Abstract: A valve for controlling the flow of gases from high pressure cylinders is provided having a projected raised annular valve seat surrounding a gas passage, a stem in threaded relation to the valve body whereby rotation of the valve stem in the valve body moves the valve stem toward and away from the valve seat, a circumferential shroud extending from the end of the valve stem and surrounding the valve seat when the valve is closed and partially open, a resilient seal member positioned within the recess on the end of the valve stem formed by the shroud, said resilient seat member having a tapered projection which extends into the gas inlet passage when the valve is in closed position and provides a gas tight seal between the valve stem and the valve seat.