This paper presents a novel shape memory alloy (SMA) valve actuator concept for active venting in injection molding applications. The developed system can be used to expel air which is trapped during the injection molding process. If such air bubbles are not properly removed from the cavity, they would result into an uncomplete cast and, in turn, in an unsuccessful molding. To address this issue, we propose a new valve system based on an agonist-antagonist SMA-spring actuator concept. By means of the developed SMA valve, the same dynamic performance of conventional actuators can be achieved with a more compact and lightweight actuator design. Design process, assembly, and validation of the novel SMA actuator are first described. In addition, development of an electronics concept and a test rig is discussed. First validation results are finally presented, showing the prototype electro-mechanical response when operating at different ambient temperatures.