Marine fuel backflow preventer and over-fill alarm system

• US 8,511,341 B2
• Filed: 03/02/2011
• Issued: 08/20/2013
• Est. Priority Date: 03/02/2011
• Status: Active Grant

• Current Assignee: Gary E. Johnston
• Original Assignee: Gary E. Johnston
• Inventors: Johnston, Gary E.
• Primary Examiner(s): Schneider, Craig
• Assistant Examiner(s): CHAUDRY, ATIF H
• Application Number:
  US13/038,448
• Publication Number:
  US 20120222755A1
• Time in Patent Office: 902 Days
• Field of Search: 137/575, 137/587, 137/588, 137/590, 137/590.5, 137/592, 137/899.2, 137/558, 114/74.R, 114/289, 141/62, 220/86.2, 60/392.81
• US Class Current: 137/575
• CPC Class Codes: B60K 15/03 Fuel tanks chassis frame comprising fluid storage compartment B62D21/16 ; Details of the fuel feeding system related to the fuel tank F02M37/0076
• CPC Class Codes: B60K 15/03504 adapted to avoid loss of fuel or fuel vapour, e.g. with vapour recovery systems
• CPC Class Codes: Y10T 137/3149 Back flow prevention by vacuum breaking [e.g., anti-siphon devices]
• CPC Class Codes: Y10T 137/8342 Liquid level responsive indicator, recorder or alarm
• CPC Class Codes: Y10T 137/8622 Plural top-to-bottom connected tanks
• CPC Class Codes: Y10T 137/86324 Tank with gas vent and inlet or outlet
• CPC Class Codes: Y10T 137/86356 Nondraining overflow type
• CPC Class Codes: Y10T 137/86372 Inlet internally extending

Abstract

A marine fuel backflow preventer and overfill alarm for use with marine vessels includes a housing provided for in-line installation in the fuel fill inlet line and directs fuel entering the a fuel filling inlet generally directly to a fuel filling outlet such that the fuel passes freely through the back flow preventer while being directed to the vessel fuel tank. The housing further functions as a reservoir for containing fuel which has accumulated therein due to over-filling and/or that has been carried into the housing via the fuel tank vent line. By providing a fuel containing reservoir disposed in-line the present invention thus functions to prevent unintended fuel spillage into the environment. The back flow preventer further includes an electro-mechanical float switch that automatically activates an alarm upon sensing the presence of fuel within the housing. The alarm provides the fuel filling attendant a prompt warning that an overflow condition is being experienced such that the flow of fuel may be terminated prior to spillage into the environment.

Claims

1. A marine fuel backflow preventer and overfill alarm system for preventing the escape of fuel from a marine vessel having a fuel tank, a fuel filling port in communication with the fuel tank, and a vent line running from the fuel tank to an overboard vent fitting, said system comprising:

a housing defining an interior volume, said housing including a top and a bottom;

said housing top including a fuel fill inlet coupled in fluid communication with the fuel filling port;

said housing bottom including a fuel fill outlet coupled in fluid communication with the fuel tank;

a pipe having an upper end in fluid communication with said fuel fill inlet and a lower end projecting into said housing interior volume;

a generally cylindrical internal baffle disposed within said housing, said baffle having a lower end connected to the bottom of said housing in concentric relation with said fuel fill outlet, and an upper end disposed in generally concentric and radially spaced surrounding relation with the lower end of said fuel fill inlet pipe, said baffle lower end including at least one notch; and

said housing top including a first vent port coupled in fluid communication with the fuel tank by a first vent line, and a second vent port coupled in fluid communication with the overboard vent fitting by a second vent line.

2. A system according to claim 1, wherein said housing bottom slopes downwardly to said fuel fill outlet.

3. A system according to claim 1, wherein said fuel fill inlet and said fuel fill outlet are axially aligned.

4. A system according to claim 1, further including an overflow alarm configured to generate an alarm when liquid fuel within said housing reaches a predetermined level.

5. A marine fuel backflow preventer and overfill alarm system for preventing the escape of fuel from a marine vessel having a fuel tank, a fuel filling port in communication with the fuel tank, and a vent line running from the fuel tank to an overboard vent fitting, said system comprising:

a housing defining an interior volume, said housing including a top and a bottom;

said housing top including a fuel fill inlet coupled in fluid communication with the fuel filling port;

said fuel fill inlet including an open ended pipe having an upper portion projecting upward from said housing top and terminating in an upper end, and a lower potion extending generally vertically downward into said interior volume and terminating in a lower end disposed in spaced relation the bottom of said housing;

said housing bottom sloping downward to a fuel fill outlet coupled in fluid communication with the fuel tank;

said fuel fill outlet disposed in generally axial alignment with said fuel fill inlet;

a generally tubular internal baffle within said housing, said baffle having lower end with at least a portion thereof fixed to the bottom of said housing and an upper end disposed in generally surrounding concentric relation with a portion of the lower portion of said fuel fill inlet pipe;

said internal baffle lower end defining at least one notch for allowing fuel to flow from said housing interior to said fuel fill outlet;

said housing top including a first vent port coupled in fluid communication with the fuel tank by a first vent line, and a second vent port coupled in fluid communication with the overboard vent fitting by a second vent line; and

said housing further including an overflow alarm configured to generate an alarm when liquid fuel within said housing reaches a predetermined level.

6. A system according to claim 5, wherein said overflow alarm includes a float switch electrically connected to an alarm, said float switch including a buoyant actuator disposed within the interior volume of said housing in spaced relation with said housing bottom.