CV Value

The Cv’s a valve property and is defined as follows. “The Flow Coefficient Cv states the flow capapcity of a valve in U.S. gallons per minute of water at a standard temperature of 60°F (15.6° C) that will flow through the valve with a pressure loss of one pound per square inch at a specific opening position”. For the metric system the analog value is Kv where measure unit are Bar, Kg and meters. The Cv show the quality and accuracy of a valve in terms of pressure loss, the highest values of Cv indicate the highest quality of a valve.

To measure the properly value of Cv there in not a standard method. G M Valve R & D team has used two different methods: 1-Using Cv definition, through the means of a specifically built test rig, it has been obtained 1Bar of pressure loss and the flow has been verified with specific equipment. Calculation is possible to convert the measure to Cv. 2-In the same machine the flow has been changed and different measure of process loss has been obtained: a table has been defined and an average value per each has been calculated.