The predictions of a new model for the contraction coefficient of single- and two-phase flows through a sharp-edged short orifice are checked against data recently obtained with water, air, and air/water mixture flows. The model includes all relevant primary design parameters. The predictions are validated for a wide range of conditions and physical properties typically encountered in industrial fluid-dynamic systems. Calculations based on the new model are sufficiently accurate for engineering purposes. Reasonable extrapolations to other test conditions with an acceptable accuracy can be expected.