Abstract: A diverter damper for controlling a gas flow in a gas duct of large cross section. The diverter damper includes a housing having an inlet and two outlets, a pivotable flap which in a first extreme position closes a first outlet and in a second extreme position closes a second outlet. The damper further includes a drive shaft connected to the pivotable flap, wherein the drive shaft extends at least partly between two opposite housing walls and through at least one of the two opposite housing walls, and at least one actuator mechanism that is located outside the housing near or against the at least one housing wall through which the drive shaft extends. The actuator mechanism includes at least one cylinder piston unit connected to the drive shaft for pivoting the flap into one of the extreme positions or into a position between the extreme positions.

Abstract: The invention relates to a diverter damper for controlling a gas flow in a gas duct of large cross section, said diverter damper comprising:—a housing having an inlet and two outlets,—a pivotable flap which in a first extreme position closes a first outlet and in a second extreme position closes a second outlet,—a drive shaft connected to the pivotable flap, wherein the drive shaft extends at least partly between two opposite housing walls and through at least one of the two opposite housing walls,—at least one actuator mechanism that is located outside the housing near or against the at least one housing wall through which the drive shaft extends, wherein said actuator mechanism comprises at least one cylinder piston unit connected to said drive shaft for pivoting the flap into one of the extreme positions or into a position between the extreme positions.

Abstract: A flap valve, particularly used for a conductor of large cross section, includes a valve housing and a flap member mounted in the housing for pivoting movement about a first axis through an angle of approximately 90.degree. between two extreme positions. A drive shaft is mounted in the housing for rotation about a second axis, and a tension lever is fixed to the drive shaft and rotatable therewith about the second axis. A joint rod is pivoted at a first end thereof to the tension lever and at a second end thereof to the flap member at a position substantially centrally thereof. Rotation of the drive shaft and the tension lever about the second axis moves the joint rod and thereby pivots the flap member about the first axis from one extreme position to the other. The second axis is positioned relative to the first axis to ensure that an angle of rotation of the tension lever to move the flap member between the two extreme positions thereof is approximately 90.degree. to 150.degree..