Shaft Smoke Dampers are used to evacuate smoke and poisonous gases formed by fire in a controlled manner. They are installed in fire and smoke shafts of buildings. The blades are normally closed and open when a fire occurs and ensures evacuation of smoke and poisonous gases. In multistorey buildings the shaft smoke dampers on every floor are open on the floor where the fire has occurred and are closed at other floors. Thus passage of smoke to unaffected floors is prevented.