If a boiler's MAWP is above 60 psi, what percentage of MAWP can the pressure relief valve be set to?

When a boiler's Maximum Allowable Working Pressure (MAWP) exceeds 60 psi, the pressure relief valve must be set to a pressure that does not exceed a certain percentage of the MAWP. The corresponding standard requires that the pressure relief valve is set to no more than 75% of the MAWP. In practical terms, this means that the pressure relief valve should be set at 10% above the operating pressure but below 75% of the MAWP.

Given that the pressure relief valve needs to be calibrated properly to ensure safety and prevent over-pressurization, setting it to 10% of the MAWP is within safe operating limits while allowing some margin for operational fluctuations. This approach minimizes the risk of boiler failure or damage due to excessive pressure.

Therefore, the correct answer reflects both compliance with safety regulations and sound engineering practices, ensuring that the pressure relief valve operates effectively to protect the boiler and its components from dangerous pressures.