Pinch valves are working with air pressure inside the valve with special rubber shrinks 6b off the pressure from the outside and sealing achieved 100%. PN22 Pinch valves provides unobstructed product flow. Corrosive and abrasive fibers containing granules, powder materials, cellulose, chemical and natural waste, which control valves are in-line. Other types of valves (ball, butterfly, etc.) Immediately lose the pinch valves sealing against abrasive wear resistance, long life and they are tolerant.