Servo Filter change?

installing a pre-filter is a non-issue, sizing will have to be appropriate - probably the filter will be ~ 4 times the size of the 10 micron recommended to allow for the double pressure drop. ANY filter service rep can help you to size the system based on flow temperature and viscosity.
However I would be very surprised if the 3-5 micron filter would remove the problem with bacteria. You'd probably do better to bring in a contractor with an electrostatic system to remove the bacteria on a one shot deal. Once the water is done the bacteria will likely start to die off. The metal working industry has lost of bug killers.
regards.......

There is already a prefilter in place. I would be changing from a 10 micron to a 5 micron. As far as an electrostatic system, I am not sure that would help in this situation. The problem is water, which in turn has accelerated the varnishing of the system. I just want to be sure that going from a 10 to a 5 micron, beta 200, won't create any problems. That is other than changing his filter more often.

Hi Sir, I am a filtration consultant. Vacuum dehydration is the first step. Once, the oil is dry (ie. free and dissolved water is removed), then you can increase the performance of your filtration. The problem is as Mr. Wallace said, the filter system may have to be resized to accomodate the flow rate and pressure drop associated, with installing the improved filter.

Again, any filter manufacturer can help determine and/or resize the filter unit.

Contact me if you need assistance.

I would recommend getting the system dry first (be it dehydrator/new oil/etc...) Then as Trigg said, put some desiccant breathers on there. Then I would have an oil analysis done and see if you have a particulate problem, if not and you are under your set limits - no need to change the filtration.

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In a GE EHC system, there should be an acid scavenging filter and a post-filter. Even though GE recommends a 10-micron filter for post filtration, a minimum 4-micron, absolute filter should be used. Many plants have made this upgrade.

Since it has been a few months since your original posting, can you report back and let us know how you made out dealing with the bacteria and deposit issue? What was the bacteria count before and how does it look now? Did you do anything other than remove the water? This is a fascinating situation - I've seen a lot of contaminated EHC systems before, but none with bacteria problems. I didn't think that phosphate ester was a yummy food for bacteria.

I am surprised why no one is talking about installing a Bye pass Oil Cleaning System to keep the oil of the tank itself dry and clean. Centrifuses are widely used throughout the world and are suitable to keep the oil clean upto a large extent, they remove some free water also, but are very costly and not very easily operable. Electrostatic Cleaners are capable of removing particles of size even smaller than 1 micron, but the machine will trip down once the moisture in oil exceeds 500ppm. There is Klarol Oil Cleaning System which is capable of removing solid particles upto 1 micron and moisture almost 100% from the oil. It is installed permanently and independent of oil- circuit on the tank, not much problem in maintaining and operating it.This system can solve all the problems, and instead of only purifying the oil of a apecial part of the oil- circuit , it keeps the whole oil of the tank itself clean and moisture free.

We did change the filters on the servo's, along with using a dehydrator to rid the system of H20. Installed a new filter block and replaced the existing servo filter assembly(Moog).. With the new ***. the filter can be changed on the run with out shutting down the system via internal by pass. The entire cause of this, a really crappy built power unit that had the manifold directly on top of the resevior and not sealed correctly, letting rain water and condensate from the piperack above to basically drain down into the resevior, has been fixed. So, the customer went from avoiding an entire shutdown becasue of this problem to up and ri=unning and his system is working fine. By the way this is a plant in Taft louisiana. I am no longer with the firm so I haven't had recent contact with this customer.