Reports zero loss coefficients measured for several flat oval tee and lateral fittings at various branch-to-main velocity ratios. The branch loss coefficients were power law functions of flow rate ratio and the data were presented in the form of a curve fit. Finds that the main loss coefficients apparently did not vary with flow rate ratio and in general were less than 0.02.

KEYWORDS: year 1996, Ducts, pressure drop, fittings, elliptic, measuring, testing,air flow