A discharge assembly apparatus for discharging a metered volume of a liquid when used in combination with a liquid-containing, pressurized or pressurizable container includes an actuator assembly incorporating a valve stem having a discharge conduit arrangement with an inlet and an outlet, a metering chamber formed within the valve stem and incorporating a liquid discharge element, an inlet/outlet arrangement, and a housing wherein the valve stem and the inner surface of the housing define a fluid transfer passageway therebetween, the discharge conduit arrangement of the valve stem providing communication between the outlet of the metering chamber and the outlet of the valve stem via the fluid transfer passageway.