4. Energy saving
4.1 Energy saving

5. Energy effiency
5.1 Energy effiency

18. Maintenance services
18.1 Assessment
18.5 Service and restoration
18.16 Modernisations, elementary improvement

19. Equipment, spare parts and accessories
19.36 Sieves and sifters

25. Mass and liquid treatment
25.1 Mass and liquid treatment

30. Surface treatments and corrosion resistance
30.5 Surface treatments and coatings

31. Process evaluation and control, on line measuring