... , power plants, light industry, textile, metallurgical industrial production. pneumatic diaphragm double-seated control valveMain parts materials: Valve body, valve cover: ZG230 ... -450, ZGlCr18Ni9Ti Spool, the valve seat: 1Cr18Ni9T, Levin Titanium Alloy Welding Division + 1Cr18Ni9Ti stuffing : PTFE flexible ...