I have a hydraulic system that we started haveing problems with about 6 months ago. The filter keeps plugging up and shutting down the machine about every month or 2. On 6-24-07 the oil was replaced and new filters put in, on 8-26
again new filter and oil samples pulled from the filter-sump-and new barrel. Requested a Micropatch Ferrography test to identify what is plugging the filter, report came back with severe amount of translucent polymer across the patch. 2 questions

1.What is translucent polymer?
2.Where could it be coming from?

Translucent polymer sounds like a snazzy way to say plastic. Does the oil run through plastic hoses? Maybe the hoses weren't thoroughly cleaned before installation.

I found out that our waste treatment facilty uses a translucent polymer in some process they use. The supervisor told me that it is a gel type of substance that has a polarity that the one they uses has a positive polarity that attracts solids. The negative polarity repels solids.
But this could be complety different.
So far we are looking at different possablies
1. That somehow somebody used a container that used to be located in the waste treatment area to add oil to the hyd unit. Not a very high proably thou the 2 areas are a long way apart and in seperate buildings.
2. As Hans commented that maybe it was inside a new hose that got changed out.
3. The oil which is Cheveron Clarity Hydraulic aw46 oil is reacting with the inside of the hyd hoses and drawing the polymer out of the rubber.

tbeards, polymers are produced as the oil goes through its oxidation processes. Are you testing via FTIR for oxidation? If not, have you conducted a 'varnish potential' analysis? Analysts, Inc., provides at test referred to as Quantitative Photospectrometric Analysis (QSA) that is useful for demonstrating a the tendency to produce oxide insolubles (which may include polymers). These insolubles build up until the oil is no longer able to carry the load. Think of a bucket that is starting to overflow. Oil is like a bucket that to an extent will suspend insoluble compounds, but the bucket does eventually overflow.

There are a couple possibilities for the reason for the oxidation (if this is discovered to be an issue). Too much heat, too much pre-existinng (seed) varnish, a significant prescence of wear metals, moisture and/or air.

You need to clean the system really thoroughly if it is oxidation byproducts, or the problem will just keep killing your new oil.

Good luck.

Thanks Mike will diffently check this out with the lab that we use.

Tom Beardsley

We contacted the Chevron Oil Tech support people, emailed the lab reports to them, This oil is supposed to be zinc free hyd oil, there was 7ppm of zinc in the oil. Tech said that the zinc will attract the phosphorus additive in the oil and create the polymer and plug the filter. Somebody must have topped off the hyd sump with our other hyd oil which has a zinc additive in it not knowing that it needed a special zinc free hyd oil.