Power Piping

ASME Code for Pressure Piping, B31

AN INTERNA TIONAL PIPING C ODE ®

ASME B31.1-2016

(Revision of ASME B31.1-2014)

ASME B31.1-2016

(Revision of ASME B31.1-2014)

Power Piping

ASME Code for Pressure Piping, B31

AN INTERNA TIONAL PIPING C ODE ®

Two Park Avenue • New York, NY • 10016 USA

Date of Issuance: June 30, 2016

The next edition of this Code is scheduled for publication in 2018. This Code will become effective 6 months after the Date of Issuance.

ASME issues written replies to inquiries concerning interpretations of technical aspects of this Code. Interpretations are published under https://go.asme.org/Interpretations. Periodically certain actions of the ASME B31 Committees may be published as Cases. Cases are published on the ASME Web site under the Committee Pages at https://go.asme.org/B31committee as they are issued.

Errata to codes and standards may be posted on the ASME Web site under the Committee Pages to provide corrections to incorrectly published items, or to correct typographical or grammatical errors in codes and standards. Such errata shall be used on the date posted.

The B31 Committee Pages can be found at https://go.asme.org/B31committee. The associated B31 Committee Pages for each code and standard can be accessed from this main page. There is an option available to automatically receive an e-mail notification when errata are posted to a particular code or standard. This option can be found on the appropriate Committee Page after selecting “Errata” in the “Publication Information” section.

ASME is the registered trademark of The American Society of Mechanical Engineers.

This international code or standard was developed under procedures accredited as meeting the criteria for American National Standards and it is an American National Standard. The Standards Committee that approved the code or standard was balanced to assure that individuals from competent and concerned interests have had an opportunity to participate. The proposed code or standard was made available for public review and comment that provides an opportunity for additional public input from industry, academia, regulatory agencies, and the public-at-large.

ASME does not “approve,” “rate,” or “endorse” any item, construction, proprietary device, or activity.

ASME does not take any position with respect to the validity of any patent rights asserted in connection with any items mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability for infringement of any applicable letters patent, nor assume any such liability. Users of a code or standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, is entirely their own responsibility.

Participation by federal agency representative(s) or person(s) affiliated with industry is not to be interpreted as government or industry endorsement of this code or standard.

ASME accepts responsibility for only those interpretations of this document issued in accordance with the established ASME procedures and policies, which precludes the issuance of interpretations by individuals.

No part of this document may be reproduced in any form, in an electronic retrieval system or otherwise,

without the prior written permission of the publisher.

The American Society of Mechanical Engineers Two Park Avenue, New York, NY 10016-5990

Copyright © 2016 by

THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS

All rights reserved Printed in U.S.A.

CONTENTS

Foreword vii

Committee Roster viii

Introduction xii

Summary of Changes xiv

1. Postweld Heat Treatment 97

2. Stamping 104

1. Assembly 104

   Chapter VI Inspection, Examination, and Testing 106

2. Inspection and Examination 106

3. Pressure Tests 110

   Chapter VII Operation and Maintenance 114

4. General 114

5. Operation and Maintenance Procedures 114

6. Condition Assessment of CPS 114

7. CPS Records 115

8. Piping and Pipe-Support Maintenance Program and Personnel

Requirements 116

1. CPS Walkdowns 116

2. Material Degradation Mechanisms 116

3. Dynamic Loading 116

Figures

100.1.2(A.1) Code Jurisdictional Limits for Piping — An Example of Forced Flow

Steam Generators With No Fixed Steam and Water Line 2

100.1.2(A.2) Code Jurisdictional Limits for Piping — An Example of Steam Separator Type Forced Flow Steam Generators With No Fixed Steam and Water

Line 3

100.1.2(B.1) Code Jurisdictional Limits for Piping — Drum-Type Boilers 4

100.1.2(B.2) Code Jurisdictional Limits for Piping — Isolable Economizers Located in Feedwater Piping and Isolable Superheaters in Main Steam Piping (Boiler Pressure Relief Valves, Blowoff, and Miscellaneous Piping

for Boiler Proper Not Shown for Clarity) 5

100.1.2(B.3) Code Jurisdictional Limits for Piping — Nonintegral Separately Fired Superheaters 6

100.1.2(C) Code Jurisdictional Limits for Piping — Spray-Type Desuperheater 7

102.4.5 Nomenclature for Pipe Bends 19

104.3.1(D) Reinforcement of Branch Connections 27

104.3.1(G) Reinforced Extruded Outlets 30

104.5.3 Types of Permanent Blanks 34

104.8.4 Cross Section Resultant Moment Loading 35

122.1.7(C) Typical Globe Valves 57

122.4 Desuperheater Schematic Arrangement 62

127.3 Butt Welding of Piping Components With Internal Misalignment 82

127.4.2 Welding End Transition — Maximum Envelope 83

127.4.4(A) Fillet Weld Size 86

127.4.4(B) Welding Details for Slip-On and Socket-Welding Flanges; Some

Acceptable Types of Flange Attachment Welds 87

127.4.4(C) Minimum Welding Dimensions Required for Socket Welding

Components Other Than Flanges 87

127.4.8(A) Typical Welded Branch Connection Without Additional

Reinforcement 87

127.4.8(B) Typical Welded Branch Connection With Additional Reinforcement 87

127.4.8(C) Typical Welded Angular Branch Connection Without Additional Reinforcement 87

127.4.8(D) Some Acceptable Types of Welded Branch Attachment Details

Showing Minimum Acceptable Welds 88

127.4.8(E) Some Acceptable Details for Integrally Reinforced Outlet Fittings 89

127.4.8(F) Typical Full Penetration Weld Branch Connections for NPS 3

(DN 80) and Smaller Half Couplings or Adapters 90