Normally Open: When the coil is energized, the pilot hole closed, the valve chamber and pressurized by the piston return spring throttle thrust, the electromagnetic valve is closed.

常开：当线圈通电时，先导孔关闭，阀上腔由活塞节流孔增压和复位弹簧的推力，电磁阀关闭。

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Valve types include Normally Open and Normally Closed valves, for use in fuel, hydraulic, or pneumatic applications.

阀门有常开和常闭两种，可用于燃油，液压或气动应用领域。

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This valve is normally automatic work, in a direction of flow of fluid under pressure, open the flap valve;

通常这种阀门是自动工作的，在一个方向流动的流体压力作用下，阀瓣打开；

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