, duplex stainless steel Seat Materials: stainless steel + satellite or satellite. Disc Materials: stainless steel/duplex steel + satelliteStem Materials: F304,F316,F316L,duplex steel Bonnet material : 304/316/316L, duplex stainless steel Handle material : stainless steelApplicable standard Size Range: 2~12"(DN50 ~ DN300）Pressure: PN10, PN16,PN40,PN64, Class 150~Class 1500Standard : DIN, ANSI End Connection: Flange, Butt weldOperate: Manual, Worm gear, Pneumatic and Electric actuated.