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Solenoid Valve Definitions

Flow Coefficient (Cv)

The flow coefficient is the volume of a medium that flows through a valve with a given pressure drop, when the valve is wide open. The flow coefficient provides a standard for comparing valves and is used in flow calculations.

Flow Rate

The volume of a medium flowing through a valve in a given period of time. Usually measured in gallons per minute (GPM) for liquids, standard cubic feet per hour (SCFH) for gases, and pounds per hour (LBS/HR) for steam.

Inlet Pressure

Pressure of liquid, gas, or steam upon entering the valve.

Back Pressure

Pressure of liquid, gas, or steam upon exiting the valve.

Pressure Drop

Difference between the pressure entering the valve and the pressure exiting the valve. Pressure Drop = Inlet Pressure – Back Pressure.

As this statement is basically true, compressible media ( Gases and Steam ) introduce complex formulas which we have accounted for in the calculations. While we believe the calculations to be accurate, please contact a Gould consultant at 800-634-6853, or e-mail us at to verify the accuracy of the selection.