A study of the injection of twin pulsed liquid jets ranging from subsonic to supersonic using a high-pressure helium gas gun was conducted. Twin diverging, parallel or impinging jets and single jet were selected. The liquid was sealed at a metal nozzle and then impacted using a polyethylene projectile. Applying laser cutting and copper-wire breaking methods, the jet and impact velocities were measured simultaneously. The results were analyzed by least squares method. From the obtained relationships between the jet and impact velocities, the threshold impact velocities for getting supersonic liquid jets were determined. A strobe light was used to visualize the injection sequence. In addition to the experiments, a theoretical analysis for the mechanism of generating the multiple liquid jets indicates that the exit hole number of a nozzle does not influence the injection velocity so much because of the three dimensional nozzle geometry and the small hole diameter.