psv inlet and discharge lines sizing
psv inlet and discharge lines sizing
(OP)
Hi,
this is my question:
sizing of the in/outlet lines must be done with the PSV required flowrate (minimum area required) or with the maximum flowrate (without kd=0,9 and with orifice area selected)?
i think the second but need a confirm, tx
this is my question:
sizing of the in/outlet lines must be done with the PSV required flowrate (minimum area required) or with the maximum flowrate (without kd=0,9 and with orifice area selected)?
i think the second but need a confirm, tx





RE: psv inlet and discharge lines sizing
a standard PSV (e.g.,a non-modulating) will pop and pass its rated capacity until it drops the pressure in the system low enough to reseat.
RE: psv inlet and discharge lines sizing
RE: psv inlet and discharge lines sizing
On the tail pipe, too much friction can take a gas PSV out of critical flow (significantly reducing flow rate).
Neither situation is good. I generally find a max required relieving rate (from the critical scenarios), double it, size the inlet piping for 0.5 psid in the inflated flow rate. For the tail pipe I look for dP less than 1 atm (i.e., I allow no more than twice the design exhaust pressure) using 2X max credible scenario.
David Simpson, PE
MuleShoe Engineering
Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat
RE: psv inlet and discharge lines sizing
RE: psv inlet and discharge lines sizing
In order to calculate the dP of the inlet line to a liquid certified (trim) relief valve, shall I still use the rated flow? or is this type of valve considered a 'modulating' one and thus, the required flow is ok?
P.S: general info about liquid trim valves is appreciated.
Thanks!