Hydraulic design of large-diameter pipes

The Hazen-Williams formula is frequently used for the design of large-diameter pipes, without regard for its limited range of applicability. This practice can have very detrimental effects on pipe design, and could potentially lead to litigation. Available evidence shows that the application of the formula is accurate only if the operation of the pipe is located within the transition or smooth, turbulent-flow regimes. Most working ranges for water-supply pipes usually fall outside such conditions. This paper presents an analysis which highlights the potential implications of current use of the Hazen-Williams formula for the design of large-diameter pipe systems.