Abstract: An apparatus and method provide automatic regulation of flow of fluid from a source where it is stored as liquified gas. The apparatus includes a flow control valve connected in a conduit connecting the source in flow communication to a vaporizer. The apparatus also includes a valve controller operable to regulate the flow of fluid in liquid phase at least partially through the valve. The controller derives the energy to operate the valve and the controller from the fluid when the fluid is in its gas phase. The vaporizer can be used to warm the fluid passing therethrough.