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[Falah]

Dear engineers
I have a question about pressure in case of check valve failure scenario, if we want to size PSV based on this scenario, what are down stream and upstream pressure of check valve we should use in sizing. To clarify more,for example in sizing psv for control valve failure, to find required relief load we consider that the upstream pressure of control valve is maximum operationg pressure and the downstream pressure is pressure for PAHH alarm. What about upstream and downstream pressure check valve failure scenario?
If any one has a reference, that will be more beneficial

Edited by Falah, 26 March 2025 - 05:24 PM.

[shvet1]

Your logic is corrupt. 

Control valve downstream pressure is irrelevant to PAHH alarm and is limited by a hydraulic profile of a downstream relief path. The same is valid for check valve.

Check valve upstream pressure depends on options whether the check valve is choked or not and for this reason is limited by a whole hydraulic profile of a relief path, up&downstream both.

 

It does not work this way.

 

The critical part is whether this check valve is choked or not. If it is choked then some assumptions related to upstream conditions can be applied. But only to upstream and with a great care.

 

The pressure source. You need to start with the pressure source and then proceed with a hydraulic profile of the relief path. A check valve is not a pressure source, it is only one of segments of the relief path and it is not predetermined that that very segment limits the relief.

Edited by shvet1, 01 April 2025 - 11:51 PM.