Friction factor, typical value range

The Darcy-Weisbach Equation applies to a wide range of fluids, while the Hazen-Williams Equation is based on empirical data and is used primarily in water modeling applications. Each of these methods calculates friction losses as a function of the velocity of the fluid and some measure of the pipe s resistance to flow (pipe wall roughness). Typical pipe roughness values for these methods are shown in Table 3.3. These values can vary depending on the product manufacturer, workmanship, age, and many other factors. 

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