Crankcase Moisture in Reciprocating Compressors

Posted on: October 13, 2015

When you buy reciprocating compressors, it is important for the compressor to be sized correctly to your air system. If the compressor is not sized properly and the compressor is not allowed to run long enough to actually heat up, the crankcase can retain moisture as a vapor. This moisture can make its way into the oil and eventually separate; or it can cause rust to develop quickly in the crankcase and lower cylinders. If the compressor is not maintained correctly by changing the oil more frequently, premature failure can occur. Failure can also occur when units are intermittently run for varying time intervals; i.e. 6 hours on Monday and then not again till the following Monday. If the compressor is started intermittently just to maintain tank pressure, and only runs a short period of time, moisture can be retained. Quincy recommends changing the oil every 500 hours or 3 months unless environmental conditions require you to change the oil more frequently. Quincy also recommends inspecting the oil for contamination and change it when necessary. If these precautions are followed, you will get many years of quality operation from your new compressor.


Contributed by Mark Clapp, Field Service Manager