Design and construction Water-supply engineering Purification 3 Sewage 3 Equipment and supplies 2 Materials 2 Materials handling 2 rhagor ... Piping 2 Plumbing 2 Refrigeration and refrigerating machinery 2 Slurry pipelines 2 Storm sewers 2 Actuators 1 Air 1 Air conditioning 1 Air-compressors 1 Airborne infection 1 Ash disposal 1 Automatic control 1 Bearings (Machinery) 1 Belts and belting 1 Brakes 1 Chemical plants 1 Chemical vapor deposition 1 Clean rooms 1 Cleaning 1 Clutches (Machinery) 1 Coagulation 1 Combined cycle power plants 1 Combustion 1 llai ...