cg or cv of varies valves

[engahmedbahgat]

Hello all,

Is there any reference giving me an approximate values for valves cg or cv when working in gasaes (scfh / psi) according to valve type (ball, plug, globe,..) and valve flanges NPS.

thank you

 

[MortenA]

Its easy enough for control valves - but for block valves most vendor wont give you a value - there are some rules of thumbs out there - also some that was discussed recently (try to search yourself).
Best regards, Morten

 

[georgeverghese]

There is a table in the GPSA - control valves section which has the data you are looking for. For block valves, a google search will help.

 

[SNORGY]

Remember that the definition of Cv is in how many USGPM of water flow through the valve at a pressure drop of 1 psi. So, with a knowledge of equivalent length or K resistance value of any valve, you should be able to derive whatever Cv you need.