6
Elbows of metal for pipes; collars of metal for fastening pipes; pipe muffs of metal; rings of metal for fastening pipes; screw rings; screw tubes; branching pipes of metal; ducts of metal, for central heating installations; ducts of metal for ventilating and air conditioning installations; water-pipe valves of metal; tubes of metal; pipes of metal; penstock pipes of metal; reinforcing materials of metal for pipes; pipework of metal; junctions of metal for pipes; clips of metal for pipes; steel pipes; steel tubes; collars of metal for fastening pipes; drain traps, valves of metal; water-pipe valves of metal
11
Regulating and safety accessories for gas pipes and gas apparatus; safety accessories for water or gas apparatus and pipes; cooling appliances and installations; parts of installation for ventilation; water, gas, oil distribution installations; gas generators; steam generating installations; flues for heating boilers; gas scrubbing apparatus; oil-scrubbing apparatus; water purifying apparatus and machines; desalination plants; water conduits installations; filters for air conditioning; water filtering apparatus; filters, parts of household or industrial installations; boiler pipes, tubes for heating installations; ventilation hoods
17
Compressed air pipe fittings, not of metal; threads of plastic for soldering; filtering materials, semi-processed foams or films of plastic; flexible tubes, not of metal; insulating materials; rings of rubber; stuffing rings; water-tight rings; gaskets for joints; pipe muffs, not of metal; gasket for pipes; reinforcing materials, not of metal, for pipes; junctions, not of metal, for pipes; gasket; goods made from plastic, gum, rubber, gutta-percha; insulating tape
19
Branching pipes, not of metal; drain pipes not of metal; rigid pipes, not of metal; water pipes not of metal; branching pipes and pipes not of metal, made of PVC, PP, fiberglass, laminated; penstock pipes not of metal; junctions not of metal for pipes; clips not of metal for pipes
37
Pipeline and gas pipeline construction and maintenance; set-up, maintenance and repair of water, gas, sanitary system; set-up, maintenance and repair of installation for gas, water, oil distribution; set-up and repair of air conditioning apparatus; set-up of heating equipment, ventilation and fire-extinguishing installation