Propane fire case PSV relief
Propane fire case PSV relief
(OP)
I have a few 2000 bbl propane bullet with a design pressure 250 psig. We have sized the PSV for fire case. My question is, can we relief all PSV to atmopshere? If we bring the PSV relief to flare system, the header will be very large. If we vent the relief to atmosphere, is there any code requirement as far as stand point of spacing. For example, how far we should keep the relief away from ignition sources? Do we need to build any berm or dyke for bullet? Thanks.





RE: Propane fire case PSV relief
But double check with your local air emission regulatory agency. Your facility permit may have some special clauses.
2. I am not aware of any specific horizontal space seperation for vents other than
a) the recommended API tank spacing and
b)spacing requirement to maintain the area electrical classification.
If the vent is near a working platform API calls for the outlet to be 10-ft above and 50-ft horizontal from platform.
For dispersion of flammables, the tail pipe velocity should be greater than 100-ft/sec for the smallest contingency.
Hopefully steam is available at your facility to be piped at end of tail pipe.
If you had a release (or small seepage) which ignited, the steam would be available to snuff the flame.
RE: Propane fire case PSV relief
RE: Propane fire case PSV relief
NFPA-30 may be useful also.....
RE: Propane fire case PSV relief
RE: Propane fire case PSV relief
RE: Propane fire case PSV relief
RE: Propane fire case PSV relief
You must remeber that the purpose of a PSV in the fire case is to prevent escalation of the accident by having the vessel rupturing.
So venting to atmosphere near the vessel may or may not make thing worse. I gues everybody knows the texas city incident. This promted BP to state that they would use cold vent. This is rather impractical in some applications. However - a LPG bullet may be one case where a cold vent could be dangeours e.g. in case of overfilling.
If this is a Shell job the theres a DEP about the subject - but i guess you would already know that.
Best regards
Morten
RE: Propane fire case PSV relief
RE: Propane fire case PSV relief
Propane bullets are protected from truck impact and are at set distances from structures, buildings etc.
Your propane storage facility should be located in conformance with NFPA 58 and the requirements of the local authorities...then
Draw a line around the propane tanks on the PID and...
Do not discharge into a flare header ..... IMHO this is a case where you have a utility (propane) that is "outside" of the rules of the process space.
Some "fun reading" about propane is contained in:
http:
http://ncsp.tamu.edu/reports/CSB/csb_4.pdf