Flow Coefficient (Cv) for the 17PFVF Series PVC Flapper Type Foot Valves

The chart below provides the flow coefficient (Cv) for the 3” 17PFV-300, 4” 17PFVF-400, and 6” 17PFV-600 PVC foot valves.

Flow Coefficient (Cv) is the number of U.S. gallons that can pass through a valve when it is in the fully opened position at a pressure drop of 1 PSI. Testing is typically done using running water (specific gravity of 1.0 centistoke viscosity) at 60°F (15.5°C) unless stated otherwise.

The Cv is used to properly size valves so that they have minimal effect on the hydraulic efficiency of your system. Cv is one of the most important things to know for selecting the right size of valve. For example, the 4” valve with a Cv of 614 has an effective port area in the fully open position such that it is capable of passing 614 GPM of water with a pressure drop of 1 PSI.

CRACKING PRESSURE: ≥ 1/2 PSI

Cracking pressure is the pressure at which a component starts to open. This term is used in reference to our check valves. When the ½ PSI cracking pressure is reached the check valve will start to open.