A slide gate valve, also known as a manual knife gate valve, is a type of valve where the gate and seat are always in tight contact for a seal. Its principle is that the gate has a circular opening the same size as the flow path; opening and closing the gate causes this opening to completely disengage and then re-engage with the flow path. The advantages of this valve are that the valve body has no grooves in the flow path, preventing media from getting stuck or blocked, and it has full-bore flow characteristics. Its sealing structure can be either soft or hard seal. Through-type knife gate valves are characterized by precision construction, good manufacturability, and a compact structure. The sealing seat has a movable structure design with wear resistance and automatic compensation functions, resulting in a longer service life.

During the closing and opening process, the valve seat and gate remain in close contact, ensuring stable valve opening and closing force and providing the ability to cut off the medium.