Cv Factor For Valves

It can be assumed that the tests are done with water (unless otherwise noted), using a specific gravity of 1.0, 1.2 centistoke viscosity, and a standard temperature of 60 degrees fahrenheit.

Cv factor for valves. Gallons per minute of water at 60°f that will flow through a control valve at a specified opening when a pressure differential of 1psi. The cv factor is the number of u.s. A valve with a high cv passes fluid more easily than one with a low cv.

The following formula is often used using a fluid’s specific gravity (g) where the relationship to water density is already considered. Kv = 0.864 cv 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. The valve flow coefficient (c v) is a convenient way to represent flow capacity of a valve across a range of fluids and process parameters.the c v calculator will calculate either c v or flow using the supplied additional parameters of fluid, inlet and outlet.

C v & flow calculator. They simplify the job of selecting an adequately sized valve without wasteful oversizing; On valves or orifices with other cv factors, the flow capacity will be directly proportional to the cv rating.

Contrast this with the resistance factor k (the one used for pipe fittings like bends etc). The required cv range for this application than is.0141 to.0703. The flow of water through a valve at 60°f in us gallons/minute (gpm) at a pressure drop of 1lb/in².

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 diagram below is a nice tool to simplify the conversion between the different coefficients. A valve cv can be described as the number of gallons per minute (gpm) at 60 o f (15.5 o c) that will pass through a valve with an associated pressure drop of 1 psi.

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. Cv is the amount of flow in gallons per minute through a valve which results in a 1 psi pressure drop. Cv & kv relation :