Fire dampers within the duct system

D.4.2 Fire dampers within the duct system
D.4.2.1 Approval
Fire dampers, including relevant means of operation, are to be of approved type 1.
D.4.2.2 Accessibility and indication
Fire dampers shall be easily accessible. Each damper shall be clearly marked by an identification number
or letters. Where they are placed behind ceilings or linings, inspection doors shall be provided. These
inspection doors shall be clearly marked with the relevant identification marks. The identification mark
shall be placed also on any remote control. The status (open/ closed) of each fire damper shall be clearly
indicated at the damper and each remote control.
D.4.2.3 Type of means of manual closing of fire dampers
Manual closing may be achieved by mechanical means of release or by remote operation of the fire
damper by means of a fail-safe electrical switch or pneumatic release (spring-loaded, etc.) on both sides
of the division.
D.5 Ventilation ducts
D.5.1 Ventilation ducts shall be of steels or equivalent material. Short flexible ducts, however, not
generally exceeding 2 m in length and with a free cross-sectional area not exceeding 0.02 m2 need not be
steels or equivalent, subject to the following conditions: