ROTATING MACHINERY This third volume in a broad collection of current rotating machinery topics, written by industry experts, is a must-have for rotating equipment engineers, maintenance personnel, students, and anyone else wanting to stay abreast with current rotating machinery concepts and technology. Rotating Machinery Fundamentals and Advances represents a broad category of equipment, which includes pumps, compressors, fans, gas turbines, electric motors, internal combustion engines, etc., that are critical to the efficient operation of process facilities around the world. These machines must be designed to move gases and liquids safely, reliably, and in an environmentally friendly manner. To fully understand rotating machinery, owners must be familiar with their associated technologies, such as machine design, lubrication, fluid dynamics, thermodynamics, rotordynamics, vibration analysis, condition monitoring, maintenance practices, reliability theory, and others. The goal of the “Advances in Rotating Machinery” book series is to provide industry practicioners a time-saving means of learning about the most up-to-date rotating machinery ideas and best practices. This three-book series covers industry-relevant topics, such as design assessments, modeling, reliability improvements, maintenance methods and best practices, reliability audits, data collection, data analysis, condition monitoring, and more. Readers will find a good mix of theory and sage experience throughout this book series. Whether for the veteran engineer, a new hire, technician, or other industry professional, this is a must-have for any library. This outstanding new vcolume includes: Machinery monitoring concepts and best practices Optimizing Lubrication and Lubricant Analysis Machinery troubleshooting Reliability improvement ideas Professional development advice

Table of Contents:
Preface xix Acknowledgements xxi Part 1: Condition Monitoring 1 1 An Introduction to Machinery Monitoring 3 By Robert X. Perez 2 Centrifugal Pump Monitoring, Troubleshooting and Diagnosis Using Vibration Technologies 15 By William D. Marscher Introduction 15 Vibration Definitions 16 How Vibration vs. Time Relates to a Vibration vs. Frequency “Spectrum” 18 What are Reasons for Excess Vibration? 19 Relationship of Vibration to Centrifugal Pump Acceptability and Reliability 20 Vibration Standards, Informal and Formal: Intent and Basis 21 Vibration Measurement Form 22 Vibration Detection Sensors 25 Accelerometers 26 Proximity Probes 27 Motion Magnified Video (aka Vibration Video Amplification) 28 International Vibration Acceptance Standards 30 Pump Components Playing Key Roles in Vibration Diagnostics 33 Rotor Support by Bearings: Fluid Film Journal Bearings vs. Rolling Element Bearings 33 Rotor Support by Seals: Annular Seal “Lomakin Effect” 35 Couplings 38 Bearing Housings and Attachment Bolts 39 Pump Casing, Feet, and Foot Attachment Bolts 39 Pump Pedestals, Baseplate, and Foundation 40 Piping, Suction, and Discharge 40 Pump Drivers 43 Evaluating Causes of Excess Vibration: Excitation vs. Amplification 43 Process of Resonant Amplification due to Coincidence of Excitation and Natural Frequencies 45 Impact Test Method of Determining Natural Frequencies 46 Specific Forces in Centrifugal Pumps 48 Mechanical Excitation Forces 48 Balance 48 Misalignment 50 Mechanical Forces Due to Dry Running Pump, Dry Running Seal, Overtightened Seal 52 Hydraulic Forces and Blade Passing Frequency 52 Hydraulic Vibration Forces Below Running Speed, Including Subsynchronous Whirl 54 Detection of Effects of Cavitation 57 Torsional Excitations 59 Vibrations Particular to Various Centrifugal Pump Types 62 Vertical Turbine Pump Evaluation 62 Vertical Dry Pit Pump Vibration Issues 65 Submersible Pump Vibration Issues 65 End Suction Overhung Single Stage Pump Vibration Issues 66 Between Bearing Double Suction Single Stage Pump Vibration Issues 66 Horizontal Multistage Pump Vibration Issues 67 Steps in Pump Evaluation through Vibration Monitoring 68 Use of the Bode and Nyquist Plots to Confirm Natural Frequencies 70 Operating Deflection Shapes (ODS) 71 Conclusions 73 Nomenclature 73 References & Bibliography 74 Acknowledgements 75 3 Proximity Probes are a Good Choice for Monitoring Critical Machinery with Fluid Film Bearings 77 By Robert X. Perez Proximity Probe Benefits 77 Theory of Operation 78 Runout Concerns 80 Grounding and Noise 80 Shaft Orbits 81 General Machinery Monitoring Recommendations 82 Final Thoughts 85 References 86 4 Optimizing Lubrication and Lubricant Analysis 87 By Jim Fitch and Bennett Fitch Introduction 87 Optimum Reference State 88 Lubrication Excellence and the Ascend Chart 91 Bringing Awareness to Lubrication, Contamination, and Oil Analysis 94 What You Might Not Know About