I would like to have some views and comments regarding check valve failure as a credible overpressure scenario while evaluating a PSV's scenario.
API 521 talks about Check valve leakage or failure and the topic addressed there is the leakage that causes reverse flow and pressurise the lower design pressure side.
I would like to know if we can consider a blocked outlet due to a check valve stuck close. I tried reasoning the same with some engineers at work and did not get a clear conclusion.
I tried checking the failure modes for the check valve and the database lists just only common mode of failure and the probability for the failure is 0.21, which will lead to a high risk level.
An example for the arrangement could be a overhead gas line from a contactor to suction drum. I am attaching a simple skrtch for the same.
I would appreciate all your suggestions.