Series F170 butterfly valves designed to comply with MSS SP-67, BS5155 and API 609.Compatible with GB, ANSI, DIN, BS flanges. Face to face according to ISO 5752 basic series 20 (wafer type short). The seat of series F170 butterfly valve is designed into without back. The tongue-and –groove seat is lower torque and field replaceable There is O-ring casted on the seal surface of the seat, negates need for flange gaskets. One-piece thru shaft ensures dependability. Square drive disc movement. Available in size 1″ to 12″. Available in wafer type body. Available with handles, manual gear operators, and electric or pneumatic actuators.