Basic design solutions of shut-off dampers and their characteristics.
In the case of fire ventilation cut-off dampers, in addition to design solutions, which are used with the fire dampers discussed earlier, wing flaps are also available on the market. The basic design difference has its functional justification. These dampers are used in escape corridors and are connected directly to vertical fire ventilation ducts.

The design of the wing shut-off damper.
From the side of the corridor, the damper is secured with a grille that covers and protects the damper control mechanism. The grille should not restrict the active surface of the damper more than 5% and should be easily removable by means of locks, in order to provide access to the website. The grille blades must be permanently immobilized. The damper body and leaf are made of fireproof board, guarantee its tightness and insulation. After opening, the flap leaf moves inside the duct and is blocked with a bolt, which prevents accidental closing of the damper. The damper wing is secured with a bumper against damage to the wall of the fire ventilation duct during opening. The above solution of dampers is particularly applicable to, when in the space under the suspended ceiling of the escape corridor there is not enough space for the horizontal smoke exhaust duct. An additional advantage of this type of solution is much lower expenditure on regulating the capacity of the supply air openings, and in particular the exhaust openings, which in the case of several exhaust points, in a horizontal duct running in the suspended ceiling space, it is laborious and time consuming. An important advantage of this type of solution is also the possibility of resigning from the actuators restoring the waiting position of the dampers, because they are easily accessible from the corridor. In the case of multi-storey buildings with extensive corridors, this can bring significant savings. Where the vertical fire ventilation duct is shallow, it may be, that the single-leaf flap will not be able to be opened. In such cases, it is possible to use double-leaf flaps, whose wings are shorter than the wing of a single-wing flap with the same active surface.

One of the design solutions of the damper is used to transfer air from the vestibule to the escape corridor, there is a curtain flap. It is the only cut-off damper used in fire ventilation, which is equipped with a thermal fuse. It is made of a steel frame, inside which a rolled curtain is placed in the upper part, fastened in this position with a thermal trigger. After the thermal release has tripped, the curtain lock releases and the curtain drops. pay attention, that in the case of steel curtain flaps, it is necessary to use appropriate additional mounting frames, which enable the damper to compensate for thermal expansion in fire conditions and protect it against tearing out of the wall. Transfer flaps, both from the corridor and the vestibule, both for aesthetic reasons and to prevent access by third parties, should be equipped with protective grilles. As with the wing flaps, grilles should not restrict the active surface of the damper by more than 5% and should be easy to dismantle by means of locks, in order to provide access to the website. The grille blades must be permanently immobilized. Transfer flaps, despite the limited space in the wall, with the door to the emergency corridor, should under no circumstances be used on doors, because in such a situation, over time, the thermal flaps or the thermal fuses are damaged. In case of, when it is not possible to place a transfer damper with the recommended dimensions, the solution may be even not to keep the maximum allowable height of the top edge of the transfer flap, by using a very narrow and high flap, with an appropriate active surface.

The most common assembly errors
In the case of fire ventilation cut-off dampers, the following issues should also be noted:
– niezachowanie wymaganych wymiarów otworu montażowego klapy skrzydłowej i montaż w sposób zmieniający geometrię klapy, which may prevent the damper from opening,
– wmurowanie klapy skrzydłowej w pozycji otwartej, which may distort the damper frame and prevent it from closing,
– montaż stalowej klapy transferowej bez kompensującej ramy montażowej.