Valve Cv Formula Si Units. At a particular percentage of opening of valve giving cv = 1 will pass 1us gpm ( at 60 °f) and a pressure differential of 1 psi upstream and downstream across the valve. 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.
※3 for p1 and p2, please use pressure close to the valve. Cv describes the relationship between the pressure drop across an orifice, valve or other assembly and the corresponding flow rate. For quick calculations, you can make use of the related calculator designed based on the flow coefficient formula given above.
If the flow coefficient is given in si units, it may be converted to u.s.
Cv = 1.156 kv conversion of units for kv to cv. Equations displayed for easy reference. 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. Kv = 0.865 · cv cv = 1,156 · kv (equivalence between flow coefficients kv and cv)