System and method for fuel tank tube routing and valve placement to prevent fuel leaks into evaporative emissions system

A fuel tank venting system comprising:

• a fuel tank having an upper wall extending generally in a horizontal direction when viewed from a side elevation view, wherein, when viewed from a plan view, the fuel tank defines a first end region, a central region, a second end region, a first side, a second side, and a longitudinal axis extending from the first end region to the second end region;
• a first outlet valve disposed in the upper wall of the fuel tank in the first end region of the fuel tank, wherein the first outlet valve is disposed on a side of the longitudinal axis closer to the first side than the second side;
• a second outlet valve disposed in the upper wall of the fuel tank in the second end region of the fuel tank, wherein the second outlet valve is disposed on the side of the longitudinal axis closer to the second side than the first side;
• a first outlet tube connected to the first outlet valve,
• wherein the first outlet tube is mounted to the upper wall of the fuel tank and extends generally in a horizontal direction along the upper wall of the fuel tank from the first end region to a second end region location that is past the second outlet valve in the second end region,
• wherein the first outlet tube extends from the first outlet valve toward the first side of the fuel tank, extends parallel and proximate to the first side, and after passing the second outlet valve, extends toward a corner of the fuel tank in the second end region at the second side;
• and
• a second outlet tube connected to the second outlet valve,
• wherein the second outlet tube is mounted to the upper wall of the fuel tank and extends generally in a horizontal direction along the upper wall of the fuel tank from the second end region, through the central region, and to a first end region location proximate to the first outlet valve in the first end region, and reverses direction extending back through the central region and to the second end region,
• wherein, in the first end region, where the second outlet tube reverses direction, at least a portion of the second outlet tube is disposed on the side of the longitudinal axis closer to the first side than the second side,
• wherein, in extending back through the central region and to the second end region, the second outlet tube extends toward the corner of the fuel tank in the second end region at the second side;
• and
• an evaporative emissions tube connected to the first outlet tube and the second outlet tube at the corner of the fuel tank in the second end region at the second side.

A method for preventing liquid fuel leaking from a submerged first outlet valve of a fuel tank from reaching an evaporative emissions system connected to the fuel tank,

• wherein the fuel tank has an upper wall extending generally in a horizontal direction when viewed from a side elevation view,
• wherein the fuel tank defines a first end region, a central region, and a second end region when viewed from a plan view, and
• wherein the fuel tank comprises the first outlet valve and a second outlet valve,
• the method comprising:
• positioning the first outlet valve in the upper wall of the first end region of the fuel tank;
• positioning the second outlet valve in the upper wall of the second end region of the fuel tank;
• connecting a first outlet tube to the first outlet valve, mounting the first outlet tube to the upper wall of the fuel tank, and routing the first outlet tube generally in a horizontal direction along the upper wall of the fuel tank from the first end region to past the second outlet valve in the second end region;
• connecting a second outlet tube to the second outlet valve, mounting the second outlet tube to the upper wall of the fuel tank, and routing the second outlet tube generally in a horizontal direction along the upper wall of the fuel tank from the second end region, through the central region, to a location proximate to the first outlet valve in the first end region, and in a reverse direction extending back through the central region and to the second end region;
• connecting the first outlet tube and the second outlet tube to a tube in the second end region leading to an evaporative emissions canister;
• positioning the first outlet valve and the second outlet valve such that at least one of the first outlet valve and the second outlet valve is above a full fuel level for a desired range of fuel tank tilted positions;
• routing the first outlet tube such that, among the desired range of fuel tank tilted positions, when the first outlet valve is positioned below the full fuel level, at least a portion of the first outlet tube is above the full fuel level;
• and
• routing the second outlet tube such that, among the desired range of fuel tank tilted positions, when the second outlet valve is positioned below the full fuel level, at least a portion of the second outlet tube is above the full fuel level.