FD-C Fire Damper

The FD-C is a circular fire damper for spiral and round ductwork, designed to maintain fire compartmentation where a duct passes through a wall or floor. Its single-blade layered design is held open by a fusible link that melts at 72°C, releasing a spring mechanism that closes the damper automatically in a fire. The fusible link is replaceable from outside the ductwork, and the damper also incorporates a manual volume-control facility — a settable blade with operating handle and preset positions — so it doubles as a balancing damper in normal service.

We stock the FD-C in eight nominal diameters: 100, 125, 150, 160, 200, 250, 300 and 315mm, covering the common circular duct sizes used in commercial kitchens, offices and residential ventilation systems.

Standards and Construction

• Conforms to fire damper product standard EN 15650; tested to BS EN 1366-2 and classified to BS EN 13501-3
• ES classification with reduced smoke leakage — ES120 in blockwork/masonry walls and concrete floors, ES90 in dry partition walls
• Galvanised mild steel to BS EN 10346 (DX51D Z275), casing to BS EN 1506, stitch-welded body for air-tightness
• Supplied with an installation plate that doubles as a fixing template, allowing one-side fixing with no infill material

For rectangular openings see our made-to-measure rectangular fire dampers; for motorised smoke control in circular duct, our circular fire & smoke dampers run from 100mm to 300mm. Order by 3pm for next-day delivery on stocked sizes — free UK mainland delivery over £400 ex VAT.