Cv Factor For Valves. Scfm air flow through a valve orifice having a cv factor of 1.00 For example, a valve with cv of 4.00 will pass 4 times as much flow at the same pressure difference as shown in the chart.
If differential pressure is same, flow rate is big so that cv factor is big. Cv value is an imperial measure of flow in us gallons per minute of water at 60° fahrenheit with a pressure drop of 1 psi across the valve. Cv is the flow coefficient in imperial units.
Full port valves will have a higher cv than reduced port valves.
In the chart below, we show the approximate cv value of butterfly valves ranging from 2 to 24 and at various disc angles. The equations below can be used to determine: The full closure curve of a ball valve is then the above graph multiplied by the valve’s flow coefficient or factor. Cv & kv relation :