Maintenance, Reliability and Troubleshooting in Rotating Machinery

ISBN-13: 9781119631644 / Angielski / Twarda / 2022 / 381 str.

Robert X. Perez

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Preface xviiAcknowledgements xixPart I: General Reliability Advice 11 Machinery Reliability Management in a Nutshell 3By Robert X. PerezCriticality 4Environmental Consequences 6Safety Consequences 6Equipment History 7Safeguards 12Compressor Operating Limits 12Compressor Flow Limits 12Critical Speeds 14Horsepower Limits 15Temperatures 16Layers of Machinery Protection 19Machinery Reliability Assessment Example 20Background 20History 22Safeguards 22Conclusion 22Closing Remarks 232 Useful Analysis Tools for Tracking Machinery Reliability 25By Robert X. PerezCommonly Used Metrics for Spared Machinery 28Mean Time to Repair (MTTR) 28Mean Time Between Failure (MTBF) 28Additional Reliability Assessment Tools for Spared Machines 29Pareto Charts & 80-20 Rule 33Cumulative Failure Trends 33Metrics for Critical Machines 36Availability 37Critical Machine Events 38Process Outage Trends 38Process Outage Related to Machinery Outages 40Planned Maintenance Percentage (PMP) 41Reliability Analysis Capabilities of your CMMS Software 433 Improving the Effectiveness of Plant Operators 45By Julien LeBleuLook, Listen and Feel 47Applying Look, Listen, and Feel Techniques to Troubleshooting 47Why the Operator's Input is Important to the Troubleshooting Process 47Operator Tools 48Understanding the Equipment - Pumps, Seals and Sealing Support Systems 50Centrifugal Pump Relationships to Remember 51Positive Displacement Pump Relationships to Remember 52Mechanical Seals 54Capital Projects 55Writing Quality Work Request 55Procedures (Procedures and Decision Trees) 56Must Give Operators Feedback 56Must be Required to Use their Training 58Discipline 58Conclusion 59Appendix A References 594 Spare Parts Strategies for Optimizing Rotating Machinery Availability 61By Robert X. PerezSome Stocking Examples 67Capital Spares 70Insurance Spares 71Analyzing Spare Part Inventories Using Monte Carlo Simulations 72Closing 72Some Definitions Related to Spare Parts 735 Switch-Over Methodology and Frequency Optimization for Plant Machinery 75By Abdulrahman AlkhowaiterMachinery Switchover Frequency Optimization Benefits 76Time-Dependent Issues Involved in Setting Switchover Frequency for Standby Machines 76Frequent Switchover Introduces the Following Negative Impact to Rotating Equipment 79Calculation of Start-Stop Damaging Cycles for A, BConfigured Equipment: See Definitions Below for More Information 81Definitions 82Examples of Short Start-Stop Intervals in Process Machinery 83Philosophy of Reliability-Centered Switchover Strategy 84Part II: Design Audits and Improvement Ideas 876 Evaluating Centrifugal Pumps in Petrochemical Applications 89By Robert X. PerezCrude Oil Processing 92Desalting 94Crude Oil Distillation 94Properties of Distillation and Fractionator Fractions 98Defining NPSHr, NPSH3, and NPSH Margin 101Natural Gas Processing: NGL Processing 101Centrifugal Pump Design Audits 104Design Standards 105The Materials of Construction 107The Hydraulic Fit 108The NPSH Margin 110Seal and Seal Flush Design 111Challenging Pump Applications 113Pumps Operating in Parallel 114Pump Liquids with Low Densities 117Low NPSH Services 120How an Impeller's Suction Specific Speed Affects the Required NPSH 122Pumps Handling a Liquid with Varying Densities 124Slurry Pumps 125FCC Slurry Pumps 127Bottoms Pumps 127Hot Pumps with Galling Tendencies 130Starting Hot Pumps 131High Temperature Concerns 132Gaskets 132O-Rings 135How Processing Issues Can Affect Pump Reliability 136Summary 138Acknowledgement 139References 1397 Practical Ways to Improve Mechanical Seal Reliability 141By Robert X. PerezSeal