Cv Factor For Valves

However, there is a problem with using this equation in pneumatic applications.

Cv factor for valves. Cv factor can be calculated as following formula. And if cv factor is same, flow rate is big so that differential pressure is big. The tables below list the full cv vs angle closure and opening curves for various valve diameters:

The flow of water through a valve at 60°f in us gallons/minute (gpm) at a pressure drop of 1lb/in². The valve flow coefficient, cv, is the number of u.s. The flow factor is commonly used outside u.s.

For the same pressure conditions, if we increase the valve opening to create cv = 10, it will pass 10 us gpm provided 1 psi pressure drop across the valve (remains same). The equations below can be used to determine: Gallons per minute that will pass through a valve with a pressure drop of (1) psi.

The diagram below is a nice tool to simplify the conversion between the different coefficients. The valve flow coefficient cv or its metric equivalent kv has been adopted universally as a comparative value for measuring the capacity of control valves. The below cv values are used to give an indication of flow rates for ball valves.

Control valve cv refers to the flow coefficient of the valve. A fitting with a high k value passes fluid less easily than one with a low k value. The required cv range for this application than is.0141 to.0703.

The process of valve size selection, the same formula is used determine the valve cv necessary for a required flow rate and desired pressure drop. The full closure curve of a ball valve is then the above graph multiplied by the valve’s flow coefficient or factor. They provide a means of comparing the flow capacities of different brands of valves;