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. Most solenoid valves are made of brass (ideal for water, fuel, air or inert gas), stainless steel (for corrosive liquids or gases, food product liquids) or plastic (mainly in the food and chemical sectors).
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 the solenoid valve.
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.
Most solenoid valves operate on an on or off basis (open or closed), while some are designed to be proportional to the current or supply voltage.
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 generally sensitive to moisture. You must check the external conditions in order to choose a solenoid valve with a sufficient protection class (IP) for the intended environment. You can also choose a lower protection rating and remotely install the solenoid valve in a less humid area.
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.
Solenoid valves may also be subject to other standards, such as those governing equipment installed in ATEX (Explosive Atmosphere) zones, particularly for the energy industries.