The pressure relief valve on the piping system is set to relieve at how many times the system's working pressure?

• A. 1 times
• B. 1 1/2 times
• C. 2 times
• D. 1/2 times

Answer: (B)

A pressure relief valve is there to protect the piping from overpressure by opening when pressure exceeds what the system can safely handle. The typical and effective setpoint is about 1.5 times the system’s working pressure. This gives a safety margin for pressure spikes, thermal expansion, pump surges, and valve wear, while ensuring normal operation stays steady and the relief only activates when needed.

If set at the working pressure, it would lift during normal operation, causing nuisance releases. If set higher than 1.5 times, there’s a risk the system could exceed safe limits before relief occurs. If set much lower, it would release too early and interfere with normal operation. So the best choice is 1.5 times the working pressure.