ROOTCAUSE FAILURE ANALYSISI ROOT CAUSE FAILURE ANALYSIS PLANT ENGINEERING MAINTENANCE pot

ROOT CAUSE FAILURE ANALYSIS I ROOT CAUSE FAILURE ANALYSIS PLANT ENGINEERING MAINTENANCE SERIES Vibration Fundamentals R. Keith Mobley Root Cause Failure Analysis R. Keith Mobley Maintenance Fundamentals R. Keith Mobley ROOT CAUSE FAILURE ANALYSIS R. Keith Mobley Newnes Boston Oxford Auckland Johannesburg Melbourne New Delhi Newnes is an imprint of Butterworth-Heinemann. Copyright 0 1999 by Butterworth-Heinemann a A member of the Reed Elsevier group 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, with- out the prior written permission of the publisher. @ Recognizing the importance of preserving what has been written, Butterworth-Heinemann prints its books on acid-free paper whenever possible. Library of Congress Cataloging-in-Publication Data Mobley, R. Keith, 1943- Root cause failure analysis / by R. Keith Mobley. Includes index. ISBN 0-7506-7 158-0 (alk. paper) 1. Plant maintenance. p. cm. - (Plant engineering maintenance series) 2. System failures (Engineering) I. Title. 11. Series. TS192.M625 1999 658.2’024~2 1 98-32097 CIP British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. The publisher offers special discounts on bulk orders of this book. For information, please contact: Manager of Special Sales Butterworth-Heinemann 225 Wildwood Avenue Woburn, MA 01801-2041 Tel: 78 1-904-2500 Fax: 78 1-904-2620 For information on all Newnes publications available, contact our World Wide Web home page at: http://www.newnespress.com IO9 8 7 6 5 4 3 Printed in the United States of America CONTENTS Part I Introduction to Root Cause Failure Analysis Chapter 1 Introduction Chapter 2 General Analysis Techniques Chapter 3 Chapter 4 Safety-Related Issues Chapter 5 Regulatory Compliance Issues Chapter 6 Process Performance Root Cause Failure Analysis Methodology Part I1 Equipment Design Evaluation Guide Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter I I Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Pumps Fans. Blowers, and Fluidizers Conveyors Compressors Mixers and Agitators Dust Collectors Process Rolls GearboxesReducers Steam Traps Inverters Control Valves Seals and Packing i 3 6 13 58 67 73 75 77 07 112 173 137 153 164 171 187 1 93 302 ‘20 vi Contents Part III Equipment Troubleshooting Guide Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Chapter 24 Chapter 25 Chapter 26 Chapter 27 Chapter 28 Chapter 29 Chapter 30 Chapter 3 1 Pumps Fans, Blowers, and Fluidizers Conveyors Compressors Mixers and Agitators Dust Collectors Process Rolls Gearboxes or Reducers Steam Traps Inverters Control Valves Seals and Packing Others List of Abbreviations Glossary References Index 237 239 246 25 1 254 264 266 269 27 1 276 278 280 282 285 288 29 1 305 306 Part I INTRODUCTION TO ROOT CAUSE FAILURE ANALYSIS [...]... step-by-step guide for evaluating most recurring and serious incidents that may occur in a chemical plant Part One, Introduction to Root Cause Failure Analysis, presents analysis techniques used to investigate and resolve reliability-related problems It provides the basic methodology for conducting a root cause failure analysis (RCFA) The procedures defined in this section should be followed for all investigations... particular system failure 8 Root Cause Failure Analysis rn Define top event Establish boundaries - m Understand system 7 Construct fault tree 1 I Analyze tree Take corrective action Figure 2-2 ljpical fault-tree process called the top event, and basic failures or causes, called primary events Top events can be broad, all-encompassingsystem failures or specific component failures Fault-tree analysis provides... of the machine types found in a chemical plant This part includes quick-reference tables that define the common failure or 3 4 Root Cause Failure Analysis deviation modes These tables list the common symptoms of machine and processrelated problems and identify the probable cause( s) PURPOSE OF THE ANALYSIS The purpose of RCFA is to resolve problems that affect plant performance It should not be an attempt... fault events by event statements and logic gates General Analysis Techniques + i/, ' ~~ ,/ Pnmry Fuse Failure )t ~ + L 7 Pnmary W h g Fadwe (Shorhd) / 9 (Closed) \ A ' \ Figure 2-3 Example of a fault-tree logic tree CAUSE- AND-EFFECT ANALYSIS Cause- and-effect analysis is a graphical approach to failure analysis This also is referred to as jshbone analysis, a name derived from the fish-shaped pattern used... sequence of logical steps, starting with the analysis of lower-level subsystems or components Figure 2-1 illustrates a typical logic tree that results with a FMEA The analysis assumes a failure point of view and identifies potential modes of failure along with their failure mechanism The effect of each failure mode then is traced up to the system level Each failure mode and resulting effect is assigned... General Analysis Techniques q + disciplines 7 I ; i Acceptfailureeffed L Figure 2-1 Failure mode and effects analysis (FMEA)flow diagram Two major limitations restrict the use of FMEA: (1) logic trees used for this type of analysis are based on probability of failure at the component level and (2) full application is very expensive Basing logic trees on the probability of failure is a problem because... fish-shaped graph to plot the cause- effect relationship between specific actions, or changes, and the end result or event This approach has one serious limitation The jshbone graph provides no clear sequence of events that leads to failure Instead, it displays all the possible causes that 10 Root Cause Failure Analysis Figure 2-4 ljpicalfishbone diagram plots four categories o causes f may have contributed... P 6 Evaluate rnair&naIXd P 1 Devebp potential mot aua(s) 1 Verify c m by tednp a Figure 3-5 Flow diagram for equipment failure investigation Tart to verify mrmotlon Root Cause Failure Analysis Methodology 27 Analyze Sequence of Events Performing a sequence-of-events analysis and graphically plotting the actions leading up to and following an event, accident, or failure helps visualize what happened... replace them with known facts 3 ROOT CAUSE FAILURE ANALYSIS METHODOLOGY RCFA is a logical sequence of steps that leads the investigator through the process of isolating the facts surrounding an event or failure Once the problem has been fully defined, the analysis systematicallydetermines the best course of action that will resolve the event and assure that it is not repeated Because of the cost associated... with the person who first observed the problem Perceived Causes of Problem At this point, each person interviewed will have a definite opinion about the incident, and will have his or her description of the event and an absolute reason for the occurrence In 14 Root Cause Failure AnaIysis Methodology 15 I YOS _ Figure 3-I Initial mot causefailure analysis logic tree many cases these perceptions are totally . ROOT CAUSE FAILURE ANALYSIS I ROOT CAUSE FAILURE ANALYSIS PLANT ENGINEERING MAINTENANCE SERIES Vibration Fundamentals R. Keith Mobley Root. Keith Mobley Root Cause Failure Analysis R. Keith Mobley Maintenance Fundamentals R. Keith Mobley ROOT CAUSE FAILURE ANALYSIS R. Keith Mobley