AWWA DSS71302

In 2007, field tests were conducted by the Greater Cincinnati Water Works (GCWW) to evaluate the Hazen-Williams C-values throughout the distribution system. The C-value tests were conducted with the use of a hydrant diffuser assembly. This poster paper shows how the use of a hydrant diffuser can result in higher than actual calculated flows and an artificially high C-value. It presents the results of the field tests conducted for the GCWW, shows the magnitude of the error that can potentially be introduced using hydrant diffusers, and presents a recommended correction to use when calculating flows using a hydrant diffuser.