Abstract: A vapor fuel recovery system for fuel tanks is provided. The vapor recovery system comprises: a canister that captures vapor fuel expelled from the fuel tank; a vent valve that controls ventilation of vapor fuel from the fuel tank to the canister; and a vent bypass disposed between the canister and the vent valve that controls the flow of vapor fuel from the fuel tank to the on-board recovery canister when a fuel level in the fuel tank is full. The bypass includes a bypass valve and at least one orifice.

Abstract: A flow-restricting plug is provided for installation within a vapor recirculation pipe that communicates with a fuel filler pipe. The plug is manufactured of fuel-impervious material and has a cylindrical shape adapted to be mounted by press fit within the vapor recirculation pipe. A flow passage of tortuous shape is formed along the outer circumferential surface of the plug between the opposed ends thereof. The tortuous shape of the flow passage permits the flow of fuel vapor through the plug but prevents the flow of liquid fuel through the plug.

Abstract: A vapor fuel recovery system for fuel tanks is provided. The vapor recovery system comprises: a canister that captures vapor fuel expelled from the fuel tank; a vent valve that controls ventilation of vapor fuel from the fuel tank to the canister; and a vent bypass disposed between the canister and the vent valve that controls the flow of vapor fuel from the fuel tank to the on-board recovery canister when a fuel level in the fuel tank is full. The bypass includes a bypass valve and at least one orifice.

Abstract: A flow-restricting plug is provided for installation within a vapor recirculation pipe that communicates with a fuel filler pipe. The plug is manufactured of fuel-impervious material and has a cylindrical shape adapted to be mounted by press fit within the vapor recirculation pipe. A flow passage of tortuous shape is formed along the outer circumferential surface of the plug between the opposed ends thereof. The tortuous shape of the flow passage permits the flow of fuel vapor through the plug but prevents the flow of liquid fuel through the plug.

Abstract: An evaporative emission control system of an internal combustion engine's fuel system including a vent valve. The vent valve provides a mechanism for closing the evaporative emission control system creating a pressure differential between system and atmospheric under various conditions whereby the system can be automatically diagnosed. The vent valve relieves pressure or vacuum in the system that exceeds a threshold necessary to detect the presence of leaks. The vent valve includes a vacuum actuator providing a low restriction flow path for system purges.

Abstract: An emission system especially for controlling evaporative emissions from the fuel system of a two cycle engine having a split exhaust wherein a combustor is provided to burn fuel vapor mixed with scavenging air exhausted from the engine and the combustor exhaust may be mixed with the engine blowdown gas for further treatment in a catalytic device or other treatment means. Additional control features are disclosed.

Abstract: Warmed returned fuel from a vehicle fuel injection system is returned only a segregating canister in the tank, and pumped back therefrom preferentially, with make up fuel allowed in only as needed. Overall heating of the stored fuel, and consequent running losses, are substantially reduced, with no ill effects on vehicle operation.

Abstract: A combined filler neck and vapor vent line valve is provided by inner and outer pipes that are maintained in concentric relation by a sleeve tightly inserted between the outer pipe and an out-turned flange at the end of the inner pipe. This provides a convenient path out of the fuel tank for displaced tank vapors. Vapor control is provided by a stepped cylindrical valve body that rides up and down within the upper end of the inner pipe and the sleeve so that a seal on the outside of the valve body can cover and uncover openings in the flange to block and un-block a vapor path to the canister.

Abstract: Both puff losses and fuel fill vapor losses are recovered by a venting arrangement that includes a vapor storage canister connected fitting opening through the upper end of a filler pipe valve, a valve downstream from the fitting, and a seal upstream from the fitting. A cap extension holds the valve closed, and also wipingly engages the seal. When the cap is removed, the valve is opened, but the seal stays engaged until the cap is fully removed and the extension fully withdrawn, so that puff loss vapors are directed out through the fitting to the storage canister. When the fuel nozzle is inserted, it wipingly engages the same seal, so that fuel fill vapors are similarly recovered.

Abstract: A vapor venting means for a vehicle fuel system in which one ball valve serves both the close off function between fuel fills, and the automatic shut off function during fuel fill, but does not depend upon falling under its own weight in order to open the vapor vent path to the canister. The ball valve is indirectly loaded against a lower valve seat, which is spaced from an upper spring seat, through the use of a spring loaded carrier that normally traps the ball valve against the lower seat. Then, when the nozzle is inserted, the carrier is pushed up so that the ball valve is freed without having to fall under its own weight. Since the ball valve is not confined or limited, it can also float up against the upper spring seat in the event of fuel overfill.

Abstract: A fuel tank filler neck has a partition providing a vent orifice for vapor flow from a fuel introduction tube to a vapor discharge fitting. A ball valve guided beneath the orifice is adapted to float into engagement across the orifice to prevent liquid fuel from passing through said orifice. A filler neck restrictor plate is carried on an actuating arm that has a cam surface engaging the ball valve. The cam surface engages the ball valve across the orifice to inhibit flow of fuel vapor through the orifice when the restrictor plate inhibits introduction of fuel through the filler neck, and permits the ball valve to drop away from the orifice to permit flow of fuel vapor through said orifice when the restrictor plate permits introduction of fuel through the filler neck.

Abstract: A fuel tank has a filler neck terminating in an upwardly opening well, and a paddle overlying the well has a pivoted arm extending adjacent a vent valve. The arm causes the valve to restrict flow through a vent orifice when fuel is not being introduced through the filler neck, but pivots to allow the valve to open the orifice in response to introduction of liquid fuel through the filler neck. A float has an actuating member adapted to cause the valve to restrict flow through the orifice when the level of liquid fuel in the tank approaches the maximum level desired.

Abstract: A fuel fill tube for a vehicle fuel tank has a canister vapor vent, a shut-off valve and an overfill protection valve. The overfill valve prevents liquid from communicating with the carbon canister during overfill and communicates the liquid to the atmospheric open end of the fill tube.