Formulas
Friction Loss Formula
The friction loss formula multiplies a hose's coefficient by the flow squared by the length to estimate the pressure a lay consumes. Because the flow term is squared, friction loss is driven mostly by how much water is moving.
The formula combines three things: the coefficient that captures the hose's diameter and roughness, the length of the lay, and the flow — entered as its square. Holding the hose and length fixed, doubling the flow roughly quadruples the loss.
It is the engine behind every pump discharge pressure calculation and the laminated reference cards. The squared flow term is the single most important idea: friction loss is a flow problem first and a hose problem second.
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Friction LossLesson
Friction Loss Basics