Steam/Water Vapor Relief Distinction?
Steam/Water Vapor Relief Distinction?
(OP)
API 520 (7th edition, Jan '00) provides a special equation specific for critical flow steam relief (section 3.7.1, eq. 3.8). This is obviously different than the normal critical flow equation for gases (section 3.6.2.1.1, eq. 3.2).
My question is as follows: if I have an ASME section VIII pressure vessel containing mostly water and I'm sizing a PSV for the "External Fire: Vapor Generation" case, do I use the steam relief equation 3.8 or would I use the normal sizing equation? Again, flow is critical.
Perhaps a dumb question, but it's caused some debate around the office here.
My question is as follows: if I have an ASME section VIII pressure vessel containing mostly water and I'm sizing a PSV for the "External Fire: Vapor Generation" case, do I use the steam relief equation 3.8 or would I use the normal sizing equation? Again, flow is critical.
Perhaps a dumb question, but it's caused some debate around the office here.





RE: Steam/Water Vapor Relief Distinction?
RE: Steam/Water Vapor Relief Distinction?
As far as i know, chemical engineers do not endorse the responsability of sizing the PRV nozzle. It is tipically the manufacturer...So, in my opinion, you can follow skearse advice and use the most conservative equation.
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