How do you calculate the CV value of a valve?

Cv by definition is the number of gallons per minute (GPM) a valve will flow with a 1 psi pressure drop across the valve. For example a valve with a Cv of 10 will flow 10 GPM with a 1 psi pressure drop. The formula used to select the valve Cv with the specified differential pressure is: Cv=GPM/((SQ RT(P)).

What happens if pressure drop is too high?

Excessive pressure drop will result in poor system performance and excessive energy consumption. Flow restrictions of any type in a system require higher operating pressures than are needed, resulting in higher energy consumption.

How do you calculate flow rate with pressure and diameter?

Divide the pipe’s internal diameter by 2. For example, if the pipe has an internal diameter of 0.1 meters: 0.1 ÷ 2 = 0.05 m This is the pipe’s radius. Square this radius: 0.05² = 0.0025 m². Multiply the result by pi, which is approximately 3.142: 0.0025 × 3.142 = 0.007855 m².

How do you calculate pressure from flow rate?

The flow rate, in turn, at a known pipe cross-sectional area, determines the fluid’s flow rate. Subtract static pressure from the total pressure. If the pipe has a total pressure of 0.035 kilopascals and a static pressure of 0.01 kilopascals: 0.035 – 0.01 = 0.025 kilopascals.

How do you find velocity with diameter and flow rate?

1: Flow rate is the volume of fluid per unit time flowing past a point through the area A. re the shaded cylinder of fluid flows past point P in a uniform pipe in time t. The volume of the cylinder is Ad and the average velocity is ¯v=d/t so that the flow rate is Q=Ad/t=A¯v.