Method for fuel vapor pressure management

Abstract

A method of managing fuel vapor pressure in a fuel system. The method includes locating between first and second ports a poppet and a seal cooperating with the poppet, positioning the seal in a substantially symmetrically deformed configuration so as to sense a negative pressure at a first pressure level, positioning the seal in a generally asymmetrically deformed configuration so as to vent negative pressure below the first pressure level, and positioning the seal in an undeformed configuration so as to vent positive pressure above a second pressure level. The poppet is movable along an axis. And the seal is flexible between the undeformed configuration when disengaged from the poppet, the substantially symmetrically deformed configuration when engaged with the poppet, and the generally asymmetrically deformed configuration when engaged with the poppet.

Dependencies are inferred from the claim text.