FIRE DOOR OPERATORS
Fire doors are designed to operate to prevent the spread of fire and smoke. The most common type of fire door is the fire shutter, which closes to prevent the spread of smoke and fire.
Fire shutters can close in one of two ways:

POWER CLOSE
As the name implies the door closes under power i.e. in the same manner as it would if the close pushbutton were pressed. Critical to this system is ensuring that the power supply can be maintained in the event of a fire.

On large installations a stand by generator may be present, another possibility is a battery back up system.

GRAVITY CLOSE
With the shutter in the open position the drive shaft must release enabling the shutter to close in a controlled manner.

Link Controls offer the NBG range of fire door operators for gravity close applications.