Enter the rate of flow, the specific gravity of the fluid, and the pressure drop across the valve to calculate the flow coefficient.

CV Flow Formula

The following formula is used to calculate the CV flow coefficient. 

Cv = Q * Sqrt ( SG / P )
  • Where CV is the coefficient of flow
  • Q is the flow rate
  • SG is the specific gravity of the fluid inflow
  • P is the pressure drop across the valve the fluid is moving through

To calculate the coefficient of flow, multiply the flow rate by the square root of the ratio of specific gravity to the pressure drop.

CV Flow Definition

A CV flow, more commonly known as the coefficient of flow, is a measure of the ability of a fluid to flow rate a valve at a certain pressure drop.

CV Flow Example

How to calculate CV flow coefficient?

First, determine the rate of flow. This is typically expressed in gallons per minute (GPM). For this example, the flow is determined to be 50 GPM.

Next, determine the specific gravity of the fluid. To make things simple, this example will assume water at 4C which has a specific gravity of 1.

Next, determine the pressure drop across the valve. In this problem, the pressure drop is found to be 5 psi.

Finally, using the formula, calculate the flow coefficient.

CV = 50* Sqrt ( 1/5) = 22.360.

cv flow calculator