A valve member is provided to a vent pipe for communicating a fuel tank with a canister. A solenoid valve is provided to a canister side bypass passage between a back pressure chamber of the valve member and the canister side vent pipe. An extending member is provided to restrict the valve lift amount in accordance with the internal pressure of the fuel tank.

A method for suctioning liquid fuel from a liquid trap in a fuel tank of a motor vehicle, includes generating a negative pressure in a gas compartment or headspace of the fuel tank, applying the negative pressure to the liquid trap through a suction line, wherein the liquid trap has a collection container collecting liquid fuel during venting of the fuel tank, and at least partially suctioning the liquid fuel located in the collection container through the suction line into the gas compartment or headspace.

A method for suctioning liquid fuel from a liquid trap in a fuel tank of a motor vehicle, includes generating a negative pressure in a gas compartment or headspace of the fuel tank, applying the negative pressure to the liquid trap through a suction line, wherein the liquid trap has a collection container collecting liquid fuel during venting of the fuel tank, and at least partially suctioning the liquid fuel located in the collection container through the suction line into the gas compartment or headspace.

A method is provided for detecting a leakage in a fuel supply system of an internal combustion engine. The fuel supply system includes a fuel line system with fuel line sections and a pressure monitoring system with monitoring segments, a set of valves, and a pressure sensor. The method includes detecting a leakage between the fuel line sections and the pressure monitoring system when the set of valves are opened to fluidly connect the monitoring segments. The method also includes performing at least two pressure measurements for at least two selected sets of neighboring monitoring segments for providing pressure behavior information for the selected sets of neighboring monitoring segments. The method further includes comparing the pressure behavior information of the selected sets of neighboring monitoring segments, and identifying a leaking monitoring segment based on the comparison.

Methods are provided for reliving excess vacuum from a fuel tank. In response to elevated fuel tank vacuum levels, a canister purge valve is opened to dissipate the vacuum to an engine intake manifold while the engine is not combusting. Alternatively, the purge valve is opened to dissipate the excess vacuum to the intake manifold while the engine is combusting during conditions when the likelihood of air-fuel ratio errors are lower or when any incurred errors are better tolerated.

An engine-driven generator that controls fuel vapor flow is provided. The engine-driven generator includes an engine having an air intake, wherein the engine is configured to drive a generator. The engine-driven generator also includes a fuel tank coupled to the engine and configured to provide fuel to the engine. The engine-driven generator includes a valve coupled between the air intake of the engine and the fuel tank. The engine-driven generator also includes a control device configured to transition the valve between a first position and a second position. The first position allows fuel vapor to flow between the fuel tank and the air intake of the engine and the second position inhibits the fuel vapor from flowing between the fuel tank and the air intake of the engine.

An active purge pump system module is provided for an evaporative emission control (EVAP) system for a vehicle. The EVAP system includes a fuel tank, a vapor collection canister in communication with the fuel tank, an air intake, and a purge valve connected between the canister and the air intake. The active purge pump system module includes a pump in fluid communication with the canister to move air independently of operation of the engine. A bypass valve assembly communicates with an upstream side and a downstream side of the pump to bypass the pump. In a closed position of the bypass valve assembly, the pump, when activated, moves purge vapor from the canister, through the purge valve, and to the engine to be consumed during combustion, and when the bypass valve assembly is opened and the pump is deactivated, vehicle refueling is permitted.

A fuel supply device includes a return fuel utilization buffer jar that conducts fuel into a fuel inlet port of a first three-way valve including a one-way check valve to allow the fuel to flow, uni-directionally, from the fuel inlet port to a fuel outlet port. Return fuel from an engine is conducted in through a return fuel inlet port of the return fuel utilization buffer jar. Fuel vapor in the return fuel utilization buffer jar is guided from a gas inlet port of a second three-way valve through a gas outlet port to a fuel tank. Vapor pressure in the return fuel utilization buffer jar is regulated by a ventilation port that is mounted in the second three-way valve and includes a one-way check valve in a direction toward the gas inlet port.

In a VST (vapor separator tank), a lower case is provided with a plurality of attachment portions attached to an engine (internal combustion engine) and drain piping for discharging liquid fuel from a fuel storage compartment. The lower case includes a first bottom surface portion including a lowermost surface, a second bottom surface portion formed in a position higher than the first bottom surface portion and supporting a pump, and a third bottom surface portion formed in a position higher than the first bottom surface portion and the second bottom surface portion. Disclosed embodiments provide a vapor separator tank in which the capacity of a fuel storage compartment is sufficiently secured, and which allows easy arrangement of other equipment and parts around the vapor separator tank while enabling easy design change.

A VST (vapor separator tank) includes a casing including a lower case and an upper case joined to each other and having a fuel storage compartment formed therein to store liquid fuel, a pump arranged in the casing and pumping the liquid fuel stored in the fuel storage compartment, and a regulator (pressure regulator) sandwiched by the lower case and the upper case inside an accommodation space formed in the casing, and adjusting a discharge pressure of the pump to be constant. The casing includes a regulator support portion abutting on and supporting the regulator. Disclosed embodiments provide a vapor separator tank capable of holding a pressure regulator with a simpler structure and suppressing an increase in the number of parts, man-hours for assembly, and manufacturing costs.