Leak Testing PSV Downstream Flange

[ChemEngSquirrel]

Are there any cases where it is unacceptable to leak test the downstream flange of a PSV i.e. can a relief valve be damaged by an artificially high back pressure due to leak testing?

I'm not proposing to leak test in excess of the flange rating but leak testing will mean that the downstream side is pressurised while upstream side is not. This is a balanced bellows PSV. Set pressure is 20 barg and downstream side will be leak tested to 17.5 barg.

Thanks.

 

[DSB123]

first of all have you checked with the RV vendor ? That is your start point.

 

[The Obturator]

As well as getting the SRV vendor views, you need to consider;-
1) That the SRV is not under pressure (ie, live and protecting the system).
2) What the test medium will be and if it can affect the SRV internals.
3) The maximum pressure at the SRV outlet will be dictated by the bellows not the outlet flange rating - can be quite lower than expected especially on large orifice.

Per ISO, only the term Safety Valve is used regardless of application or design.