Comparison between Condition Monitoring & Condition Assessment
Condition Monitoring and Condition Assessment are often confused with each other, leading to a significant amount of confusion in the field. Many people mistakenly believe that Condition Assessment is synonymous with Condition Monitoring. The purpose of this blog is to shed light on the distinctions between the two and provide a clear understanding of their differences. By unraveling these variances, readers will gain valuable insights that can contribute to more effective asset management practices.
Condition Monitoring
- It is the periodic inspection of parameters of the component of equipment
- CM is the monitoring of the Fatigue level of any fault condition of a component of equipment.
- CM is NOT the process carried out to find whether the equipment is OK or not. CM is carried out to get the idea of the inception of fault in the equipment.
- CM is done when the machine is operating in its useful life. That means when the equipment is operating in good acceptable condition.
- CM is always a Trend Analysis – Trend of periodic readings of parameters is managed as a continuous process and the trend is observed for any rise in any parameter like Temperature, Vibration, Pressure, Ultrasound, Oil Condition etc.
- CM is carried out only for the component that undergoes Fatigue Failures. This process is not possible for the equipment that may not fail due to fatigue.
- CM maintains the level of parameters much below the maximum levels in the severity chart as per the ISO/IS standards. The severity chart is not considered in CM rather the trend of parameters is followed.
- For example – If the maximum level of vibration as per ISO 10816 is say 4 mm/ sec and the actual vibration at a component of any equipment is, say, 2 mm/sec, which started raising from 2 mm/sec and the trend started moving upwards and may reach to 2.8 mm/sec in few days, then it is considered as inception of fault in the equipment, this is the symptom we learned about & Root Cause Symptom Analysis (RCSA) is carried out, although the fault is below the maximum limit of 4 mm/sec & then the corrective action is taken to eliminate the symptom/ fault.
- It is a continuous process and has to be carried out for years at definite intervals by maintaining a trend of all readings.
- The equipments on which CM can be carried out are mostly dynamic equipment (those which fail because of fatigue). For example, Electric Motors, Compressors, Gear Boxes, Engines, Process Machinery, Pumps, Blowers etc. The static equipment like Oil Filled Transformers needs to undergo CM as the oil quality deteriorates & may lead to failure of the transformer.
Condition Assessment
- It is One Time Inspection of parameters of a component of equipment
- Condition Assessment (CAss) is the monitoring of the Stress level of the components of the equipment.
- CAss is the process carried out to find whether the equipment is OK or not. CAss is the process to know the condition of equipment at that instant.
- CAss is done at any instant of the machine life cycle.
- CAss is not Trend Analysis –
- CAss is carried out for the component that undergoes sudden or stress failures.
- The parameters are checked and compared with the maximum level in the parameter severity chart as per the ISO/IS standards. If higher then the maximum level than RCA needs to be conducted to find the root cause.
- For example – If the maximum level of vibration as per ISO 10816 is say 4 mm/ sec and then it is checked that whether the vibration level of any component has gone higher than the limit or not. If the level of parameter crossed the maximum level as per ISO standard, then the component is considered faulty and RCA is done on it to find out the root cause.
- It is necessary to do CAss many times in a year. This is because CAss gives assurance about the equipment for that particular instant only & as its not condition monitoring, we may not get an early sign of the faults.
- The equipment on which CAss can be carried out is mostly static equipment in which the fault increases very rapidly and leads to component failure. Like Short Circuit in Cables or Wiring in panels. It is difficult to keep inspecting the capacitance of each insulation of every cable for fatigue failure. In such cases, CAss of electric panels is the only tool that remains in hand. The equipment that can go only under CAss are Electric Panels, Compressed Air Lines, Insulated Pipelines, Steam Traps, Transmission Towers, Switch Yards, Pressure Vessels, Boiler, Furnaces, Refractories, Tankers, Ship Hatches, Solar Panel, Solar Arrays.
The CAss – One-time inspection of parameters can be done even for dynamic equipment, those not undergoing CM. The CAss of like Electric Motors, Blower Fans, Gear Boxes, Compressors, Blower Fan is carried on those which are not listed as critical.
