Introduction to Direct-Acting Solenoid Valves

secureluokai January 31, 2026

The direct-acting solenoid valve is the most basic type of solenoid valve, with a relatively straightforward operating principle. When its electromagnetic coil is energized, it generates an electromagnetic force that lifts the valve core off the valve seat, thereby opening the valve. Once de-energized, the electromagnetic force dissipates, and a spring pushes the valve core back against the valve seat to close the valve.

For a normally closed valve, the operating state is the opposite of a normally open one: the valve remains closed in its default state and only opens when an electric current is applied.

Performance Characteristics
The most significant advantage of the direct-acting solenoid valve is that it can operate normally under zero pressure, vacuum, or even negative pressure conditions, making it particularly suitable for specialized fluid environments. For instance, it plays a critical role in high-precision, high-demand hydraulic control systems.

However, it also has notable limitations: its orifice diameter generally does not exceed 25 mm, so it is not suitable for applications requiring large flow rates or high pressure.