Can any one can explain about Preventive maintenance, predective maintenance, corrective maintenance ?

Question

please expalin with some workouts, which is related to oil field maintenance..

Answer 1

Corrective maintenance - the pump has failed and must be replaced to restore the equipment to working order.

Preventative maintenance - the pump should be replaced every 5,000 hours of operation to prevent it from failing when it is needed. Generally this is based on historical information and is considered a conservative estimate "just to be safe".

Predictive maintenance - the pump performance is measured. Inlet and outlet pressures are recorded and charted. Motor temperatures are observed and so forth. Any feature that could potentially indicate that the part is wearing out. Based on this actual part performance, the pump is then replaced when it begins to indicate some signs of nearing the point of failing. While this method improves with historical data, it attempts to maximize the useful life of a pump based on its actual performance. Some pumps may last longer, some may last shorter spans of operation, but it is not based on an overly conservative estimate of the AVERAGE life of the part. Essentially during preventative maintenance you may be replacing a perfectly good parts with several thousand hours of service remaining. Predictive maintenance also allows the maintenance department to anticipate repairs and schedule them to have less impact on pump operation. Corrective maintenance may be required during a peak operation period which is less than ideal. Also, failure of equipment may damage other components.

Predictive maintenance requires more training and equipment than the "replace at a fixed interval" method used by preventative. It requires an upfront investment in employees and specialized equipment for them, but has returns in reduced or eliminated downtime and maximized used of parts.

Answer 2

Lets do these in the correct order.
Corrective maintenance is the work required to fix a broken item.
Preventative maintenance is fixing an item because your history of that item says it usually fails around this time.
Predictive Maintenance is monitoring an item (like vibration monitoring or heat) and determining when it is near it's useful life span based on the collected data.
This is the hierarchy of maintenance, with additional data and skills required to get to each successive step.

Answer 3

Predictive maintenance is when you anticipate the failure of a component within the machinery, by replacing parts at reccomended intervals e.g. a car timing belt replacement in 3 years/15000 miles whicheve comes first....the cost of a belt is minimal as well as the labour for a belt replacement. now imagine the belt had snapped...there would be a lot of damage and the cost of repair would be significant in respect to the cost of regular maintenance......

p.s. Preventive Maintenance - You change the bulb after 7,500hours of its 10,000 hour life, so it is unlikely ever to blow.

Predictive Maintenance - You change the bulb after 9,999 hours as it should blow in the next hour.

Corrective Maintenance - You change the bulb when it blows! ****

|****This is known as breakdown maintenance.....



Predictive maintenance is usually having some sort of condition monitoring, e.g. temperature, pressure, rpm, vibration , viscosity etc... whereas the analysis of the running machinery can me compared with the "typical smooth operation" to discover if any failure is occuring...There is actually a enourmous database of vibrational analysis for bearings failing....these can be used in conjunction with the bearing codes in the machinery from the manuals, to determine what vibrational problem is occuring....as a massive amount of the time it is bad vibration and heat as a first sign of failure...Ultimatley if your looking after machinery its all about cost...if the cost of expensive monitoring equipment is more than the cost to replace and maintain (remembering cost if it fails......"downtime" production halted and loss of more money) than it would be to correct the problem after the equipment has failed...it wouldnt be done....

Answer 4

Preventive Maintenance - You change the bulb after 7,500hours of its 10,000 hour life, so it is unlikely ever to blow.

Predictive Maintenance - You change the bulb after 9,999 hours as it should blow in the next hour.

Corrective Maintenance - You change the bulb when it blows!

Answer 5

Jeffrey S got it right.

All the others are wrong in one way or another.

The book mentioned below is a good reference for this sort of thing.

Answer 6

Preventive - Whatever you need to do, to keep an equipment functioning. (Taking you car to th shop, to change the oil every 6 months, for example)
Predectiv - Be ready with spare parts, that, with the time need to be replaced. (Like the spare tire you keep in the car)
Corrective - When you need to fix, something is not working OK. (buy a new tire)