How Does a 2 Way, 3 Way and 4 Way Solenoid Valve Work?

How does a 2 way solenoid valve work?

A 2 way solenoid valve, also known as a two-position 2 way solenoid valve, is a simple and efficient control device. It consists of a solenoid coil, a valve spool and a valve seat. When the solenoid coil is energized, a magnetic field is generated, causing the spool to be attracted and lifted from the seat, opening the valve; when the solenoid coil is de-energized, the magnetic field disappears, the spool springs back due to spring force, and the valve closes. This simple switching mechanism makes 2 way solenoid valves very effective in controlling the on-off of fluids.

Energized state (valve open):

When the solenoid coil is activated by an electric current, a magnetic field is generated which causes the spool to be attracted and lifted from the valve seat. As the spool lifts, fluid can flow from the inlet through the opening between the spool and the seat and out the outlet. At this point, the valve is in the open state and fluid can pass through smoothly.

Disconnected state (valve closed):

When the solenoid coil is no longer activated by current, the magnetic field disappears. In the absence of the magnetic field, the force of the spring pushes the spool back to the seat, blocking the passage between the inlet and outlet. At this point, the valve is closed and fluid cannot pass through.

2 way solenoid valve is widely used in the hydraulic system and pneumatic system of construction machinery, used to control the flow of hydraulic oil or gas. For example, in excavators, 2 way solenoid valves can be used to control the expansion and retraction of the hydraulic cylinder to realize the lifting and lowering action of the excavator.

How does a 3 way solenoid valve work?

A 3 way solenoid valve, also known as a three-position 2 way solenoid valve, is a little more complicated than a 2 way solenoid valve. It consists of a solenoid coil, spool and seat. Unlike a 2 way solenoid valve, a 3 way solenoid valve functions with two channels and one open and closed channel. When the solenoid coil is energized, the valve spool is attracted and lifted from one channel to connect with the other channel to open the valve; when the solenoid coil is de-energized, the valve spool springs back to its original position, closing the original channel and closing the valve.

Energized state (valve open):

When the solenoid coil is activated by electric current, a magnetic field is generated, attracting the spool to lift from one channel and connect with another channel. At this point, fluid can flow from one channel through the opening between the spool and seat, into the other channel, and out of the outlet. In this way, the valve is in the open state, the two passages are connected to each other, and the fluid can flow between the different passages.

Disconnected state (valve closed):

When the solenoid coil is no longer activated by current, the magnetic field disappears and the spring pushes the spool back to its original position. At this point, the spool closes the original channel, so that the two channels are no longer connected, the diesel solenoid valve is closed. Fluid cannot flow between the two channels.

How does a 4 way solenoid valve work?

A 4 way diesel solenoid valve, also known as a four-position 2 way solenoid valve, is a complex control device. It consists of a solenoid coil, spool and seat. Unlike a 3 way solenoid valve, a 4 way solenoid valve has two channels and two open and closed channels. When the solenoid coil is energized, the magnetic field makes the valve spool lift from one channel and connect with the other channel, and at the same time closes the other channel and opens the valve; when the solenoid coil is de-energized, the magnetic field disappears, and the valve spool springs back to its original position and closes the original channel and closes the valve.

Energized state (valve open):

When the solenoid coil is activated by electric current, a magnetic field is generated, which makes the valve spool lift up from one channel and connect with another channel. At the same time, another spool closes the other channel. At this point, fluid can flow from one passage through the opening between the spool and the seat, into the other passage, and out the outlet. In this way, the valve is open and the two passages are connected to each other, allowing fluid to flow between the different passages, thus ensuring that diesel engine spare parts and other components can function properly.

Disconnected state (valve closed):

When the solenoid coil is no longer activated by current, the magnetic field disappears and the two spools spring back to their original position. At this time, the two spools are closed to the two channels, so that the two channels are no longer connected, the valve is closed. Fluid cannot flow between the two channels.

4 way solenoid valve is widely used in the hydraulic system and pneumatic system of construction machinery, used to control the flow of multiple channels. For example, in the hydraulic system of excavators, 4 way solenoid valves can be used to control the complex action of hydraulic cylinder to realize multiple functions such as digging and gripping. In the pneumatic system of construction machinery, the 4 way solenoid valve can be used to control the cylinder's expansion and contraction, rotation and stop and other actions.