rotary screw compressor oil problem

Questions & AnswersCategory: Generalrotary screw compressor oil problem
Guest Staff asked 6 months ago

Dear Sir,

I am Mr. Wai Yan from Myanmar.

I have problem for rotary screw air compressor. It caused, all of the compressor oil were changed milk shape and came out when manual drain. In the oil separator, fulled of the milk shape compressor oil.

Why the problem were caused and how can I solve the problem?

Another case, smoke air were came out through air filter while loading/unloading a few minutes.

When unloading smoke air were came out more then when loading.

Why the problem were caused and how can I solve the problem?

Please answer the two problem.

Looking forward to your reply.

Best Regards,
Wai Yan

1 Answers
Cas Staff answered 6 months ago


This can happen when the wrong compressor oil is used. Or when compressor oil is mixed.

Even if you used the correct type of oil, if it is mixed with another brand/type, then foaming and white milky oil can occur.

This can also happen if there’s a lot of water in the compressor oil. The water comes from condensation and happens most often with compressors that don’t run very much.

This can also be the cause of the smoke coming out of the inlet valve!

Hope this helps!