mainet managae

7/24/2019 mainet managae

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Predictive maintenance basics1.1 The maintenance philosophy of operating the machine until it fails is called:(a) Breakdown maintenance (b) Proactive maintenance (c) Predictivemaintenance (d) Preventive maintenance.

1. The maintenance philosophy under which an operating machine is taken upfor maintenance based on the condition of its health to prevent a breakdown iscalled: (a) Breakdown maintenance (b) Proactive maintenance (c) Predictivemaintenance (d) Preventive maintenance. 1.! "oot cause failure analysis is atechni#ue adopted under: (a) Breakdown maintenance (b) Proactivemaintenance (c) Predictive maintenance (d) Preventive maintenance. 1.$%ibration analysis is a techni#ue adopted under: (a) Breakdown maintenance (b)Proactive maintenance (c) Predictive maintenance (d) Preventive maintenance.1.& 'ame the three categories under which plant e#uipment can be classied.1. *n a typical process plant+ there are ve cooling water supply pumps.,epending on the weather conditions+ four of the ve pumps are operational atany point in time. -lectrical motors with a rating of ! ppendi/ 1.& 0 drive

these pumps. 2nder which category would you classify these pumps3


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1.4 Predictive maintenance principles are analogous to: (a) 5rime detection (b)0edical science (c) 6orensic medicine (d) 6ailure analysis of electroniccomponents. 1.7 8ne of the following is not a predictive maintenance techni#ue:(a) "oot cause failure analysis (b) 2ltrasonic thickness measurement (c)Performance evaluation (d) %ibration analysis. 1.9 %ibration analysis (in thedetection mode) is done: (a) 8n a regular basis for selected machines (b) Todetect the severity of fault in a machine (c) To ascertain the time after whichmachine or its component will fail (d) To detect faults in vibration measuringtools. 1.1 %ibration analysis and the trending of vibration data cannot detectone of the following: (a) "otor imbalance (b) 6ouling of internals (c) Bad bearingsor gears (d) 0achinery alignment.

%ibration basics.1 spring;mass system has three characteristics that resist the vibrationscaused by an e/ternal force. Tick the one that is not one of them. (a) 0ass (b),amping (c) oung?s modulus. .


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point at the Aeroth second+ what is the amplitude after s3ppendi/ !4

.$ 'umber of cycles per second of a wave is a measure of: (a) mplitude (b)Phase (c) 6re#uency (d) avelength. .& mplitude of vibration is not a measureof: (a) ,isplacement (b) %elocity (c) cceleration (d) Phase. . Phase di=erenceis: (a) The o=set between the crests of two time waveforms (b) The o=setbetween the troughs of the two time waveforms (c) The o=set between similarpoints of the two time waveforms (d) The angle di=erence of a point onwaveform from the origin. .4 s#uare waveform is a resultant of: (a) Timewaveforms having odd harmonic fre#uencies (b) Time waveforms having evenharmonic fre#uencies (c) Time waveforms having integer harmonic fre#uencies(d) 'one of the above. .7 5rest factor of a waveform is a ratio of: (a) Peak torms (b) rms to peak (c) Peak to mean (d) Peak to 1.$1$ times rms. .9 6or amachine running at 9 A (&$ cpm)+ which parameter is most suitable formeasuring vibrations: (a) ,isplacement (b) %elocity (c) cceleration (d) Phase..1 *n the *


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(d) *n haAardous areas. !.! hich of the following is used to measure shaftvibrations: (a) Photocell (b) %elocity transducer (c) ccelerometer (d) -ddycurrent probes. !.$ *n -ddy current probes+ the oscillator@demodulatordemodulates the signal and provides a modulated ,5 voltage where the ,5portion is directly proportional to: (a) Cap between the probe and shaft (b)%ibration of the shaft (c) 0echanical and electrical runout of the shaft (d) -ddycurrents generated by the high radio fre#uency. !.& hich of the followingvibration transducers does not need an e/ternal power source: (a)ccelerometers (b) %elocity pickups (c) -ddy current probes (d) 'one of theabove. !. 0easurements from handheld vibration meters can be subDect toerrors on account of: (a) Position of measurement and probe angle (b) Probe typeand the pressure applied (c) ll the above;mentioned reasons (d) 'one of theabove. !.4 Phase di=erence measurement is possible using: (a) ccelerometer(b) ,ata collector (c) %elocity pickup (d) ,ual channel analyAer.ppendi/ !9

!.7 ,ata manager software collects and stores data from: (a) 8nline monitoring

systems (b) ,ata collectors@analyAers (c) andheld vibration meters (d) Torsionalvibrometers. !.9 hich of the following does not need a reference on the shaftfor phase measurement: (a)


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(a) alf of the highest fre#uency of interest (b) Twice of highest fre#uency ofinterest (c)


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(b) Proportional (c) -/ponential (d) 8ne;third of 6;ma/.

