A trunk line in a large municipality should have an isolation valve every how many feet?

The correct answer indicates that in a large municipality, an isolation valve should be installed every 300 to 600 feet along a trunk line. This spacing is essential for effective system management. Isolation valves play a critical role in maintenance and emergency situations; they enable operators to isolate sections of the water system without needing to shut down large portions of the grid.

Having isolation valves spaced within this range allows for quick responses to leaks, repairs, or emergencies, minimizing water loss and service disruption to customers. Additionally, if valves are spaced too closely, it can lead to unnecessary costs and complexities in the system. Conversely, spacing them too far apart may hinder operators’ abilities to efficiently manage the water supply during routine operations or emergencies. Hence, the 300 to 600 feet guideline strikes an ideal balance between functionality and practicality in the design and operation of trunk lines in municipal water systems.