The Beswick flow control valve provides control of small bore air cylinders with hysteresis-free control down to bubble-tight shut off. The size of the radial inlet orifice is selected to be compatible with the approximate maximum flow needed in the application. An O-ring is fitted into an eccentric cavity in the same plane as the radial inlet orifice. This O-ring is pressed against the radial inlet orifice when the valve is closed and becomes free of the hole as the sleeve rotates. The sleeve rotates 360 degrees and is restricted from sliding axially. The selected seals fit to make the valve insensitive to vibration preventing inadvertent changes to the setting. The flow control valve is rated to 200 psi maximum pressure and has a poppet check valve to permit free return flow.