Wallis’ flooding correlation is generalized for both small and large pipes by the use of the critical Kutateladze number. A drift flux correlation is then obtained that is tangential to the generalized flooding curve. A simple function of void fraction for the correlation parameter is sufficient to provide good agreement with steam generator test data, without using flow regime maps. After the drift flux correlation is determined with the large-pipe test, it is implemented in the TRAC-PD2 computer code to be tested against the flooding curve for a small-diameter pipe. The Chexal-Lellouche formulas are also applied to the data analysis, and the results are compared with the present correlations. Discussion is extended to the Zuber-Findlay method of data analyses for the drift velocity and the distribution parameter, in relation to the flooding curve.