psv - set pressure higher critical pressure
psv - set pressure higher critical pressure
(OP)
we have a vessel to protect by overpressure during a fire, the fluid has a critical pressure below the set pressure of the PSV so there isn't true latent heat.
How must the flowrate of fire contingency be set?
Tx for replies
How must the flowrate of fire contingency be set?
Tx for replies





RE: psv - set pressure higher critical pressure
RE: psv - set pressure higher critical pressure
It's important to understand that safety valves are generally incapable of protecting a vessel from fire exposure unless that vessel is at least partly filled with liquid, and that liquid will boil at a temperature that is not too excessive.
Moltenmetal provided real good advice - treat this supercritical fluid as if it's a gas - a very high density gas. If you're going to rely entirely on a relief device to protect a gas filled vessel from fire, then a non-reclosing device is what you need. A safety valve will not prevent the vessel from failing.
I just wanted to add that there's an alternate solution, if you hate rupture disks as much as I do. Whenever you use disks, you have to worry about premature disk failure, and that in itself can have some pretty unacceptable consequences. The alternative is to use a safety valve, but rely on other means to provide real protection. That is, use one, or any combination of the following protective measures, depending on the severity of the hazard: (1) auto depressurization, (2) water spray, (3) fire resistant insulation.
RE: psv - set pressure higher critical pressure
RE: psv - set pressure higher critical pressure