2901906000 is an OEM part from Chicago Pneumatic. Sometimes this is displayed in a parts manual as 2901 9060 00 or 2901-9060-00. The 2901906000 MPCV kit was used on several versions of the Chicago Pneumatic rotary screw compressors. This was also work on several of the Quincy QGS series of rotary screw compressors, NAPA rotary screw, and several of the Atlas Copco air compressors. Please contact our parts department if you would like confirmation that this part will work with your air compressor.
The minimum pressure check valve keeps air pressure inside of the sump during the initial startup of the compressor. This helps the oil circulate throughout the compressor on start-up. Once the pressure inside of the oil sump reaches approximately 60psi, the valve will open and let compressed air flow downstream. A properly functioning MPCV will prevent oil carryover into your piping system. This will also prevent high pressure air from your receiver and air piping from re-entering internal compressor components. If air is leaking from the inlet after the compressor has been shut off for a period of time, there is a good chance that this valve failed and is letting high pressure air flow back inside of the compressor.
This kit may have been used on the following rotary screw compressors from Chicago Pneumatic. Different kits could have been used, so if you are not 100% sure if this kit is correct for your compressor please give us a call.