Solenoid Valves: Common Types Used and Industrial Applications

In modern fluid control systems, solenoid valves offer significant advantages, such as low energy consumption, fast response, and long service life. With the continuous improvement in control precision and system integration, solenoid valve design has become increasingly compact and modular. They are no longer limited to simply switching a single medium on or off, but can now precisely regulate the flow and ratio of mixed media.

In addition, an increasing number of solenoid valves are equipped with remote communication interfaces, allowing for automated operation and remote control without human intervention—meeting the demands of control systems for efficiency, reliability, and remote monitoring.

As a result, solenoid valves are no longer just simple on/off components, but have evolved into a wide variety of specialized types based on media type, control method, and system structure.
The following sections will provide a systematic overview of the main classifications of solenoid valves from the perspectives of medium type, structural principle, control method, and typical application scenarios.

What is a solenoid valve?

A solenoid valve is a device that uses an electromagnetic coil to drive the valve core, thereby enabling the opening, closing, or flow regulation of fluids or gases. It further controls the operation of downstream actuators. Solenoid valves are widely used in fields such as industrial automation, like heating, ventilation, and air conditioning, medical equipment, and irrigation systems.

Working Principle of a Solenoid Valve

A solenoid valve is essentially a control valve driven by electricity. When energized by an electrical signal, it generates a magnetic field that attracts the moving iron core (plunger), thereby opening, closing, or switching the flow path.

Basic structure of a solenoid valve includes:

Coil

Moving iron core (plunger)

Spring

Valve body and valve seat

Working process:

Electromagnet energizing:
When the coil in the solenoid valve is energized, it creates a magnetic field that attracts or pushes the iron core (plunger) to move.

Plunger action:
The movement of the plunger opens or closes the valve passage, controlling the flow of the medium (gas, liquid, steam, etc.).

Power off and reset:
When the coil is de-energized, the plunger returns to its initial position under the action of the spring or other reset mechanisms, closing or opening the flow path accordingly.

There are several different versions of solenoid valves with different features, benefits, and use cases.

Classification by Medium

Gas solenoid valves: Designed for air or other gas media, with different structural and sealing materials.

Steam solenoid valves: Specifically designed for high-temperature and high-pressure steam systems.

Water solenoid valves: Specially made for water or liquid media, with sealing materials and structures adapted to water characteristics.

Classification by Working Pressure

Low-pressure solenoid valves: Suitable for low-pressure environments, generally below 0.5 MPa.

Medium-pressure solenoid valves: Suitable for moderate pressure ranges.

High-pressure solenoid valves: Able to withstand higher pressures, used in high-pressure fluid control.

Controlled Actuator Types

Pneumatic actuators: Motors, cylinders.

Hydraulic actuators: Motors, hydraulic cylinders.

Electric actuators: Ball valves, butterfly valves, gate valves.

Pneumatic clamps: Pneumatically driven clamping devices commonly used in automated assembly lines.

Classification by Structure and Function

2/2 solenoid valve: 2-way, 2-position; two ports, two valve positions; simple ON/OFF switch.

3/2 solenoid valve: 3-way, 2-position; three ports, two valve positions; commonly used for single-acting cylinder control.

4/2 solenoid valve: 4-way, 2-position; four ports, two valve positions; commonly used for double-acting cylinder control.

5/3 solenoid valve: 5-way, 3-position; five ports, three valve positions; used for complex air circuit control.

How to check air solenoid valve

1.Visual Inspection

Check the solenoid valve's body for cracks, deformation, corrosion, or signs of air leakage. Ensure all connections and seals are intact.

2.Solenoid Coil Power Test

Measure the coil resistance with a multimeter to confirm there is no open or short circuit. When powered, listen for a clicking sound to verify the coil is functioning properly.

3.Airflow Test

Make sure the valve’s inlet and outlet ports are not blocked. Confirm smooth airflow and that the valve switches air passages correctly.

4.Electrical Signal Check

Verify that the control signal is properly reaching the solenoid coil terminals, and that voltage and current meet the specifications.

5.Response Time and Operation Test

Observe whether the valve responds quickly and accurately when energized, ensuring it switches states as expected.

If you want to learn more about how to check the starting solenoid valve, you can browse our technical article.

Get What You Need at Fokcavalve

There are many other different types of solenoid valves, like Namur-mounted, two-way, and pilot operated, just to name a few, that are designed for use in specific applications.

Fokcavalve offers many of these different solenoid valves, including the most used direct-acting variation, at a competitive price and short lead time. Contact us directly!