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Head Loss Factor:Calculation & Prevention

Please tell me what is the head loss factor while distributing water from supply source to consumer?  How can it be prevented?





The Darcy-Weisbach equation used to calculate head loss is explained here:

More details about head loss, calculation as per Darcy's equation, remediation:

A Manual on Head loss and related articles:


Dear Prabir,

From the manner you have asked the question (what is head loss “factor” and how to “prevent” head loss) I take it that that you have not studied any hydraulics. My answer is based on this assumption.

There is a limit to how much of technology can be simplified and explained to a layman who does not have the necessary background in related subjects. Your question goes well beyond that limit. Francis has given to you references to Darcy-Weisbach equation. That is correct, but I doubt if that will really help you.

For example there is a factor f in the equation and you need to know what is the value of this factor. If you look up the references further you will find it says f depends on Reynolds number. So next you will be asking what is Reynolds number and how is this Re related to f. That brings in Moody’s charts, or an even more scary looking equation, and knowledge of mathematics to solve transcendental equations by numerical methods. Where does it end ?

Further, your question is about head loss from source to consumer. This depends not only on the friction in the pipe but also the loss in various bends, reducers, valves, and other pipe fittings. Applying the equation without understanding all this can very likely get you to make some terrible mistakes.

Just as I – not having studied medicine - need to consult a qualified doctor to know which antibiotic to take for my fever, likewise you need to consult a qualified hydraulics engineer to solve your problem about head loss.

And by the way, headloss can not be “prevented”. It can only be reduced.

Chetan Pandit
National Water Academy

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