Sourcing pump mechanical seals from China

Pump seal duty and classification

Heading 8484 covers mechanical seals alongside composite metal gaskets and mixed-composition gasket sets. Pump mechanical seals fall within the other mechanical seals line, 8484 20 00 90. The table shows different pump seal arrangements sharing that code, rather than separate tariff subdivisions.

Read from the UK Trade Tariff on 25 October 2026, the supplied extract lists 0% duty for goods from China under 8484 20 00 90, with no anti-dumping or countervailing duty, suspension or attached import control. The separate compressor seal line concerns manufacture of vehicle air-conditioning units, rather than pump seals.

Confirm the commodity code using the assembly drawing and supplied components. Separately supplied rubber seals need their own classification. For other products within the heading, see engine cylinder head gaskets.

Specify the shaft, faces and operating fluid

Send the pump model and a dimensioned drawing showing shaft or sleeve diameter, seal chamber, installed length and mounting details. State whether you want component or cartridge construction, the seal arrangement and rotation direction. Agree the replacement parts supplied with each assembly.

Name the fluid, operating temperature, pressure, shaft speed and cleaning conditions. Specify the rotating and stationary face materials, elastomer grade and metal parts. Agree face flatness, dimensional tolerances and a leak-test procedure before production; a matching shaft diameter alone does not establish interchangeability.

REACH restrictions can limit, ban or set conditions on substances in articles. Ask the supplier for the material composition so you can check applicable restrictions before sale. Arrange testing and certification support around the actual materials and intended application.

Worked duty example

Illustrative example, not a quote: 40 cartridge pump mechanical seals, illustrative order under 8484 20 00 90, invoiced at £28,000 free on board, with £1,500 of freight and insurance to the UK. The customs value is £29,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £29,500, so it is £5,900. 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

Fit: measure the shaft bore, installed length, stationary seat and mounting features against the approved drawing; trial-fit an assembly on the intended pump.

Faces: inspect for chips, scratches and contamination, and check flatness with an optical flat against the agreed specification.

Materials: match face, elastomer and metal grades to the approved material records; check elastomer compatibility with the actual fluid and cleaning chemicals.

Assembly and packing: check spring movement, drive features and the agreed leak test; inspect protective packing on arrival for displaced seats, damaged faces and mixed replacement parts.

What goes wrong

A seal can fit the shaft but have the wrong installed length or stationary seat. Faces that are damaged or insufficiently flat leak at start-up; an unsuitable elastomer can swell in service. Approve a drawing and a tested sample rather than accepting a catalogue cross-reference alone.

Material substitutions and transit damage can undermine an approved sample. Keep material records linked to the shipment and agree acceptance checks before dispatch. Use quality inspection to check production against the approved specification.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For machinery and equipment, see machinery imports.