Pipe and isolation valve failure-impact analysis and prioritization model for an urban water distribution network

Abstract

Pipe and isolation valve failure in an urban water distribution network (WDN) causes service interruption to the water users. It is important to identify and prioritize the maintenance of the most severe impact-causing pipes and valve failures. This study investigates the impacts of such failures in terms of the number of isolation elements, the number of affected customers, and the supply shortfall (SS). The study proposes an impact-based prioritization model for pipe and isolation valve repair/replacement in a WDN using the analytic hierarchy process (AHP). The WDN modeling, simulation, and generation of segments are carried out using the WaterGEMS software. The proposed methodology is illustrated with the help of a real-time WDN of Dire Dawa city in Ethiopia. Through the study, it is noticed that each valve/pipe failure has varied impacts and gets reduced with the increase in valve density. Further, the SS is the most important parameter for prioritizing the maintenance. The failure of the valves and pipes significantly affects the system's performance and should be repaired/replaced on priority basis. It is hoped that the proposal will help the decision-makers in the optimal utilization of limited resources available for repair/ maintenance.