Popular fire dampers: Trox FK-EU and FKRS-EU in stock

Fire dampers are safety-relevant components. They require approval from the building authorities to ensure that the products meet the prescribed requirements. In addition, these components must be inspected and serviced regularly (usually annually). They serve to shut off ventilation ducts in the event of fire. This prevents fire and smoke from entering the adjacent fire compartment. On Felderer24 you will find a large selection of fire dampers.

Functions and designs of fire dampers

Standard version

In the simplest case, fire dampers have a fusible link, which releases the closing mechanism at a temperature of 72 °C (or 95 °C for warm air heaters). The fire resistant damper blade closes and closes the air duct safely. In order to monitor the current status of a fire damper (open or closed), it can be equipped with one or two optional auxiliary switches which are connected to the fire control centre or the central building control system.

Benefits of motorised fire dampers
Fire dampers equipped with a spring return actuator offer more possibilities. The actuators themselves have auxiliary switches and signal the current status of the respective damper. When the ventilation system is in operation, voltage is applied to the actuators and the dampers are open. If the power supply fails, the spring in the actuator automatically closes the damper. This is also the case if, as a result of a fire alarm, the building control system specifically disconnects some or all of the fire damper actuators from the mains. This also means that all fire dampers are closed when the ventilation system is switched off. If a fire were to occur now, it would not be detected by the switched-off safety devices. Nevertheless, it could not spread via the ventilation system with its closed fire dampers.

The function of the fusible link is performed by a temperature sensor connected to the actuator, which permanently interrupts the power supply for its actuator if the temperature exceeds 72 °C (or 95 °C). A motorised fire damper thus reacts automatically to fires in its vicinity, even if no fire alarm has yet been set from a central location. The triggered sensors can be replaced after the event if the damper or actuator are not otherwise damaged by fire.

Motorised fire dampers can also be opened and closed remotely outside fire events. This way, for example, a functional check of the fire dampers can be carried out from the GLT control centre without each individual damper having to be checked by maintenance personnel at its installation location.

Trox fire dampers

Trox GmbH has been one of the small circle of manufacturers of fire dampers in German-speaking countries for decades. There are only a few companies which, due to their experience and economic strength, are in a position to manufacture these components in accordance with the normative requirements and to bear the high costs of the building authority approvals. Their products are of the highest quality and are sold worldwide. The two types FK-EU and FKRS-EU mentioned here are only part of the range, but the most frequently used fire dampers.


The FK-EU is a cornered fire damper in the nominal size range 200 x 200 to 1500 x 800 mm. In this range it can be manufactured individually according to the dimensions of the customer. The length of the component is 375 or 500 mm. The damper has 2 inspection openings. In the open state it is characterised by a low pressure difference and sound power. It can also be used as an overflow damper.

In the standard version, the housing is made of galvanised sheet steel. For higher surface requirements, powder coating or stainless steel is also possible.

The flap can be installed very universally in or in front of a wide variety of walls, ceilings or shafts, whereby installation in ceilings and walls can be wet or dry. The air flow direction is arbitrary.

The following further characteristics characterise the flap:

  • Classification according to EN 13501-3, up to EI 180 (ve, ho , i ↔ o) S
  • complies with the European product standard EN 15650
  • Fire protection tested according to EN 1366-2
  • Approval Z-56.4212-991 for fire behaviour
  • corrosion protection according to EN 15650 in conjunction with EN 60068-2-52 proven
  • Leakage air flow with damper blade closed according to EN 1751, class 2
  • Housing leakage air flow acc. to EN 1751, class C; (B + H) = 700, class B
  • ex-proof version (ATEX) also possible

Optionally the damper can be equipped with one or two auxiliary switches, with spring return actuator 24 V or 230 V and with Trox smoke detector.


This is a round fire damper in nominal sizes 100 – 315 mm. The technical data and properties otherwise correspond to those of the square damper FK-EU. Only the leakage air flow when the damper blade is closed deviates slightly. It corresponds to class 3 according to EN 1751. The possible optional equipment is also the same as for the square version.

An additional marking indicates the features of each flap. The most frequently used variants are marked as follows:

  • Z00 – Basic version
  • Z01 – one limit switch for position CLOSE
  • Z43 – Damper actuator 230 V
  • Z45 – damper actuator 24 V

>We now have the Trox fire dampers FK-EU and FKRS-EU in the most common dimensions and versions in the housing length of 500 mm in stock. This enables us to supply you with these important components at short notice. <<<