group of welding processes in which cence is produced by heating with a flame or flames obtained from the combustion
coales-of fuel gas with oxygen, with or without the application coales-of pressure and with orwithout the use of filler metal
Oxygen Cutting (OC ). A group of cutting processes used to sever or removemetals by means of the reaction of oxygen with the base metal at elevated tempera-tures In the case of oxidation-resistant metals, the reaction is facilitated by use of
a chemical flux or metal powder.8
Oxygen Gouging. An application of oxygen cutting in which a chamfer or groove
Peening. The mechanical working of metals by means of hammer blows
Pickle. The chemical or electrochemical removal of surface oxides Following
welding operations, piping is frequently pickled in order to remove mill scale, oxides
formed during storage, and the weld discolorations
Pipe. A tube with a round cross section conforming to the dimensional ments for nominal pipe size as tabulated in ASME B36.10M and ASME B36.19M.For special pipe having diameter not listed in the above-mentioned standards, thenominal diameter corresponds to the outside diameter.5
require-Pipe Alignment Guide. A restraint in the form of a sleeve or frame that permitsthe pipeline to move freely only along the axis of the pipe.8
Trang 40A.22 PIPING FUNDAMENTALS
Pipe Supporting Fixtures. Elements that transfer the load from the pipe or tural attachment to the support structure or equipment.8
struc-Pipeline or Transmission Line. A pipe installed for the purpose of transmittinggases, liquids, slurries, etc., from a source or sources of supply to one or moredistribution centers or to one or more large-volume customers; a pipe installed tointerconnect source or sources of supply to one or more distribution centers or toone or more large-volume customers; or a pipe installed to interconnect sources
of supply.2
Piping System. Interconnected piping subject to the same set or sets of design ditions.1
con-Plasma Cutting. A group of cutting processes in which the severing or removal
of metals is effected by melting with a stream of hot ionized gas.1
Plastic. A material which contains as an essential ingredient an organic substance
of high to ultrahigh molecular weight, is solid in its finished state, and at some stage
of its manufacture or processing can be shaped by flow The two general types ofplastic are thermoplastic and thermosetting
Polarity. The direction of flow of current with respect to the welding electrodeand workpiece
Porosity. Presence of gas pockets or voids in metal
Positioning Weld. A weld made in a joint which has been so placed as to facilitatethe making of the weld
Postheating. The application of heat to a fabricated or welded section subsequent
to a fabrication, welding, or cutting operation Postheating may be done locally, as
by induction heating; or the entire assembly may be postheated in a furnace
Postweld Heat Treatment. Any heat treatment subsequent to welding.5
Preheating. The application of heat to a base metal immediately prior to a welding
h⫽ height of fluid column above the point, ft (m)
p a⫽ atmospheric pressure, psi (kg/cm2)