What is the purpose of a pressure decay test in pneumatic systems?

What is the purpose of a pressure decay test in pneumatic systems?

• A. To measure humidity changes in air supply
• B. To test electrical safety of control circuits
• C. To verify leaks by observing pressure drop over a defined period
• D. To grade lubricant purity

Answer: (C)

A pressure decay test is about finding leaks by watching how the system’s pressure changes over time after it’s been pressurized and sealed. The idea is to bring the pneumatic circuit to a known pressure, close off the system, and monitor the pressure for a defined interval. If the pressure stays steady, the system is effectively leak-tight; if it drops, the rate of decay indicates the presence and size of leaks. This helps ensure the system won’t lose air during operation and that hoses, fittings, and valves aren’t leaking. It’s not used for humidity in the air, electrical safety of control circuits, or lubricant purity.

A pressure decay test is about finding leaks by watching how the system’s pressure changes over time after it’s been pressurized and sealed. The idea is to bring the pneumatic circuit to a known pressure, close off the system, and monitor the pressure for a defined interval. If the pressure stays steady, the system is effectively leak-tight; if it drops, the rate of decay indicates the presence and size of leaks. This helps ensure the system won’t lose air during operation and that hoses, fittings, and valves aren’t leaking. It’s not used for humidity in the air, electrical safety of control circuits, or lubricant purity.