The opening and closing parts of knife gate valve are gate plate. The movement direction of gate plate is perpendicular to the direction of fluid. The medium is cut off by knife-edge gate which can cut fibre material. The gate plate has two sealing faces. The common used two sealing faces form wedge shape and wedge angle, which vary with the valve parameters, usually 5 degrees. Knife gate valve has less installation space, low working pressure, not easy to accumulate debris.
When the knife gate valve closes, the sealing surface can be sealed only by the medium pressure, that is to say, the sealing surface of the gate can be pressed to the seat on the other side to ensure the sealing surface sealing, which is called as self-sealing. Most gate valves are sealed by force, when the valve closes, the gate must be forced to the seat by external force to ensure the sealing surface. Knife gate valve should generally be installed vertically in the pipeline.