Tweec
Mechanical
- Mar 16, 2007
- 11
A late stage water filtration vessel operates fluid-packed. When sizing the PSV for FIRE condition only, should a liquid, steam, or vapor valve be used? The contents are mostly water with some oil. One school of thought says that the vessel will first relieve liquid, then vapor, so liquid is the determining factor. Another feels that the valve should be rated for the vapor, in particular, steam. While the third says that although the contents are primarily liquid water, that the valve only needs to be rated for vapor service. There is a significant cost difference between vapor and steam service valves.
