FDML

FDML multi blade fire dampers are in motor-driven versions with servo drives and they have the following two main applications:■ They are applied as fire closures without following air condition duct with cover grids for closure of vents in fire dividingwalls, constructions, elevator and other shafts, cable and other channels preventing spread of fire heat and other combustion products.■ If applied as multi blade fire damper with air condition connecting pipes from both ends (without grids) or with connecting pipe at one end (1x grid) they prevent spreading of heat and combustion products through such piping system.If the damper is hit with fire it will automatically (or remotely as the case may be) be closed and spread of fire from one fire sector to another will be prevented. Damper blades automatically close air flow using servo check spring. The servo check spring is put into operation at activation of thermo-electric actuator by pressing reset button or with interruption of servo feeding. Once the blades have been closed the damper is sealed using rubber seal against fume penetration. At the same time damper blade is placed in a material which increases its volume by actuating higher temperature and seals the damper hermetically. Dampers are not furnished with inspection chambers. If these dampers are used as dampers for simple maintenance and revision they must be completed with connecting inspection equipment installed just behind the damper.