System and method for preventing the release of vapor into the atmosphere

摘要

A vane pump is provided which can be used for the pumping of gasoline vapor, particularly in a sealed environment. The vane pump has an inlet, an outlet and a safety valve that recirculates vapor from the outlet to the inlet when a blockage occurs upstream or downstream of the pump. The invention further provides a system and method, incorporating the pump, for recovering gasoline vapor proximal to a nozzle dispensing liquid gasoline.