Cv Calculation For Butterfly Valve. When sizing (calculating which size valve is needed for your application ) a control valve specialist needs to calculate the flow coefficient. You can do a quick check by seeing what the dp will be for your wide open flow using the equation q = cv (dp/sg)^2 i posted earlier.
Calculation of cv/d 2 [valve world] the calculation of cv/d 2 is required for the next steps of the valve sizing. This depends on how the valve has been designed to let the flow going through the valve. The valve flow coefficient, cv, is the number of u.s.
The larger this value, the higher the flow rate through the valve will be at a given pressure drop.
The use of this flow coefficient (c v) calculator leads to a standard calculation to compare valve capacities. Gallon per minute of 60 degree fahrenheit water that flows through a valve with a one psi pressure drop. The full closure curve of a butterfly valve is then the above graph multiplied by the valve’s flow coefficient or factor. Suppose a certain valve has a published cv factor of 3.75.