美国欧可进口先导式电磁阀，由先导阀与主阀组成，两者有通道相联系，当电磁阀线圈通电，动铁芯与静铁芯吸合使导阀孔开放，阀芯背腔的压力通过导阀孔流向出口，此时阀芯背腔的压力低于进口压力，利用压差使阀芯脱离主阀口，介质从进口流向出口。当线圈断电，动铁芯与静铁芯脱离，关闭了导阀孔，阀芯背腔压力受进口压力的补充逐渐趋于和进口平衡，阀芯因弹簧力作用下把阀门紧密关闭。

The United States of America Ou imports electromagnetic valve, a pilot valve and main valve, both of them have the channel connection, when the solenoid coil is energized, the movable iron core and the static iron core attracts the valve guide hole opening, the valve core cavity pressure through the pilot valve to the outlet when the valve core Kong Liu, back cavity pressure is lower than the inlet pressure, using the pressure differential valve from the inlet of the main valve, medium to flow from the inlet to outlet. When the coil is de-energized, the movable iron core and the static iron core from, off pilot valve hole, the valve core cavity pressure inlet pressure supplement tends gradually and import balance, spool due to spring force the valve tightly closed.