How to Calculate Cv

What is Cv ?

Cv = Flow coefficient or flow capacity rating of a valve. The flow coefficient  Cv is the volume (in US gallons) of water at 60°F that will flow per minute through a valve with a pressure drop of 1 psi across the valve.

This formula can assist in determining the correct valve for an application .

Mathematically the flow coefficient can be expressed as:

C_v = F \sqrt{\dfrac{SG}{\Delta P}}

where:
Cv = Flow coefficient or flow capacity rating of valve.
F = Rate of flow (US gallons per minute).
SG = Specific gravity of fluid (Water = 1).
ΔP = Pressure drop across valve (psi).