Seating Arrangement for Dampers
1. Free swing (without landing bar): In this type, Flapper is free to swing, without landing bar, leakage allowed, used for only volume control.
2. Fixed metal seat: Flapper seat on fixed metal landing bar, partial leakage allowed.
3. Flexible metal seat: Flexible spring loaded seats are mounted on flapper, seats on landing bar with 100% sealing.
TYPES OF DAMPERS
1. Single louver Butterfly Damper: Round or Rectangular type single flapper centrally mounted on single shaft.Various Seat options are available. Actuated by gear Pneumatic or electrical actuators.
2. Tandem Louvers: Multiple Blades are mounted on multiple shafts. For 100% shutoff, blower air pressure can be applied between two blades.Actuated by manual, pneumatic or electrical actuators.
3. Flap Damper: Small size damper,drive shaft is directly mounted periphery of flapper. In larger size drive shaft is centrally mounted and toggle actuated.
4. Guillotine Damper: A Gate is sliding between corrugated flexible seats and actuated by gear, screw, pneumatic, electric or hydrolic actuators. Provide 100% shutoff.