Machinery Failure Analysis Handbook - Sustain Your Operations and Maximize Uptime

266 Pages·2006·13.021 MB·266\266

by  Affonso, Luiz Octávio Amaral

Machinery Failure
Analysis Handbook
Sustain Your Operations
and Maximize Uptime
Luiz Otiivio Amaral AfFonso
Houston, Texas
Machinery Failure Analysis Handbook
Sustain Your Operations and Maximize Uptime
Copyright 0 2006 by Gulf Publishing Company, Houston, Texas.
All rights reserved.
No part of this publication may be reproduced or transmitted in any form
without the prior written permission of the publisher.
Gulf Publishing Company
2 Greenway Plaza, Suite 1020
Houston, TX 77046
1 0 9 8 7 6 5 4 3 2 1
Printed in the United States of America.
Printed on acid-free paper.
Text design and composition by Ruth Maassen.
Library of Congress Cataloging-in-Publication Data
Affonso, Luiz Otivio Amaral.
Machinery failure analysis handbook : sustain your operations
and maximize uptime / Luiz Ot6vio Amaral Affonso.
p. cm.
Includes bibliographical references and index.
ISBN 1-93 3762-08-X (alk. paper)
1. Machinery-Maintenance and repair-Handbooks, manuals, etc.
2. Plant maintenance-Handbooks, manuals, etc. I. Title.
TS191.A.34 2006
658.2'74~22
Preface
Process industries are home to a huge number of machines, most of
them critical to the industry’s mission. Failures of these machines
can result in consequences that range from the simple replacement
of a cheap bearing to an accident that may cost millions in lost pro-
duction or cause injuries or pollution.
Competition forces corporations to try to keep pace in opti-
mization. On the machinery side of the history, this means improv-
ing efficiency and reliability and reducing maintenance cost. Design
and purchase specifications, shop testing, installation, maintenance,
and operation all play a role in these efforts.
The objective of this book is to help anyone involved with
machinery reliability, be it in the design of new plants or the main-
tenance and operation of existing ones, to understand why the pro-
cess machine fails, so some preventive measures can be taken to
avoid another failure of the same kind.
The book is divided in four parts:
1. An introduction that discusses the fundamental causes of fail-
ures, including some definitions and examples. Here, we exam-
ine the failure analysis procedure, including some approaches
suitable for different types of problems. We also look at how
plantwide failure prevention efforts should be conducted,
including a discussion about the importance of the role of the
plant operator in the reliability of the machinery.
xi
xii Preface
2. A discussion of the failure mechanisms that affect process
machinery most often, such as fractures and wear.
3. An examination of how the actual machine parts fail, with sev-
eral examples of bearings, seals, and other components failures.
4. Examples of real machinery failures analyzed by the author.
I offer no warranty regarding the applicability of the informa-
tion contained in this book to any particular situation.
This English edition has been based on the second Portuguese
edition, published in Brazil in 2006.
Contents
Preface xi
PART I Introduction to Failure Analysis
1 Fundamental Causes of Failures 3
1.1 Design Failures 4
1.2 Material Selection Deficiencies 6
1.3 Material Imperfections 7
1.4 Manufacturing Defects 8
1.5 Assembly and Installation Errors 9
1.6 Maintenance and Operation Errors 10
Conclusion 11
2 Failure Analysis Practice 13
2.1 Failure Analysis Objectives 13
