Direct acting solenoid valve(DIN solenoid valve connector）
Principle: when energized, the electromagnetic coil generates electromagnetic force to lift the closing part from the valve seat and open the valve; When the power is off, the electromagnetic force disappears, the spring presses the closing part on the valve seat, and the valve closes.
Features: it can work normally under vacuum, negative pressure and zero pressure, but the drift diameter is generally no more than 25mm.
Step by step direct acting solenoid valve（DIN solenoid valve connector)
Principle: it is a combination of direct action and pilot type. When there is no pressure difference between the inlet and outlet, after power on, the electromagnetic force directly lifts the pilot small valve and the closing parts of the main valve up in turn, and the valve opens. When the inlet and outlet reach the start-up pressure difference, after being energized, the electromagnetic force pilot small valve will increase the pressure in the lower chamber of the main valve and decrease the pressure in the upper chamber, so as to push the main valve upward by using the pressure difference; In case of power failure, the pilot valve uses spring force or medium pressure to push the closing part downward to close the valve.
Features: it can also operate under zero differential pressure, vacuum and high pressure, but the power is large, so it must be installed horizontally.