Mechanical Fault Diagnosis and Condition Monitoring

Although the most sophisticated fault diagnosis and condition monitoring systems have their origin in the aerospace and nuclear energy industries, their use is by no means restricted to such areas of 'high technology'. Modern machinery in most industrial plants is now so complex and expensive that mechanics find it increas- ingly difficult to detect failure by, for instance, recognising changes in sound 'signatures', and few plants can afford the luxury of regular 'stripping down'. Increasingly, therefore, eady-warning devices are being employed in an effort to prevent catastrophic breakdown. This book provides the first co-ordinated compilation of fault diagnosis and con- dition monitoring devices. It proceeds in three logical steps. The eady chapters deal with those conditions which contribute to deterioration and the consequent likely development of faults. The middle part of the book considers the various tech- niques of monitoring and discusses the criteria for their selection in different situ- ations. The final chapters provide a guide to the interpretation of the information signals deriving from monitoring, relating to reliability science and the mathematics of probability, and thus providing decision data on which management can act.

Table of Contents:
1 Failure types, investigation and occurrences.- 1.1 Introduction.- 1.2 System failure and component failure.- 1.3 Failure decisions.- 1.4 Failure classifications.- 1.5 Types of failure.- 1.6 Failure investigations.- 1.7 Failure case studies.- 1.8 Human factors in failure incidents.- 2 Causes of failure.- 2.1 Introduction.- 2.2 Service failures.- 2.3 Fatigue.- 2.4 Excessive deformation.- 2.5 Wear.- 2.6 Corrosion.- 2.7 Blockage, sludges.- 2.8 Blockage in cooling systems.- 2.9 Design, manufacturing and assembly causes of failure.- 3 Fault detection sensors.- 3.1 Introduction.- 3.2 Contaminant monitoring.- 3.3 Corrosion monitoring.- 3.4 Force monitoring.- 3.5 Gas leakage monitoring.- 3.6 Air pollution monitoring.- 3.7 Liquid contamination monitoring.- 3.8 Non-destructive testing techniques.- 3.9 Optical examination.- 3.10 Temperature sensing.- 3.11 Particle testing.- 3.12 Proximity monitors.- 3.13 Sound monitoring.- 3.14 Vibration transducers.- 3.15 Telemetry.- 4 Data processing and analysis.- 4.1 Introduction.- 4.2 Fourier analysis.- 4.3 Frequency analysis techniques.- 4.4 Derived functions.- 5 Vibration analysis.- 5.1 Introduction.- 5.2 Vibration-simple harmonic motion concept.- 5.3 Vibration signature of active systems.- 5.4 Vibration monitoring equipment.- 5.5 System monitors and vibration limit detectors.- 5.6 Vibration monitoring experience.- 5.7 Critical vibration levels.- 6 Sound monitoring.- 6.1 Introduction.- 6.2 Sound frequencies.- 6.3 Sound loudness measurement.- 6.4 Acoustic power.- 6.5 Sound measurement.- 6.6 Magnetic tape recorders.- 6.7 Sound level meters.- 6.8 Sound analysers.- 6.9 Sound signal data processing.- 6.10 Sound monitoring.- 7 Discrete frequencies.- 7.1 Introduction.- 7.2 Simple vibrations.- 7.3 Transverse vibrations of bars - approximate frequency calculations.- 7.4 More precise evaluations - overtones.- 7.5 Torsional oscillation of flywheel-bearing shafts.- 7.6 Belt drives.- 7.7 Whirling of marine line shafting.- 7.8 Gear excitation.- 7.9 Rolling element bearing.- 7.10 Blade vibration.- 7.11 Cam mechanism vibration.- 8 Contaminant analysis.- 8.1 Introduction.- 8.2 Contaminants in used lubricating oils.- 8.3 Carrier fluid degradation.- 8.4 Contaminant monitoring techniques (wear processes).