filterability

You can speak to your oil supplier to check what tests have been completed on the filterability. This was typically done on hydraulic oils and sometimes with the addition of water to the oil to measure its' effects. It used to be done in accordance with ISO 13357 part 1 & 2. I am not sure if this has been extended to other oil types such as turbine oils.
As for the high ISO code on the air compressor oil, check how the sample is being taken and where it's been taken from. Check the ISO for the new oil drums - as it may be due to poor oil storage and dispensing that has caused the high ISO. It's also good to compare the ISO codes obtained by the automated particle counter with say a filter patch test to see visually what has caused the high ISO codes. Also check with the manufacturer that you are using the correct filter media, correctly fitted with the required micron rating and beta ratio.
I hope this helps.

Laleh,

Filterability has more applicability to fuels and Hydraulic fluids.

Suggest reading TLT article from following link. Please read all pages.


http://findarticles.com/p/articles/mi_qa5322/is_200611/...g_1?tag=artBody;col1

I suggest you have varnish potential test run, this can be one of the first signs of varnishing when the particle count will not come under control.

Good Luck

I agree with Rene, check what size filter medium is fitted to the compressors. Typically they are quite large >10 micron and the particles are small <10 micron. Conduct a filter patch test to determine what the particles are: dust / varnish / etc.

Regards,

Rodney Fitzpatrick