Lubrication 94 Machine Surface Interaction 94 The Lubricant Film 95 Film Strength 96 Unlubricated Surface Interactions 96 Friction and Wear Generation 96 Mitigating Surface Interactions 97 Physics and Chemistry 97 Contamination: The Antagonist to Lubrication 98 Contamination Control and Condition Monitoring is More Often about Training than Advanced Technology 98 Contamination Control 99 Don’t Leave It to Instinct 99 Creating a Balance Between Exclusion and Removal 100 Why Perform Oil Analysis 102 Fluid Properties Analysis 102 Contamination Analysis 103 Wear Debris Analysis 103 Achieving Oil Analysis Success by Looking Holistically 103 Obtaining a Representative Oil Sample 105 Select the Right Machines for Oil Analysis 105 Clean and Correct Sampling Containers and Extraction Tools 105 Correctly Located Sampling Ports 106 Proper Sampling Frequency 107 Proper and Consistent Sampling Procedures 107 Forward Samples Immediately to the Laboratory 108 Ensuring Reliable Testing 108 Certified Training of Laboratory Technicians 108 Optimized Selection of Tests 109 Onsite Oil Analysis 109 Determining the Optimum Course of Action 110 Effective Organization of Analysis with Proper Trending 110 Accurate Data Interpretation by the Laboratory 110 Enhanced Data Interpretation by the End-User 111 Take Corrective Action and Determine the Root Cause 112 Continuous Improvement and Key Performance Indicator (KPI) 112 Oil Analysis Tests 112 Viscosity 113 Acid Number and Base Number 113 Ftir 114 Elemental Analysis 114 Particle Counting 114 Moisture Analysis 115 Interpreting Oil Analysis Reports 116 Following the Data Trends 118 Looking Back at the Past 123 Inspection 2.0: Advances in Early Fault Detection Strategy 124 Low-Hanging Fruit 124 Inspection Frequency Trumps High Science 125 Beware of Short P-F and Sudden-Death Failures 127 Inspection Windows and Zones 128 Inspection 2.0 is a Nurturing Strategy 129 Final Tips to Help Error-Proof Your Lubrication Program 130 References 134 5 Troubleshooting Temperature Problems 135 By Robert X. Perez Temperature Assessments 135 How do Infrared Thermometers Work? 136 Bearing Temperature Trending 137 Rolling Element and Sleeve Bearing Temperature Guidelines 139 Rule of Thumb for Rolling Element Bearings: 142 Bearing Temperature Guidelines for Instrumented Hydrodynamic Bearings 142 Recommended Guidelines for Babbitt Bearings 142 Bearing Temperature Sensor Placement 143 Sleeve Bearings 143 Tilting Pad Journal (TPJ) Bearings-Load on Pad 144 Tilting Pad Journal Bearings-Load between Pads 144 Thrust Bearings-Tilting Pad 144 General Temperature Probe Installation Guidelines 145 Compressor Discharge Temperature Assessments 146 Heat of Compression 146 Types of Compression Processes 147 Adiabatic Compression 148 Polytropic Compression 152 Polytropic Example 1: 154 Polytropic Example 2: 154 Why Compression Ratio Matters 155 What Role It Plays in Compressor Design and Selection 155 Compression Ratio versus Discharge Temperature 155 Design Temperature Margin 158 Design Tradeoffs 159 Reciprocating Compressor Temperature Monitoring 160 Valve Temperature Monitoring 162 Temperature Monitoring Example 164 Summary 165 References 165 6 Assessing Reciprocating Compressors and Engines 167 By Robert X. Perez Overview of Reciprocating Compressors 169 General Monitoring Guidelines for Reciprocating Compressors 174 Impact Monitoring 177 Rod Drop Monitoring 178 Using Ultrasonics to Assess Reciprocating Machinery 178 Mystery Reciprocating Compressor Knock 179 Natural Gas Engines 181 How Accurate are Rotating Equipment and Reciprocating Equipment Analyst Findings? 190 References 193 7 Managing Critical Machinery Vibration Data 195 By Robert X. Perez Beware of False Positives and False Negatives 195 Vibration Analysis Strategies 197 Part 2: Troubleshooting 201 8 Addressing Reciprocating Compressor Piping Vibration Problems: Design Ideas, Field Audit Tips, and Assessment Methods 203 By Robert X. Perez Piping Restraints 205 Pipe Clamping Systems 207 Guidelines 207 Preloading Clamp Bolts 209 Piping Assessment Steps 210 Small-Bore Piping 211 Attaching Pipe Clamps to Structural Members 212 The Ideal Pipe Clamp Installation 213 Installation Examples 214 Collecting and Assessing Piping Vibration 217 Piping Analysis Steps 220 Piping Vibration Examples 221 Bolt Torque Tables 223 Chapter Glossary 224 9 Remember to Check the Rotational Speed When Encountering Process Machinery Flow Problems 227 By Robert X. Perez 10 Troubleshooters Need to be Well Versed in the Equipment They are Evaluating 233 By Robert X. Perez What is the Difference Between Troubleshooting and Conducting a Failure Analysis? 