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US 6,681,789 B1Granted
Fuel tank ventilation system and method for substantially preventing fuel vapor emissions
AssigneeThe United States of America as represented by the United States Environmental Protection Agency
InventorsCharles E. Moulis, Leon S. Jones
Life of this patent
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Abstract
A fuel tank ventilation system and method are provided for substantially preventing fuel vapor emissions without significant increase in tank pressure. The system and method include a flexible bladder within the fuel tank that alternately deflates and inflates in response to a change in fuel vapor pressure and fuel volume.
Claims12
The method for substantially preventing fuel emissions comprising the steps of:
- Providing a tank containing volatile fuel and wherein said volatile fuel has a vapor pressure;
- Positioning a flexible bladder within the tank above the fuel and containing air under a second pressure;
- and
- connecting a vent to said flexible bladder and through which air may alternately be received into and emitted outside of said flexible bladder;
- in response to an increase in said vapor pressure above said second pressure, emitting at least a portion of said air located in an interior of said flexible bladder outside of said flexible bladder through said vent until said vapor pressure and said second pressure equilibrate;
- in response to a decrease in said vapor pressure bellow said second pressure, receiving air located outside of said flexible bladder to be received into said flexible bladder through said vent until said vapor pressure and said second pressure equilibrate.
3 more elements
A ventilation system for a sealed tank, comprising:
- a sealed tank for containing an organic liquid that emits vapors and wherein said liquid has a vapor pressure;
- a flexible bladder located within the sealed tank and containing air under a second pressure;
- a vent connected to said flexible bladder and through which air may alternately be received into and emitted outside of said flexible bladder;
- wherein an increase in said valor pressure above said second pressure causes at least a portion of said air located in an interior of said flexible bladder to be emitted outside of said flexible bladder through said vent until said vapor pressure and said second pressure equilibrate;
- wherein a decrease in said vapor pressure below said second pressure causes air located outside of said flexible bladder to be received into said flexible bladder through said vent until said valor pressure and said second pressure equilibrate.
2 more elements
Dependencies are inferred from the claim text.