The Hazen-Williams pressure loss equation is used worldwide to calculate the pressure loss in fire sprinkler systems, wet risers, fire hydrant systems, and many other fire protection systems, including low-pressure water mist.
Below, you will find an online Hazen-Williams calculator, which you can use to calculate the pressure loss in a pipe using the Hazen-Williams pressure loss equation. The equation we have used is based on the equation in EN 12845, NFPA 13 and NFPA 750 and uses metric units. So the pressure is in bar, flow in Litre per minute (L/min) the internal pipe diameter (ID) is in millimetres (mm).
Then using the calculator, please remember to use the pipe's internal diameter, not the nominal; otherwise, the answer will not be valid. You can find out more information about the pressure loss equation in our article Hazen-Williams pressure loss equation. If you regularly need to calculate the pressure loss in sprinkler pipes using the Hazen-Williams equation, then we have a helpful tool you can download for free and use on your desktop. Why not find out more about Hcalc and download your free copy?