2.2 How Far Should We Go? 14
2.3 Main Steps 17
2.4 Reports and Databases 22
3 Failure Prevention Efforts 25
3.1 Types of Failures 26
3.2 Prevention of Failures 27
3.3 Machinery Monitoring and Anticipatory Action 28
3.4 Operator’s Role in Machinery Reliability 28
V
vi Contents
PART lI Failure Modes
4 Ductile and Brittle Fractures 33
4.1 Ductile Fracture Morphology 34
4.2 Ductile Fracture Mechanism 36
4.3 Brittle Fracture 37
4.4 Brittle Fracture Morphology 38
4.5 Brittle Fracture Mechanism 39
5 Fatigue Fractures 43
5.1 Fatigue Fracture Mechanism 44
5.2 Fatigue Fracture Surface Morphology 47
5.3 Factors That Influence Fatigue Strength 50
6 Wear 55
6.1 Sliding Wear 55
6.2 Hard Particle Wear 71
6.3 Liquid Impingement Wear 78
6.4 Cavitation 80
7 Corrosion 83
7.1 Electrochemical Corrosion Mechanism 84
7.2 Uniform Corrosion 86
7.3 Corrosion Fatigue 89
7.4 Pitting Corrosion 91
7.5 Galvanic Corrosion 92
7.6 Corrosion Erosion 94
7.7 Stress Corrosion Cracking 95
8 Incrustation 101
8.1 Coke Deposition 102
8.2 Salt Deposition 105
8.3 Biological Incrustation 107
9 Electric Discharge Damage 109
Contents vii
PART III Machinery Component Failures
10 Shafts 117
10.1 Stresses Acting on a Shaft 119
10.2 Fatigue Failures 12 1
10.3 Shaft Wear 123
10.4 Shaft Distortion 124
11 Hydrodynamic Bearings 125
11.1 Operation of a Hydrodynamic Bearing 126
11.2 Hydrodynamic Bearing Construction 128
11.3 Hydrodynamic Bearing Failure Analysis 128
11.4 Fatigue Failures 129
11.5 Bearing Metal Wear 129
11.6 Corrosion 132
11.7 Effect of Hard Particles on Bearings 132
11.8 Effect of Lubrication 134
11.9 Effect of Temperature 134
11.10 Effect of Overloads 136
11.11 Assembly Deficiencies 136
11.12 Electrical Discharge Damage 136
11.13 Fabrication-related Failures 138
11.14 Design-related Failures 140
12 Antifriction Bearings 143
12.1 Antifriction Bearing Lubrication 144
12.2 Antifriction Bearing Design Life 145
12.3 Contact Patterns on Bearing Races 147
12.4 Antifriction Bearing Failure Analysis 148
12.5 Types of Failure 151
13 Mechanical Seals 173
13.1 How a Mechanical Seal Works 174
13.2 Seal Mechanical Design 176
13.3 Seal Hydrodynamic Design 179
v
13.4 P x 179
...
Contents
vlll
13.5 Sealing System 182
13.6 Mechanical Seal Failure Analysis 184
13.7 Face Contact Patterns 185
13.8 Failure Mechanisms and Causes 186
13.9 Corrosion of Seal Components 186
13.10 Mechanical Damage 190
13.11 Thermal Damage 201
13.12 Design and Manufacturing Defects 203
14 Bolts 205
14.1 How a Bolt Works 206
14.2 Application of the Preload 206
14.3 Reusing Bolts 208
14.4 Bolt Failure 208
15 Gears 215
15.1 Gear Tooth Contact and Lubrication 215
15.2 Loads Acting on the Gear Teeth 2 19
15.3 Gear Failure 2 19
16 Reciprocating Compressor Valves 229
16.1 How a Compressor Valve Works 230
16.2 Valve Failure 23 1
17 Belt Transmissions 237
17.1 'V" Belts 238
17.2 Synchronized Belts 2 40
18 couplings 243
18.1 Disc Coupling Couplings 244
18.2 Grid Couplings 2 46
18.3 Gear Couplings 247
18.4 Coupling Standardization 251
19 Turbomachinery Blades 253
19.1 How a Turbomachinery Blade Works 253
19.2 Blade Failure Analysis 2 54
Con tents ix
PART lV case studies
20 Failure Analysis Examples 271
20.1 A Pump Failure Caused by Turbine Driver
Overspeed 271
20.2 Hydrogen Compressor Seal Failure 2 79
20.3 Vibration-induced Fatigue Failures of Identical
Reciprocating Compressors 2 82
20.4 A Gearbox Failure from the Electrical Discharge
Damage of a Bearing 2 88
Bibliography 293
Index 29J
Part I
Introduction to
Failure Analysis