Standard shock-tube technology has been modified to provide a tool for the simulation of aspects of pipeline flow. It was found adaptable to investigation of transient behaviour in accelerating/expanding, uniform/stratified and outflowing/emerging situations. Concurrence between the nature of the flow field in such an experimental facility and the predictions from ideal, centred wave theory was investigated. The conservation equations, the equation of state and expressions for perfect gas properties provided a base for describing the full range of expansion flow properties for which solutions were obtained by the method of characteristics. Procedures and a full set of equations are described. Sensitive real influences were considered and critical conditions identified. Validation by reversed shock-tube experiments with air, conducted within limits set by the critical conditions, are discussed. In expanding and stratified flow from initial pressure across the shock-tube diaphragm in the range 2.0-8.0, representing expansion strengths in thr : range 0.3-0.7, excellent agreement with theoretical predictions was found for pressure variations and for predicted and recorded wave and particle velocities. Although the latter remained firmly in the subsonic range, it was shown that relatively high Reynolds numbers of 5-10 x 10(6) were achieved. The technique has wider applicability, of which the use for flame propagation studies in expanding flow is indicated.