Design and construction Pipelines Cleaning 1 Compressed air 1 Costs 1 Fire prevention 1 Gas 1 espandi ... Gas as fuel 1 Inspection 1 Maintenance and repair 1 Management 1 Petroleum 1 Piping 1 Public utilities 1 Quality control 1 Refrigeration and refrigerating machinery 1 Sewage disposal 1 Sewage sludge ash 1 Slurry pipelines 1 Steam-heating 1 Storm sewers 1 Technological innovations 1 Trenchless construction 1 Water 1 riduci ...