ABSTRACT
The flow of water, oil and gas in pipes is of immense practical significance in civil engineering. Water is conveyed from its source, normally in pressure pipelines (Fig. 4.1), to water treatment plants where it enters the distribution system and finally arrives at the consumer. Surface water drainage and sewerage is conveyed by closed conduits, which do not usually operate under pressure, to sewage treatment plants, from where it is usually discharged to a river or the sea. Oil and gas are often transferred from their source by pressure pipelines to refineries (oil) or into a distribution network for supply (gas).
