Abstract
This paper presents part of the results of a study of the performance of a complete series of primary metering devices in a 3-in. pipe line. The devices tested were as follows: Three types of orifices (concentric, eccentric, and segmental) with diameter ratios varying from 20 to 90 per cent; flow nozzles with diameter ratios varying from 30 to 88 per cent; also two venturi tubes with three throat sections each, with diameter ratios varying from 33 to 50 per cent. Discharge coefficients are given for these elements, using water as the metered fluid, with a wide range of differential heads. Coefficients are given also on some of the elements where superheated steam at various temperatures was the metered fluid. The effect of sharpness of orifice edge, of roughness of approach pipe, and of surface finish of flow nozzle on water coefficients is shown. The effect of temperature upon the diameter of the primary device and upon the coefficient of discharge for steam is also given.
