2521 Manufacture of central heating radiators, steam generators and boilers

25.21.1 Radiators for central heating; superheated water and vapour generating boilers, auxiliary plant and vapour power units
25.21.11 Central heating radiators, not electrically heated, of iron or steel
25.21.12 Steam or other vapour generating boilers; superheated water boilers
This subcategory excludes:
- central heating boilers, for producing hot water or low pressure steam, see 28.21.16
25.21.13 Auxiliary plant for use with boilers; condensers for steam or other vapour power units
25.21.14 Parts of steam generators
25.21.2 Nuclear reactors and parts thereof
25.21.21 Nuclear reactors, except isotope separators
25.21.22 Parts of nuclear reactors, except isotope separators
25.21.9 Sub-contracted operations as part of manufacturing of radiators for central heating, superheated water and vapour generating boilers, auxiliary plant and vapour power units and nuclear reactors
25.21.99 Sub-contracted operations as part of manufacturing of radiators for central heating, superheated water and vapour generating boilers, auxiliary plant and vapour power units and nuclear reactors