93-Leak Detection Work for Unaccounted Water.

Abstract

Rehabilitation of an existing pipe network depends on the Unaccounted Water (UW). Leak detection and water losses constitute the main reason for rehabilitation of existing networks. Field data was collected throughout leak detection, consisting of measurements of flow, pressure, consumption, location of leaks, length of pipelines, and correct diameters. Leakage can occur in reservoirs, transmission mains, and the distribution network. The objective of the leak detection program is to minimize losses and save quantities of precious potable water. This study presents details of a leak detection fieldwork. The location and methodology of leakage measurements are discussed, based on leakage management strategies. Leakage management strategies are classified into three groups, passive control, regular survey and leakage monitoring. The water balance calculation entails the measurement of distribution input and water consumption. Many techniques for detecting where leakage takes place in a network are discussed. The equipment used for leak detection are illustrated, including pipe locator, sound detector, and leak detector corrlator. Case studies of fieldwork are presented. Night Flow Test (NFT) is used to evaluate leak detection works for each zone. NFT is applied to measure flow and pressure in certain zones at night for the period (10 PM to 6 AM), whenever leakage is maximized. The case studies are selected from many countries where zones have different values of pressure, consumption and flow. The case studies are selected at the location where the ground level is varied and also where the ground level is flat. The results of analysis explain how to reach right conclusions and recommendations.