Hazen-Williams Water Pressure Drop Flow Rates Equations and Calculator
The Hazen–Williams equation is an empirical relationship which relates the flow of water in a pipe with the physical properties of the pipe and the pressure drop caused by friction. It is used in the design of water pipe systems such as fire sprinkler systems , water supply networks , and irrigation systems. It is named after Allen Hazen and Gardner Stewart Williams.
The Hazen–Williams equation has the advantage that the coefficient C is not a function of the Reynolds number , but it has the disadvantage that it is only valid for water . Also, it does not account for the temperature or viscosity of the water.