Valve Cv Equation Si Units

The flow coefficient of a device is a relative measure of its efficiency at allowing fluid flow.

Valve cv equation si units. From cv table, the corresponding valve position is 70% open. Specific formulas used to estimate cv for different fluids is indicated below: Gallons/min d nominal valve size mm d internal diameter of piping mm d o equivalent circular flow passage diameter mm d h hydraulic diameter of a single flow passage mm f d valve style modifier dimensionless f f

It describes the relationship between the pressure drop across an orifice valve or other assembly and the corresponding flow rate. Cv and kv are singles values in units of flowrate that may be used to characterise the relationship between flowrate and pressure loss for fittings and equipment. For any specific valve opening with an equivalent pressure drop and equivalent temperature, by applying multiplication factor we get equal flows in both imperial and metric units.

950 units or less 9unusual demand hunter’s method 9more than 50 units 9typical demand. The valve would regulate at 91% of its maximum cv. In metric units, the same valve with cv = 1 pass 0.864 m3/hr.

For quick calculations, you can make use of the related calculator designed based on the flow coefficient formula given above. Cv for fluids cv for liquids is the volume of 68°f water in u.s. If the flow coefficient is given in si units, it may be converted to u.s.

A valve cv can be described as the number of gallons per minute (gpm) at 60 o f (15.5 o c) that will pass through a valve with an associated pressure drop of 1 psi. Units by dividing it by 54.9. The use of this flow coefficient (c v) calculator leads to a standard calculation to compare valve capacities.

Pressure drop 7.5 gpm 100 psi 95 psi. This article demonstrates how to calculate the cv or kv values, and how to use these values to determine the pressure loss for a given flowrate. Equations displayed for easy reference.