11 Apparatus, installations and systems consisting thereof for heat treatment of metals, namely, heat guns; apparatus, installations and systems consisting thereof for heat treatment of metals, namely, heat exchangers; furnaces for use in metal treatment processes; furnaces and bath installations used in connection with metal treatment, namely, nitriding, nitrocarburizing and carbonitriding of metals; loading apparatus for furnaces, namely, mechanical arms specially adapted for use as components of furnaces for loading pieces of metal; gas scrubbing apparatus and gas purification apparatus; parts of gas installations, namely, gas scrubbers; air filtering installations; gas filter systems for household and industrial use, namely, filtering devices for gas conditioning for household and industrial use; air purifying apparatus and machines; heating apparatus for industrial purposes; furnaces, in particular industrial furnaces; foundry furnaces; foundry ovens; furnaces for industrial use, namely, nitriding furnaces; furnaces for industrial use, namely, nitrocarburizing furnaces; furnaces for industrial use, namely, shaft furnaces; furnaces for industrial use, namely, form furnaces, chamber furnaces, pusher-type furnaces, rotary hearth furnaces; heat generating apparatus, namely, for the heat treatment of metals; ventilating installations and devices, namely, ventilating exhaust fans; industrial cooling apparatus, namely, compax coolers for use in connection with moulds; industrial cooling apparatus, namely, coolers for furnaces; cooling appliances and cooling installations for furnaces; vacuum drying chambers for drying treated or processed metals; heat dryers for drying treated or processed metals; curing ovens for industrial use; industrial heating apparatus for wax melting; regulating accessories for water or gas apparatus and pipes, namely, metered valves; apparatus and systems for nitriding metals, namely, industrial furnaces for nitriding metals; industrial heating furnaces for the treatment of metals; gas burners for industrial use; furnaces, other than for laboratory use; heating apparatus for solid, liquid or gaseous fuels; drying installations in the form of drying chambers for metallurgic processing; parts and accessories for all the aforementioned goods, included in this class