Sourcing malleable iron pipe unions from China
Malleable iron threaded pipe unions from China carry 0% UK duty on the supplied tariff line, with no listed trade remedy. Specify the thread, sealing seat and pressure rating; for drinking-water applications, confirm the applicable water fittings requirements with the relevant water authority. Cambridge China Bridge sources malleable iron threaded pipe unions.
Duty and classification for threaded unions
Read from the UK Trade Tariff on 30 September 2026, heading 7307 covers iron or steel tube and pipe fittings. The relevant supplied line for malleable cast iron threaded unions is 7307 19 10 10. The table shows product variants within that same commodity line, rather than separate tariff classifications.
The supplied line carries 0% duty for goods from China, with no listed anti-dumping or countervailing duty, suspension, attached import control or steel trade measure. Confirm the material and construction through the commodity code guide. For other materials and fitting types, see steel and iron pipe fittings.
Confirm with HMRC or your customs broker whether these fittings fall within the UK carbon border adjustment mechanism and when any obligations apply. Ask the supplier for emissions data before repeat orders and check the registration position in the UK carbon border adjustment guide.
| Goods | Commodity code | Duty | Anti-dumping or countervailing duty on China |
|---|---|---|---|
| Black malleable iron threaded pipe unions | 7307 19 10 10 | 0% | None |
Specify the threads and union sealing seat
Give the factory a drawing covering end connections, nominal size, thread form, assembled length, nut dimensions and sealing-seat design. State whether sealing is metal-to-metal or through a gasket, and specify gasket material where used. Record the intended fluid, operating pressure, temperature and black or galvanised finish. Ask for material certificates linked to the batch.
Agree the threaded-fitting standard and the matching gauges before approving samples. Specify BS EN 10242 where appropriate to the application. For drinking-water use, confirm the applicable water fittings requirements with the relevant water authority; the reference guide notes that merchants often request third-party approval.
For pressure-system use in Great Britain, check the pressure-equipment classification before deciding what conformity evidence to request. The regulations apply above a maximum allowable pressure of 0.5 bar, subject to exclusions. Equipment below the classification limits follows sound engineering practice and must not carry CE or UKCA marking under these rules unless another applicable law requires it.
Worked duty example
Illustrative example, not a quote: Illustrative mixed-size order of malleable iron threaded pipe unions under 7307 19 10 10, invoiced at £4,000 free on board, with £2,000 of freight and insurance to the UK. The customs value is £6,000. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £6,000, so it is £1,200. 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
Threads: check both pipe connections with the agreed gauges, inspect for damaged starts and confirm that coating has not clogged the threads.
Union assembly: dismantle and reassemble sampled unions, check nut engagement and seat alignment, and compare dimensions and gasket fit with the approved drawing.
Leak tightness: test assembled samples against the agreed pressure and leak-test specification. Look for leakage through the casting and around the sealing seat.
Finish and traceability: measure galvanising against the order, inspect for rust and casting cracks, and match batch identification to material certificates. Use quality inspection before shipment and repeat arrival checks.
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What goes wrong
A union can screw together yet leak because its seat is damaged, off-centre or paired with the wrong gasket. Mixed components from different designs can fit loosely while failing to seal. Keep matched assemblies together and check the complete union against the approved sample.
Other failures include casting porosity, cracked nuts, mismatched thread forms and galvanising left inside threads. A catalogue pressure rating does not establish the performance of the delivered batch. Agree acceptance checks before ordering and retain failed samples with their batch identification.
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.
Frequently asked questions
What is the UK import duty on malleable iron unions from China?
The supplied tariff line 7307 19 10 10 carries 0% duty from China, with no listed anti-dumping or countervailing duty.
Which commodity code covers malleable iron threaded unions?
The relevant supplied line is 7307 19 10 10 for other threaded fittings of malleable cast iron. Confirm the actual material and construction before declaring it.
Can I use these unions on drinking-water pipework?
Check suitability for the intended use and compliance with the applicable Water Fittings Regulations. Match any approval evidence to the exact model and sealing materials.
What should I check on galvanised pipe unions?
Check coating thickness against the order, gauge the pipe threads, inspect the sealing seats and assemble samples. Coating inside threads or on sealing faces can prevent proper fitting.