If the suction pressure of a reciprocating compressor rises rapidly after stopping, what is the most probable cause?

The most probable cause of a rapid rise in suction pressure after stopping a reciprocating compressor is a malfunction of a compressor valve. When the compressor operates normally, the compressor valves are designed to open and close at specific times to allow the refrigerant to flow into and out of the compression chamber. If these valves malfunction, they may not close properly when the compressor stops, allowing refrigerant to flow back into the suction side, which leads to an increase in suction pressure.

Additionally, a properly functioning compressor valve ensures that any refrigerant that has been compressed is effectively separated from the suction line once the compressor is off. If a valve is defective, it can cause unintended backflow of refrigerant, leading to abnormal suction pressure readings.

In contrast, the other options, such as failure of the motor, excessive refrigerant charge, or blockage in the suction line, do not directly explain a rapid suction pressure increase after the compressor has stopped. A motor failure would typically prevent the compressor from cycling properly, while a blockage would likely cause low pressure instead of a rapid increase. An excessive charge could certainly cause operational issues but would not specifically result in a rapid suction pressure rise immediately after stopping. Thus, the malfunction of a compressor valve stands out as the most