What is the maximum water velocity allowed when filling a main?

The maximum water velocity allowed when filling a water main is 1 ft/sec. This limit is put in place to ensure that the filling process does not generate excessive turbulence, which can cause problems such as water hammer or sediment disturbance. Maintaining a controlled velocity helps protect the integrity of the pipes and the quality of the water being conveyed.

In most regulatory frameworks, velocities higher than this may increase the risk of damaging the main or leading to potential system failures. For example, velocities that exceed the limit can lead to erosion within the pipes and can disrupt sediment that may be present, leading to discolored or compromised water quality. Therefore, a filling rate of 1 ft/sec is optimal for maintaining system integrity and ensuring the quality of the water supply.