We have a couple of gas/liquid separators. We calculated relief requirements due to fire considering the wetted surface heat absorption rate (API 521 eq. 3).
Were wondering about the possibility that the liquid could completely evaporate. After that, expanding vapour would have to be relieved...
I've seen in a couple of old cryogenic gas processing plants that sometimes stainless steel (or 3.5% Ni steel) is used in PSV discharge lines for a short length (e.g.: 10 to 15 m), before the discharge line ties-in to a carbon steel flare header.
This is applied in PSVs that relieve gases at...
