... production. pneumatic diaphragm double-seated control valveMain parts materials: Valve body, valve cover: ZG230-450, ZGlCr18Ni9Ti Spool, the valve seat: 1Cr18Ni9T, Levin Titanium Alloy ... and differential pressure5. Valve and valve components of materials6. Connection7. Transmission8. Flow characteristics9. Suitable temperature pneumatic diaphragm double-seated control valve (ANSI ,API,GB ...