Galvanised Concentric Spiral Duct Reducer (315mm – 630mm)

Galvanised Concentric Reducer – Spiral Duct Reducer / Increaser

A galvanised steel concentric reducer for connecting round ducting of two different diameters – for example a 450mm fan to a 400mm duct run. The smooth tapered body keeps airflow even and limits pressure loss. Fit it either way round to reduce or increase the duct size.

Sizes & Prices (including VAT)

• 315mm to 250mm – £28
• 315mm to 300mm – £28
• 355mm to 300mm – £34
• 355mm to 315mm – £34
• 400mm to 315mm – £34
• 400mm to 355mm – £34
• 450mm to 355mm – £39
• 450mm to 400mm – £39
• 500mm to 400mm – £59
• 500mm to 450mm – £59
• 560mm to 450mm – £75
• 560mm to 500mm – £75
• 630mm to 500mm – £73
• 630mm to 560mm – £73
• Custom size (any other combination) – £125

Custom Sizes

Need a combination that is not listed? Select Custom size and write the two diameters you need in the order note at checkout, or contact us before ordering. Custom reducers are made to order (approx. 4 working days).

Specifications

• Material: Galvanised steel
• Type: Concentric (centred) reducer
• Fit: Spiral ducting and fittings of the matching diameters

Delivery

Sent by post across England and Wales for a flat £15 per order (small duct fittings), typically within 1–3 working days. Free collection from our Birmingham workshop is also available.

Complete Your Duct Run

• Spiral pipe in matching diameters
• 90-degree and 45-degree spiral bends
• Round T-pieces
• Male couplers, reducers and end caps
• Split ring duct clamps and threaded rod for hanging