An accident involving a two-phase release can result in serious consequences for people as well as the environment. Consequently, tools are needed to give accurate predictions of the discharge rate, physical state, composition of released material, and chocked pressure in order to improve process safety efficiency. This paper discusses possible approaches to the examination of two-phase critical releases and presents a slip equilibrium model which provides critical flow rate critical pressure, and phase function of the two phases emerging from an accidentally broken pipe containing a liquefied gas mixture under pressure. Comparisons between experimental critical flow rates and model predictions are favorable in both monocomponent and multicomponent mixtures.