Laboratory tests on cylindrical pipe yield the empirical forrnula \(h_{L}=0.002583 \mathrm{lV}^{2.14} d^{-0.86}\) with head loss, length, and diameter in \(\mathrm{m}\), and velocity in \(\mathrm{m} / \mathrm{s}\). Water of kinematic viscosity \(9.3 \times 10^{-7} \mathrm{~m}^{2} / \mathrm{s}\) was used in the tests and ranges of \(d\) and \(V\) were: \(0.03