What is co-efficient (CV) of control valve?

Valve sizing coefficient ‘Cv’ is defined as the number of US gallons per minute of water that will pass through a given restriction with a pressure drop of one psi.

co-efficient (CV) of control valve

This is basic equation for liquid calculations, in volumetric flow Where -

Q - flow rate in US gpm
P1 - upstream pressure in psia
P2 - downstream pressure in psia
G - liquid specific gravity @ flowing temp.