Pressure losses for fluid flow in 90 degree pipe bends

Abstract

Pressure losses were determined for nine 4-inch steel, 90° pipe bends of radii from 6 to 80 inches. The results are discussed in relation to those found by previous investigators under comparable test conditions. For bends having radii of four pipe diameters or less, all the results which are discussed may be correlated on the basis of pipe roughness. Further data are needed to establish a working formula. No correlation could be obtained for the bends of larger radii. For such bends the maximum published values should be used in engineering work until more compre-hensive data become available.