Method for installing product monitoring device in underground storage tanks

• US 4,999,900 A
• Filed: 06/29/1990
• Issued: 03/19/1991
• Est. Priority Date: 06/22/1989
• Status: Expired due to Fees

• Current Assignee: Centroid International, Inc.
• Original Assignee: Robert V. Anderson
• Inventors: Anderson, Robert V.
• Primary Examiner(s): Gorski, Joseph M.
• Assistant Examiner(s): VO, PETER DUNG BA
• Application Number:
  US07/546,674
• Time in Patent Office: 263 Days
• Field of Search: 29/237, 29/272, 29/406, 29/407, 29/709, 29/434, 29/455.1, 29/506, 29/514, 29/705, 29/890.14, 73/49.1, 73/49.2, 73/149, 73/301, 285/138, 285/140, 285/141, 285/133.1, 285/162, 285/370
• US Class Current: 29/407.01
• CPC Class Codes: F16L 39/005 for concentric pipes
• CPC Class Codes: G01F 23/263 by measuring variations in capacitance of capacitors
• CPC Class Codes: G01M 3/3245 using a level monitoring device G01M3/3272 takes precedence
• CPC Class Codes: Y10T 29/49428 Gas and water specific plumbing component making
• CPC Class Codes: Y10T 29/49764 with testing or indicating
• CPC Class Codes: Y10T 29/4984 Retaining clearance for motion between assembled parts
• CPC Class Codes: Y10T 29/49879 Spaced wall tube or receptacle
• CPC Class Codes: Y10T 29/49909 Securing cup or tube between axially extending concentric annuli

Abstract

A method is shown for installing a product monitoring device in an underground storage tank, such as the tanks used to store petroleum products. A product sensor is passed through the annular space defined between the tank riser pipe and fill pipe into the tank interior. The product sensor is used to sense representative characteristics of the product located within the tank interior.

Claims

1. A method for installing a product monitoring device in an underground fuel storage tank having an interior space and having a riser pipe extending upwardly therefrom to the surface of the ground, the riser pipe having an open interior surface which communicates with the interior space of the underground fuel storage tank, the method comprising the steps of:

telescopingly installing a fill tube within said interior surface of said riser pipe, said fill tube having an upper end, a lower end and an exterior surface between the upper end and the lower end, thereby forming a coaxial vapor recovery refueling system having an annular space created between said exterior surface of said fill tube and said interior surface of said riser pipe, said annular space defining a return vapor passage of said system;

supporting a product sensor in the annular space thus created between the exterior surface of the fill tube and the riser pipe interior surface, the product sensor being used to sense representative characteristics of a product located within the tank interior space; and

leaving the product sensor so supported within the annular space of the coaxial vapor recovery refueling system during refueling of the underground fuel storage tank.

2. The method of claim 1,

supporting said product sensor in the annular space thus created between the exterior surface of the fill tube and the riser pipe interior surface comprises attaching said product sensor to the exterior surface of the fill tube.

3. A method for installing a level monitoring device in an underground fuel storage tank having an interior space and having a riser pipe extending upwardly therefrom to the surface of the ground, the riser pipe having an open interior surface which communicates with the interior space of the underground fuel storage tank, the method comprising the steps of;

telescopingly installing a fill tube within said interior surface of said riser pipe, said fill tube having an upper end, a lower end and an exterior surface between the upper end and the lower end, thereby forming a coaxial vapor recovery refueling system having an annular space created between said exterior surface of said fill tube and said interior surface of said riser pipe, said annular space defining a return vapor passage of said system;

installing a centering means within the riser pipe interior for centering the fill tube within the riser pipe interior;

supporting a level sensor in the annular space thus created between the exterior surface of the fill tube and the riser pipe interior surface the level sensor being used to detect changes in a liquid level within the tank interior space for inventory control purposes; and

leaving the level sensor so supported within the annular space of the coaxial vapor recovery refueling system during refueling of the underground storage tank, whereby fuel is supplied through the fill tube to the interior space of the underground fuel storage tank and vapor is simultaneously conducted through the annular space containing the level sensor.

