A two stage float actuated shutoff valve for use in underground fuel storage tanks having a co-axial vapor recovery system utilizes a drop tube co-axially mounted within the storage tank fill pipe. Fuel flowing into the tank is passed through the drop tube which projects downwardly into the interior of the tank to a valve housing located at the lower end of the drop tube. Tubular floats slidably mounted on the drop tube within the tank independently operate pivoted flapper valves to a closed position within the valve housing, a lower float closing one valve flapper to block a major portion of the incoming fuel flow passage when the level of fuel in the storage tank reaches a predetermined first level and a second upper float closing a second flapper to completely close the flow passage when the level of fuel rises to a predetermined level about the first level. A float actuated locking arrangement for preventing inadvertent premature closing of either valve flapper is disclosed.