The sealing principle and structural characteristics of flanged butterfly valves are the same as those of ordinary centerline butterfly valves.

The opening and closing part of the flanged butterfly valve is a flange. The movement direction of the flange is perpendicular to the direction of the fluid. The flanged butterfly valve can only be fully opened and fully closed and cannot be adjusted or throttled.

Large flanged butterfly valves are usually equipped with gearbox type actuator, where the handwheel is connected to the stem via a gearbox. This will reduce the force but at the same time reduce the speed of the operation. The flanged butterfly valve should be installed in the open position.