- 8.5 Oil degradation analysis.- 8.6 Abrasive particles in lubricating oil.- 8.7 Abrasive particles in bearings.- 8.8 Abrasive particles in hydraulic systems.- 8.9 Dissolved gas fault monitoring.- 9 SOAP and other contaminant monitoring techniques.- 9.1 Introduction.- 9.2 Spectrometric oil analysis procedure.- 9.3 Magnetic chip detectors.- 9.4 'Ferrograph' particle precipitation.- 9.5 STM control kit.- 9.6 Used oil blotter test.- 9.7 Thin-layer chromatography.- 9.8 Capacitative oil debris monitor.- 9.9 X-ray fluorescence detection of contamination (XRF).- 9.10 X-ray photoelectron spectrometry.- 9.11 Particle classification.- 10 Performance trend monitoring.- 10.1 Primary monitoring - performance.- 10.2 Primary and secondary performance parameters.- 10.3 Performance trend analysis.- 10.4 Turbine gas path performance monitoring thermodynamics.- 10.5 Steam turbine performance analysis.- 10.6 Case studies in performance monitoring.- 10.7 Performance monitoring systems.- 11 Static testing.- 11.1 Introduction.- 11.2 Visual testing.- 11.3 Liquid penetrant inspection.- 11.4 Thermal methods.- 11.5 X-ray photography.- 11.6 Sonics.- 11.7 Ultrasonics.- 11.8 Stress wave emission.- 11.9 Magnetic testing methods.- 11.10 Electrical NDT techniques.- 11.11 Eddy current testing.- 11.12 NDT selection.- 12 Monitoring systems in operation.- 12.1 Introduction.- 12.2 Marine monitoring systems.- 12.3 Marine condition monitoring requirements.- 12.4 Marine diesel engine monitoring.- 12.5 Marine turbine monitoring systems.- 12.6 Shipboard vibration monitoring.- 12.7 Spectrometric oil analysis programme - marine.- 12.8 Monitoring integrity verification.- 12.9 Aircraft condition monitoring.- 12.10 Condition monitoring - generating plant.- 12.11 Automotive diagnostic equipment.- 12.12 Systematic fault monitor selection.- 13 Fault analysis planning and system availability.- 13.1 Introduction.- 13.2 Availability.- 13.3 Failure prediction/reliability assessment.- 13.4 Hazard rate curve.- 13.5 Complex system reliability - Monte Carlo simulation.- 13.6 Hazardous chemical plants - high integrity protective systems (HIPS).- 14 Reliability/failure concepts.- 14.1 Introduction.- 14.2 Probability of reliability and failure.- 14.3 Failure pattern-exponential distribution.- 14.4 Load and strength - statistical distribution.- 14.5 Reliability assurance -1 Failure types, investigation and occurrences.- 1.1 Introduction.- 1.2 System failure and component failure.- 1.3 Failure decisions.- 1.4 Failure classifications.- 1.5 Types of failure.- 1.6 Failure investigations.- 1.7 Failure case studies.- 1.8 Human factors in failure incidents.- 2 Causes of failure.- 2.1 Introduction.- 2.2 Service failures.- 2.3 Fatigue.- 2.4 Excessive deformation.- 2.5 Wear.- 2.6 Corrosion.- 2.7 Blockage, sludges.- 2.8 Blockage in cooling systems.- 2.9 Design, manufacturing and assembly causes of failure.- 3 Fault detection sensors.- 3.1 Introduction.- 3.2 Contaminant monitoring.- 3.3 Corrosion monitoring.- 3.4 Force monitoring.- 3.5 Gas leakage monitoring.- 3.6 Air pollution monitoring.- 3.7 Liquid contamination monitoring.- 3.8 Non-destructive testing techniques.- 3.9 Optical examination.- 3.10 Temperature sensing.- 3.11 Particle testing.- 3.12 Proximity monitors.- 3.13 Sound monitoring.- 3.14 Vibration transducers.- 3.15 Telemetry.- 4 Data processing and analysis.- 4.1 Introduction.- 4.2 Fourier analysis.- 4.3 Frequency analysis techniques.- 4.4 Derived functions.- 5 Vibration analysis.- 5.1 Introduction.- 5.2 Vibration-simple harmonic motion concept.- 5.3 Vibration signature of active systems.