Distribution network elements

The water distribution network is an essential element of the service provision to water-using customers. It is too simplistic to think of this service as simply processes (treatment) and pipelines. Beyond the water treatment works the distribution network is a complex system that stores, transports and reconditions the water both from a quality and pressure perspective. The largest asset base of potable water service provider (WSP) is the pipeline network. This chapter is concerned with the main elements of water distribution networks, including pipelines, pumps, valves and service reservoirs. The chapter begins with an overview of the history of water transportation and explains how pipelines are designed and maintained. The importance of valves and fittings for managing pressure and controlling water as it is transported around the distribution network is explained. To complement this, some practical aspects of surge control are also covered. Types of pump and pump selection are explained. WSPs must cope with a wide variety of normal and abnormal operating conditions, such as very large flows for fire-fighting, routine repairs and maintenance and the inherent variability in water consumption. This chapter also includes service reservoirs that play a key role in this respect.