A gate adapter for use in a hot runner co-injection molding system includes a hollow gate adapter body defining a gate outlet at a free end thereof. At least a pair of nozzle assemblies is disposed in the adapter body, each of nozzle assemblies having an inlet end in fluid communication with a source of liquid extruded material and an outlet end in the adapter body. At least a pair of nozzle passages is formed in the adapter body and extends from the outlet of the nozzle assemblies to a passage outlet adjacent the gate outlet. A valve stem is disposed adjacent each of the passage outlets and is operable to selectively allow flow from the passage outlets to the gate outlet. The nozzle passages extend for a short predetermined distance within the adapter body to minimize heat transfer.