Improved Design of Branched Networks by Using Pressure‐Reducing Valves

Abstract

Economical design of hydraulic networks has been a subject of research for some time. Piping has been the main focus of this research because it represents the greatest percentage of the investment in a network. Pipe cost increases with size, but in addition, depends on the material chosen and the pipe class (thickness). However, optimization methods currently available usually take into account only the pipe diameter, as the variable that relates pipe cost to hydraulic capacity. In this paper a method for optimal design achieving greater savings in the investment in irrigation systems by considering factors other than pipe size alone is proposed. The method identifies optimal strategies for use of pressure‐reducing valves (PRVs) in order to reduce pressure in the downstream pipes, thereby reducing wall thickness and investment cost in those pipes. PRVs are common elements in irrigation networks so optimal strategies for location represents an opportunity to achieve considerable savings in investment cost. The method is based on a dynamic programming formulation and is demonstrated by application to an example network.