- 5.4 Vibration monitoring equipment.- 5.5 System monitors and vibration limit detectors.- 5.6 Vibration monitoring experience.- 5.7 Critical vibration levels.- 6 Sound monitoring.- 6.1 Introduction.- 6.2 Sound frequencies.- 6.3 Sound loudness measurement.- 6.4 Acoustic power.- 6.5 Sound measurement.- 6.6 Magnetic tape recorders.- 6.7 Sound level meters.- 6.8 Sound analysers.- 6.9 Sound signal data processing.- 6.10 Sound monitoring.- 7 Discrete frequencies.- 7.1 Introduction.- 7.2 Simple vibrations.- 7.3 Transverse vibrations of bars - approximate frequency calculations.- 7.4 More precise evaluations - overtones.- 7.5 Torsional oscillation of flywheel-bearing shafts.- 7.6 Belt drives.- 7.7 Whirling of marine line shafting.- 7.8 Gear excitation.- 7.9 Rolling element bearing.- 7.10 Blade vibration.- 7.11 Cam mechanism vibration.- 8 Contaminant analysis.- 8.1 Introduction.- 8.2 Contaminants in used lubricating oils.- 8.3 Carrier fluid degradation.- 8.4 Contaminant monitoring techniques (wear processes).- 8.5 Oil degradation analysis.- 8.6 Abrasive particles in lubricating oil.- 8.7 Abrasive particles in bearings.- 8.8 Abrasive particles in hydraulic systems.- 8.9 Dissolved gas fault monitoring.- 9 SOAP and other contaminant monitoring techniques.- 9.1 Introduction.- 9.2 Spectrometric oil analysis procedure.- 9.3 Magnetic chip detectors.- 9.4 'Ferrograph' particle precipitation.- 9.5 STM control kit.- 9.6 Used oil blotter test.- 9.7 Thin-layer chromatography.- 9.8 Capacitative oil debris monitor.- 9.9 X-ray fluorescence detection of contamination (XRF).- 9.10 X-ray photoelectron spectrometry.- 9.11 Particle classification.- 10 Performance trend monitoring.- 10.1 Primary monitoring - performance.- 10.2 Primary and secondary performance parameters.- 10.3 Performance trend analysis.- 10.4 Turbine gas path performance monitoring thermodynamics.- 10.5 Steam turbine performance analysis.- 10.6 Case studies in performance monitoring.- 10.7 Performance monitoring systems.- 11 Static testing.- 11.1 Introduction.- 11.2 Visual testing.- 11.3 Liquid penetrant inspection.- 11.4 Thermal methods.- 11.5 X-ray photography.- 11.6 Sonics.- 11.7 Ultrasonics.- 11.8 Stress wave emission.- 11.9 Magnetic testing methods.- 11.10 Electrical NDT techniques.- 11.11 Eddy current testing.- 11.12 NDT selection.- 12 Monitoring systems in operation.- 12.1 Introduction.- 12.2 Marine monitoring systems.- 12.3 Marine condition monitoring requirements.- 12.4 Marine diesel engine monitoring.- 12.5 Marine turbine monitoring systems.- 12.6 Shipboard vibration monitoring.- 12.7 Spectrometric oil analysis programme - marine.- 12.8 Monitoring integrity verification.- 12.9 Aircraft condition monitoring.- 12.10 Condition monitoring - generating plant.- 12.11 Automotive diagnostic equipment.- 12.12 Systematic fault monitor selection.- 13 Fault analysis planning and system availability.- 13.1 Introduction.- 13.2 Availability.- 13.3 Failure prediction/reliability assessment.- 13.4 Hazard rate curve.- 13.5 Complex system reliability - Monte Carlo simulation.- 13.6 Hazardous chemical plants - high integrity protective systems (HIPS).- 14 Reliability/failure concepts.- 14.1 Introduction.- 14.2 Probability of reliability and failure.- 14.3 Failure pattern-exponential distribution.- 14.4 Load and strength - statistical distribution.- 14.5 Reliability assurance - BS 9000 system.- 15 Reliability data sources.- 15.1 Introduction.- 15.2 Systems Reliability Service (SRS).- 15.3 Failure data.- 15.4 Environmental influences on instrument failure rates.- 15.5 Failure data-confidence level.