The gate valve is an opening and closing gate. The movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled. The gate valve is sealed through the contact between the valve seat and the gate plate. Usually, the sealing surface will be surfacing with metal materials to increase wear resistance, such as surfacing 1Cr13, STL6, stainless steel, etc. The gate has a rigid gate and an elastic gate. According to the different gates, the gate valve is divided into a hard-sealed gate valve and an elastic gate valve.
Advantages and disadvantages of gate valves
The medium channel inside the valve body is straight, the medium flows in a straight line, and the flow resistance is small.
Compared with the globe valve, because whether it is open or closed, the direction of movement of the gate is perpendicular to the flow direction of the medium.
The opening and closing stroke of the gate is large, and the lowering is carried out by the screw.
The phenomenon of water hammer is not easy to occur. The reason is the long closing time.
The medium can flow in any direction on both sides, which is easy to install. The gate valve channel is symmetrical on both sides.
The length of the structure (the distance between the two connecting end faces of the shell) is small.
The shape is simple, the length of the structure is short, the manufacturing process is good, and the scope of application is wide.
The structure is compact, the valve rigidity is good, the channel is smooth, the flow resistance is small, the sealing surface is made of stainless steel and hard alloy, the service life is long, and the PTFE packing is used. The sealing is reliable, and the operation is light and flexible.
It is easy to cause erosion and scratches between the sealing surfaces, and maintenance is more difficult. The external size is large, a certain space is required to open, and the opening and closing time is long. The structure is more complicated.