Automatic pressure correcting vapor collection system

Abstract

A Stage II Vapor Recovery System that provides for efficient fuel vapor collection while automatically correcting for pressure differentials between the Ambient Atmospheric Pressure and the pressure in the fueling facility's Fuel Storage Tanks (FSTs). The FSTs may be either Underground Storage Tanks (USTs) or Above Ground Storage Tanks (ASTs). The system has advantages over current Stage II systems by providing only the pressure necessary to return vapors to the FSTs without under- or over-pressurizing the FSTs, with the appropriate values of returned volume of vapor to provide Vapor to Liquid Ratios (V/Ls) that ensure efficient vapor collection. It eliminates the anticipated problems associated with earlier Stage II Vapor Recovery systems which work well with current automobile fueling systems, but have unique problems when used with the mandated Onboard Refueling Vapor Recovery (ORVR) systems.

Dependencies are inferred from the claim text.