Trinath Sahoo - Root Cause Failure Analysis

1 Cover

2 Title Page

3 Copyright Page

4 Preface

5 About the Author

6 Acknowledgment

7 Dedication Page

8 1 FAILURE: How to Understand It, Learn from It and Recover from It Failure Type Benefits of Failure Analysis Conclusion

9 2 What Is Root Cause Analysis The Causes of TITANIC disaster What Is Root Cause Analysis? Top Reasons Why We Need to Perform RCFA Conclusion

10 3 Root Cause Analysis Process What is root cause analysis Define the problem Collection of data Analyze Sequence of Events Design Review The Five Whys Fishbone Diagram Fault Tree Analysis Identify the Root Cause Recommend and Implement Solution Conclusion

11 4 Managing Human Error and Latent Error to Overcome Failure Review of Some of the Accidents Types of Human Failure: The Prevention of Human Error Ways to Reduce Human Error Conclusion

12 5 Metallurgical Failure Understanding the Basics Brittle vs. Ductile Fracture characteristics Example: Failure of a Pipe Stages in Ductile Fracture Brittle Fracture Characteristics Origin of Fractures (Ductile and Brittle) Fatigue Failures Stress Concentration Stress Corrosion Cracking Hydrogen Damage Failure Investigation Collection of Background Data and Samples Data Analysis, Conclusions and Report Conclusion

13 6 Pipe Failure Classification of Failure Mechanisms Causes of Premature Failures in Piping How to Overcome Piping System Failure How to Mitigate Corrosion How to Reduce the Risk of Water Hammer Inspection and Maintenance Plan to Avoid Failure Understand the Ways in Which the Piping Can Fail Conclusion

14 7 Failure of Flanged Joint Creating the Seal Forces Acting on a Gasket Joint Integrity of the Bolted Flange Connections Protection of Bolts Gasket Reliability Failure Related to Flange Problems with Installation Conclusion

15 8 Failure of Coupling Flanged Rigid Couplings Ribbed Rigid Couplings Sleeve Rigid Couplings Quill Shaft Rigid Couplings Flexible Coupling How General‐Purpose Couplings Work Special‐Purpose Couplings Coupling Selection for Reliability Coupling Fit Cause of Coupling Failure Proper System Maintenance Special‐Purpose Coupling Failure Mode Conclusion

16 9 Bearing Failure Anti‐Friction Bearings AntiFriction Bearing – Type, Selection, and Failure Mode Bearing Basics Bearing Selection Process Bearing Service Life Bearing Tolerances, Fits, and Clearances Sealing Devices Journal Bearing Journal Bearing Failure Mechanisms Conclusion

17 10 Mechanical Seals Failure Type of Mechanical Seal Application Cooling System and API Plans Seal Installation, What to See Conclusion

18 11 Centrifugal Pump Failure Pump Failure Causes Failure Due to Operational Reasons Other Mechanical Consideration Bearing Failure Seal Failure Conclusion

19 12 Reciprocating Pumps FailureWorking Principle Power Pump Operation and Construction Conclusion

20 13 Centrifugal Compressor Failure Characteristics of Centrifugal Compressor Major Components of a Centrifugal Compressor Conclusion

21 14 Reciprocating Compressor Failure Major Components Reciprocating Compressor Failure Causes Pressure Packing Failure Piston Ring/Rider Ring Wear Process Related Problems in Reciprocating Compressor Maintenance Related Issues Machine Monitoring Conclusion

22 15 Lubrication Related Failure in MachineryIntroduction Lubrication Related Failure in Sump and Circulating System of Turbomachinery Lubrication Related Failure Specific to Reciprocating Compressor Lubrication Program Management Important Points to Be Considered for Developing an Effective Lubrication Program Understanding Oil Analysis: How It Can Improve Reliability Conclusion

23 16 Steam Traps Failure Thermodynamic Trap Float Trap Inverted Bucket Trap Thermostatic Traps Thermostatic Metallic‐Expansion Trap Balanced‐Pressure Thermostatic Trap Bimetallic Trap Selection Criteria Common Problems of Steam Traps Maintenance of Steam Traps Conclusion

24 17 Proactive Measures to Avoid Failure What Are Proactive Maintenance Tasks Evolution of Different Type of Maintenance Condition Monitoring Technologies Proactive Inspection Program for Static Equipments Condition Monitoring and The Internet of Things Conclusion

