Page 14 - Caswell Firesafe Manual 2018

TECHNICAL MANUAL

FFRDL / TM / BS / 01 / 2018

5 System Construction Types and Specifications
The design of a dedicated fire resisting ductwork system is focused on ensuring the prevention of the
spread of fire and / or smoke from one compartment to another. A fire resisting duct must also comply with
the requirements of either DW144 and / or DW172 in normal working conditions.

®
All CASWELL FIRESAFE systems meet the requirements of DW144 and Kitchen Extract DW172. They also
can, where required, achieve successful air leakage test results in accordance with DW 143 for low, medium
and high pressure ratings.

®
CASWELL FIRESAFE ductwork has been independently tested and technically assessed to cover
the following:

• Horizontal and Vertical (Riser) applications
• Rectangular and Circular shapes (Flat Oval is also available under separate assessment if required)
• Mild Steel, Galvanised Mild Steel or Stainless Steel construction
• Fully welded Mild Steel or Stainless Steel construction
• Stability and Integrity up to 4 hours to BS476:Part 24 (1987) (ISO 6944: 1985)
• Insulation for up to 4 hours (2 hours on Kitchen Extract systems) to BS476:Part 24 (1987)
• Ducts up to 3m x 3m using conventional methods / up to 8m x 6m using panel construction
• 1, 2 and 3 sided applications
• Decorative paint finishes

6 Ancillary Components

Silencers
The use of silencer pods designed to meet specific noise criteria can be incorporated into our CASWELL
®
FIRESAFE ductwork systems and are covered by assessment report.
Volume Control Dampers
Fire / Smoke dampers converted for manual use as VCDs have been approved for use within the CASWELL
®
FIRESAFE ductwork system. We can also incorporate specifically designed, dedicated VCDs within our
systems based on our latest assessments.
Fire / Smoke Dampers
®
Fire / Smoke dampers are approved for use in conjunction within the CASWELL FIRESAFE system
provided they have been tested to EN 1366 parts 2 & 10 or BS 476:Part 20. Their most common use in
conjunction with fire resisting ductwork is across escape corridors. Generally, standard DW144 ductwork is
secured to the room side of the smoke damper and then fire resisting duct runs across the corridor to just
inside the compartment wall where it connects back to DW144 ductwork.

This is a particularly cost-effective solution as it negates the need for a damper at the other side of
the corridor, along with actuators and the associated costs of control wiring back to the Building
Management System.
Access Doors
We can incorporate access doors into any system as required to satisfy the specified cleaning regime and
offer alternative designs for Galvanised Steel, Stainless Steel and fully welded constructions.

Internal Flanging / Notched Flanging
If required, due to space restrictions or the installation of motorised fire / smoke dampers, we can provide
internal flanges or notched flanges to facilitate insertion and removal of damper actuators.

14 www.firesafeductwork.co.uk