Investigating Effect of Water Hammer on Gravity Water Transmission Lines using Fiberglass Pipes

This study investigates water hammer control strategies in gravity-fed water transmission systems using the drinking water pipeline from wells west of Mashhad as a case study. Key sections of the system include the transfer routes from Islamabad reservoir to Coward reservoir and from Coward reservoir to Area F reservoir, where abrupt flow stoppages have been shown to induce considerable pressure variations. The analysis reveals that sudden closures generate maximum positive pressures of ۱۶۱ and ۱۸۱ meters of water column, while negative pressures can drop to -۱۰ meters, posing significant risks of structural damage to the pipeline. The research demonstrates that extending the valve closing time to at least ۱۰ minutes substantially reduces the occurrence of extreme pressure fluctuations. Additionally, installing a pressure control valve upstream of the final valve effectively moderates peak pressures in emergency scenarios, such as sudden valve closures. These adjustments significantly enhance the system's resilience without requiring extensive or expensive shock control equipment. The findings underscore the importance of operational modifications over mechanical interventions. By implementing controlled valve operations with a closing time of ۱۵–۲۰ minutes and strategically integrating pressure control valves, it is possible to mitigate water hammer effects effectively. This approach not only minimizes potential damage but also reduces maintenance costs and enhances the system's longevity The results of this study have broad implications for the design and operation of gravity-fed water transmission systems. By adopting such strategies, operators can optimize system performance, ensure the safety of infrastructure, and avoid unnecessary expenditures on specialized equipment. These outcomes highlight the feasibility of combining practical operational changes with targeted engineering solutions to address common challenges in water supply systems.

کلیدواژه ها:

Water Hammer ، Gravity transmission lines ، Valve opening and closing ، Fiberglass pipe ، West Mashhad