Table Of Content

Prelims-H7880.qxd 2/1/06 9:59 AM Page i Piping and Pipeline Assessment Guide Prelims-H7880.qxd 2/1/06 9:59 AM Page v This Page is Intentionally Left Blank Prelims-H7880.qxd 2/1/06 9:59 AM Page iii Piping and Pipeline Assessment Guide A. Keith Escoe AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY• TOKYO Gulf Professional Publishing is an imprint of Elsevier Prelims-H7880.qxd 2/1/06 9:59 AM Page iv Gulf Professional Publishing is an imprint of Elsevier 30 Corporate Drive,Suite 400,Burlington,MA 01803,USA Linacre House,Jordan Hill,Oxford OX2 8DP,UK Copyright ©2006,Elsevier Inc. All rights reserved. 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. Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford,UK:phone:((cid:2)44) 1865 843830,fax:((cid:2)44) 1865 853333, E-mail:[email protected]. You may also complete your request on-line via the Elsevier homepage (http://elsevier.com),by selecting “Support & Contact” then “Copyright and Permission”and then “Obtaining Permissions.” Recognizing the importance of preserving what has been written,Elsevier prints its books on acid-free paper whenever possible. Library of Congress Cataloging-in-Publication Data Escoe,A. Keith. Piping and pipeline assessment guide/Keith Escoe.—1st ed. p. cm.—(Stationary equipment assessment series; v. 1) Includes bibliographical references and index. ISBN-13:978-0-7506-7880-3 (casebound :alk. paper) ISBN-10:0-7506-7880-1 (casebound :alk. paper) 1. Piping—Maintenance and repair. 2. Pipelines—Maintenance and repair. 3. Service life (Engineering) I. Title. II. Series. TJ930.E83 2006 621.8’672—dc22 2005027032 British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. ISBN 13:978-0-7506-7880-3 ISBN 10:0-7506-7880-1 For information on all Gulf Professional Publishing publications visitour Web site at www.books.elsevier.com 06 07 08 09 10 10 9 8 7 6 5 4 3 2 1 Printed in the United States of America Working together to grow libraries in developing countries www.elsevier.com | www.bookaid.org | www.sabre.org Prelims-H7880.qxd 2/1/06 9:59 AM Page v This book is dedicated to my beloved wife,Emma. We have lived and seen so much together! Prelims-H7880.qxd 2/1/06 9:59 AM Page v This Page is Intentionally Left Blank Prelims-H7880.qxd 2/1/06 9:59 AM Page vii Contents Preface xiii 1 An Introduction to In-plant Piping and Pipeline Fitness-for-Service 1 Introduction 1 What Is Piping? 8 Areas Where Corrosion Attacks Piping 9 The Maximum Acceptable Operating Pressure (MAOP) 9 Assessment Procedure 14 Classification of Corroded Regions 15 External Versus Internal Corrosion 15 Localized Versus General Corrosion 15 Interaction of Closely Spaced Areas of Corrosion 16 Circumferential Extent of Damage 17 Welds,Elbows,and Branch Connections 17 Corroded Pit Region Interaction Parameters 18 Methodology 19 Determining the Allowable Length of Corrosion 26 Corrosion Allowance 27 Assessing Type 3 Flaws 28 Burst Test Validation 30 Circumferential Corrosion 31 Criteria for Circumferential Metal Loss 31 Methodology of Circumferential Metal Loss 33 Corrosion in Pipe Bends 35 Branch Connections and Fittings 37 Determining a Maximum Allowable Operating Pressure 37 Flaws in Heat Affected Zones of Welds 38 vii Prelims-H7880.qxd 2/1/06 9:59 AM Page viii viii Contents Example 1-1 39 Example 1-2 43 Checking for the Circumferential Direction Criteria 46 Example 1-3 47 2 An Introduction to Engineering Mechanics of Piping 50 Piping Criteria 51 Stress Categories 53 Allowable Stress Range for Secondary Stresses 53 Stresses Acting on Piping Elements 58 Stress Calculations 61 ASME B31.1 Code Stress 63 ASME B31.3 Code Stress 63 The Pipeline Codes—ASME B31.4 and B31.8 65 ASME B31.4—Liquid Transportation Pipelines Code 65 ASME B31.8—Gas Transmission and Distribution Pipeline Code 66 Flexibility and Stiffness of Piping 68 Stiffness and Large Piping 77 Flexibility Method of Piping Mechanics 78 Pipe Offsets and Loops 79 Pipe Restraints and Anchors 87 Criteria for Flexibility Analysis 90 Example Using the Empirical Flexibility Criterion 91 Suggested Criteria for Level of Piping Flexibility Analysis 96 Closure 98 3 Fitness-for-Service Topics of Local Thin Areas, Plain Dents, Dents-Gouges, and Cracks for Piping 100 Useful RSF Equations Using API 579 105 Assessment Techniques and Acceptance Criteria 110 Remaining Life Assessment 110 Remediation 111 In-Service Monitoring 111 Documentation 111 Damage Mechanisms 112 Blisters and Laminations 115 Assessment of Local Thin Areas 116 General Metal Loss Assessment 117 Individual Point Readings 121 Thickness Profiles 121 Structural Discontinuities 122 Level 1 Part 4 Acceptance Criteria 126 Level 2 Assessments 127 Level 2 Part 4 Acceptance Criteria 128 Prelims-H7880.qxd 2/1/06 9:59 AM Page ix Contents ix Local Metal Loss Assessment 129 Determining the LTA Boundary 132 Level 1 Part 5 Acceptance Criteria 133 Level 2 Part 5 Acceptance Criteria 138 Assessing Supplemental Loads 141 Level 3 Assessments 147 Elastic-Plastic Analysis of LTAs 148 Common Mistakes Made in Level 3 Assessments 152 Performing the Remaining Life Assessment 154 The MAWP Approach 154 The Thickness Approach 155 Material Property Data 157 Material Property Data Required for Assessment 157 Crack-like Flaws 169 Remediation of Crack Defects 177 Grooves,Plain Dents,and Dents with Gouges 179 Plain Dents 179 Dents and Gouge Combination Type Flaws 181 Example 3-1:API 579 Example 5.11.1 Revisited 184 Example 3-2:Dents and Gouge Combination Example 186 Example 3-3:Testing for General Metal Loss 189 Example 3-4:Surface Crack-Like Flaw in a Pipe 190 4 Fitness-for-Service for Brittle Fracture Concerns 201 Introduction 201 Brittle Fracture Concepts 203 Defect 203 Stress 204 Toughness 205 Definitions 208 Safe Operation at Low Temperatures Existing Equipment 209 Safe Operating Envelopes 209 Example 4-1:Determining the Basic MAT and Constructing the MAT Curve 213 Determining the MAT Using Fracture Mechanics 217 Variations to MAT 218 Considering the Maximum Allowable Working Pressure 218 Material That Is Already Impact Tested 218 Pressure Reduction 219 Charpy Exemption Pitfalls—Words of Caution 219 Welding 220 Considerations for Design Codes Other Than ASME 220 Selecting Materials and Defining Impact Requirements—New Piping andComponents 221 Use Good Quality Steel in the Base Case 222 Impact Test Temperature 222