Opening and closing mechanisms, pneumatic, for doors, Engines and mechanical parts, Metals, Machinery & Engineering, Valves, pneumatic, diaphragm, Valves, pneumatically operated (compressed air operated), Hydro-pneumatic and oleopneumatic equipment, Valves, pneumatic, three-way, Manifolds, compressed air and gas (pneumatic), Pneumatic valves, Valves, pneumatic, pressure reducing and pressure regulating