Cv to Pressure Drop Calculator

Formula

The formula to calculate the pressure drop (ΔP) is:

\[ \Delta P = \left( \frac{Q}{Cv \times \sqrt{SG}} \right)^2 \]

Where:

\( \Delta P \) is the pressure drop
\( Q \) is the flow rate
\( Cv \) is the flow coefficient
\( SG \) is the specific gravity

What is Cv?

Cv, or flow coefficient, is a measure of the capacity of a valve to pass fluid. It is defined as the flow rate of water in gallons per minute (GPM) at 60°F that will pass through a valve with a pressure drop of 1 psi. The higher the Cv, the greater the flow rate through the valve for a given pressure drop.

Example Calculation

Let's assume the following values:

Flow Rate (Q) = 100 GPM
Flow Coefficient (Cv) = 50
Specific Gravity (SG) = 1

Using the formula to calculate the pressure drop:

\[ \Delta P = \left( \frac{100}{50 \times \sqrt{1}} \right)^2 = \left( \frac{100}{50} \right)^2 = 4 \]

The Pressure Drop (ΔP) is 4 psi.