TWO-STAGE FUEL TANK VAPOR RECOVERY VENT VALVE AND METHOD OF MAKING SAME

摘要

A two-stage venting on-board refueling vapor recovery (ORVR) valve for controlling fuel tank venting to a storage canister during tank filling. A float actuated poppet has a small second stage venting hole therethrough. The poppet is mounted for relative movement with respect to a second stage vent valve member disposed on the float. During tank filling, venting is through a first stage relatively large flow area passage until rising fuel level causes the poppet to close the first stage vent flow area. Venting during continued filling is through the second stage venting hole in the poppet. After first stage valve closure relative movement or lost motion occurs between the first and second stage valve members. The poppet has an integrally molded annular resiliently flexible seal thereon which has a first stage annular sealing surface formed on one side of the poppet for sealing the first stage flow area, and a second stage annular sealing surface about the poppet hole on the opposite side of the poppet for sealing the second stage vent flow area and closing the vent passage.