Question 25Refrigeration & AC - 1st Asst/Chief

The correct answer is A) rising and falling with each stroke. When testing a reciprocating refrigeration compressor for leaking discharge valves, turning the compressor over by hand with the discharge service valve closed will cause the pressure on the compound gauge to rise and fall with each stroke of the compressor. This is because if the discharge valves are leaking, the refrigerant gas will be able to flow back from the discharge side to the cylinder during the suction stroke, causing the pressure to fluctuate. The other options are incorrect because a decreasing pressure to a vacuum (B) would indicate a leak on the suction side, an increasing pressure with each stroke (C) would indicate a blockage in the discharge line, and a decreasing pressure with each stroke (D) would not be the expected behavior for a leaking discharge valve.