What is the minimum flow velocity that a hydrant should be flushed to adequately flush the line?

Flushing hydrants is an important maintenance practice that helps to remove sediment, improve water quality, and ensure that the fire hydrants are fully functional. The minimum flow velocity for effective line flushing is critical to achieving these objectives.

A flow rate of 100 gallons per minute is generally accepted as the minimum for adequately flushing a line. This specific flow rate is sufficient to ensure that sediments, rust, and any buildup that may have settled within the pipes can be effectively disturbed and carried away. This velocity helps to create the necessary turbulence in the water flow, which helps in dislodging debris and contaminants.

Options that suggest lower flow rates do not provide adequate velocity for effective cleaning. Flushing at 50 or 75 gallons per minute may not create enough momentum to fully cleanse the lines, potentially allowing some contaminants to remain. Therefore, the choice of 100 gallons per minute strikes a balance, ensuring that the flushing process is both effective and efficient, supporting the overall functionality of the water distribution system.