6
Airlock chambers of metal
7
Machines and machine tools for treatment of materials and for manufacturing; Pumps, compressors and blowers; Shaving exhaust installations; Industrial robots; Painting machines; Robotic painting machines; Centrifugal blowers; Industrial blowers
11
Cyclones [air purifying apparatus]; Dust filters; Filters for industrial installations; Extractor fans; Industrial treatment installations; Filters for industrial and household use; Air filters for use as dust arrestants in industrial processes; Air filters for use as dust extractors in industrial processes; Air filtering installations; Air cleaning filters [parts of air cleaning machines or installations]; Filters for use with apparatus for ventilating; Filters for air purifiers; Industrial air filter machines; Heating, ventilating, and air conditioning and purification equipment (ambient); Ventilating fans for industrial use; Axial fans; Axial fans for air-conditioning; Ventilating fans; Fans for exhaust extractors; Installations for air extraction; Air conditioning installations for industrial purposes
37
Installation of dust extraction apparatus; Installation of ventilation and dust extraction systems; Overhaul of machines; HVAC (Heating, ventilation and air conditioning) installation, maintenance and repair; Installation of industrial plant; Machinery installation, maintenance and repair; Installation of industrial machinery; Repair of industrial machinery; Pump repair or maintenance; Maintenance of industrial machinery; Cleaning of industrial plant