Pilot PSV overpressure
Pilot PSV overpressure
(OP)
hi folks,
I am looking for a pilot operated relief valve (set pressure @ 214 barg to flare b.p 10 barg max)that will pass full flow of gas (PSV full opened)with absolutely no overpressure, i.e. at full relief the pressure upstream PSV is 214 barg only. I understand that is one attribute of pilot operated psv.
thanks
I am looking for a pilot operated relief valve (set pressure @ 214 barg to flare b.p 10 barg max)that will pass full flow of gas (PSV full opened)with absolutely no overpressure, i.e. at full relief the pressure upstream PSV is 214 barg only. I understand that is one attribute of pilot operated psv.
thanks





RE: Pilot PSV overpressure
As for brand, ther are lots, Mercer, Taylor, Consolidated, Axelson,
RE: Pilot PSV overpressure
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RE: Pilot PSV overpressure
If you specify a valve that will pass your full flow at 204 bard (bars differential), then you should not have any overpressure other than the normal hardware tolerances. Yours would not be a "normal" specification, so work with the vendor to ensure he/she understands your requirements. I don't see why you are inclined towards a pilot operated PSV, though one would certainly be acceptable. (But so would other types of PSV.)
Doug
RE: Pilot PSV overpressure
RE: Pilot PSV overpressure
RE: Pilot PSV overpressure
RE: Pilot PSV overpressure
A pilot is a good choice if you want seat tightness up to ~97% of set pressure. A modulating pilot is better than a pop acting in that it will elliminate full capacity releases for small contingencies or upsets - and also as stated, reduce chatter. You might need to have the set pressure lowered though in order for the maximum opening to occur at your desired pressure.
Are you sure you have the contingency nailed? What if someother contingency can generate more capacity than the SV can handle?? Pressure will definitely go above set pressure then.
You could equally use a conventional SV with a reduced set pressure, designed for full flow at the 10% accumulation equalling your desired pressure. That's been done in my work place before, but normal operating pressure needs to be well controlled or else spurious lifts can occur.
Definitely definitely concur with the clean service requirements for POSV's.