A Field Study on Peak Factor of Rural Water Distribution Networks (Northern-East Part of Khuzestan Province, Iran)

Evaluation of the short-term fluctuations in water demand and consumption is one of the most important consideration in design and optimization of drinking water distribution networks. According to necessity of system ability to distribute water during peak demand conditions، the capacity and pipe sizing of network are determined based on multiplying Peak Factor in Average Daily Flow. It seems that Diurnal Demand Pattern through which Peak Factor is obtained، regionally varies due to many complicated reasons، mainly because of the number of subscribers. So، most of standards and references have recommended their own specific Daily Peak Factor، Hourly Peak Factor and Peak Factor with emphasis on localization of these terms. Considering the importance of regional studies on Peak Factors، this research was conducted for a group of rural networks in north-east part of Khuzestan Province، Iran. After installation of electro-magnetic flowmeter with maximum error of 0. 3% and measurement of demand flow in 7. 5-minute time intervals by data logger، during one-year period، Diurnal Demand Patterns and Peak Factors were determined. The considerable difference between Peak Factors resulted in this research and those recommended by national and some international standards or references، makes the importance of peak factor localization more and more obvious. For example، in the case of the smallest investigated network، the peak factor proposed by national standard 117-3 is 27. 3% less than the actual factor acquired in present study. Also، the results show that calculation of peak factors without any notice on the negative effects of physical loss of unaccounted-for water can sensibly reduce peak factors 14. 5% to 24. 5% compared to reality.