Piping Design and construction 3 Plumbing 3 Purification 3 Water 3 Water-supply engineering 3 Drainage 2 more ... Equipment and supplies 2 Heat 2 Insulation (Heat) 2 Low temperature engineering 2 Pipelines 2 Refrigeration and refrigerating machinery 2 Standards 2 Steam engineering 2 Storm sewers 2 Transmission 2 Vacuum technology 2 Water leakage 2 Actuators 1 Air conditioning 1 Air-compressors 1 Animal housing 1 Ash disposal 1 Automatic control 1 Bearings (Machinery) 1 Belts and belting 1 Brakes 1 Clutches (Machinery) 1 Combined cycle power plants 1 less ...