WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
84.04 - Auxiliary plant for use with boilers of heading 84.02 or 84.03 (for example, economisers, super-heaters, soot removers, gas recoverers); condensers for steam or other vapour power units. 8404.10 - Auxiliary plant for use with boilers of heading 84.02 or 84.03 8404.20 - Condensers for steam or other vapour power units 8404.90 - Parts (A) AUXILIARY PLANT FOR USE WITH BOILERS OF HEADING 84.02 OR 84.03 These include : (1) Economisers for pre-heating the boiler feed water by utilisin the waste heat of the flue gases or, in some types, exhaust steam. They usually consist of eaders fitted with a s stem of cast iron or steel gilled tubing, sometimes contamed within a separate chamber o sheet metal into which the flue gases or exhaust steam are discharged. In the mixing type econorniser waste steam is passed directly into a chamber containing the feed water. 8, ? (2) Air pre-heaters. These also make use of the waste heat. They consist of air chambers with heat-exchange systems of varying es, e.g., tubular types through which the hot flue gases circulate thus heating the air in t e chamber; plate- e in which air and smoke gases circulate separately in adjoining narrow compartments. ertain types incorporate rotating bame plates. F (3) Super-heaters. These consist of headers with a high-pressure steel tube system in which the saturated steam from the boiler is further heated to remove moisture and to produce steam at hi temperature. Super-heaters are often part of the main boiler assembly, but in some cases ve a separate flue system. % (4) De-super-heaters. These are used to prevent the development of too high a tem erature in the super-heaters. Normally they are placed between two sections of the super-!l eater, and generally consist of a cast lron body into which the steam is passed and cooled by a flow of water. (5) Steam collectors. Cylindrical bodies for collecting the steam from a group of boilers. (6) Steam accumulators. Large insulated cylindrical steel high-pressure reservoirs for the storage of a reserve of steam. (7) Thermic or heat accumulators. These are used to store the surplus heat from steam boilers. (8) Tubular furnace-walls, i.e., a system of vertical tubing connected to conduits in which the feed water circulates, and designed to be mounted in front of the interior surface of the h a c e walls. They serve the double function of preventing the over-heating of the furnace walls and at the same time pre-heating the feed water. (9) Soot removers (soot blowers), automatic or not. These remove soot and similar deposits from the tubular parts of the steam-generating installation (e.g., super-heaters, watertubes, firetubes and economisers) by the use of jets of steam or compressed air. They consist of a tube (fixed or retractable) with a number of jets controlled by a valve and coupled to the steam or compressed air conduit. In other cases soot removers take the form of retractable jets. (10) Gas recoverers. These are devices by which the exhaust gases are returned to the furnace for combustion of unburnt particles. (1 1) Sludge scrapers. (B) CONDENSERS FOR STEAM OR OTHER VAPOUR POWER UNITS These include steam condensers of various kinds, whose function is to reduce the back pressure in steam engines by cooling and condensing the exhaust steam, thus increasing the power of the engine. They include : (1) Surface-condensers. These consist of a cylindrical shell enclosing a system of tubes. The steam is led into the cylinder, and cold water circulates through the pipes (or occasionally vice versa) thus condensing the steam. (2) Mixing condensers. In these the steam is mixed direct1 with water. The heading includes ejector condensers in which a partial vacuum is create in the condenser chamber by a jet of water (acting in the same way as the jet in an ejector pump). d (3) Air-cooled condensers. These consist of gilled steam tubing cooled by a forced current of air. PARTS Sub'ect to the general provisions regarding the classification of arts (see the General Exp anatory Note to Sechon XVI),the heading also covers parts o f t e above apparatus and appliances. R Metal tubes or i es which have been bent or curved but not otherwise worked, resented unassembled, are not identifia%Peas parts of goods of this heading and are therefore to be clsssigd in Sertiao XV. The heading excludes the following, whether or not for use in boiler-houses : (a) Pumps (including water-injectors for force-feeding the boiler), blowers, fans and other machinery of heading 84.13 or 84.14. (b) Furnace burners, mechanical grates, mechanical stokers and the like (heading 84.16). (c) Distillation and other condensers of heading 84.19. (d) Filters and purifiers for water, gases, etc. (heading 84.21).
