Valve Flow Coefficient (Cv) is the flow capability of a control valve at fully open conditions relative to the pressure drop across the valve. It is defined as the volume of water (GPM in the US) at 60°F that will flow through a fully open valve with a pressure differential of 1 psi across the valve.
How is flow coefficient calculated in Cv?
Control Valve Sizing – FluidFlow
- Control Valve Sizing.
- When sizing a control valve, the most common approach is to calculate the flow coefficient, Cv which is a measure of the capacity of the valve body and trim.
- C = Q/N1 * √ (ρ1/ρ0) / (∆P)
- ρ1/ρ0 is the relative density.
- Fluid Density: 965.4 kg/m3.
What is Cv in piping?
Valve Flow Coefficient (Cv) is a valve’s capacity for a liquid or gas to flow through it. It is technically defined as “the volume of water at 60°F (in US gallons) that will flow through a valve per minute with a pressure drop of 1 psi across the valve.”
What is an acceptable Cv value?
Basically CV<10 is very good, 10-20 is good, 20-30 is acceptable, and CV>30 is not acceptable.
What is CV calculation?
In statistics, CV or coefficient of variation is a measure of the variability of a sample dataset expressed as a percentage of the mean. Divide the standard deviation by the mean (calculated previously), and then multiply by 100 to get the coefficient of variation.
What is CV (valve flow coefficient)?
Valve Flow Coefficient (Cv) is a valve’s capacity for a liquid or gas to flow through it. It is technically defined as “the volume of water at 60°F (in US gallons) that will flow through a valve per minute with a pressure drop of 1 psi across the valve.”
What does CV mean on a water pump?
The definition of Cv is the # of gallons of water that will flow through the valve with a 1 PSI pressure differential when the valve is open. The equations below can be used to determine: Cv Factors. The CV factor is the number of U.S. gallons per minute that will pass through a valve with a pressure drop of (1) PSI.
What is the CV of a fully open valve?
As a valve is opening, the Cv increases until the valve is fully open, where it reaches its highest possible Cv, or 100% open Cv. On the right, we have a Cv chart showing flow curves for two different valves: a 2-inch and 3-inch Kimray back pressure regulator.
How do I determine the CV rating for a valve?
The Cv rating for each valve is listed in the tables found in the valve catalog. The definition of Cv is the # of gallons of water that will flow through the valve with a 1 PSI pressure differential when the valve is open. The equations below can be used to determine:
