For best results, what is the minimum flushing velocity when using the unidirectional flushing method?

The minimum flushing velocity for effective unidirectional flushing is generally considered to be 5 feet per second (fps). This velocity is important because it ensures that sediment and debris are adequately mobilized and removed from the pipes.

At this flow rate, water can effectively dislodge and carry away particulates that may settle in the distribution system over time. Flushing at velocities lower than 5 fps may not generate enough turbulence to effectively remove contaminants, thus diminishing the effectiveness of the flushing process.

Unidirectional flushing operates on the principle of creating a dominant flow direction, which helps in clearing the pipeline more efficiently compared to standard flushing methods. Therefore, adhering to the minimum velocity guideline of 5 fps is crucial for maintaining clean water distribution and ensuring the integrity of the water supply.