Pressure losses were determined for 13 mm, return refrigeration pipe bends of radii from 7.95 to 95 mm during the single-phase flow of water. The results are discussed in relation to those found by previous investigators for 90° pipe bends having radii of eight times the pipe diameter or less. The pressure loss coefficient of the return pipe bend was found to be 0.5 to 1.5 which is less than the published value of 2.2 for the range of r/D between 0.730 and 8.323. Furthermore, it was found that this coefficient is independent of Reynold's Number. It is recommended therefore to use the author's results for accurate engineering design of refrigeration plant evaporators and condensers.
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