拍门属于止回阀类，用于防止水倒灌。依靠管道内水压力开启阀门，依靠自重或外力关闭阀门。
The door is a check valve to prevent water pouring. The valve is opened by water pressure in the pipe and the valve is closed by self - force or external force.
结构特点
Structural characteristics of

 
拍门由阀座、门体、密封圈、销轴等组成。有方形、圆形，单门、多门等多种形式。
The door is composed of seat, door body, sealing ring and pin shaft. There are square, round, single door, multiple doors and other forms.

 
常用的主要有浮箱式拍门和配重式拍门。
There are mainly floating box door and heavy - type door.

 
浮箱拍门门体比重稍大于水，利用门体在水中的浮力，在水流的作用下使门页开启或关闭，开启水头极小。
The float box is slightly larger than water, which USES the buoyancy of the door body in the water to open or close the door under the action of water flow, and the water head is very small.

 
浮箱式拍门门页为密封腔体构造，门页比重大约为1.2-1.5，无需悬挂配置配重，门页关闭时冲击力小。
The float box type door door is sealed cavity structure, the weight of the door is about 1.2-1.5, no suspension configuration is required, and the impact is small when the door is closed.

 
配重式拍门悬挂有配重锤，借助于配重的平衡作用，在水流的作用下使门页自动开启或关闭，或稍加外力作用使门页开启或关闭。
The weight of the door is mounted with a heavy hammer, which can be turned on or off automatically by the water flow with the help of the balancing act, or a little external force can be used to open or close the door.

 
配重式拍门工作牢靠，门页的开启需求借助配重的均衡，但是门页关闭时，冲击力较大，易损坏门座。
It is easy to make the door work firmly, and the opening demand of the door is balanced by weight, but when the door is closed, the impact is bigger and it can damage the door seat.

 
应用
apply

 
广泛应用于水利系统、市政污水、城市防洪排涝、污水处理厂、自来水厂等。安装于排水管道的尾端，具有防止外水倒灌。一般用于低扬程泵（10m以下），出水管较短的场合。其构造简单，无需专门人员看守，经济投入低，但是做不到完全密封防水。
It is widely used in water conservancy system, municipal wastewater, flood prevention and drainage, sewage treatment plant, water supply plant etc. The tail end of the drainage pipe is installed to prevent water pouring. It is commonly used for low lift pump (below 10m) and out of short water pipes. Its structure is simple, without special personnel guards, economic input is low, but cannot be fully sealed waterproof.

 
淹没在水中（比如水库底部、河底等），用于扬程高达7m的泵停机时，拍门上游侧水回流，将产生很大的负压，淹没在水中的拍门有被破坏的危险，因此淹没于水中的拍门在这种情况下需要设置真空破坏管，以保护拍门。
Submerged in water, such as the bottom of the reservoir, river, etc.), is used to lift up to 7 m when the pump stop, flap valve upstream side water back, will produce very big pressure, submerged in the flap valve are in danger of destruction, in the water so submerged in the water on the door in this case you need to set up the vacuum tube, in order to protect the door.