236 Equipment Details 237 Performance Characteristics 238 Centrifugal Compressors 238 Reciprocating Compressors 239 Basic Fluid Film Bearing Troubleshooting Tips 240 Design Basis: Speed, Pressures, Flows 241 System Design Details 243 OEM Recommendations 244 History 244 Putting it All Together 245 11 Precise Coupling Properties are Required to Accurately Predict Torsional Natural Frequencies 247 By Robert X. Perez Introduction 247 Case Study 247 Start-Up Issues 249 Field Vibration Study 249 Lesson Learned 252 Final Thoughts 253 12 Is Vibration Beating on Machinery a Problem? 255 By Robert X. Perez and Andrew P. Conkey What is Vibration Beating? 255 Zoom FFT (Fast Fourier Transform) Analysis 257 Electric Motor Zoom Analysis 258 Field Case Study: “Beating” Effect Caused by Two Closely Spaced Mechanical Frequencies Observed on Two-Shaft, Gas Turbine Drive 259 Background Information 260 Vibration Response Analysis 261 Investigation of System and Analysis 261 Frequency Analysis 262 Case Study Solution 263 Case Study Conclusions and Lessons Learned 263 Final Comments 263 References 264 Part 3: Reliability 265 13 Using Standby Machinery to Improve Process Reliability 267 By Robert X. Perez Introduction 267 Basic Reliability Theory 267 Exercising Spared Machinery 273 Alternating Twin, Non-Critical, Process Pumps 273 Recommended Swapping Procedures for Critical Motors, Pumps, Blowers, Compressors, Generators, and Steam Turbines 274 Recommended Swapping Procedures for Reciprocating Process Plant Machinery above 200 HP 275 Raptor Modeling Software 276 Modeling Examples 277 Example 1: Unspared Compressor 278 Example 2: Main and Spare Compressor Installation 279 Example 3: Two out of Three (2oo3) Compressor Configuration 280 The Cost of Redundancy 282 Example 4: Cost of Unreliability 283 Economics 284 Justifying of a Spare Compressor 285 Closing Thoughts 287 References 287 14 Gas Turbine Drivers: What Users Need to Know 289 By Robert X. Perez Overview 289 Theory of Operation 292 How Does a Gas Turbine Work? 292 Air Compressor 294 Combustors 296 Transition Pieces 297 Expansion Turbine 298 Turbine Section Challenges and Solutions 299 Two Shaft Gas Turbine Construction Details 301 Gas Producer 301 Lower Pressure Power Turbine (LP) 301 Typical Conditions Inside an Industrial Gas Turbine 303 Effect of Atmospheric Conditions 304 Gas Turbine Controls 305 Protection 305 Fuel and Fuel Treatment 306 Gas Fuels 306 Degradation and Water Washing 306 Advanced Materials for Land Based Gas Turbines 307 Blade Degradation 308 Condition Monitoring Approaches 309 Aerothermal Performance Analysis 309 Vibration Analysis 310 Transient Analysis 311 Mechanical Transient Analysis 311 Dynamic Pressure Analysis 312 Lube Oil Debris Analysis 312 Borescope Inspection 312 Condition Monitoring as a System 313 Gas Turbine Maintenance Inspections 313 Standby Inspections 314 Running Inspections 314 Combustion Inspections 316 Hot Gas Path Inspections 316 Major Inspections 316 Life Cycle Management 318 Non-Destructive Testing (NDT) 320 Spare Parts 321 Final Words of Advice 322 References 323 15 Reliability Improvement Ideas for Integrally Geared Plant Air Compressors 325 By Abdulrahman Alkhowaiter Integrally Geared Plant Air Compression Packages 325 Reliability Concerns 327 Developing Enhancements for Air Compressor Reliability and Performance 330 Reliability Improvement Program to Achieve Reliability and Eliminate Frequent Failures 330 Reliability Improvements (based on 2008 Report) Made to Five (5) 850 HP Air Compressor Failures by Engineering and Maintenance: 331 16 Failure Analysis & Design Evaluation of a 500 KW Regeneration Gas Blower 341 By Abdulrahman Alkhowaiter Introduction 341 Detail Design Analysis 343 Conclusion 349 Needed Action by Repair Shop 350 Action Required by Refinery 350 17 Operating Centrifugal Pumps with Variable Frequency Drives in Static Head Applications 353 By Robert X. Perez VFD Advantages 354 Static Head Systems 356 Recommended Startup Sequence 359 Final Thoughts 362 References 362 18 Estimating Reciprocating Compressor Gas Flows 363 By Robert X. Perez Swept Volume 364 Clearance Volume 365 Volumetric Efficiency 365 Flow Calculation Example 370 Factors Affecting Compressor Flow 371 Final Words 371 19 Use Your Historical Records to Better Manage Time Dependent Machinery Failure Modes 373 By Robert X. Perez Part 4: Professional Development 379 20 Soft Skills and Habits that All Machinery Professionals Need to Develop 381 By Robert X. Perez Asking Probing Questions 383 Listening More Carefully 384 Observing 385 Continuously Learning 386 Praising 387 Teaching 388 Closing Remarks 390 21 Developing Rotating Machinery Competency 391 By Robert X. Perez Part I: Preparing Students to Work with Rotating Machinery 391 Rotating Machinery Related Job Functions 391 Part II: Steps to Improving Rotating Machinery Competency: Study-Practice-Share 396 About the Editor 403 About the Contributors 405 Index 409