Please use this identifier to cite or link to this item:
|Title:||Predicting internal roughness in water mains|
|Authors:||Construction Engineering Research Laboratory (U.S.)|
Walski, Thomas M.
Sharp, Wayne W.
Shields F. Douglas.
Water distribution systems
|Publisher:||Environmental Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; EL-88-2.|
Abstract: A method is presented for predicting the Hazen-Williams C-factor for unlined metal water mains as a function of pipe age. The method has two steps: (a) finding the growth/rate of internal roughness, alpha, for the water main using either historical C-factor data or water quality data, and (b) using predictive equations for an estimate of a future C-factor. The predictive equations presented herein were derived using linear regression of some 319 data points from seven utilities as well as values from the 1920 text entitled Hydraulic Tables, by G. S. Williams and A. Hazen. The regression equations for C-factor as a function of pipe age have a 95-percent confidence interval of ±15 and a coefficient of determination (r) of 0.87.
|Appears in Collections:||Documents|