Redundant seal for tank filler neck closure

摘要

A redundant seal for a vehicle fuel tank filler neck closure is provided for closing and opening an automobile fuel tank to the atmosphere. The redundant seal (48) includes a lower shoulder (51) which sealably engages a first valve seat and an upper shoulder (53) which sealably engages a second valve seat. The redundant seal (48) is appropriate for use in applications such as filler neck closures, pressure and vacuum-relief systems within tank filler neck closures, and capless filler neck closure systems.