Has anyone had any experience with removing varnish from lube oil in gas turbines. If so what methods have you used?

Jimmy,

I've done research on the root causes of varnish in gas turbines, preditive tests to determine varnish potential and removing varnish from gas turbines. If you're interested, I can share this research with you, and put you in contact with other gas turbine users who have solved their varnish problems. It's a complicated issue and is too detailed for me to go into in this forum. Although there is not necessarily a silver bullet for all applications, there are tried and tested solutions to this problem.

Please feel free to e-mail me and I will point you in the right direction.

Greg

Greg, We are seeing varnishing problems also- in our older Gas Turbines, and in the newer, CTs. I would be very interested in any research that has been done.

Gary

Gary,

Please drop me an e-mail at gregjlivingstone@yahoo.com and I will send you several papers. I have a presentation on varnish issues in CT's and can upload this to a site for you to download as well.

Thanks,

Greg

In the refrigeration world varnishes form on internal surfaces from mineral oil degradation. The primary route is a Friedel-Krafts alkylation reaction catalyzed by acids and moisture interacting with iron. Phosphites make good inhibitors for stopping this reaction, but several other Friedel-Krafts inhibitors will work as well.

Removing the varnishes is accomplished by using polyolester lubricants that have more affinity for the metal surface than the varnishes. In about 48 hours the varnishes are lifted off the surfaces and are circulated to filters. Two POE lubricant changes are normally required to completely remove all the varnish.

You will have to decide if these experiences are applicable to gas turbines or not.

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Originally posted by Greg Livingstone:
Jimmy,

I've done research on the root causes of varnish in gas turbines, preditive tests to determine varnish potential and removing varnish from gas turbines. If you're interested, I can share this research with you, and put you in contact with other gas turbine users who have solved their varnish problems. It's a complicated issue and is too detailed for me to go into in this forum. Although there is not necessarily a silver bullet for all applications, there are tried and tested solutions to this problem.

Please feel free to e-mail me and I will point you in the right direction.

Greg

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Dear Mr Greg,
I am interested to know the root cause and process of varnish buildup in gas turbines bearings. Can you help directing the the concern web sites and sharing your findings?

Regards,

kumar
kumartr2@yahoo.com

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Originally posted by Jimmy3:
Has anyone had any experience with removing varnish from lube oil in gas turbines. If so what methods have you used?

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Electrostatic filters and low-flow 3-micron cellulose fiber filters have shown good results in controlling varnish level. Although there are some indication that such systems could eventually (over time) remove varnish from equipment surfaces, the jury on this is still out.

Jimmy
My company has co authored a white paper discussing the cause and effect and solutions to varnish in GT's. If you would like this info, please send an email to me.
Eric

Eric,
I am interested in the information you have on varnishing in gas turbines. Is there any way you can send me this information?
Joe D.

GE has issued a TIL on Lube Oil Varnishing with comments and recommendations for varnishing. ExxonMobil has an article Gas Turbine Lubrication: Filter Plugging & Valve Sticking. There are a couple of filtration technologies discussed in these documents. While you are figuring out the choices, consider a PM to replace all you hydraulic filters and clean / swap out all your hydraulic servos and valves during scheduled TARs. Some oil test labs have new tests for varnish, so check with you oil lab.

Hello Rob

While you wait for a chance to do your PM cleaning and only to find it needs to be done a short time later, you could be cleaning your oil and your components using CC Jensen filtration. After operating head to head for several years with several different technologies of electrostatic systems CJC has emerged as the undisputed leader of varnish removal technology. For more information and customer references: CJC Varnish removal
P.S. 2 customers selling several electrostatic units "cheap"please contact for details.

Thanks