Sourcing aluminium pipe flanges from China

UK duty on aluminium pipe flanges

Read from the UK Trade Tariff on 25 October 2026, heading 7609 covers aluminium tube or pipe fittings. Ordinary aluminium pipe flanges should be checked against 7609 00 00 90, the other fittings line. The flange types shown share this code; the specialised automotive connection-block lines are not general flange categories.

The supplied snapshot lists 4% duty on goods from China throughout the heading. It lists no anti-dumping or countervailing duty, suspension or attached import control. This tariff snapshot does not establish whether a flange is suitable for its intended pressure system.

Confirm the material, construction and function against the drawing before choosing the commodity code. For other connection types, see the wider aluminium pipe fittings guide.

Specify the flange and its mating joint

Send a controlled drawing showing flange type, bore, outside diameter, thickness, bolt-hole diameter, bolt-circle diameter and hole arrangement. Define the sealing face, gasket contact area, surface finish and dimensional tolerances. For loose flanges, include the mating stub end; for threaded flanges, define the thread form and engagement.

Specify alloy and temper, manufacturing route, coating, fluid, working pressure and temperature range. Ask for material certificates linked to the batch. Pressure equipment rules can apply to flanges attached to pressurised parts. Agree the applicable pressure equipment evidence with the system designer before ordering, rather than treating a supplier's pressure rating as sufficient.

Worked duty example

Illustrative example, not a quote: Illustrative order of aluminium pipe flanges in mixed sizes for business stock under 7609 00 00 90, invoiced at £24,000 free on board, with £1,200 of freight and insurance to the UK. The customs value is £25,200. Duty at 4% is £1,008. Import VAT at 20% is charged on the customs value plus duty, £26,208, so it is £5,241.60. Import taxes total £6,249.60; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £1,008 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Dimensions: measure bore, thickness, bolt circle and hole positions against the approved drawing, and trial-fit the mating flange, bolts and pipe.

Sealing faces: check flatness, machining marks, scratches and burrs across the gasket contact area; inspect again after unpacking on arrival.

Material and traceability: match alloy and temper certificates to batch identification, and check that the supplied manufacturing route matches the order.

Joint performance: test a representative assembled joint using the agreed gasket, bolts and test procedure. Record leakage and deformation, and retain the results with the inspection record.

What goes wrong

A flange can match the nominal pipe size while its bolt circle or sealing face does not match the existing joint. Thin sections, distorted faces, substituted alloy and damaged gasket surfaces can undermine sealing. Loose backing flanges also fail to seat correctly when the mating stub end was omitted from the supplier's drawing.

Approve the complete joint before production and protect machined faces during packing. Compare arrival samples with the approved drawing and material records before releasing stock for installation.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For repeat volumes, see container programmes.