Subcritical and Critical Flow Through Straight-Through, Elbow, and Tee A-N Fittings and Sharp-Edged Orifices at Elevated Temperatures

Abstract

Abstract This paper presents the results of an investigation of the flow through straight-through, elbow, and tee A-N standard fittings at negligible approach velocity with approach temperatures up to 1100 F and head pressures up to 60 psia. The element pressure ratio, i.e., the ratio of downstream to upstream static pressure across the test element, was varied between 1.0 and approximately 0.25. Empirical equations for the subcritical and critical flow regimes are derived for the rate of weight flow as a function of element pressure ratio, flow area, and approach temperature and pressure. Empirical equations for a given geometry are derived for a flow factor which is shown to be a function of pressure ratio only in both the subcritical and critical regions. In addition, previous work at room temperature on the flow through sharp-edged orifices in the subcritical and critical regimes has been extended to include a variation of approach temperature up to 1100 F.