A diesel exhaust fluid (DEF) cap assembly for a vehicle includes: a body having a first opening and a second opening arranged at an opposite side of the first opening, the second opening configured to be opened and closed; a flange portion protruding radially outward between the first opening and the second opening of the body, and having a plurality of through holes and a flange gasket configured to be sealably coupled to a mounting subject on which the flange portion is mounted; and a membrane member coupled to the flange portion, and configured to cover the plurality through holes and allow air flow.

A fuel filler structure includes a vehicle body panel, a filler housing, a filler tube cap and a tether. The vehicle body panel defines a fuel filler opening. The filler housing has an outboard side and an inboard side. The outboard side is installed to the vehicle body panel at least partially surrounding the fuel filler opening and is dimensioned to receive and surround a portion of a fuel filler tube. The filler tube cap is configured to removably attach to the fuel filler tube at least partially within the filler housing. The tether is attached at a first end to the filler tube cap and is attached at a second end to the filler housing for pivoting movement about a vertical axis.

Some embodiments are directed to a cover assembly for a fuel filler pipe that is disposed adjacent vehicle suspension components. The cover assembly can include a first cover portion that includes a first extension that extends in a first direction and a second extension that extends in a second direction that intersects the first extension at an angle, the first cover portion forming a channel defined by a first cover portion wall that is configured to wrap around a portion of an outer perimeter of the fuel filler pipe so as to leave a section of the outer perimeter of the fuel filler pipe exposed so as to permit movement of the exposed outer perimeter section, the first cover portion being configured to extend more than half a length of the fuel filler pipe.

A closure system for a pressurized container system for a motor vehicle includes a fuel filler flap and at least one refueling connection. The refueling connection has a non-return valve and a protective cap. The protective cap is designed to be pluggable onto an end of the refueling connection. The fuel filler flap covers a refueling compartment which is set back from the vehicle body. On the side facing the refueling compartment, the fuel filler flap has such a contour that the fuel filler flap can be closed only if the protective cap is fitted on the refueling connection.

A saddle riding vehicle includes: a fuel tank supported by a body frame; a filler opening provided in an upper surface of the fuel tank; a tank cover covering the upper surface of the fuel tank; and a fuel sump collecting fuel overflowing from the filler opening. The saddle riding vehicle includes a shroud covering a side surface of the fuel tank. The fuel sump is placed around the filler opening and under the tank cover. The fuel sump includes a drain pipe discharging fuel downward. The drain pipe extends between the tank cover and the shroud.

Methods and systems are provided for an adapter for a fluid refilling system. In one example, an adapter configured for use with a diesel exhaust fluid (DEF) system may include a first end configured to couple with a DEF refill passage, a second end including an aperture shaped to receive a DEF nozzle, a pivotable door closing the aperture and biased against the aperture by a biasing member, and a magnetic ring positioned within the adapter and downstream of the pivotable door. The pivotable door may be formed of a material permeable to DEF vapors and may include a plurality of vent holes configured to flow vapors from the DEF system to atmosphere.

A pressure relief cap includes a body engageable with a container and rotatable about an axis for coupling or decoupling the body from the container. The pressure relief cap also includes a handle and a motion control mechanism operable to selectively couple the handle to the body. The motion control mechanism includes a clutch plate moveable between an engaged position in which the clutch plate permits torque transfer from the handle to the body, and a disengaged position in which the clutch plate inhibits torque transfer from the handle to the body. The pressure relief cap also includes a relief valve for releasing pressure in response to elevated pressure within the container.

A fuel tank for a work vehicle is disclosed. The fuel tank includes a tank body, an oil filling cylindrical portion protruding from the tank body, and an oil filler cap detachably attached to the oil filling cylindrical portion for opening/closing an oil filling opening of the oil filling cylindrical portion, A cap body of the oil filler cap has a tubular portion to be detachably fitted on the oil filling cylindrical portion and a lid portion formed at an upper end portion of the tubular portion for opening/closing the oil filling opening. A skirt portion extends from the cap body to opposite side to the lid portion relative to the tubular portion, a diameter of an extending end portion of the skirt portion being larger than a diameter of the tubular portion of the cap body.

A fuel tank for a work vehicle is disclosed. The fuel tank includes a tank body, an oil filling cylindrical portion protruding from the tank body, and an oil filler cap detachably attached to the oil filling cylindrical portion for opening/closing an oil filling opening of the oil filling cylindrical portion, A cap body of the oil filler cap has a tubular portion to be detachably fitted on the oil filling cylindrical portion and a lid portion formed at an upper end portion of the tubular portion for opening/closing the oil filling opening. A skirt portion extends from the cap body to opposite side to the lid portion relative to the tubular portion, a diameter of an extending end portion of the skirt portion being larger than a diameter of the tubular portion of the cap body.

A saddle riding vehicle includes: a fuel tank supported by a body frame; a filler opening provided in an upper surface of the fuel tank; a tank cover covering the upper surface of the fuel tank; and a fuel sump collecting fuel overflowing from the filler opening. The saddle riding vehicle includes a shroud covering a side surface of the fuel tank. The fuel sump is placed around the filler opening and under the tank cover. The fuel sump includes a drain pipe discharging fuel downward. The drain pipe extends between the tank cover and the shroud.