Model 4800 Multi-Blade Type


The Bullock Model 4800 multi-blade type fire damper is designed to stop materials of combustion (fire) passing through air-conditioning and ventilation systems which penetrate fire rated masonry walls or concrete slabs.


The model complies with AS1668.1 and AS1682.1 and has been tested and certified by the C.S.I.R.O. for a 4 hour rating (FRL)




  • Australian certified to AS1530.4-1997 by the CSIRO in:
    • a) Masonry wall for 4 hour FRL – Sponsored investigation #-569
    • b) Concrete slab for 4 hour FRL – Sponsored investigation #-855
  • All galvanised steel construction or stainless steel construction complying with AS1682.1
  • Single use brass fusible link 68 degree celsius
  • High yield stainless steel springs and blade pivots
  • Brass blade bushes
  • Expansion Gap Spacers allow the damper to be installed instu with a factory controlled expansion gap (AS1682.2-1990) This means no added installation or inspection costs plus the elimination of health hazardous high temperature fibre wraps. (Australian patent – #624288)
  • Optional Channel Flanges compatible with market available TDF, TDC, Engelmate or Ductmate duct flanging systems in sizes 25mm, 35mm or 50mm profiles. (NOTE: Bolts are to be made of a low melting point material).

Manufactured sizes available:
Wall: 150mm x 150mm up to 2745mm x 2440mm
Slab:  150mm x 150mm up to 2900mm x 1830mm
Round: 150mm diameter up to 1200mm diameter


Blade Linkages                Flange Channels              Metal Expansion Gap Spacers



Installation of this product is critical. Refer to seperate manufacturers installation instructions.
Maintenance to AS1851.6 shall be complied with, refer to this standard for detailed servicing procedures.


“Openings in fire rated walls or slabs shall be protected by a Bullock model 4800 multi-blade fire damper or approved equivalent. Dampers shall be provided where shown on drawings and wherever required to meet local regulations and must comply with AS1682. and AS1668.1-1998


Dampers shall be installed in strict accordance with the manufacturer’s installation instructions, to comply with certificates of test furnished by the manufacturer.


The damper’s construction must be in compliance with the tested protype. The body being made with galvanised steel and any exposed welds to be coated with cold zinc primer type paint to prevent rusting. The damper body must be design engineered for strength and rigidity to reduce the chances of operational damage during transport and/or site installation.


The damper’s expansion gap shall be constantly maintained with the patented Bullock Metal Gap Spacer system, complying with AS1682.1 or approved method. Fusible links are to operate at 68 degree celsius or have an AS1890 rating.”