A diverter valve controlling input of two different extruded materials has a valve body having an axially extending opening, and a valve piston axially movable in the opening between first and second positions. The body defines a first inlet for receiving a first material, and a second inlet for receiving a second material with first and second outlets opposite the inlets. The piston has first and second through channels and first and second cross-over channels, each with inlet side and outlet side ports. A first flushing channel communicates with the first inlet and end ports, a second flushing channel communicates with the second inlet and end ports, and a third flushing channel opposite the first two communicates with the second outlet and includes a plurality of ports, with all the ports, inlets and outlets open to the axial opening.