Dear all,
Please, need some clarification from you guys.
Our contractor is design a Mercury bed inlet KO with two design pressure and two design temperature. This KO drum is installed at the downstream of compressor air coolers.
For information:
OP = 71 barg @ 62°C.
PSV set @ 78 barg.
He considered two scenarios for that :
Scenario 1 :
Operating pressure (71 barg) with failure of the air cooler (120°C). Design condition : 77 barg @ 120°C
Scenario 2 :
Operating pressure (78 barg) with blocked outlet @ (62°C). Design condition : 78 barg @ 100°C
However, as per my understanding, pressure vessel shall be designed with coincidental conditions. in our cas, it shall be (78 barg @ 120°). But the contractor insist that this is not correct since blocked outlet+air cooler failure is not envisaged as double jeopardy.
So, please can some explain which scenario shall be considered for the (datsheet, name plate,..) why and any standard that treat this subject.
Thanks in advance.
Edited by Abdelilah, 06 August 2019 - 01:21 AM.