WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
84.05 - Producer gas or water gas generators, with or without their purifiers; acetylene gas generators and similar water process gas generators, with or without their purifiers. 8405.10 - Producer gas or water gas generators, with or without their purifiers; 8405.90 - Parts acetylene gas generators and similar water process gas generators, with or without their purifiers This heading covers self-contpined a paratus and plant for generating -any kind of gas (e.g., producer gas, water gas and rmxtures t ereof, or acetylene) whatever the intended use of the gas produced (lighting, industrial heating, feeding gas engines, welding or cutting metals, chemical synthesis, etc.). % The heading also includes producer gas generators specially constructed for use in motor vehicles, but excludes acetylene generators which are in fact lamps requiring only the fitting of a burner (heading 94.05). (A) PRODUCER GAS GENERATORS These usually consist of a closed cylinder, general1 fitted with a refractory lining or a watershaking or revolving t e), wth provision cooled double wall enclosin a grate (either of of air and steam) by suction or blowing. A ick bed of fuel is for passing a current of air burned on the grate and the of air and steam is regulated so that combustion is incomplete. The decomposition of the water and the incomplete combustion of the fuel yield carbon monoxide and hydrogen. The resultant mixture of carbon monoxide, hydrogen and nitrogen (producer gas) is drawn off at the top of the apparatus. fix2 In certain enerators of the " reversed combustion " type, the air is blown from the top to the bottom an alon the sides of the cylinder and the gas is collected at the bottom of the apparatus, below k e grate. This allows for more complete combustion of tars, etc. (B) WATER GAS GENERATORS These are of similar construction, but are arranged so that air and a spray of water or steam are blown in alternate phases into the a paratus. The gas resulting from the water hase is a mixture gas having a higher heatipg power &an poducer gas. of hydrogen and carbon monoxide It may be collected separately from the pro ucer gas obtained d w g the air phase or the two gases may be mixed. d Both producer gas and water gas enerators may be adapted for burning many kinds of solid fuel(e.g., coal, coke, charcoal, woo$ vegetable or other waste). For certain uses, articularly for su lying gas engines, producer or water gases must be cleaned of im urities suc as dust, tars, su p urous compounds, etc,, and sometimes reheated or cooled. For &is urpose, the generators are often fitted with purifiers (comprising perforated cones, coke bedl= s, scrubbers, etc.), coolers, dryers, reheaters, etc. Such pmfiers and other auxiliary apparatus are classified with the generators when presented therewith, provided they are clearly sultable for use together. When presented separately they fall in their own respectwe headings (e.g., purifiers in heading 84.21). f PR (C) ACETYLENE WATER PROCESS GAS GENERATORS These are generally of simple construction, consisting of a water-sealed as reservoir, the movement of which, as it is charged and discharged, automatically controls e gas generating device. There are three types of generating devices : f (1) Producing intermittent immersion of the mass of calcium carbide in the water. (2) Providing for the gradual. addition of carbide to water. (3) Causing water to be dripped on to the carbide. (D) OTHER WATER PROCESS GAS GENERATORS These include oxygen generators (e.g., those used in submarines) and ethylene generators (e.g., those based on the action of water on certain chemicals). PARTS Sub'ect to the general provisions regarding the classification of parts (see the General Exp anatory Note to Section XVI), parts of the apparatus of this heading are also classified here (e.g., gas generator bodies, grates, gas collectors and water-carbide mixers). * * * The heading also excludes : (a) Free-piston generators for gas turbines (heading 84.14). (b) Coke ovens (e.g., town gas generators) (heading 84.17). (c) Ozone generating and diffusing apparatus, electric, designed for non-therapeutic purposes (e-g., for industrial uses, for the omnisahon of premises), and electrolytic gas generators for the generation of, e.g., nitro en dioxide, hydrogen sulphide or prussic acid (heading 85.43) and ozonotherapy apparatus beading 90.19).
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.