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. Kv = 0.865 · cv cv = 1,156 · kv (equivalence between flow coefficients kv and cv) A valve with a one psi pressure drop. In simple terms, a fully open control valve with a cv of 14 usgpm/psi passes 14 usgpm of fluid with 1 psi pressure drop.
The cv was designed for use with liquid flows, it expresses the flow in gallons per minute of 60º f water with a pressure drop across the valve of 1 psi. It allows you to calculate the flow or c v (flow coefficient) to make the relationship visible between the pressure drop (the difference in pressure between two points in a network transporting a liquid or gas) and the flow rate. Cv is determined by the manufacturer of the valve and can be found on the valve manufacturer's website and/or related valve data and specification sheets.
In metric units, the same valve above with a specified opening giving cv = 1 will pass 0.862m3/hr of water (at 15 degree celsius) if 1bar pressure difference(δp) exist between upstream and downstream points on each side of the valve. 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 Q is the rate of flow (expressed in us gallons per minute),
It is defined as the flow rate in us gallons per minute [gpm] of water at a temperature of 60º fahrenheit with a pressure drop across the valve of 1 psi. Online calculator to quickly determine valve and orifice cv & kvs values for steam. The cv corrected is equal to 10.96 while the valve selected has a cv of 12.
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. The flow of water through a valve at 60°f in us gallons/minute (gpm) at a pressure drop of 1lb/in². If the flow coefficient is given in si units, it may be converted to u.s.
For example, you can calculate required control valve capacity (cv or kv) for minimum, normal, maximum and one additional flow condition. Such as the renault number (reynolds number), flow rate (flow), the shock (choking), the involved joints in pipes (fitting) and the other by the values of these. Cv describes the relationship between the pressure drop across an orifice, valve or other assembly and the corresponding flow rate.