Knife gate valve, also known as knife gate valve, knife slurry valve. Its opening and closing parts are gates, whose moving direction is perpendicular to the fluid direction, and the medium is cut off by the knife-edge gate which can cut the fibre material. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valve are wedge-shaped, and the wedge angle varies with the valve parameters, usually 50. The gate of the wedge-knife gate valve can be made into a whole, called a rigid gate. In order to make a gate which can produce slight deformation to improve its technicality and make up for the deviation caused by the angle of sealing surface in the process of processing, this kind of gate is called elastic gate. In fact, there is no chamber in the valve body. The gate rises and falls in the side guide groove, and is pressed on the seat by the bottom lug. If high medium sealing is needed, O-shaped sealing seat can be used to achieve bidirectional sealing. Knife gate valve has less installation space, low working pressure, not easy to accumulate debris, low price.