Notes. 1.- This Chapter does not cover : (a) Millstones, grindstones or other articles of Chapter 68; (b) Machinery or appliances (for example, pumps) of ceramic material and ceramic parts of machinery or appliances of any material (Chapter 69); (c) Laboratory glassware (heading 70.17); machinery, appliances or other articles for technical uses or parts thereof, of glass (heading 70.19 or 70.20); (d) Articles of heading 73.21 or 73.22 or similar articles of other base metals (Chapters 74 to 76 or 78 to 81); (e) Vacuum cleaners of heading 85.08; (f) Electro-mechanical domestic appliances of heading 85.09; digital cameras of heading 85.25; (g) Radiators for the articles of Section XVII; or (h) Hand-operated mechanical floor sweepers, not motorised (heading 96.03). 2.- Subject to the operation of Note 3 to Section XVI and subject to Note 11 to this Chapter, a machine or appliance which answers to a description in one or more of the headings 84.01 to 84.24, or heading 84.86 and at the same time to a description in one or more of the headings 84.25 to 84.80 is to be classified under the appropriate heading of the former group or under heading 84.86, as the case may be, and not the latter group. (A) Heading 84.19 does not, however, cover : (i) Germination plant, incubators or brooders (heading 84.36); (ii) Grain dampening machines (heading 84.37); (iii) Diffusing apparatus for sugar juice extraction (heading 84.38); (iv) Machinery for the heat-treatment of textile yarns, fabrics or made up textile articles (heading 84.51); or (v) Machinery, plant or laboratory equipment designed for a mechanical operation, in which a change of temperature, even if necessary, is subsidiary. (B) Heading 84.22 does not cover : (i) Sewing machines for closing bags or similar containers (heading 84.52); or (ii) Office machinery of heading 84.72. (C) Heading 84.24 does not cover : (i) Ink-jet printing machines (heading 84.43); or (ii) Water-jet cutting machines (heading 84.56). 3.- A machine-tool for working any material which answers to a description in heading 84.56 and at the same time to a description in heading 84.57, 84.58, 84.59, 84.60, 84.61, 84.64 or 84.65 is to be classified in heading 84.56. 4.- Heading 84.57 applies only to machine-tools for working metal, other than lathes (including turning centres), which can carry out different types of machining operations either : (a) by automatic tool change from a magazine or the like in conformity with a machining programme (machining centres), (b) by the automatic use, simultaneously or sequentially, of different unit heads working on a fixed position workpiece (unit construction machines, single station), or (c) by the automatic transfer of the workpiece to different unit heads (multi-station transfer machines). 5.- For the purposes of heading 84.62, a “slitting line” for flat products is a processing line composed of an uncoiler, a coil flattener, a slitter and a recoiler. A “cut-to-length line” for flat products is a processing line composed of an uncoiler, a coil flattener, and a shear. 6.- (A) For the purposes of heading 84.71, the expression “automatic data processing machines” means machines capable of : (i) Storing the processing program or programs and at least the data immediately necessary for the execution of the program; (ii) Being freely programmed in accordance with the requirements of the user; (iii) Performing arithmetical computations specified by the user; and (iv) Executing, without human intervention, a processing program which requires them to modify their execution, by logical decision during the processing run. (B) Automatic data processing machines may be in the form of systems consisting of a variable number of separate units. (C) Subject to paragraphs (D) and (E) below, a unit is to be regarded as being part of an automatic data processing system if it meets all of the following conditions : (i) It is of a kind solely or principally used in an automatic data processing system; (ii) It is connectable to the central processing unit either directly or through one or more other units; and (iii) It is able to accept or deliver data in a form (codes or signals) which can be used by the system. Separately presented units of an automatic data processing machine are to be classified in heading 84.71. However, keyboards, X-Y co-ordinate input devices and disk storage units which satisfy the conditions of paragraphs (C) (ii) and (C) (iii) above, are in all cases to be classified as units of heading 84.71. (D) Heading 84.71 does not cover the following when presented separately, even if they meet all of the conditions set forth in Note 6 (C) above : (i) Printers, copying machines, facsimile machines, whether or not combined; (ii) Apparatus for the transmission or reception of voice, images or other data, including apparatus for communication in a wired or wireless network (such as a local or wide area network); (iii) Loudspeakers and microphones; (iv) Television cameras, digital cameras and video camera recorders; (v) Monitors and projectors, not incorporating television reception apparatus. (E) Machines incorporating or working in conjunction with an automatic data processing machine and performing a specific function other than data processing are to be classified in the headings appropriate to their respective functions or, failing that, in residual headings. 