If you have a vessel with a wire mesh demister pad, some companies insist that the relief valve should be below the demister pad. Others put it above the demister pad (top of vessel).
Question:
- Is anyone aware of a standard that gives us any guidance ?
- Is anyone aware of an actual case...
For flow and restriction orifices and nozzles, the Kd values are the same for liquids and gases.
Question: Why is there then such a big difference in Kd values for relief valves between gases (0.975) and liquids (0.62) ?
Suppose you have a relief valve in the vapour space of a feed surge drum. Some of the relief cases are vapour (like fire), and some are liquid (like outlet fail close).
Now, suppose the largest orifice area is from a liquid relief case, does this relief valve then need liquid certification ?
