Rotating SystemRotating System anomaly / failure symptom take time to failure. However, the failure symptom is detectable in much earlier time, but is usually left unattended due to ignorance, negligence and lack of proper monitoring methods.
The introduction of the predictive maintenance via NDT technologies (infrared thermography, acoustic ultrasound, high & low frequency vibration monitoring, power solution and etc) are able to detect, monitor and trigger for an appropriate time to repair / countermeasure on a specific equipment to reduce the total system failure and loss, maximize the usage and economic value of the equipment, provide sufficient time management for proper schedule shut down / repair, as well as, to reduce the repair and resuming cost of the related equipment.
A. Motor system – electric motor / pump / fan / compressor
- a. Failure mode
i. Motor Winding fault ii. Bearing over / under lubrication iii. Bad / failed bearing iv. Misalignment / unbalance v. Friction vi. Loose belting vii. Loose structure viii. Overloading ix. Etc.
B. Valve –
- a. Failure mode
i. passing (in close position), ii. flow or no flow / clogged (in open position) iii. poor workmanship during installation - b. Type of Valve
i. Flow control / Pressure control / Fluid logic control ii. Ball / Butterfly / Plug / Gate (disc-shaped) valve, etc. iii. Hydraulic / Pneumatic / Manual / Solenoid / Motor actuated valve, etc. - c. Example of
i. Inlet / outlet safety valve ii. Emergency drain valve iii. Steam pipe stop valve iv. Bypass control valve
C. Leakage – due to pressure differential or seal deterioration
- a. Compressed Air
- b. Gas – Oxygen, Helium, Nitrogen, Natural Gas, Etc
- c. Vacuum
- d. Pressure
- e. Steam
- f. Heat exchanger, Boiler, Underground pipe
- g. Etc.
D. Steam trap (type of mechanical, thermodynamic, thermostatic & fixed orifice)
- a. Condensate drainage failure / blockage
- b. Wear and tear
- c. Steam leakage
- d. Improper selection
E. Flare stack – heat radiation survey to the surrounding environment
F. Furnace – furnace tube, insulation and refractory condition survey
G. Fluid holding tank / vessels – sludge level identification
Samples of Mechanical Failure
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| Bad bearing at non-drive end | |
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| High temperature motor winding – cautionary condition | |
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| Unbalance symptom at motor drive end |
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| Motor & pump vibration analysis – alarming condition |
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| Compressed air leakage detected and tagged |
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| Pipe joint leakage detected and tagged |
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| Steam pipe leakage |
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| Valve passing |
