Gas dispersion from an orifice located in the non-separated flow region of a cylindrical impeller blade was investigated, with four regimes ranging from discrete, orderly bubbling to stable jetting being identified. A prediction of the upper limit for the discrete bubbling regime corresponded well with that of previous authors. An algorithm which balances the pressure loss as gas flows through the system with the driving pressure gradient derived from potential flow theory was developed to model the gas flow rate for a given liquid flow past the orifice. Model predictions are compared with experimental measurements.