a valve gate system for an injection molding machine , having a valve gate unit configured to be in contact with a manifold of an injection molding machine for delivering a molten plastic flow from a hot runner system to an injection chamber . the valve gate unit has a valve pin for controlling the flow of the molten plastic from a hot runner system to an injection chamber and an activating unit coupled with the valve gate unit . the activating unit is configured to be mounted external to a mold unit that houses the injection chamber . in addition , the activating unit has an element that extends through the mold unit to engage the valve pin , so as to control the molten plastic flow from a runner system to an injection chamber .