1 reply to this topic

[Mohamed94]

Gents, 
  I have a question I encountered while sizing a PSV. I have separator with class rating #900. I set the pressure to be the max. pressure class #900 can withstand at this temperature. In case of fire, I have to add 21% allowable over-pressure according to the API 521, which will produce pressure above that of rating #900 can withstand. To cut a long story short, my question is how it is acceptable to set the PSV pressure to be the MAWP because when adding the allowable over pressure (10% for blocked outlet, 21% for fire), the equipment's flanges will be exposed to pressure higher than they can withstand.
 
Thanks in advance.
 
Regards,
Mohamed M. Abdelhameed

[Art Montemayor]

Mohamed:

 

Perhaps the attached document found at our thread, https://www.cheresou...ation-pressure/

 

may be of help in resolving your application of the MAWP with regards to the appropriate PSV to protect your system (not just the separator).