Reciprocating compressor valves are usually automatic and open and close by:

Reciprocating compressor valves are typically designed to operate automatically based on pressure differences within the system. In a reciprocating compressor, when the pressure inside the cylinder drops below the inlet suction pressure, the valve opens due to the higher pressure on the inlet side. Conversely, when the pressure inside the cylinder exceeds the discharge pressure, the valve closes due to the higher pressure in the cylinder. This operation is crucial for maintaining the compressor's cycle of intake and discharge, facilitating effective gas compression.

The automatic nature of these valves enhances operational efficiency and responsiveness to changing pressure conditions, ensuring that the compressor functions effectively and maintains its designed performance characteristics. Understanding this principle is essential for troubleshooting and optimizing the performance of reciprocating compressors in various applications.