An improper fuel nozzle insertion-inhibiting assembly may include a cover having a nozzle inlet barrier door pivotally secured to the cover. The cover may include a safety-release groove that is configured to separate the cover into separate pieces upon exertion of sufficient force. A main body is secured to the cover and configured to connect to a fuel fill pipe. The main body may include a nozzle outlet barrier door pivotally secured to the main body. A debris filter may be secured to one or both of the cover and/or the main body. The debris filter is configured to prevent debris from passing into an internal chamber. A pivot-restricting member(s) may be secured within the internal chamber. The pivot-restricting member(s) is configured to prevent one or both of the nozzle inlet barrier door and the nozzle outlet barrier door from over-pivoting. At least one seal member may be configured to sealingly engage at least portions of the fuel fill pipe, the cover, and the main body.

Concepts and technologies disclosed herein for relief valves (relief valves). A relief valve can include a flow path, a primary valve poppet that is urged or biased into a closed position by a tensioned spring, and a pilot valve in communication with a valve compartment of the relief valve. When an exterior space pressure overcomes the tensioned spring, the primary valve poppet can be overcome and pressure between an interior space and the exterior space can equalize, at least partially. When the pressure within the interior space increases beyond a defined threshold, which can be defined by a spring of the pilot valve, the pilot valve can open, the valve compartment can vent, and the tensioned spring again can be overcome and can open to allow at least partial equalization of pressures within the interior space and the exterior space.

Methods and systems are provided for detecting and mitigating the presence of liquid fuel carryover in an evaporative emissions control system of a vehicle in response to a refueling event. In one example, an electric motor is operated to spin a vehicle engine unfueled in reverse in order to pressurize the evaporative emissions system and the fuel system responsive to an indication of liquid fuel in the vapor recovery lines. In this way, indication of liquid fuel carryover following a refueling event may be quickly diagnosed, and mitigating actions may be taken to ensure liquid fuel is returned to the tank prior to contacting the adsorbent material within the vapor canister.

A fuel drip retention system includes a computer programmed to actuate one of a pump or a starter motor to generate a vacuum in an evaporation line between a fuel nozzle receiving port and a vapor canister. The vacuum is generated upon determining that fuel has stopped flowing into a fuel tank.

A valve, a multi-functional combination valve and a CFLVV valve simultaneously achieve the functions of a refueling limit valve and a rolling-over valve in a fuel tank. The valve body includes a valve core accommodating cavity, and first and second inflow passages, a first discharge port, and a second discharge port communicating therewith are provided. The valve core accommodating cavity includes two independent vertical-sliding first valve core assemblies and second valve core assemblies for opening or closing the first discharge port and the second discharge port. The pressure maintaining part is connected to the second discharge port and contains a certain opening pressure. After the first valve core assembly closes the first discharge port, and a certain pressure value has to be reached in the valve core accommodating cavity, the pressure maintaining part will open the second discharge port, and the fluid will flow out of the second discharge port.

A positive crankcase ventilation gas diversion system comprises a positive crankcase ventilation gas diversion line to divert oil laden positive crankcase ventilation gases from the air intake manifold of an internal combustion engine. A positive crankcase ventilation gas diversion interconnect directs oil laden positive crankcase ventilation gases into an oil-vapor diffuser which at least partially separates crankcase oils from the oil laden positive crankcase ventilation gases. A pressure sensor measures a vapor pressure in a headspace of a fuel tank, and a fuel tank vent valve is operative with a fuel tank vent line. A controller actuates the fuel tank vent valve into an open position and discharges fuel enriched vapor to the air intake manifold of the internal combustion engine, thereby maintaining the vapor pressure in the headspace of the fuel tank within a predetermined pressure range.

Provided is a saddle type fuel tank in which liquid fuel does not reach a canister through an exhaust passage immediately after full-tank refueling. The saddle type fuel tank includes a saddle type tank body and a full-tank regulating valve. The full-tank regulating valve includes a valve body, a float valve, a first hanging pipe communicatively connected to the valve body and having a first opening at a hanging end thereof, and a second hanging pipe communicatively connected to the valve body and having a second opening at a hanging end thereof. The first opening of the first hanging pipe is located at a height corresponding to a full-tank liquid level RA1_full in the first chamber. The second opening of the second hanging pipe is located at a height lower than that corresponding to a full-tank liquid level RA2_full in the second chamber.

A method for controlling a pressure inside a fuel tank system an board a vehicle is provided. The fuel task system comprises a feel tank and a venting circuit having at least one controllable pressure relief valve. The vehicle comprises a source of energy adapted to activate the pressure relief valve so as to move it from a closed position to a pressure relief position. The method composes detecting a key off event indicative of the vehicle shut-down; determining an amount of energy available at the source of energy; starting at least one pressure relief operation comprising: verifying whether the amount of energy available is lower than a first predetermined threshold amount, and if the verifying is positive, activating the pressure relief valve. The method further composes terminating the pressure relief operation.

A pressure reducing valve device includes a first body; a second body; a valve mechanism accommodated in the first body, and including a valve seat and a valve element; and a piston that is accommodated in the second body, defines a pressure reducing chamber, and is configured to move in accordance with a pressure in the pressure reducing chamber so as to move the valve element. The first body is connected to an inner portion of a connection portion having a bottomed cylindrical shape. The connection portion is provided in the second bods to protrude outward. The valve seat is held between the first body and the second body in a direction in which the first body and the second body are attached to each other such that the valve seat is fixed in a flow passage.

A venting apparatus is provided for regulating discharge of fuel vapor from a fuel tank and admission of outside air into the fuel tank.