A large amount of performance data on larger-scale trays without downcomers has become available recently, and the data have been examined with a view toward understanding and modeling the contacting mechanisms under distillation conditions. The objective of this paper is to describe new predictive models for efficiency, pressure drop, and flooding of trays without downcomers and to show how they can be applied to distillation separations. Such an effort has not been reported previously. The contacting devices are assigned the generic name of dual-flow trays. The models are shown to give reasonable estimates of the performance of these trays in larger columns with open areas in the range of 15-25%, hole diameters in the range of 1225 mm, and tray spacings in the range of 0.3-0.6 m.