4
Biomass fuel; Fuel; Electrical energy; Gas fuel; Oil-gas; Solidified gas (fuel)
7
Feeding apparatus for engine boilers; Machine boiler scale collectors; Steam condensers (parts of machines); Steam/oil separators; Heat exchangers (parts of machines); Filters being parts of machines or engines; Electric generators; Condensing installations; Dust exhausting installations for cleaning purposes; Suction machines for industrial purposes; Pressure regulating valves parts of machines; Separators; Blowing machines for the compression, exhaustion and transport of gases; Superheaters; Superchargers
11
Regulating and safety accessories for water and gas installations; Heat accumulators; Steam accumulators; Heating apparatus for solid, liquid or gaseous fuels; Burners, boilers and heaters; Apparatus for heating; Heat exchangers, other than parts of machines; Chemical processing equipment; Equipment for heating; Installations for evaporating; Furnaces, other than for laboratory use; Fire pits; Incinerators; Ash conveyor installations, automatic; Hot water heating installations; Steam generating installations; Industrial treatment installations; Gas cleaners and purifiers; Distillation columns; Gas scrubbers as parts of gas installations; Refining towers for distillation; Steam boilers, other than parts of machines