What is the procedure for checking the suction valves on a compressor?

The procedure for checking the suction valves on a compressor involves front seating the service valve and running the compressor to check for vacuum. This method is crucial because it allows the technician to monitor the performance of the suction valves while the compressor is operating. By front seating the service valve, the technician ensures that the system is isolated from any external pressures, enabling a more accurate assessment of the vacuum being created by the compressor.

When the compressor is running, observing the vacuum level provides insights into the function and integrity of the suction valves. If the valves are functioning correctly, a consistent and appropriate vacuum will be maintained. If there are issues, such as leaks or malfunctioning valves, the vacuum reading will be less than expected, indicating the need for further examination or potential repairs.

Other techniques, like running the compressor with the service valve open, may not provide accurate readings of the suction valve performance. Removing the compressor for visual inspection, while sometimes necessary, is more invasive and doesn't provide real-time data. Bleeding the pressure before opening the service valve does not check the suction valves directly and might not give any indication of their operational status under load. Thus, the preferred method involves a combination of front seating the service valve and actively monitoring the vacuum during operation.