Instructions How to use a GATE VALVES in Molding 1 Size and select a valve gate in tandem with the hot runner system. The hot runner system provider will aid in the selection process. In many cases, the mold maker will coordinate this effort. The material to be molded and the overall part design will be the fundamental keys to sizing a valve gate. 2 Install the mold with a hot runner system and the valve gate in an injection press. The electronic controls for the valve gate will need to be tied to the press timer that times the injection cycle. Additionally, valve gates are often pneumatically or hydraulically actuated. Ensure that proper controls are set up to actuate the valve. 3 Determine the time in the injection cycle when the gate should be closed. This will be a function of the rate of material flow and the size of the part. Once the mold has been sufficiently filled by molten plastic to produce acceptable quality, there is no need for additional plastic to be injected. This is when the gate can be closed and the melt procedure for the next cycle can begin. 4 Set the actuator on the valve gate to shut when the injection timer reaches the time determined in the previous step. 5 Set the actuator on the valve gate to open when the injection timer is reset at the beginning of the next cycle. 6 Commence operating the injection press as per normal operating conditions.