I'm interested if anyone has had any experience with Atlas Copco G200 screw compressors having a varnish problem. We are using the OEM Roto-extend oil that A/C claims would not produce any varnish deposits. I grabbed a sample and am in the process of having a vanish potential test performed and will compare the results to a "virgin" sample. We had an Atlas compressor at another plant catch fire and the cause is being attributed to a flash over fire in the unloader valve area due to varnish buildup. They related it to a chimney fire due to cresote buildup. I didn't think these machines ran that hot. Any input would be appreciated.
rgf

What temperatures do you estimate your machine to be running at? Is the duty cycle of the compressor extremely high? Is there an oil cooler for this system?

Hooch

We have small systems for removal of varnish in compressor systems. Not only will it remove varnish from the system, the reduction in submicron particle contamination will extend the life of the entire compressor.

Is the compressor under some type of service or extended year warranty whereby you must use their recommended oil? If not, perhaps a better oil might eliminate varnish. As for temperatures, a rule of thumb on operating temps is 100 dgrees F over ambient (room) temp where compressor is located.