& 0achinery fault diagnosis using vibration analysis&.1 *n an overhung fan rotor with an unbalance+ the conrmatory test is: (a) 1 Grpm peak with similar phase readings in a/ial direction on both bearings (b) 1 Grpm peak with similar phase readings in radial direction on both bearings (c) 1 Grpm peak with unsteady phase in a/ial direction (d) 1 G rpm peak with oppositephase readings in a/ial direction on both bearings.ppendi/ $1

&. /ial phase readings with sensors on each bearing of a bent shaft will have:(a) 'o phase di=erence (b) Phase di=erence of 17H (c) Phase di=erence of 9H(d) 2nsteady phase readings. &.! *f the phase di=erence is 17H measured in theradial direction on bearings across the coupling of a pump and a motor+ thesuspected fault is: (a) 6oundation looseness (b) ,amaged coupling (c) ngularmisalignment (d) Parallel misalignment. &.$ hen sub;harmonic multiples of 1@Gor 1@!G are observed in the 66T spectra+ it could indicate: (a) 8il whirl (b) 8il whip

(c) "otating stall (d) *nternal assembly looseness. &.& "esonance fre#uency ofstructural members can be detected with: (a) Phase analysis (b) Time waveformanalysis (c) Ibump test? (d) 6ast 6ourier transform. &. hen two dots and twoblank spaces are observed in an orbit plot+ it indicates that the vibrationfre#uency is: (a) 1@G rpm (b) 1G rpm (c) G rpm (d) There is no correlation. &.4 *fthe assembly phase factor ' J 1+ the number of gear teeth is 97 running at &&7rpm and the pinion has & teeth+ what is the hunting tooth fre#uency3 (a) 7&cpm (b) && cpm (c) 14 cpm (d) &$1 4$$ cpm. &.7 motor running at 1$& rpmis installed with a pulley with 1 mm


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diameter. The belt length is 19& mm. The pump pulley diameter is 17 mm. Thebelt defect fre#uency will be: (a) $ cpm (b) !! cpm (c) 14 cpm (d) 11 cpm.&.9 *f a rotor bar pass fre#uency is surrounded by sidebands of G line fre#uency+then the defect in the motor is: (a) 5racked rotor bars (b) -ccentric rotor (c)Koose stator coils (d) Koose rotor bars. &.1 *n a turbo machine+ a sudden changein 1G amplitude and phase is an indicator of: (a) 2ne/pected fouling (b) *ncreasedbearing clearances (c)


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(c) /ial Foat of shafts (d) -lectrical runout. . *n the two dial method ofalignment+ which mathematical principle is used to calculate the shim thickness3(a) 5ongruent angles (b) Trigonometry (c) Pythogoras? theorem (d)


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(b) Bottom of the sump (c) 0iddle level of the sump (d)


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(d) 5an travel large distances.$ ppendi/

7.! 2ltrasound can normally not be heard by the human ear+ yet using a certainprocess it can be converted into the audible range. This process is called: (a),igital signal processing (b) 6ast 6ourier transform (c) eterodyning (d)mplication. 7.$ The ultrasound techni#ue is not an e=ective techni#ue todetect: (a) Keaks (b) Bearing defects (c) -lectrical defects such as arcing andcorona (d) 6ouling. 7.& Thermography utiliAes which part of the electromagneticspectrum: (a) *nfrared (b) 2ltrasonic (c) 2ltraviolet (d) %isible. 7. Thermographyis generally not e=ective at temperatures below: (a) H5 (b) H5 (c) 1 H5 (d)17 H5. 7.4 Thermography is not very e=ective to detect: (a) Koose connectionsin an electrical circuit (b) 0isalignment of a coupling (c)

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