Latching valves are ideal for achieving energy-saving operation, particularly in battery-powered applications. This type of solenoid valve has built-in permanent magnets, which usually hold the movable magnetic core of the solenoid valve in its respective end position together with a built-in compression spring. A short pulse from the magnetic coil is then sufficient to move the core to the respective end position. After this has taken place, the coil no longer needs to be energized and the magnetic core remains in its position due to the attraction of the permanent magnet or the compressive force of the spring. The energy saving potential is particularly high with long operating times.
A latching valve can be implemented in several ways. The figure below shows three variants. In the first version, the permanent magnet is built into the pole of the valve. In the second variant, the permanent magnet sits in the core of the valve. A conical spring is now attached to the core instead of the compression spring. In the third variant, the permanent magnet is integrated in the iron yoke of the magnetic coil. This variant requires a special coil or a costly revision of existing coils.