The fluid used as a source of actuating power against the underside of the unloader power element piston of the refrigeration compressor capacity control mechanism illustrated is obtained from where? Illustration GS-RA-13

Illustration GS-RA-13: the U.S. Coast Guard has not released this illustration.

Question

The fluid used as a source of actuating power against the underside of the unloader power element piston of the refrigeration compressor capacity control mechanism illustrated is obtained from where? Illustration GS-RA-13

Illustration GS-RA-13: the U.S. Coast Guard has not released this illustration.

Accepted Answer

Option D: discharge of the compressor lube oil pump. Unloader mechanisms in large marine reciprocating compressors utilize high-pressure lube oil discharge from the internal gear or positive displacement pump to actuate the power element pistons, modulating capacity by lifting suction valves.