Used on some cylindrical shapes. This gate encircles the core to permit the melt to first move around the core before filling the cavity.

A Ring Gate is an annular opening through which plastics enter the cavity of an injection or transfer mold.

(civil engineering) A type of gate used to regulate and control the discharge of a morning-glory spillway; like a drum gate, it offers a minimum of interference to the passage of ice or drift over the gate and requires no external power for operation.