Vapor recovery system and method with leakage and air flow sensing

摘要

A system and method for recovering a gasoline vapor/air mixture from a vehicle tank during the dispensing of a gasoline from a storage tank into the vehicle tank, according to which a flow line is established for the flow of the mixture from the vehicle tank to the storage tank during the dispensing. A pump is activated during the dispensing to flow the mixture from the vehicle tank to the storage tank, and the mixture flow is terminated in response to the termination of the dispensing. The pump is then activated to pressurize the flow line after which any reduction in the pressure of the mixture in the flow line is sensed. According to another embodiment, the mixture flow is terminated in response to termination of the dispensing and ambient air is introduced into the flow line. The pump is activated to pump the ambient air at a desired flow rate, and the flow rate of the air through the flow line is sensed. This latter flow rate can be compared to known pump performance data to determine the performance of the pump.