The opening and closing part of the gate valve is the gate. The movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and closed, and can not be adjusted and throttled. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valves form wedges. The wedge angle varies with the valve parameters, usually 5 degrees, and the medium temperature is 2 degrees 52'. Wedge gate valve can be made into a whole, called rigid gate; it can also be made into a gate that can produce slight deformation to improve its workability and make up for the deviation of sealing surface angle in the process of processing. This kind of gate is called elastic gate.