Section 16 Machinery and mechanical appliances; electrical equipment; parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers and parts and accessories of such articles 84 Nuclear reactors, boilers, machinery and mechanical appliances; parts thereof 84 81 Taps, cocks, valves and similar appliances for pipes, boiler shells... 84 81 10 With an internal diameter of 2.5 cm or less 84 81 10 21 With an internal diameter of 2.5 cm or less Commodity Code Description 84 81 10 21 00 With an internal diameter of 2.5 cm or less