FD Series Circular Curtain Fire Damper Angle Frame 355mm dia

The BSB FD Series circular curtain fire damper is a mechanical, fusible link fire damper for circular ductwork passing through fire rated walls, floors and cavity barriers. When duct air reaches 72°C the link melts and a spring-loaded steel curtain closes across the duct, maintaining the compartment. Each damper is supplied with an angle frame for building in. Because the folded curtain sits clear of the airstream in normal running, pressure drop and noise are very low, which makes it a good choice for larger ducts and higher air velocities. It is made to order by BSB in the UK. 100mm to 630mm diameter (11 sizes) E classified to BS EN 13501-3, up to E120 depending on installation Supplied with angle frame Made to order, approx. 1 week lead time What it is best used for Ducted supply and extract systems in commercial buildings, schools, healthcare and residential blocks where a circular duct passes through a fire compartment wall or floor. It suits plant room and riser penetrations, and larger diameter mains where a single-blade damper would add noticeable resistance. Curtain blade or FD-C? Our BSB FD-C is a single-blade damper with external reset, volume control and an ES (reduced smoke leakage) rating, but only goes up to 315mm. The FD Series curtain damper is E rated (integrity), is tested and reset through an access panel in the ductwork, and covers sizes up to 630mm. If the specification calls for ES or you need external reset in a tight ceiling void, choose FD-C. For larger ducts, low pressure loss or a straightforward like-for-like curtain damper replacement, choose this one. Installation notes Install to BSB's tested installation method for the wall or floor type, using the supplied angle frame, so the fire rating is valid. Allow at least 75mm clearance to adjacent walls, floors and ceilings, and use break-away joints on the connecting ductwork. Fit an access panel next to the damper. Fire dampers must be drop tested and inspected at least annually (BS 9999 Annex W) and records kept under the Regulatory Reform (Fire Safety) Order. Made to order These dampers are built to order and are not held in stock. The current lead time is around 1 week from order. Because they are made to order they cannot be returned or cancelled, so please check the duct diameter before ordering. Need a size or option not listed, such as stainless steel, a HEVAC frame or a microswitch? Email hello@efans.co.uk or call 0161 399 3825 for a quote. Specifications Brand BSB Model FD Series, circular (type C), galvanised, angle frame Type Mechanical curtain blade fire damper Classification E rated, BS EN 13501-3, tested to BS EN 1366-2, up to E120 depending on installation Standards BS EN 15650, BS EN 1751 Class 2 blade leakage, LPS 1162, DW 144/145 Fusible link 72°C Construction Galvanised steel casing (min 1.2mm) and curtain blades, stainless steel closure springs Frame Angle frame (AF) supplied Size range 100mm to 630mm diameter (11 sizes) Testing and reset Via access panel in ductwork Lead time Made to order, approx. 1 week Manuals & Guides BSB FD Series Curtain Fire Damper Data Sheet Browse our full range of fire dampers.