Compliance of ASME SEC VII for Pressure Vessels 1

[Sawsan311]

Dear All,

if the design involves a pressure vessel which shall be designed (UV stamped) in accordance with ASME SEC VII code, and if fire is the only overpressure scenario, would it be acceptable to waive the requirement of PSV since UG-140 of the same code is stating overpressure protection by system design.

I am under the understanding that PSV requirement is mandatory on any PV irrespective to having only one single overpressure scenario. Additionally, I think fire case protection is not one of the measures discussed by UG-140 such as as including a SIL-3 system or strict administrative controls?

Do you agree that any ASME UV stamped vessels shall have a PSV for OPP for fire case protection if no other SIF/measure is considered adequately applicable for its prevention

Regards,

 

[The Obturator]

UG-140 is essentially describing a HIPPS System.

My opinion re your described scenario:
Should a Pressure-relief Valve be fitted? Yes.
Will the Inspector signing off the design allow no overpressure protection in the form of a pressure relief device? Unlikely.


*** Per ISO-4126, the generic term
'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

 

[Latexman]

"If fire is the only overpressure scenario", yes, a PSV is mandatory.

Good Luck,
Latexman

 

[Sawsan311]

Thank you very much for your feedback

 

[georgeverghese]

If there is a credible fire case, then a PSV is the lower risk ultimate safeguard, if there is no overriding justification for HIPPS.
Things get a little weird when design folks ask for a "firecase only" (ie there is NO credible firecase overpressure scenario) PSV on a PV that is not handling flammables, is not sitting in a dike that could contain hydrocarbons, and there is no future intent to relocate this vessel to some place where there could be a credible firecase scenario either.