Reliability Tracking 142MTBR Data from Across the Industry 143Reliability Tracking Tools 144Bad Actors 145Mechanical Seal Best Practices 150Improved Mechanical Seal Support System Designs 153Reducing Potential Leak Points 154Simplifying Operation and Maintenance 155Building Better Seal Support Systems 157Common Mechanical Sealing Design Challenges 157Sealing Light Hydrocarbon Liquids 157Sealing Hazardous Organic NESHAP Liquids 159Buffer Gas Absorption 160Excessive Solids 160Seal Cooler Issues in Hot Applications 162Piping Plan 21 162Advantages 163Disadvantages 163Piping Plan 23 164Advantages 165Disadvantages 165Common Considerations for Flush Plans 165General Seal Piping Plan Recommendations 166Ways to Improve Seal Reliability Performance 167Seal Failure Analysis 167Common Seal Failure Modes 168Seal Failure Inspection Notes 174Possible Causes 175Meeting with Manufacturer 175Writing the Seal Failure Report with Recommendations 175Post-Analysis Activities 175Justifying Seal Upgrades 175Closing Thoughts 179References 1808 Proven Ways to Improve Steam Turbine Reliability 181By Robert X. Perez and David W. LawhonRepairs versus Overhauls 181Expected Lifetimes of Steam Turbines and TheirComponents 181Common Failure Modes 184Steam Turbine Leaks 184Bearing and Lubrication Failures 184Governor Failures and Sticking T&T Valves 184Improvement Reliability by Design 185Acknowledgements 1879 General Purpose Steam Turbine Reliability Improvement Case Studies 189By Abdulrahman AlkhowaiterGovernor Valve Packing Gland Leakage: Sealing & Reliability Improvements 190Steam Turbines Carbon Seals Upgrade to Mechanical Seals 192Typical Benefits of Dry Gas Seal in a 1500 HP Turbine 193Modification of GP Turbines for Fast Start without Slow Rolling 195How the GP Turbine Fast Startup Modification Works 195Dry Flexible Metal Coupling Upgrade with Split Spacer, for Short Coupled Turbines with Insufficient ength Coupling Spacers 196General Purpose Lube Oil System Upgrade for Self-Contained Bearing Housings to Eliminate Overheating & Bearing Failures 198Governor and Trip System Upgrade from Hydraulic to Electronic-Pneumatic 198Governor Requirements 198Electronic Governor with Pneumatic Actuator & Pneumatic Trip System 199Governor and Trip Requirements 200Overview of All-Electronic Trip and Overspeed Protection System 201Outboard Bearing Improved Flex Foot: Higher Turbine Reliability & Lower Vibration 201Results 203Part III: Maintenance Best Practices 20510 Rotating Machinery Repair Best Practices 207By Robert X. PerezWorld-Class Reliability Performance Should be the Goal of Every Repair Facility 207Cutting Corners = Unreliability 208The Importance of Alignment 209Alignment Tolerances 210Alternative Alignment Guidelines 210Alignment Calculation Example 211Rotor Balance 211Imperial Units 212Metric Units 213Static Unbalance 213Dynamic Unbalance 213Balancing 213Common Causes of Rotor Unbalance 214Balancing Grades 215The Importance of Fit, Clearance & Tolerance 217Fits, Clearances and Tolerances 217Tolerance 217Clearance 218Coupling Hub Fits 219Keyed Interference Fits 219Keyless Interference Fits 219Effects of Excessive Looseness 220Rotating Element Looseness 221Effects of Internal Looseness 222Structural Looseness 223As Found and As Left Measurements 223Closing Thoughts 225References 22511 Procedures + Precision = Reliability 227By Drew Troyer12 The Top 10 Behaviors of Precision-Maintenance Technicians 231By Drew Troyer13 Optimizing Machinery Life Cycle Costs through Precision and Proactive Maintenance 235By Drew TroyerPrecision Maintenance 101 235Life-Extension Equations 237Worked Example 238Life Cycle Costs 239Considering Energy Consumption 239Life Cycle Inventory Analysis 242Justifying Precision Maintenance 242Estimating the Benefits 242Now for the Cost-Benefit Analysis 24514 Optimum Reference States for Precision Maintenance 253By Drew TroyerFasteners 254Lubrication 255Alignment 257Balance 258Flab Management 260Conclusion 26115 Writing Effective Machinery Work Order Requests 263By Drew TroyerPart IV: Analyzing Failures 26916 Improving Machinery Reliability by Using Root Cause Failure Analysis Methods 271By Robert X. PerezIntroduction 271What Is a Root Cause Failure Analysis? 