The gate valve is a gate valve with opening and closing parts. The movement direction of the gate valve is perpendicular to the fluid direction. The gate valve can only be fully opened and fully closed, not adjusted and throttled. The gate valve is sealed by the contact between the valve seat and the gate. Usually, the sealing surface will be overlaid with metal materials to increase the wear resistance, such as overlaying 1Cr13, stl6, stainless steel, etc. The gate valve has rigid gate valve and elastic gate valve. According to different gate valves, the gate valve is divided into rigid gate valve and elastic gate valve.

闸阀的启闭件是闸板，闸板的运动方向与流体方向相垂直，闸阀只能作全开和全关，不能作调节和节流。闸板有两个密封面，较常用的模式闸板阀的两个密封面形成楔形、楔形角随阀门参数而异，通常为5°，介质温度不高时为2°52'。

The opening and closing part of the gate valve is the gate, and the movement direction of the gate is perpendicular to the fluid direction. The gate valve can only be fully opened and closed, not adjusted and throttled. The ram has two sealing surfaces. In the more common mode, the two sealing surfaces of the ram valve form a wedge, and the wedge angle varies with the valve parameters, usually 5 °, and 2 ° 52 'when the medium temperature is not high.

楔式闸阀的闸板可以做成一个整体，叫做刚性闸板；也可以做成能产生微量变形的闸板，以改善其工艺性，弥补密封面角度在加工过程中产生的偏差，这种闸板叫做弹性闸板。

The gate of wedge gate valve can be made into a whole, which is called rigid gate valve; It can also be made into a ram that can produce slight deformation to improve its manufacturability and make up for the deviation of the angle of the sealing surface in the processing process. This kind of ram is called elastic ram.

闸阀关闭时，密封面可以只依靠介质压力来密封，即依靠介质压力将闸板的密封面压向另一侧的阀座来保证密封面的密封，这就是自密封。大部分闸阀是采用强制密封的，即阀门关闭时，要依靠外力强行将闸板压向阀座，以保证密封面的密封性。

When the gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, the sealing surface of the gate valve can be pressed to the valve seat on the other side by the medium pressure to ensure the sealing of the sealing surface, which is self sealing. Most gate valves are forced sealed, that is, when the valve is closed, the gate shall be forced to the valve seat by external force to ensure the tightness of the sealing surface.

闸阀的闸板随阀杆一起作直线运动的，叫升降杆闸阀，亦叫明杆闸阀。通常在升降杆上有梯形螺纹，通过阀门顶端的螺母以及阀体上的导槽，将旋转运动变为直线运动，也就是将操作转矩变为操作推力。开启阀门时，当闸板提升高度等于阀门通径的1：1倍时，流体的通道畅通，但在运行时，此位置是无法监视的。

The gate of the gate valve moves in a straight line with the valve stem, which is also called rising stem gate valve. Generally, there are trapezoidal threads on the lifting rod. Through the nut at the top of the valve and the guide groove on the valve body, the rotary motion is changed into linear motion, that is, the operating torque is changed into operating thrust. When the valve is opened, when the lifting height of the ram is equal to 1:1 times the valve diameter, the fluid channel is unblocked, but this position cannot be monitored during operation.

实际使用时，是以阀杆的顶点作为标志，即开不动的位置，作为它的全开位置。为考虑温度变化出现锁死现象，通常在开到顶点位置上，再倒回1/2－1圈，作为全开阀门的位置。因此，阀门的全开位置，按闸板的位置即行程来确定。有的闸阀，阀杆螺母设在闸板上，手轮转动带动阀杆转动，而使闸板提升，这种阀门叫做旋转杆闸阀，或叫暗杆闸阀。

In actual use, the vertex of the valve stem is used as the mark, that is, the position that cannot be opened is used as its fully open position. In order to consider the locking phenomenon caused by temperature change, it is usually opened to the peak position and then turned back 1 / 2-1 turn as the position of fully open valve. Therefore, the fully open position of the valve is determined according to the position of the ram, that is, the travel. For some gate valves, the valve stem nut is set on the ram, and the rotation of the hand wheel drives the valve stem to rotate and lift the ram. This kind of valve is called rotary rod gate valve or Non rising rod gate valve.