A valve assembly for a pressurized container includes a valve stem and a mechanical seal. The valve stem has an open top portion, a closed bottom portion, at least one primary radial opening, at least one secondary radial opening and a valve stem passageway between the open top portion and both the at least one primary radial opening and the at least one secondary radial opening. The mechanical seal comprises a longitudinal passageway that seals the at least one primary radial opening and the at least one secondary radial opening, respectively, when the valve stem is in a closed position. Longitudinal translation of the valve stem exposes the at least one primary radial opening or both the at least one primary radial opening and the at least one secondary radial opening to the pressurized container when the valve stem is in an open position.