Dear All,
I am working on a adequacy check for existing PSVs in a refinery. I have a case where a centrifugal pump discharges to a series of filers. The case here is the downstream filters all have a design pressure of 150 psig and the pump's blocked in pressure turns out to be 156 psig. Now technically I have to provide a PSV as there is 6 psig more than the design pressure, but even If I provide a PSV, it wont be able to have a full lift as I believe these PSVs would have a 10% overpressure and would not lift completely. So I cant predict the area available for a lift of 156 psig and check adequacy. I want to makes sure if this case is really exist. My thought was if API can allow 10% overpressure can I take credit for that and say that PSV is not required for a blocked outlet? please share your thoughts
Thanks,
G
P.S: The vessels are also stamped for 150 psig for MAWP