7.- Heading 84.82 applies, inter alia, to polished steel balls, the maximum and minimum diameters of which do not differ from the nominal diameter by more than 1 % or by more than 0.05 mm, whichever is less. Other steel balls are to be classified in heading 73.26. 8.- A machine which is used for more than one purpose is, for the purposes of classification, to be treated as if its principal purpose were its sole purpose. Subject to Note 2 to this Chapter and Note 3 to Section XVI, a machine the principal purpose of which is not described in any heading or for which no one purpose is the principal purpose is, unless the context otherwise requires, to be classified in heading 84.79. Heading 84.79 also covers machines for making rope or cable (for example, stranding, twisting or cabling machines) from metal wire, textile yarn or any other material or from a combination of such materials. 9.- For the purposes of heading 84.70, the term “pocket-size” applies only to machines the dimensions of which do not exceed 170 mm x 100 mm x 45 mm. 10.- For the purposes of heading 84.85, the expression “additive manufacturing” (also referred to as 3D printing) means the formation of physical objects, based on a digital model, by the successive addition and layering, and consolidation and solidification, of material (for example, metal, plastics or ceramics). Subject to Note 1 to Section XVI and Note 1 to Chapter 84, machines answering to the description in heading 84.85 are to be classified in that heading and in no other heading of the Nomenclature. 11.- (A) Notes 12 (a) and 12 (b) to Chapter 85 also apply with respect to the expressions “semiconductor devices” and “electronic integrated circuits”, respectively, as used in this Note and in heading 84.86. However, for the purposes of this Note and of heading 84.86, the expression “semiconductor devices” also covers photosensitive semiconductor devices and light-emitting diodes (LED). (B) For the purposes of this Note and of heading 84.86, the expression “manufacture of flat panel displays” covers the fabrication of substrates into a flat panel. It does not cover the manufacture of glass or the assembly of printed circuit boards or other electronic components onto the flat panel. The expression “flat panel display” does not cover cathode-ray tube technology. (C) Heading 84.86 also includes machines and apparatus solely or principally of a kind used for : (i) the manufacture or repair of masks and reticles; (ii) assembling semiconductor devices or electronic integrated circuits; (iii) lifting, handling, loading or unloading of boules, wafers, semiconductor devices, electronic integrated circuits and flat panel displays. (D) Subject to Note 1 to Section XVI and Note 1 to Chapter 84, machines and apparatus answering to the description in heading 84.86 are to be classified in that heading and in no other heading of the Nomenclature. Subheading Notes. 1.- For the purposes of subheading 8465.20, the term “machining centres” applies only to machine-tools for working wood, cork, bone, hard rubber, hard plastics or similar hard materials, which can carry out different types of machining operations by automatic tool change from a magazine or the like in conformity with a machining programme. 2.- For the purposes of subheading 8471.49, the term “systems” means automatic data processing machines whose units satisfy the conditions laid down in Note 6 (C) to Chapter 84 and which comprise at least a central processing unit, one input unit (for example, a keyboard or a scanner), and one output unit (for example, a visual display unit or a printer). 3.- For the purposes of subheading 8481.20, the expression “valves for oleohydraulic or pneumatic transmissions” means valves which are used specifically in the transmission of “fluid power” in a hydraulic or pneumatic system, where the energy source is supplied in the form of pressurised fluids (liquid or gas). These valves may be of any type (for example, pressure-reducing type, check type). Subheading 8481.20 takes precedence over all other subheadings of heading 84.81. 4.- Subheading 8482.40 applies only to bearings with cylindrical rollers of a uniform diameter not exceeding 5 mm and having a length which is at least three times the diameter. The ends of the rollers may be rounded.