PSV set pressure vs vessel design pressure
PSV set pressure vs vessel design pressure
(OP)
Dear all,
One question occuring recently is when the design pressure of vessel is 5.5 MPaG, is it reasonable to determine its PSV set pressure as 4.5 MPaG with the operating pressure of 4MPaG?
Any comments about this item are greatly appreciated. Thank you.
One question occuring recently is when the design pressure of vessel is 5.5 MPaG, is it reasonable to determine its PSV set pressure as 4.5 MPaG with the operating pressure of 4MPaG?
Any comments about this item are greatly appreciated. Thank you.





RE: PSV set pressure vs vessel design pressure
If the MAX operating pressure is 4MPag, with a PSV set at 4.5MPag, ratio would be 89%, which is just within the max permissible of 90% for a conventional PSV. You havent said if the MAX operating pressure is indeed 4MPag. This should cover all operating modes for this vessel, and should include reasonable process control margins for pressure excursions beyond the normal range due to process upsets.
RE: PSV set pressure vs vessel design pressure
RE: PSV set pressure vs vessel design pressure
RE: PSV set pressure vs vessel design pressure
But if the operating pressure is 3.5 MPaG is it also OK for such PSV setting?