Online Hazen Williams Calculator for pressure loss in sprinkler systems

The Hazen-Williams pressure loss equation is used throughout the world for calculating the pressure loss in fire sprinkler systems, wet risers, fire hydrant systems and many other types of fire protection systems including low-pressure water mist.

Bellow, 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 which we have used is based on the equation in EN 12845, NFPA 13 and NFPA 750 and uses the 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 internal diameter of the pipe and not the nominal otherwise the answer will not be valid.  You can find out more information about the Hazen-Williams pressure loss equation.  If you regularly need to use the HW to calculate pressure loss then we have a useful calculate Hcalc which you can download and use for free.


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