Shop by Size (imperial)

Shop spiral ducting and fittings by imperial size, from 3 inch to 40 inch across 22 size pages. Each page pulls together every part we offer in that diameter — 90° curved boots, 45° pipe saddles, reducers and 90° pressed saddles and more — making it easy to specify a full duct run in one visit.

Alpha Air Ventilation Supplies is a Leicester-based supplier of commercial and industrial ventilation equipment. Stocked items ordered before 3pm are dispatched for next-working-day delivery, and UK delivery is free on orders over £400 ex VAT.

Working in millimetres? The same range is organised under our metric size categories — 4 inch is about 100mm, 6 inch about 150mm, and so on.