Locomotive engine accessories fuel pump pressure regulating valve 294-8620

Solenoid valve Working principle

    1. Direct acting solenoid valve
Principle: When the normally closed type direct acting solenoid valve is energized, the solenoid coil produces electromagnetic suction to lift the spool, so that the seal on the spool leaves the seat port and the valve is opened; When the power is off, the electromagnetic force disappears, and the seal on the valve core is pressed on the seat port by the spring force. (Normally open type is the opposite)
Features: In vacuum, negative pressure, zero pressure difference can work normally, the larger the valve diameter, the larger the volume and power of the electromagnetic head. For example, the direct-acting solenoid valve produced by the technology introduced by Detsen Company can be used for 1.33×10-4 Mpa vacuum.

        2. Step direct acting solenoid valve (i.e. recoil type)
Principle: Its principle is a combination of direct action and pilot, when energized, the solenoid valve will first open the auxiliary valve, the main valve lower chamber pressure is greater than the upper chamber pressure and the use of differential pressure and electromagnetic force at the same time to open the valve; When the power is off, the auxiliary valve uses spring force or medium pressure to push the closing seal and moves the closing valve port downward.
Features: It can also work reliably when there is zero pressure difference or about a certain pressure, the general working pressure difference does not exceed 0.6MPa, but the power and volume of the electromagnetic head are large, requiring vertical installation.