How often are low pressure air compressor relief valves lifted by hand?

The correct answer is that low-pressure air compressor relief valves are lifted by hand prior to their first daily use. This practice ensures that the relief valves are functioning properly and are not stuck, which is critical for safety and equipment reliability. By manually lifting the relief valves, operators can verify that they are in good working condition and capable of relieving pressure as needed during operations.

This procedure is a preventive maintenance step that helps avoid potentially dangerous situations that could arise from a malfunctioning relief valve, allowing for the safe operation of the air compressor throughout the day. By performing this check before the first daily use, the operator can ensure that any issues are addressed right away rather than risking operational failures later on.