OK so what you are saying is for a GB150 vessel exposed to an external fire the allowable overpressure is 0%? As opposed to an ASME code vessel which is 20% above the MAWP for the fire case.
I am designing a pressure relief valve for a gb150 vessel. I need to know the allowable overpressure for this standard in the fire case. Is it similar to ASME Sec VIII (20%)? I cannot find this information anywhere. I would also need justification for using 20% if this is possible.