Wafer metal-seat Butterfly Valve Mental Seat butterfly Valve Concentric Butterfly Valve Concentric Butterfly Valve <<Butterfly ValveDesign Standard: API 609 ... worm screw, pneumatic driving, electric drivingButterfly ValveSingle Eccentric Butterfly ValveDesign Standard: API 609, MSS. SP-68Flanged ... B16.10, MSS. SP-68Connection: Lug, Wafer, Flange, Weld ConnectionDriving Manner: Hand wheel, worm wheel & ...