The flow resistance is small, and the flow resistance of the non-shrinking mouth is similar to that of the short tube. A slab gate valve with a diversion hole is installed on the pipeline and can also be cleaned directly with a pig. Since the shutter slides on the two seat surfaces, the flat gate valve fluid can be applied to the medium with suspended particles, and the sealing surface of the flat gate valve is actually automatically positioned. The seat sealing surface is not damaged by thermal deformation of the valve body. Moreover, even if the valve is closed in a cold state, the thermal elongation of the valve stem will not overload the sealing surface. At the same time, when the valve is closed, the slab gate valve without the diversion hole does not require the high precision of the closed position of the ram, so the electric slab valve can control the opening and closing position by the stroke.