Failed nozzle relief for a mechanically sealed refueling nozzle in a filler tube

摘要

A fuel tank filler tube has a seal disposed therein for sealing about a refueling nozzle upon insertion in the tube. When the tank is filled and fuel backs up in the filler tube, in the event of failure of the automatic nozzle shutoff, an annular pressure relief valve surrounding the seal opens and provides for by-pass flow around the seal to the upper end of the filler tube. The annular valve includes a rigid ring member with an annular flexible seal attached and is spring biased to the normally closed position.