What must dead-end mains be provided with?

Dead-end mains are sections of a water distribution system that do not connect to other pipes at both ends, leading to stagnant water, which can lead to water quality issues over time. Therefore, providing flush valves is essential for maintaining water quality in these dead-end sections.

Flush valves serve the purpose of allowing operators to regularly purge stagnant water from the dead-end main. This purging helps to refresh the water in the pipe and prevent the build-up of contaminants and undesirable characteristics that can develop due to stagnation. Regular flushing can also help to manage sediment accumulation, ensuring that the water supplied to consumers remains safe and of high quality.

Other options, while important in various contexts within a water distribution system, do not specifically address the unique requirement for dead-end mains. For example, air valves are used to release trapped air from pipelines, control valves manage flow and pressure, and isolation valves allow for segmenting sections of the pipeline for maintenance or emergencies. However, it is the flush valves that are specifically designed for the maintenance of water quality in dead-end mains.