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gate valve (gate valve) is a opening and closing part of the gate plate, the direction of motion of the gate plate is perpendicular to the direction of the fluid, the gate valve can only be fully opened and fully closed, can not be adjusted and throttled. Gate valves are sealed by the contact between the seat and the gate plate. Usually, the sealing surface will be surfacing with metal materials to increase the wear resistance, such as surfacing 1Cr13, STL6, stainless steel, etc. There are rigid gate and elastic gate, according to the different gate, gate valve is divided into rigid gate valve and elastic gate valve.