Abstract: A fuel storage system includes a tank, a check valve having an inlet tube, an anti-siphon device and a fuel intake tube. The anti-siphon device includes a ring defining an interior opening having a diameter. The ring abuts an upstream end of the inlet tube of the check valve, which includes an inner diameter substantially equal to the diameter of the interior opening of the ring. The ring includes and supports a plurality of fins within the inlet tube without narrowing the inlet tube to maximize fluid flow through the inlet tube. The anti-siphon device is rotatable relative to the check valve and the fuel intake tube. The shape, size and orientation of the fins are optimized to minimize flow interruption through the anti-siphon device and minimize vaporization of the fluid.

Abstract: A fuel tank cap including a vapor storage receptacle and a discriminator that discriminates between liquid fuel and fuel vapor for protecting the vapor storage receptacle from liquid and adsorbent granulated carbonaceous material. A fuel storage system including a fuel tank cap having a vapor storage receptacle is also disclosed.

Abstract: A small engine fuel system includes a vent valve configured to be disposed within a tank having at least a portion of a filler pipe defined therein. The filler pipe includes an upper portion configured to receive a fluid and a lower portion located at a predetermined depth in the tank, where the predetermined depth defines a liquid fill level of the tank. The small engine fuel system further includes spring valve arranged in series with the vent valve. The spring valve is configured to close during a refilling event, thereby substantially preventing overfill of the tank with the fluid.

Abstract: A fuel vapor emission system for small engine gas tank which does not require redesign or retooling for manufacturing of the tank. A new filler tube has the lower end positioned to cause fuel to rise rapidly in the tube before the tank is full, signaling the operator to stop refueling and maintain a vapor dome in the tank when the filler cap is replaced. A vapor vent valve is disposed in a separate access opening and includes a float operated rollover valve. The vent valve opens when a predetermined positive pressure is reached in the tank; and, a reverse flow vacuum relief valve is disposed in the vent valve. The outlet of the vent valve is intended to be connected to either a storage canister or the engine air inlet.

Abstract: A small engine fuel tank vapor emission system is described with a separate surge tank having a vapor vent/rollover valve and separate a vapor storage space which may be found in a common housing or remote from the surge tank. The surge tank is located at a level above the fuel tank and is connected to have its inlet receive vapor from the fuel tank. The outlet of the vapor vent/rollover valve is connected to supply vapor purge flow to the engine air inlet either directly or through the storage space, which may be charged with adsorbent.

Abstract: A fuel tank assembly for small engines having a vapor storage canister disposed within the tank in the vapor dome with an atmospheric vent line to the canister through the tank wall and a canister vapor outlet line also through the tank wall. A liquid/vapor discriminator is disposed in the vapor dome of the tank with the discriminator outlet connected to the canister inlet. A fuel filler tube extends through the tank wall to a desired depth to prevent vapor from escaping through the filler tube when the fuel level rises to the lower end of the filler tube and alerts the operator by rapid rise of fuel in the filler tube.

Abstract: A combination fuel vapor storage canister and vapor vent/tipping valve in a common housing with ports for connection to a fuel tank, a purge line and an atmospheric vent. The vapor vent/tipping valve includes a pressure relief valve which prevents vapor venting until a predetermined vapor pressure is reached; and, the pressure relief valve may also include a vacuum relief valve.

Abstract: A fuel vapor emission system for small engine gas tank which does not require redesign or retooling for manufacturing of the tank. A new filler tube has the lower end positioned to cause fuel to rise rapidly in the tube before the tank is full, signaling the operator to stop refueling and maintain a vapor dome in the tank when the filler cap is replaced. A vapor vent valve is disposed in a separate access opening and includes a float operated rollover valve. The vent valve opens when a predetermined positive pressure is reached in the tank; and, a reverse flow vacuum relief valve is disposed in the vent valve. The outlet of the vent valve is intended to be connected to either a storage canister or the engine air inlet.

Abstract: A small engine fuel system has a tank with an integrally formed filler tube having the lower end located at a level below the upper portion of the tank wall which is formed of vapor impermeable material which may include HDPE interspersed with EVOH or polyamide. In one exemplary embodiment the filler neck is disposed in a depression in the upper portion of the tank wall; and in another exemplary embodiment the filler tube has an insert which extends into the tank to a position below the upper portion of the tank wall to form a vapor space. The tank includes a fill limiting vapor vent/tipping valve with its outlet connected to a storage canister which outputs to the engine and which has an atmospheric air vent.

Abstract: A fuel tank assembly for small engines having a vapor storage canister disposed within the tank in the vapor dome with an atmospheric vent line to the canister through the tank wall and a canister vapor outlet line also through the tank wall. A fuel vapor vent valve is disposed in the vapor dome of the tank with the vent valve outlet connected to the canister inlet. A fuel filler tube extends through the tank wall to a desired depth to prevent vapor from escaping through the filler tube when the fuel level rises to the lower end of the filler tube and alerts the operator by rapid rise of fuel in the filler tube.

Abstract: A combination vapor vent/rollover valve and surrounding storage canister are disposed in a common housing for positioning inside a small engine fuel tank. In one embodiment described, the canister surrounds the vapor vent/rollover valve which may include a gravity pressure relief valve and a vacuum relief valve. In another embodiment a pressure relief valve and adjacent storage canister are disposed in a common housing for positioning inside a small engine fuel tank.

Abstract: A fuel vapor vent valve is formed of different plastic material than the fuel tank. A U-shaped or cupped attachment member formed of tank material is received over the valve with the upper end slotted to permit the hose fitting to extend outwardly through the slot for hose attachment within the tank. The rim of the attachment member is secured by weldment to the undersurface of the upper tank wall.

Abstract: A fuel vapor venting system for fuel tanks having a saddle-shaped upper wall. A vapor vent valve is disposed entirely within the tank in each vapor dome compartment formed by the upper tank wall. The vent valves are interconnected by a conduit passing under the lowest portion of the upper tank wall and a drain valve installed in the lowest point of the conduit. The drain valve may be pressure operated or float operated.

Abstract: A fuel vapor venting system for fuel tanks having a saddle-shaped upper wall. A vapor vent valve is disposed entirely within the tank in each vapor dome compartment formed by the upper tank wall. The vent valves are interconnected by a conduit passing under the lowest portion of the upper tank wall and a drain valve installed in the lowest point of the conduit. The drain valve may be pressure operated or float operated.

Abstract: A fuel vapor vent valve is formed of different plastic material than the fuel tank. A U-shaped or cupped attachment member formed of tank material is received over the valve with the upper end slotted to permit the hose fitting to extend outwardly through the slot for hose attachment within the tank. The rim of the attachment member is secured by weldment to the undersurface of the upper tank wall.

Abstract: A combination rollover/vent valve, fuel pump and fuel level sender which is installed through a single access opening in the top of a fuel tank. The rollover/vent valve has a resilient mounting strip attached and the rollover/vent valve is attached to the fuel pump level sender module by a substantially rigid vent tube and the vent tube is ported exteriorly through the module. Upon insertion of the rollover/vent valve through the access opening, the mounting strip engages ratchet teeth formed in the top and bottom of the tank to secure the rollover/vent valve at a location of the highest level of the tank, remote from the module. The module thus locates the vent line, fuel feed line and electrical connections all at a single location on the tank top. The vent tube may be formed to a curved configuration to accommodate a dished or recessed tank top.