1. advanced equipment 2. strong commonality 3. compact form 4. reliable in use 5. matching spool are provided It widely used in chemical, petroleum, 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 ...