The function of direct-acting solenoid valves
Direct-acting solenoid valves are used for small-diameter and low-pressure fluid media. When the direct-acting solenoid valve is opened, it does not require the opening pressure of the medium and can start at zero pressure. To enhance its service life, it is recommended to install it with the horizontal pipeline ring facing upwards. Direct-acting solenoid valves feature small size, large flow rate, and fast response speed. They are suitable for applications with high opening and closing frequencies or those requiring rapid shut-off. All are particularly suitable for the selection of direct-acting solenoid valves.
The working principle of direct-acting solenoid valves
Direct-acting solenoid valve: When powered on, the electromagnetic coil generates electromagnetic force to lift the seal from the valve seat, opening the valve. When the power is cut off, the electromagnetic force disappears, and the spring presses the seal onto the valve seat, closing the valve.
Normally closed direct-acting solenoid valve: When powered on, the electromagnetic coil generates sufficient electromagnetic force to lift the moving parts (valve stem, valve core, sealing parts) from the valve seat, and the valve opens. When the power is cut off, the spring force presses the moving parts against the valve seat, and the valve closes.
Normally open direct-acting solenoid valve: The action direction is opposite to that of the normally closed type.
Structural composition diagram of direct-acting solenoid valve
The nominal size of the small-diameter direct-acting solenoid valve (Figure 1) is no more than DN10. The lower part of the moving iron core is embedded with a sealing plug. The up and down movement of the moving iron core can achieve the on-off control of the working medium of the solenoid valve, so it is called a direct-acting solenoid valve.
Figure 1: Small-diameter direct-acting solenoid valve
1 - Valve body; 2 - Spring; 3 - Valve cover; 4 - Moving iron core; 5 - Coil; 6 - Static iron core
Direct-acting bidirectional solenoid valve This type of solenoid valve is advanced in design and reliable in performance. Its working pressure can range from 0 (no pressure difference) to 4.0MPa, and it is particularly suitable for vacuum systems with a pressure of less than or equal to 1.33×10-7 mpa. This valve can achieve the flow of medium in both forward and reverse directions (with sealing in both directions).
Figure 2 Direct-acting bidirectional solenoid valve
1 - Electromagnetic head; 2 - Moving iron core; 3 - Valve stem assembly; 4 - Valve seat; 5 - Valve Body
Direct-acting three-way solenoid valves with small diameters (Figure 3) are very common in China, generally ranging from 0 to 1.0MPa. Direct-acting solenoid valves with diameters less than or equal to DN3 are widely used both at home and abroad, mostly serving as pilot valves for multi-way pneumatic solenoid valves.
Figure 3 Direct-acting three-way solenoid valve
However, for large-diameter three-way, four-way (five-way) solenoid valves with diameters ranging from DN12 to 50, there has always been a gap in China in the past. After introducing the manufacturing technology of German HERI-ON Company to China, through digestion and absorption, domestic production has been achieved. It is not only applied as a multi-way solenoid valve for actuators, but also found in hydraulic and pneumatic actuators.
The direct-acting two-position three-way solenoid valve (Figure 4) can achieve four functions: normally closed, normally open, reversing and converging, depending on the position of its connecting pipe.
Direct-acting bidirectional solenoid valve This type of solenoid valve is advanced in design and reliable in performance. Its working pressure can range from 0 (no pressure difference) to 4.0MPa, and it is particularly suitable for vacuum systems with a pressure of less than or equal to 1.33×10-7 mpa. This valve can achieve the flow of medium in both forward and reverse directions (with sealing in both directions).
Figure 4 Direct-acting two-position three-way solenoid valve
1 - Valve body; 2 - Valve seat; 3 - Valve stem assembly; 4 - Moving iron core; 5 - Electromagnetic head
The inlet direction and working port direction (normally open and normally closed) of the direct-acting two-position four-way solenoid valve (Figure 5) and the two-position five-way solenoid valve are fixed. Among them, the direct-acting two-position four-way solenoid valve combines the exhaust ports of "A" and "B" working ports into one, forming a direct-acting two-position four-way solenoid valve.
Figure 5 Direct-acting two-position four-way (two-position five-way) solenoid valve
1 - Valve body; 2 - Valve seat; 3 - Valve stem assembly; 4 - Sealing ring; 5 - Moving iron core; 6 - Reset spring; 7 - Electromagnetic head
Above is The working principle of direct-acting solenoid valves and the structural composition diagram of direct-acting solenoid valves content, to learn more related information are available at https://www.joosungauto.com/.
