Series DF306 butterfly valve designed to company with MSS-SP-67,BS5155 and API609.Compatible with GB,ANSI,DIN,BS,JIS flanges,The seat of series DF126 butterfly valve is designed into without back.The touque-and-groove seat is lower torque and replaceable . There is O-ring casted on the seal surface of the seat,needless for flange gaskets,Available in size 2''-20''.Acailable in water type and lug body electric or pneumatic actuators.