Storage tank flow control valve assembly

A passive flow control valve assembly for controlling the flow of fuel through the fill pipe of an underground fuel storage system is disclosed comprising a valve housing mounted to the discharge end of the fill pipe, a valve assembly for controlling flow through the housing which is mounted for movement between a first open position permitting substantially unrestricted flow through the housing and at least a second position substantially restricting the flow through the housing, an actuator arm assembly for moving the valve between the first and second positions with the actuator arm being interconnected to the valve so as to progressively correspondingly move the valve from the first open position to the second closed position as the actuator arm moves from a first position to a second position, and a float assembly connected to the actuator arm for moving the arm responsive to the liquid level in the storage tank.