Cv Value For Air Valves. Flow is proportional to the value of cv. Because air is compressible, cv must have additional factors built into the equations to compensate for that compressibility.
It is defined as the flow rate in us gallons per minute [gpm] of water at a temperature of 60º fahrenheit with a pressure drop across the valve of 1 psi. Control valve tips and tricks. The required cv range for this application than is.0141 to.0703.
The formulas provided here are simplified for general use.
For measuring the valve capacity of control valves, the coefficient cv or its metric equivalent kv is adopted. Flow is proportional to the value of cv. Because the fluid is a gas and δp ≥ p1 / 2 so we will use the formula. It allows you to calculate the flow or c v (flow coefficient) to make the relationship visible between the pressure drop (the difference in pressure between two points in a network transporting a liquid or gas) and the flow rate.