Water loss through leaking pipes is a major threat to water utilities around the world. It is a general agreement that reducing pressure will reduce the leakage flow rate as well as the possibility of pipe burst. Frequent variations in pressure, are associated with higher frequency of new leaks. Undoubtedly pressure management is a fundamental tool in any leakage management strategy. Several pressure management strategies are available for leakage reduction in water distribution systems.
Pressure management in urban water distribution networks is one of the options that can significantly reduce water loss. The pressure reducing valve (PRV) and the variable speed pump (VSP) are two devices that are most used in water distribution system (WDS) pressure management.
In water distribution networks, leakage outflows are sensitive to pressure in the pipe. Minimization of excessive pressure is performed using a system of the Pressure Reducing Valves (PRVs), Flow Control Valves (FCVs) and using Variable Speed Pumps (VSPs). These valves are variable closure devices that allows water to flow through it until a set pressure is achieved downstream. PRVs are often controlled with different approaches like hydraulic or electronic controllers. Electronic controllers are often used perfectly in supervisory control and data acquisition (SCADA) systems, consistent with the momentary operation conditions.
The most common types of pressure control valves are the pressure relief valve and the pressure reducing valve. Pressure relief valves control the system pressure by relieving part, or all, of the flow to tank. Pressure reducing valves reduce the pressure supplied to a sub-system of a hydraulic system. Sequence valves are used to direct the flow to a secondary circuit. Unloading valves are used to direct flow to tank at pre-set system pressure.