How to select a suitable solenoid valve for your project?

Choosing the Right Solenoid Valve

A solenoid valve is an electromechanical device in a hydraulic circuit that uses an electric current to generate a magnetic field and thus actuate a solenoid that controls the opening of the fluid flow in a valve.

A solenoid valve should not be confused with an electro-controlled valve. An electro-controlled valve is powered by an electrical system that can be dissociated from the valve body. A solenoid valve on the other hand is made up of a single block and the valve body can’t be dissociated from the system powering it. A solenoid valve is generally more compact than a valve.


HOW TO SELECT THE CORRECT SOLENOID VALVE

Uses
Solenoid valves can be used in any application requiring the control of a fluid or gas.
Simple on/off valves are popular as many process lines only need flow or no flow conditions. Solenoid valves are ideal for commercial use in a wide range of industrial applications such as autoclaves, cooling plants, watering plants, fire extinguishing systems, hygienic & sanitary equipment as well as water jet machinery and many other fluid control situations.

Considerations
When considering what type of solenoid valve to employ, it is vital to understand the application into which the switch is to be introduced. Important factors are:
• Non energised state: Normally open or normally closed.
• Flow Rate: The size of the valve (port size) dictates the maximum flow rate that can be achieved.
• Electrical supply requirement: The voltage and current required to actuate the solenoid.
• Electrical connection requirement.
• The fluid type (to ensure chemical compatibility with the valve wetted parts).
• Minimum and maximum working pressure.
• Protection class requirement (IP rating).
• Ambient and fluid temperature requirement.
• Duty cycle required

Types
Valves can be either normally open or normally closed. 
Port sizes available are: G3/8”, G1/2”, G3/4”, G1”, G1-1/4”, G1-1/2” and G2”. Dependent upon valve size
solenoids are available in 24V dc 10W – 19W, 110V ac 10.5 VA –21VA and 230V ac 9VA – 15VA.



How to choose a solenoid valve?

When choosing a solenoid valve, you will need to know what type of media it will be used for. As a general rule solenoid valves are designed to operate with media without solid particles such as water, oil, petroleum products, steam, compressed air or heat transfer fluids. This important information allows you to define the materials your solenoid valve will be made of. 

To avoid any risk of malfunction due to the presence of solid particles, also called impurities, we recommend that you use an upstream filter before 

Solenoid valves can be two-way or have multiple ports. They are generally defined by two digits, one determining the number of ports and the other the number of positions. For example, a 3/2 solenoid valve is one with 3 ports and 2 positions.
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Depending on your application and in order to optimize the supply time of your solenoid valve, you have the choice between normally closed (NC) solenoid valves and normally open (NO) solenoid valves:

A normally closed solenoid valve opens when it is powered by electricity.
A normally open solenoid valve closes when it is powered by electricity.
If necessary, you can also choose a bistable solenoid valve whose flap remains in position even in the event of a power failure. The main advantage of these solenoid valves is that they use very little energy.


Solenoid valves are also defined by a nominal diameter (DN) because they are integrated directly into a circuit. The connection and pipe diameters are specified by standards according to the country or geographical area they are to be used in and according to the media they will be used for.