Abstract: A method and apparatus for remotely opening a manual valve of a gas cylinder from a remote location. The gas cylinder is first connected to a purge system which is purged of oxygen and pressurized with an inert gas to a pressure near that of the gas cylinder. The manual valve is then engaged with a pneumatic stepper mechanism. Pneumatic fluid is supplied to the pneumatic stepper mechanism to rotate the manual valve a predetermined stepped increment. The step of supplying pneumatic fluid to the pneumatic stepper mechanism is repeated, after pausing to let the system settle, to rotate the manual valve another stepped increment. The steps of rotating and pausing are repeated until the manual valve is opened. The purge system is then vented to atmosphere through a diffuser. Both the pneumatic stepper mechanism and the purge system are fully operable from the remote location. The pneumatic stepper mechanism includes a ratchet assembly and an attachment assembly connecting the ratchet assembly to the manual valve.