Maximum pressure drop across control valves

[markzu3]

What would be the maximum possible pressure drop for a vent station control valve with upstream pressure of 135psia and venting to a rockmuffler diffuser from where the steam pressure is further reduced to atmospheric. My question really is to confirm that the maximum pressure drop across the CV happens when the downstream pressure reaches chocked flow condition - is this a correct assumption? Thanks

 

[Latexman]

You are correct. Most vendors catalogs have the equations and constants for the exact valve and trim being used to figure this out. I know Fisher has a Control Valve Manual that does.


Good luck,
Latexman