Slide gate valve, also known as knife gate valve. Knife gate valve is a kind of valve that the gate and the valve seat are always in close contact and sealed. Its principle is that there is a circular opening with the size of the diameter on the gate. Through the gate opening and closing, the circular opening on the gate is completely separated from and matched with the diameter. The advantages of this valve are that the valve body has no groove, the medium will not jam, and it has full diameter flow characteristics. Its sealing structure can be divided into soft seal and hard seal. The penetrating knife gate valve has the characteristics of precise structure, good process and compact structure. The sealing valve seat is designed with movable structure. It has the functions of anti-wear and automatic compensation, so it has a longer service life. In the process of closing and opening, the valve seat keeps close to the gate, which makes the opening and closing force of the valve stable and has the characteristics of cutting off the medium.