Valve sizing calculator

The Kv-value is a measure of the flow rate through a valve for a given medium and pressure drop. The larger this value, the higher the flow rate through the valve will be at a given pressure drop. Usually, the Kv-value is given in the product description or datasheet. It provides a more accurate indication than for example the pipe connection size or orifice diameter. The Kv-value is measured as the flow rate of water in m3/h with a pressure drop of 1 bar at 20°C.

If the medium characteristics, the pressure drop and the desired flow rate are known, the minimal required Kv-value for the valve can be calculated. Different formulas apply for fluids and gases.

Kv-value calculator fluids

Fill a value for the inlet pressure, the outlet pressure and the minimal required flow rate. Click calculate and the Kv and Cv value will be calculated. Choose a valve with a Kv-value equal or higher than the calculated value.

Liquid:

waterglycerinegasolineethyl alcoholuser defined

Specific gravity:

Inlet pressure:

kPa absMPa abspsi absbar abskg/cm² absmmHg absinHg abskPa gaugeMPa gaugepsi gaugebar gaugekg/cm² gaugemmHg gaugeinHg gauge

Outlet pressure:

kPa absMPa abspsi absbar abskg/cm² absmmHg absinHg abskPa gaugeMPa gaugepsi gaugebar gaugekg/cm² gaugemmHg gaugeinHg gauge

Flow rate:

m³/hm³/minl/hl/mingal/h (US)gal/min (US)gal/h (UK)gal/min (UK)

Valve Kv value:

Valve Cv value:

where:
Q  Flow rate[m3/hour]
Kv  Hydraulic factor
dp  Pressure differential [bar]
SG  Specific Gravity (Water 1)

Find a suitable valve for this calculation

2-Way Solenoid Valve Online Selection3-Way Solenoid Valve Online Selection2-Way Electric Ball Valve Online Selection3-Way Electric Ball Valve Online Selection

Kv-value calculator gases

Choose a gas type and the inlet temperature. Choose the inlet pressure, the outlet pressure, the required flow rate and click calculate. Choose a valve with an equal or higher Kv-value to achieve the desired flow rate. The N in the flow rate stands for normal conditions (atmospheric pressure and 0 degrees Celsius).

Gas:

AirButaneCarbon dioxideMethaneNitrogenOxygenPropaneuser defined

Specific gravity:

Air temperature:

°C°FK

Inlet pressure:

kPa absMPa abspsi absbar abskg/cm² absmmHg absinHg abskPa gaugeMPa gaugepsi gaugebar gaugekg/cm² gaugemmHg gaugeinHg gauge

Outlet pressure:

kPa absMPa abspsi absbar abskg/cm² absmmHg absinHg abskPa gaugeMPa gaugepsi gaugebar gaugekg/cm² gaugemmHg gaugeinHg gauge

Flow rate:

Nm³/hNm³/minNl/hNl/mingal/h (US)gal/min (US)gal/h (UK)gal/min (UK)

Valve Kv value:

Where:
Q_N= Normal Flow rate [m³/hour]
Kv = Hydraulic factor
T = Inlet gas temperature [K]
p1 = Inlet Pressure [bar]
p2 = Outlet Pressure [bar]
dp = Pressure differential [bar]
SG = Specific Gravity (Air = 1)

Find a suitable valve for this calculation

2-Way Solenoid Valve Online Selection3-Way Solenoid Valve Online Selection2-Way Electric Ball Valve Online Selection3-Way Electric Ball Valve Online Selection

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