Hello,

Can someone please give me an evaluation of the advantages and disadvantages of Oil Analysis as a PdM tool, or may please indicate me where can I find some sort of this information. I need general information not product specific?

Thanks

Rennie
I will give you my two cents. First there is two types of "oil analysis" PdM programs. You can do analysis on oil cleanliness and condition. This information can be used to replace a calander driven PM program where the oil and filter are change on a set schedule. Using this analysis you would let the condition of the oil determine when a PM is done. The second analysis is on the the wear particles in the oil. You look at the type of metal(brass, chrome, hard steel, etc.)and how it was removed (rubbing, shear, etc.). I have found this information great in slow turning equipment < 100 RPM because vibration trending is difficult on slow equipment. It also is good on equipment that runs two short of a cycle for vibration trending. I also find wear particle analysis great for multi stage gearboxes.

If I already ahev vibration monitoring, why do I need to do lubrication analysis for the same rotating equipment which use high volumes of lube oil?

By high volumes, do you mean large reservoirs or lots of leaks? We sample many critical machines looking for cleanliness and wear materials. On the large systems that we do not regularly change oil in, we use the data to monitor the additive package in the oil. It is the additive package that gives oil its characteristics and allows it to perform as expected. Some of the additives are consumed and must be replaced. By sampling the oil, we can verify the additive package and determine whether actions are needed.

Gary B

I mean a large volume of lube oil being used by a machine eg >1 drum. I understand those reasons that you stated but I was asked why should we do oil analysis because eventually everything eg bearing wear will be detected by vibration analysis. So why should we do oil analysis if I already do vibration analysis?

This message has been edited. Last edited by: Josh,

If you do oil analysis, like particle count, you can tell where from the inside the wear is happening, only by checking hydraulic oil for metal particles can tell you which part is desgasting. Sand is an indication that somewhere dirt is entering the system (leaks). If you find copper, where will you look? Big hydraulic machines, like escavators use a lot of oil. Would you put a vibration transducer on the track motors, to measure vibrations? Would you take a waveform on the valve bank to detect anormalities? Vibration monitoring is more the just looking at bearings (although a lot of people think that it is limited to bearings, because de transducer is normally mounted on a bearing housing). Vibration monitoring is great for stationary equipment, but dangerous for mobile equipment. In this case oil monitoring is the preferred method.