25 Index

26 End User License Agreement

1 Chapter 4 Table 4.1 Industrial accidents caused by human error.

2 Chapter 9Table 9.1 Max DN value of bearing.

3 Chapter 14Table 14.1 Percentage failure due to separate compressor components.and proce...

1 Chapter 2 Figure 2.1 Events leading to compressor failure.

2 Chapter 4 Figure 4.1 Contributing factors to human error.

3 Chapter 5 Figure 5.1 Stress–strain diagram of a medium‐carbon structural steel. Figure 5.2 Stress–strain curve of brittle and ductile material. Figure 5.3 Ductile vs brittle fracture. (a) Very ductile, soft metals (e.g.,... Figure 5.4 Different stages before ductile fracture. (a) Necking (b) formati... Figure 5.5 Cup and cone fracture in Al. Figure 5.6 Brittle fracture in a mild steel. Figure 5.7 Ductile failure: ‐one piece ‐large deformation (after some amount... Figure 5.8 Brittle failure: ‐many pieces ‐small deformation, (even when the ... Figure 5.9 Schematic representation of the fatigue crack (three stage) pheno... Figure 5.10 Stress concentration at corners. Figure 5.11 Stress corrosion on a bar. Figure 5.12 Stress corrosion cracking.

4 Chapter 7Figure 7.1 Forces acting on a gasket.Figure 7.2 Tensile stress strain diagram of fastener.Figure 7.3 Use of sleeve around bolt.Figure 7.4 Use of conical washer around bolt.Figure 7.5 Gap in flange.Figure 7.6 Flange cocked.Figure 7.7 Mis‐aligned flange.Figure 7.8 Out of parallel flange.Figure 7.9 Wrong surface finish of flange.Figure 7.10 Bolting sequence of flange.

5 Chapter 8Figure 8.1 Flanged rigid coupling.Figure 8.2 Cutaway view (DBC‐ Bolt circle dia.)Figure 8.3 Ribbed rigid coupling.Figure 8.4 Sleeve rigid coupling.Figure 8.5 Quill shaft rigid coupling.Figure 8.6 Gear coupling.Figure 8.7 Grid coupling.Figure 8.8 Disc coupling.Figure 8.9 Pin bush type coupling.Figure 8.10 Jaw coupling.Figure 8.11 Corded tire couplings.Figure 8.12 Disc couplings.Figure 8.13 Diaphragm type couplings.Figure 8.14 Hydraulic hub installation tool.Figure 8.15 Couplings tire failure.Figure 8.16 Improperly fitted key.Figure 8.17 Gear teeth worn from excessive misalignment.Figure 8.18 Disc pack coupling.Figure 8.19 Disc pack failure.Figure 8.20 Bolt damage.Figure 8.21 Excessive angular misalignment and axial movement diaphragm fail...

6 Chapter 9Figure 9.1 Type of antifriction bearings.Figure 9.2 Bearing internal clearance.Figure 9.3 Mounting force applied to the wrong ring.Figure 9.4 Advanced spalling due to subsurface initiated fatigue of the mate...Figure 9.5 Spalling (surface distress) caused by ineffective lubrication.Figure 9.6 Moisture acids in a spherical roller bearing – Moisture corrosion...Figure 9.7 Water in bearing.Figure 9.8 False brinelling.Figure 9.9 Fatigue fracture of the outer ring flange in a double row full co...Figure 9.10 Typical plain journal bearing.Figure 9.11 Pressure profile in a journal bearing.Figure 9.12 Stribeck curve relating friction factor to viscosity, speed, and...Figure 9.13 Sleeve journal bearing.Figure 9.14 Two‐lobe lemon‐shaped sleeve bearing with pressure‐dam.Figure 9.15 Tilting pad journal bearings.Figure 9.16 Bearing melting.Figure 9.17 Bearing damage due to abnormal load.Figure 9.18 Regions of babbitt material creep in a hot‐running region of a c...Figure 9.19 Severe wiping on a thrust shoe (circumferential scratching, narr...

7 Chapter 10Figure 10.1 Cross section view of centrifugal pump.Figure 10.2 Cross section view of Mechanical seal.Figure 10.3 Leakage path in seal.Figure 10.4 Components of Mechanical seal.Figure 10.5 Pusher seal.Figure 10.6 Cross section view of pusher seal.Figure 10.7 High‐speed stationary welded metal bellow seal schematic.Figure 10.8 API seal Plan 11 (Recirculation from the pump discharge through ...Figure 10.9 H–Q curve of a centrifugal pump.Figure 10.10 Balance pressure mechanical seal schematic drawing.Figure 10.11 Operating envelope for a contacting seal.Figure 10.12 Radial force and total dynamic head vs. capacity.Figure 10.13 Shaft length – L3/D4.Figure 10.14 Critical pump dimensions.Figure 10.15 Critical pump features.Figure 10.16 Concentric runout.Figure 10.17 Perpendicular runout.Figure 10.18 Shaft end float.