Valve Flow Coefficient Cv / Kv

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Valve flow coefficient, abbreviared as \(C_v\), also called valve sizing coefficient, is the number of US gallons of water at 60°F that will flow throuhg a valve in one minute when the pressure differential across the valve is one pound per square inch (psi).

 

Valve Flow Coefficient Cv / Kv Formulas

\(\large{ C_v =   Q  \sqrt{  \frac{SG}{\Delta P} } }\)   
\(\large{ Q =   C_v  \sqrt{  \frac{\Delta P}{SG} }  }\)   
\(\large{ \Delta P =   SG  \left( \frac{Q}{C_v} \right)   }\)   
\(\large{ K_v =   Q  \sqrt{  \frac{SG}{\Delta P} } }\)  
\(\large{ Q =   K_v  \sqrt{  \frac{\Delta P}{SG}  } }\)  
\(\large{ \Delta P =   SG  \left( \frac{Q}{K_v} \right)   }\)  

Where:

\(\large{ C_v }\) = valve flow coefficient (US units)

\(\large{ K_v }\) = valve flow coefficient (SI units)

\(\large{ Q }\) = valve flow rate

\(\large{ \Delta P }\) = valve pressure differential

\(\large{ SG }\) = specific gravity of fluid

 

Tags: Equations for Pressure Equations for Coefficient Equations for Flow Equations for Valves Equations for Valve Sizing