Abstract: A sliding plate is located across a pipe body to form a sliding plate valve having two positions: a through position and a flush position. In the through position, material flows through the pipe body. In the flush position, the flow of material is diverted so it goes out a side opening in the pipe body. An opening in the sliding plate permits material to pass through the plate only when the valve is in the through position, not when the valve is in the flush position. A side cut-out section of the body is attached to the sliding plate so that the section blocks the side opening when the valve is in the through position, but not when the valve is in the flush position.