BSB Dampers
Air, Fire and Smoke Control
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BSB Engineering Services Ltd.
Unit 56, Trinity Trade Centre,
Mill Way, Sittingbourne,
Kent ME10 2PD, United Kingdom
Sales Office: +44(0)1795 422609
General Enquiries:
+44(0)1795 505366
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FSD-TD Series - Elements of Construction


Where detailed, galvanised mild steel is to the following specification: hot dipped zinc coated steel to BS EN 10142 DX51D + Z 275-N-A-C.

Zinc plating

Zinc electroplated to BS EN ISO 2081: 2008

Casings/inner frames

The FSD-TD casings are manufactured from 1.2mm galvanised mild steel and are fully welded. All welds, seams and joints are coated with heat resistant alkyd aluminium finish paint.

As an option, outer casings are available in Ferritic (430) type 1.4016 or Austenitic (316) 1.4401 grade stainless steel, also fully welded. As standard these welds are simply cleaned, but may be painted or passivated on request.

The inner bearing channels are manufactured from 1.2mm galvanised mild steel. The bearing channel incorporates punch formed low friction bearing surfaces that allow the blades to rotate freely.

Where necessary, sealant is applied to seams and joints.


FSD-TD Series dampers are supplied with opposed blade operation only.

Blade material 0.7mm available as galvanised steel, Ferritic (430) type 1.4016 or Austenitic (316) 1.4401 grade stainless steel.

The blades are a specially formed double skin airfoil shape, specific to BSB, on a 100mm pitch that interlock when closed.

Jamb seals and gaskets

To complete the damper seal there are 0.4mm 301 grade stainless steel gaskets. They are fitted down the sides and across the top and bottom of the damper.

Blade shafts, bearings and linkage

The blades are each mounted on two 19mm diameter spindles (1.2mm wall thickness) made from zinc plated mild steel to BS EN ISO 2081: 2008.

The spindles are linked using a gear system, link arms and drive bars to give the opposed blade action. The gears are made from zinc plated 2.5mm thick mild steel. The link arms and drive strips are made from 2.5mm thick galvanised mild steel.

This linkage is fully enclosed and outside the airstream.

Other components

All other components are manufactured from zinc plated mild steel, with 316 stainless options available.


The FSD-TD series of fire and smoke dampers are supplied with a range of spring return actuators, controlled to close automatically on loss of power or when the thermal fuse exceeds 72°C.

Stainless steel versions are not available.

           1. BSB PM24-TF - 24VAC/DC spring return actuator

           2. BSB PM230-TF - 230VAC spring return actuator

           3. BSB PM-P-TF - spring return pneumatic actuator

BSB Engineering Services Ltd. reserves the right to modify or withdraw any specification without prior notice that may result from continuous product development. The information contained within this website is for reference only. Full product details should be obtained from our Sales Office.

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