الفهرس 
WATER NETWORKS ELEMENTS
CorrosionOnly 14 pages are availabe for public view
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Abstract
Water supply systems reliability is the ability of the system to supply the required demand with sufficient pressure at normal and abnormal conditions. Reliability of water systems is generally overlooked in design.
A methodology is developed for the assessment and enhancement of water distribution networks reliability. Upgrade scenarios are introduced to increase the network reliability, then optimization analysis is carried out for the selection of the optimum upgrade scenario according to a predefined objective function.
A case study of Monshaat Al Qanater is conducted to illustrate the application of proposed methodology. It can be concluded that single supply pipeline should be avoided. Network Loops should be balanced as possible in terms of hydraulic capacity. Increasing number of working pumps and percentage of standby pumping capacity improve network reliability. Network reliability can also be improved by reducing the break rate, by preventive maintenance of the system components, or using high quality of pipe materials and pumps.
Design guidelines to improve system reliability are introduced which indicated that: in order to achieve a system target reliability of 99%, transmission pipelines with break rate exceeding 0.05 break/km/year and 1-day repair time should be duplicated if longer than 73 km. Pumps with break rate exceeding 3 break/year and 5-day repair time should have standby capacity of at least 150%, 67% or 25% in case of 2, 3 or 4 working pumps respectively. If the target reliability cannot be achieved, then water storage at destination should be provided. A design formula is proposed to calculate the required minimum storage.