lpg pipeline blowdown
lpg pipeline blowdown
(OP)
Would the forum members preference be to blowdown a 12" x 100ft liquid LPG line (after closing SDVs) within a plant, in the event of an emergency - or would the preference be to shut in the volume and protect with fireproofing such as Chartek





RE: lpg pipeline blowdown
I would guess this LPG stream is an overhead stream of a tower, in which case you would probabely want to depressurise the whole column. So you could also take this line with the same column and depressurise at the same time.
RE: lpg pipeline blowdown
If you are talking about overpressure protection for a fire event, I would point out that fireproofing will not prevent an overpressure concern. It will reduce the amount of heat input to the system and reduce the temperature that the pipe wall will directly see. You would still need some other means of limiting the pressure as the liquid temperature increases.
RE: lpg pipeline blowdown
This is a fairly trivial set of calculations that needs to be performed in order to asses the sizing of either a blowdown valve or a PSV. You should however also consider that while vapours may be generated it could be that it is liquid that need to be relieved at the valve.
If you only will consider a limited fire with some limited duration then maybe fireinsulation will be enough to ensure that within this time the pipe does not get so hot that the vapour pressure of the LPG exceeds the MAWP of the pipeline?
Best regards
Morten