1. Field of the Invention
The present invention generally relates to an access/isolation riser assembly for use in combination with an underground storage tank. More particularly, the present invention relates to an access/isolation riser assembly and kit for outfitting any number of underground storage tanks enabling users thereof to gain access to the given underground storage tank and isolate certain storage tank accessibility from certain underground elements.
2. Description of the Prior Art
The prior art specifically directed to underground storage tank access riser assemblies is relatively undeveloped as compared to the prior art more broadly directed to underground storage tank spill containment art and the like. A brief listing of certain prior art specifically relating to underground storage tank riser assemblies and the like, is briefly described, hereinafter.
U.S. Pat. No. 4,685,585 ('585 Patent), which issued to Robbins, discloses a Double Wall Tank Manway System. The '585 Patent teaches a double wall manway assembly for double wall tanks intended primarily for underground use, wherein an inner wall provides primary fluid containment and an outer wall provides secondary fluid containment, and a monitor between the walls can detect leakage past the inner wall into the space between the walls. The double wall manway assembly of the invention includes a riser conduit extending through apertures in the two tank walls and having an in-turned inner flange and an out-turned outer flange, with inner and outer cover members removably sealingly engaged over the respective inner and outer flanges. The space within the riser between the two covers communicates with the space between the two tank walls through one or more vent holes through the wall of the riser, for conducting any fluid leakage through the inner cover flange seal to the monitor between the tank walls. In some forms of the invention, a plurality of pipe fittings is embodied in the double wall manway as structural parts thereof.
U.S. Pat. No. 5,595,456 ('456 Patent), which issued to Berg et al., discloses a Water—Tight Riser for Underground Storage Tank Manway. The '456 Patent teaches an underground storage tank provided with a manway equipped with a riser extending from the storage tank, about the manway, to a point just below the access way provided in the ground level of the installation. The riser is provided with a water-tight cover which is released through operation of a cam. The water-tight riser excludes water from the interior of the riser and the manway, ensuring access to the manway, operation of the fittings provided in the manway, an additional containment of fluid passing through the manway and the area of the tank adjacent thereto. Because it is water-tight, an alarm sensitive to liquid may be placed in the interior of the riser to alert the operator to the possible loss of containment, or loss of water-tight sealing between the cover and the riser.
U.S. Pat. No. 5,882,045 ('045 Patent), which issued to Bravo, discloses Secondary Containment for Underground Storage Tank Riser. The '045 Patent teaches a secondary containment system for use in preventing leakage to or from an underground storage tank at a joint where a riser line connects to the tank. The system includes a secondary riser tube for surrounding the riser line and a sealing ring for providing a seal between the outer wall of the storage tank and the secondary riser tube. The sealing ring has a sleeve for sealing against the outer wall of the secondary sealing tube and a flexible bell-shaped skirt for sealing against the outer wall of the storage tank. A support bracket clamps to the outer wall of the riser line and includes three threaded arms extending radially outward. Three acorn nuts cooperate with the threaded arms and can be jacked in an outward direction against the inner wall of the secondary riser tube to fix the riser line and the secondary riser tube to one another and hold the secondary riser tube pressed downwardly to hold the flexible skirt of the sealing ring into sealing engagement with the outer wall of the storage tank.
Related to the '045 Patent is U.S. Pat. No. 5,944,361 ('361 Patent), which also issued to Bravo, and discloses Secondary Containment for Underground Storage Tank Riser. The '361 Patent further teaches a secondary containment system for use in preventing leakage to or from an underground storage tank at a joint where a riser line connects to the tank. The system includes a secondary riser tube for surrounding the riser line and a sealing ring for providing a seal between the outer wall of the storage tank and the secondary riser tube. The sealing ring has a sleeve for sealing against the outer wall of the secondary sealing tube and a flexible bell-shaped skirt for sealing against the outer wall of the storage tank. A support bracket clamps to the outer wall of the riser line and includes three arms extending radially outward. The three arms engage the secondary riser tube to hold it into engagement with the sealing ring and thereby hold the sealing ring in sealing engagement with the tank wall by maintaining a downward force on the secondary riser tube.
It will be seen from a further review of the above-referenced patents and other prior art generally known to exist relating to underground storage tank riser assemblies, that the prior art does not teach a storage tank access system or kit for enabling installers of riser assemblies to quickly outfit variously sized underground storage tank assemblies with a riser assembly having tank saddle means. Thus, the prior art perceives a need for a storage tank access system or kit and methodology for enabling installers of riser assemblies to quickly outfit variously sized underground storage tank assemblies with a riser assembly having tank saddle means.