# Pipe flow calculators

## Gas control valve sizing

#### Calculator Description

For known flow coefficient Cg or Kg of some gas control valve you can calculate that control valve capacity for known upstream and downstream pressure of pressure regulator with this calculator. If you know gas control valve capacity and upstream and downstream pressure of pressure regulator, you can calculate control valve flow coefficient, either Cg or Kg, with this calculator too. With that calculated value of flow coefficient you can pick correct pressure regulator from manufacturer's table. Gas control valve sizing calculator is based on the EN 334 standard - control valves and pressure regulators for pressures up to 100 bar.

• Calculate:

• Maximum flow rate through gas control valve
• Flow velocity
• Flow coefficient
• Input:

• Valve diameter
• Pressure drop
• Gas properties

#### Calculator Features

• For compressible gas flow
• Metric and imperial flow coefficient calculation

If you would like to use the calculator, but actually can't see the blue CALCULATOR button in the upper left part of the page than please read instructions.

Q: Calculate flow coefficient of gas control valve for 500 gpm. Valve diameter is 2 in. Pressure in front of valve is 45 psi and after the valve is 25 psi. Gas temperature in front of valve is 288 K, gas constant 287 J/kgK and kappa is 1.4

A: Calculation setup:
Input values:
q = 500 gpm US
D = 2 in
pu = 45 psi
pd = 25 psi
Tu = 288 K
R = 287 J/kgK
kappa = 1.4

Q: Calculate pressure drop in gas control valve with flow rate of 500 gpm and flow coeffient of Cg 150. Valve diameter is 4 in. Upstream pressure is 45 psi. Gas temperature in front of valve is 288 K, gas constant 287 J/kgK and kappa is 1.4

A: Calculation setup:
Input values:
q = 500 gpm US
D = 4 in
pu = 45 psi
Cg = 150
Tu = 288 K
R = 287 J/kgK
kappa = 1.4

Q: Calculate capacity of gas control valve with flow coeffient of Cg150 and pressure drop of 10 psi. Upstream pressure is 45 psi. Valve diameter is 3 in. Gas temperature in front of valve is 288 K, gas constant 287 J/kgK and kappa is 1.4

A: Calculation setup:
Input values:
D = 3 in
pu = 45 psi
deltap = 10 psi
Cg = 150
deltap = 4 psi
Tu = 288 K
R = 287 J/kgK
kappa = 1.4

Gas flow coefficient calculation is based on the following formula:

Read more about used theory on flow in valves and fittings page.

If you experience problems with calculator start try to find answers on instructions page.

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