The three-position three-way solenoid valve is composed of a liquid inlet valve, a liquid return valve, a main spring, an auxiliary spring, a fixed iron core and an armature sleeve.
The working process is: when the electromagnetic coil is not energized, under the tension of the main spring, the liquid inlet valve is opened, the liquid return valve is closed, the liquid inlet and the liquid outlet are kept unblocked – pressurization; the electromagnetic coil is fed with a small current (2A ), the electromagnetic suction force is small, and the suction armature moves up less, but it can properly compress the main spring, close the liquid inlet valve, relax the auxiliary spring, and the liquid return valve does not open – maintaining pressure.