272Root Cause Failure Analysis Example #1: Ill-Advised Bearing Replacement 273History 273Corrective Measures 273Comments 273Root Cause Failure Analysis Example #2: Reciprocating Compressor Rod Failure 274Background 274Physical Root Cause 274Latent Root Causes 274Comments 275RCFA Steps 275Step 1: Define the Problem 275Step 2: Gather Data/Evidence 276Identifying the Physical Root Cause of the Primary Failure 276Fatigue Example: Fin-Fan Cooler Shaft Failures 279Preserving Machine Data 282Step 3: Ask Why and Identify the Causal Relationships Associated with the Defined Problem 283Causal Chains 283Bearing Failure Sequence of Events with Descriptions 284Five Why RCFA Example 286Cause Mapping 287Cause Map Example #2 289Single Root Cause versus Multiple Causes 290Cause Mapping Steps 290Inhibitors to Effective Problem Solving 297When Is a Root Cause Failure Analysis Justified? 297RCFA Levels 300Closing Thoughts 301Appendix A 301No Magic Allowed 301Identifying Sequence of Events and Causal Chains 3015-Why Method of Investigation 304Advice on Failure Sequences 306Appendix B 307Analyzing Component Failure Mechanisms 307Common Mechanical Failure Modes 309Foreign Object Damage (FOD) 309Stress Corrosion Cracking 309Erosion 310Cavitation 310Hydrogen Embrittlement 310Galling 311Fretting 311Hot Corrosion (Gas Turbines) 312Common Hydrodynamic Bearing Failure Modes 313Rolling Element Bearing Failure Characteristics 318Tips for Analyzing Mechanical Seal Failures 320Common Seal Failure Modes 321Appendix C 323Common Machinery Failure Modes 323Pluggage 325Erosive Wear 326Fatigue 326Compressor Blade Fatigue Example 327Hydrodynamic Bearing Failure Examples 328Rubbing 329Unique Failure Modes 330References 33117 Investigation and Resolution of Repetitive Fractionator Bottom Pump Failures 333By Abdulrahman AlkhowaiterIntroduction 333List of Additional Failure Inherent Causes to Be Rectified 334Key Shop and Field Pump Measurements 336Conclusion 340Actual Findings 340Effect of Improvements on Pump Radial Shaft Vibration 342Reference 34218 Reliability Improvements Made to 6000 KW Water Injection Pumps Experiencing Wear Ring Failures 343By Abdulrahman AlkhowaiterSummary 343Sequence of Events 344New Design Proposal of Eliminating Grub Screws or Flash Butt Welding 346Example: Wear ring ID = 8.0 inches. Apply Taper Fit Principle 346Upgrade Options 347Detailed Analysis of Problem & Solution Related to All Pump Wear Rings 348Discussion on Reliability Improvements Added to Achieve High Reliability 349The Five Root Causes of Machinery Failure 350Design Errors 350Manufacturing Errors: None Found 351User Specification Errors 351User Maintenance Errors: None Found 351About the Editor 353About the Contributors 355Index 357

O autorze

Robert X. Perez is a mechanical engineer with more than 40 years of rotating equipment experience in the petrochemical industry. He has worked in petroleum refineries, chemical facilities, and gas processing plants. He earned a BSME degree from Texas A&M University at College Station, an MSME degree from the University of Texas at Austin and holds a Texas PE license. Mr. Perez has written numerous technical articles for magazines and conferences proceedings and has authored five books and coauthored four books covering machinery reliability, including several books also available from Wiley-Scrivener.