The pinch valve mod. GS 21, consists of a cast iron or aluminium body (two pieces) and of a natural or synthetic rubber sleeve, resistant to fluid flow (acids – alkaline fluids – dusts – concrete – sewage and industrial waters – muds). Closing is performed by pressing a screw on a buffer, which squeezes sleeve to a complete or partial closing. This valve is special since no stuffing box and load loss appear. One-piece printed rubber sleeve includes two terminal flanges used as coupling gaskets.