Method for adjusting air to liquid ratio in vapor recovery system

A vapor recovery system that recovers vapors expelled from a vehicle during refueling at a fuel dispensing point and returns the vapors to an underground storage tank in a service station environment, comprising:

• an air to liquid regulator valve associated with the fuel dispensing point, comprising:
• a housing defining vapor return path;
• a vapor return orifice defined by the housing and disposed between a first portion and a second portion of the vapor return path so that vapor flow occurs through the vapor return orifice whenever fuel is dispensed through the fuel supply passage;
• a vapor piston including a metering element, the metering element being insertable into the vapor return orifice to regulate the flow of vapors therethrough, and the metering element being configured to prevent the flow of vapors through the vapor return orifice when the metering element is fully seated in the vapor return orifice;
• and
• a vapor flow bypass in fluid communication with the first portion and the second portion of the vapor return path such that the flow of vapors through both the vapor flow bypass and the vapor return orifice is possible,
• a vapor pump that is in fluid communication with the underground storage tank;
• and
• a vapor flow passage that is in fluid communication with the vapor flow path of the air to liquid regulator valve and the vapor pump.

An air to liquid regulator valve for use with a vapor recovery system that recovers vapors expelled from a vehicle receiving fuel through a fuel supply passage and returns the vapors to an underground storage tank through a vapor return passage in a service station environment, comprising:

• a housing defining a fuel flow path in fluid communication with the fuel supply passage and a vapor return path in fluid communication with the vapor return passage;
• a vapor return orifice defined by the housing and disposed between a first portion and a second portion of the vapor return path;
• a vapor piston including a metering element, wherein the metering element is insertable into the vapor return orifice to regulate the flow of vapors therethrough, and the metering element is configured to prevent the flow of vapors through the vapor return orifice when the metering element is fully seated in the vapor return orifice;
• a vapor flow bypass in fluid communication with the first portion and the second portion of the vapor return path such that the flow of vapors through the vapor flow bypass is possible when the metering element prevents the flow of vapors through the vapor return orifice;
• and
• a first flow adjustment mechanism that selectively adjusts the vapor flow bypass such that an amount of vapor that is allowed to bypass the vapor return orifice during a fueling operation is adjustable.