Sourcing seamless exchanger tubes from China

Duty and classification for stainless exchanger tubes

Read from the UK Trade Tariff on 1 October 2026, the supplied stainless tube lines carry 0% duty for goods from China. They show no anti-dumping or countervailing duty, steel trade measure, suspension or attached import control. Heading 7304 covers seamless tubes, pipes and hollow profiles of iron other than cast iron, or steel. This guide concerns stainless tubes purchased for heat exchanger manufacture.

The circular stainless entries supplied here cover tubes other than cold-drawn or cold-rolled tubes. The file contains no cold-drawn stainless tube entries, so the table cannot establish the duty for that product. Large circular sizes and non-circular profiles are included only as classification alternatives. Confirm the actual process, cross-section and dimensions using finding your commodity code. See seamless boiler tubes for the wider heading.

The UK carbon border adjustment mechanism commences on 1 January 2027. For deliveries from that date, check your confirmed code against its scope and review whether registration is required. Read the UK carbon border guide.

Specify the tube for the exchanger duty

State the stainless grade, seamless manufacturing process, outside diameter, minimum wall thickness, length, straightness and dimensional tolerances. Describe the fluids, operating temperature and pressure so the exchanger designer can approve the material. Agree the heat treatment, internal and external finish, cleanliness and tube-end preparation. For bent tubes, include the bend drawing and acceptance criteria for thinning and ovality.

Pressure-equipment safety requirements include suitable materials. The regulations govern pressure equipment and assemblies with maximum allowable pressure above 0.5 bar, subject to exclusions. Ask the exchanger manufacturer to establish how these requirements apply to the intended supply. Agree material certificates linked to heat numbers, chemical analysis, mechanical test results and the required leak or non-destructive testing records before production.

Worked duty example

Illustrative example, not a quote: Illustrative tube bundle order for a small heat exchanger fabricator; FOB and freight values are hypothetical, not a quotation under 7304 49 83 90, invoiced at £32,000 free on board, with £4,000 of freight and insurance to the UK. The customs value is £36,000. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £36,000, so it is £7,200. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Traceability: match bundle labels and tube identification to heat numbers, material certificates and the purchase specification. Check that test records describe the supplied material and manufacturing condition.

Dimensions: measure outside diameter, wall thickness, length, straightness and ovality against the agreed tolerances. Trial-fit sample ends to the tube-sheet holes; check bent tubes against the drawing.

Surface and bore: inspect for scratches, dents, cracking, embedded contamination and residues. Check internal cleanliness, end squareness and burr removal before accepting the bundles.

Testing and packing: review the agreed leak and non-destructive test records. Check end caps, dry wrapping, bundle supports and lifting damage. Use quality inspection to plan checks before dispatch and on arrival.

What goes wrong

A tube can match the nominal diameter yet fail to fit the tube sheet because of ovality or poor straightness. Wall variation and thinning at bends can defeat the agreed design. Surface damage, dirty bores and mixed material batches create further rejection risks. Keep suspect bundles separate until measurements and certificates have been reconciled.

A supplier may quote welded tube against a seamless specification, or describe cold-drawn tube using a code from the table above. Require the manufacturing route in the order and inspection documents. Approve substitutions with the exchanger designer before shipment, and obtain testing and certification support where the acceptance evidence needs independent review.

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.