An experimental investigation was conducted to study the dynamical behaviour of a model valve in a pulsatile flow. The valve is modelled as a pair of curved, rectangular, flexible leaflets that open and close under a time-periodic flow. Using image analysis, the range of flow parameters for which a valve (of a particular geometry and material properties of the leaflets) works correctly were identified. A correct performance was considered to be when the valve opened in one direction but blocked the flow in the reversed direction. A model is proposed to predict the performance of the valves. Furthermore, an analysis of fluid strains is conducted for valves that operate correctly to identify the influence of the valve’s design on fluid stresses. The main purpose of this investigation is to gain insight for the design of future prosthetic heart valves.