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.

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 Selection 3-Way Solenoid Valve Online Selection 2-Way Electric Ball Valve Online Selection 3-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).

⇨

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 Selection 3-Way Solenoid Valve Online Selection 2-Way Electric Ball Valve Online Selection 3-Way Electric Ball Valve Online Selection

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Selection Wizard

Complete the questions to find suitable valves directly:

2-way
3-way

Type:

2-Way Solenoid Valve

2-Way Electric Ball Valve

Solenoid Valve or Ball Valve?

Solenoid Valves: 2-Way Solenoid Valve

The valve is actuated with an electric current through the solenoid (electromagnet).

Switches directly.
From 1/8 inch up to 2 inch.
Normally Closed or Normally Open.
Only for clean media.
Uses energy as long as electrically energized.
(Semi-)direct operated: from 0 bar pressure differential.
Indirect operated: from ±0.5 bar pressure diff.
Only one direction of pressure.
Brass, Stainless Steel or Plastic housing.
EPDM, FKM, NBR of PTFE seals.

Electric Ball Valves: 2-Way Electric Ball Valve

The flow is controlled with a drilled sphere (ball) which rotates around its axis, perpendicular to the bore. The ball rotates with the help of an electric motor.

Operates from 0 bar.
Close gradually (±10s).
Energy efficient.
1/2, 3/4 or 1 inch.
For both flow directions.
Brass Housing / PTFE sealing.
Less sensitive to dirt.

Function:

NC = Normally Closed (most chosen): The valve is closed when the coil is not electrically energized.
NO = Normally Open: The valve is open when the coil is not electrically energized.

System:

Indirect operated solenoid valves need a pressure differential over the inlet and outlet port for proper operation. If the pressure differential is too low (f.e. a gravity fed system or a closed circuit), only (semi-)direct operated solenoid valves can be used. These operate from a zero bar pressure differential.

Medium:

The type of medium defines the material choice of the valve body and seals. By selecting 'Other', you can choose the material for the valve body and seals.

Tip: Use the material table.

Valve:

Seal:

Port:

Most valves are provided with internal thread (BSPP = British Standard Pipe Parallel). Use the table as a guideline for sizing:

Valve	Pipe ∅
1/8 inch	± 4 - 8 mm
1/4 inch	± 6 - 12 mm
3/8 inch	± 8 - 15 mm
1/2 inch	± 10 - 16 mm
3/4 inch	± 15 - 22 mm
1 inch	± 20 - 30 mm
1½ inch	± 25 - 50 mm
2 inch	± 40 - 60 mm