Dear Forum members,
I have recently found that initial pressure of the vessel for fire case depressuring is different from standard to standard.
For example, design pressure, PSV set pressure, high-high pressure of the vessel are recommended.
But most of the case, it seems design pressure to be used.
While operating temperature or maximum operating temperature is used as initial temperature which seems to be appropriate, why is design pressure used as the initial pressure for depressuring?
Is it just because higher pressure is more conservative and more peak flow?
For me, it looks more reasonable to use maximum operating pressure.
Please let me know the reason why we use design pressure.
Thanks in advance.