Under what conditions should fire service mains be flushed?

Flushing fire service mains periodically to remove sediment is essential for maintaining the operational integrity and safety of the fire protection system. Over time, sediment and debris can accumulate in the pipelines, which may obstruct water flow, reduce pressure, and impair the functioning of fire service mains during an emergency. By conducting regular flushing, these systems ensure that water can be delivered quickly and effectively when needed, maintaining the reliability of fire protection capabilities.

This practice enhances water quality, thereby preventing potential contamination that could arise from stagnant water within the system. It also helps to identify and mitigate any issues related to pipeline deterioration or buildup that could compromise the overall system.

While other options mention scenarios that might involve the mains, they do not represent routine maintenance actions aimed at ensuring the continued effectiveness of the system, as periodic flushing does. Flushing after fire drills, when pressure drops, or during the installation of new mains might be necessary in specific situations, but they do not encapsulate the ongoing requirement to keep the mains free from sediment, which is the key focus here.