ASME Section I Overpressure for a single PSV

[e43u8]

Dears,

Referring to the thread1203-196378 i think for a single PSV in ASME Section I application, 6% overpressure respect to the set pressure could be applied provided that the relieving pressure not to be more than 6% above the maximum allowable working pressure. What is your opinion?...

 

[Krimskiy]

For the boiler?

 

[Duwe6]

A 400 psi boiler requires a 400 psi PSV. AFTER the PSV lifts at the MAWP, then some pressure accumulation above the 400 psi MAWP is allowed. You do not get to start above the MAWP, and hope that you will not exceed the allowable accumulation pressure.