4. A method for installing a product monitoring device in an underground fuel storage tank having an interior space, the tank being buried in a subterranean location beneath a concrete apron having a cross-sectional depth and having a riser pipe extending upwardly from said tank to the ground surface, the riser pipe having an open interior which communicates with the interior space of the underground fuel storage tank, the product monitoring device being used to output a signal representative of product characteristics of interest, the signal so output being monitored by computation means located at the surface of the ground, the method comprising the steps of;

telescopingly installing a fill tube within said interior surface of said riser pipe, said fill tube having an upper end, a lower end and an exterior surface between the upper end and the lower end, thereby forming a coaxial vapor recovery refueling system having an annular space created between said exterior surface of said fill tube and said interior surface of said riser pipe, said annular space defining a return vapor passage of said system;

supporting a product sensor on the exterior surface of the fill tube in the annular space thus crated between the exterior surface of the fill tube and the riser pipe interior surface, the product sensor being used to sense representative characteristics of a product located within the tank interior space;

saw cutting a shallow trench in the concrete apron, the shallow trench being less than the cross-sectional depth of the concrete apron;

electrically connecting a cable to the product sensor supported on the exterior surface of the fill tube located in the annular space and running the connecting cable through the shallow trench provided in the concrete apron to the computation means situated remotely at the surface of the ground; and

leaving the product sensor so supported within the annular space of the coaxial vapor recovery refueling system during refueling of the underground storage tank.

5. The method of claim 4, wherein the shallow trench is sawcut with a concrete saw to a maximum width of 3/8 inch.

6. The method of claim 5, wherein the connecting cable run through the shallow trench is U.L. approved for direct burial.

7. The method of claim 6, further comprising the steps of:

installing the product sensor by threadedly engaging an adapter onto an upper extent of the riser pipe, the adapter having a complementary profile for engaging a liquid vapor coupling and having a junction for joining the connecting cable to the product sensor so supported on the exterior surface of the fill tube in the annular space.

8. The method of claim 7, further comprising the steps of caulking the shallow trench containing the connecting cable with a mortar caulk.

9. A method for installing a product monitoring device in an underground fuel storage tank having an interior space, the tank being buried in an subterranean location beneath a concrete apron having a riser pipe extending upwardly therefrom to the surface of the ground, the riser pipe having an open interior surface which communicates with the interior space of the underground storage tank, a fill tube having an exterior surface and being spaced within the riser pipe, a nozzle coupling being threadedly attached to an upper extent of the riser pipe, the product monitoring device being used to output a signal representative of product characteristics of interest, the signal so output being monitored by computation means located at the surface, the method comprising the steps of:

removing the nozzle coupling from the riser pipe;

pulling the fill tube from the riser pipe;

installing an adapter on an upper extent of the fill tube and engaging the adapter with the nozzle coupling;

supporting a product sensor on the exterior surface of the fill tube;

inserting the fill tube telescopingly within the riser pipe, and engaging the adapter to the riser pipe, said interior surface of said riser pipe thereby forming a coaxial vapor recovery refueling system having an annular space created between said exterior surface of said fill tube and said interior surface of said riser pipe, said annular space defining a return vapor passage of said system, the product sensor being located in the annular space so created between the exterior surface of the fill tube and the interior surface of the riser pipe; and

leaving the product sensor so supported within the annular space of the coaxial vapor recovery refueling system during refueling of the underground fuel storage tank.

10. A method for installing a product monitoring device in an underground fuel storage tank having an interior space, the tank being buried in a subterranean location beneath a concrete apron having a cross-sectional depth and having a riser pipe extending upwardly therefrom to the surface of the ground, the riser pipe having an open interior surface which communicates with the interior space of the underground storage tank, a fill tube having an exterior surface and being spaced within the riser pipe, a nozzle coupling being threadedly attached to an upper extent of the riser pipe, the product monitoring device being used to output a signal representative of product characteristics of interest, the signal so output being monitored by computation means located at the surface, the method comprising the steps of:

removing the nozzle coupling from the riser pipe;

pulling the fill tube from the riser pipe;

installing an adapter on an upper extent of the fill tube and engaging the adapter with the nozzle coupling;

supporting a product sensor on the exterior surface of the fill tube;

inserting the fill tube telescopingly within the riser pipe, and engaging the adapter to the riser pipe, said interior surface of said riser pipe thereby forming a coaxial vapor recovery refueling system having an annular space created between said exterior surface of said fill tube and said interior surface of said riser pipe, said annular space defining a return vapor passage of said system, the product sensor being located in the annular space so created between the exterior surface of the fill tube and the interior surface of the riser pipe;

saw cutting a shallow trench in the concrete apron, the shallow trench being less than the cross-sectional depth of the concrete apron, whereby the shallow trench so cut has the appearance of an expansion joint in the concrete apron;

electrically connecting a cable to the product sensor supported in the annular space and running the connecting cable through the shallow trench provided in the concrete apron to the computation means situated remotely at the surface; and

leaving the product sensor so supported within the annular space of the coaxial vapor recovery refueling system during refueling of the underground fuel storage tank.