Methods and systems are provided for depressurizing a fuel tank prior to refueling the fuel tank. One example method includes adjusting a latchable refueling valve to a latched open position to enable vapor flow from the fuel tank to a vapor canister at a first rate, and responsive to fuel tank pressure being higher than a first pressure threshold after a pre-determined duration at the latched open position, modifying the latchable refueling valve to an unlatched open position. The unlatched open position of the latchable refueling valve enables a second flow rate for fuel vapors, the second flow rate higher than the first flow rate at the latched open position.

A method for controlling a filling operation of a vehicular liquid storage system including a tank including a fill level limiting valve. The method includes: detecting start of a first filling event; measuring a first fill level of the tank; verifying whether the measured first fill level has reached a predetermined fill level; if the verifying is positive, starting a first timer for a first amount of time; upon expiry of the first timer, closing the fill level limiting valve.

A fuel tank system 12 includes: a communicating pipe 30 that has plural open portions 54A and 54B positioned higher than a full level inside a fuel tank 14 and communicates the inside of the fuel tank 14 with a canister 32; and a valve member 42 that is disposed outside the fuel tank 14 and, on the basis of a state of inclination of fuel detected by a fuel inclination sensor 60, closes the communicating pipe corresponding to an open portion predicted to be positioned in the fuel and opens the communicating pipe corresponding to an open portion predicted to be positioned in a gas layer section.

A fuel vapor processing apparatus includes a vapor path connecting an adsorbent canister to a tank, where a valve is disposed in the vapor path and comprises a body and a seat, and a control unit configured to detect a movement distance of the body from the seat as a valve movement distance at a valve opening start position. This position results when a change in inner pressure of the tank after starting movement of the body toward a valve opening direction becomes greater in magnitude than a predetermined amount, wherein the control unit stores the valve movement distance in the valve opening direction as a learning value, and also stores one of two predetermined restriction values as the learning value instead of the valve movement distance when the valve movement distance is not within a range between a previously stored learning value and one of the restriction values.

A vent valve includes a vent body including an outlet and at least one inlet, a main chamber, a main closable device movable from an open position to allow fluidic communication between the main chamber and the outlet, to a closed position to block fluidic communication between the main chamber and the outlet, and a first tubing having a first end and a second end, the first end connected to a first inlet, the second end spaced from the vent body, the first tubing further including a first closable device adjacent the second end. The first closable device allows fluidic communication between an exterior of the first tubing and an interior of the first tubing in a first orientation of the vent valve, and blocks fluidic communication between the exterior of the first tubing and the interior of the first tubing in a second orientation of the vent valve.

A vapor purge system having a tank isolation valve and a canister vent valve, where each valve includes a latching mechanism for maintaining the valves in an open position. A diagnostic test is performed on the purge system to prove that each of the valves are functioning correctly. Using latching valves in these applications reduces electricity draw from the battery and reduces electrical interference with integrated pressure sensors. The fuel tank is sealed by the tank isolation valve between the fuel tank and a vapor storage canister, and the canister vent valve provides sealing between the canister and the atmosphere, and controls venting of the canister. The tank isolation valve reduces power consumption from the battery, while the valve is being held in either an open position or a closed position by the latching mechanism, and uses only a single pulse of voltage to change the state of the valve.

Methods and systems are provided for a fuel system. In one example, a fuel system includes a plurality of canisters with a fuel tank isolation valve (FTIV) configured to control a fluid coupling between each of the plurality of canisters and a fuel tank. The FTIV is actuated based on one or more of a fuel tank pressure and a load of each of the plurality of canisters.

A fuel system comprising a fuel tank, a mixing volume configured to mix fuel vapor and air, the mixing volume comprising an outlet configured to be fluidly coupled to an engine, and a fuel vapor line configured to fluidly couple the fuel tank to the mixing volume.

A fuel-tank control valve includes: casing; main float; plate with upper surface that constitutes bottom portion of casing, and that includes first gas-storage chamber formed of plate and peripheral wall portion that is provided upright from rim of upper surface to lower side; sub float arranged above the plate; second gas-storage chamber formed of a part including gas supply hole of first gas-storage chamber among parts of upper surface, and partition-wall portion which is away from peripheral wall portion, and that is provided in first gas-storage chamber; and clearance which is formed between casing and peripheral wall portion, and through which fuel in fuel tank can flow in, second gas-storage chamber and clearance being provided for sub float. Upper surface includes protruding seating portion that forms inflow space through which gas through gas supply hole can flow in under state in which sub float is seated on protruding seating portion.

When a driver manipulates a fuel filler lid switch, a tank shutoff valve is opened. Then, time t is calculated, and then, remaining time, obtained by subtracting elapsed time from the time t, is presented on a display device. If the fuel filler lid switch is manipulated again, the tank shutoff valve is closed to seal a fuel tank, and a message to the effect that opening action of the fuel filler lid is cancelled is presented on the display device. If the time t has elapsed without the fuel filler lid switch being manipulated again, the fuel filler lid is opened, determining that internal pressure in the fuel tank has decreased to a level predetermined to ensure that the fuel tank can be filled safely without fuel or fuel evaporative gas spouting from the fuel tank.