摘要:
A form suitable for use in an underground storage tank installation includes an upper portion sized and shaped to receive a street box and a lower portion that fits over and surrounds an upper portion of a riser on the tank. In preferred embodiments, the riser acts as a containment sump, a portion of the riser sidewall is double walled, and the bottom of the lower portion of the form extends to a depth below the top of the double walled portion of the riser. Preferably, the cross sectional shape of the form is circular and the bottom of the riser's lower portion is outwardly flanged, which serves to support the form during installation operations. The form has a stepped structure, with the upper portion of the form having a smaller circumference than the lower portion and a transition between the upper and lower portions forming the step.
摘要:
A retaining system in which straps are provided with hooks that remain engaged with retaining loops even when tension on the straps is released and in which the tightening mechanism includes rods which are located partially below a rib surface on which the straps are placed such that the ends of the rods are near the plane of the strap ends, thereby greatly reducing the bending moment applied to the strap ends and threaded rods. The hook preferably includes a cavity opposite the hook end that will engage the retaining loop when no tension is on the line. In some embodiments, the hook includes a spring-loaded retaining clip to further ensure that the hook does not become disengaged from the retaining loop. The tightening mechanism includes two rods, each of which is positioned to one side of a rib on which the straps rest.
摘要:
A triple-walled underground storage tank is provided with primary, secondary and tertiary walls. Between each two adjacent walls, an annular space is provided. The annular space is continuous throughout, and permits the flow of liquid therein. Monitors may be provided separately for each annulus, to detect the formation of leaks, or a lack of containment, in either wall defining the annular space. In one embodiment, the tertiary wall is a smooth cylinder formed about the circumferential ribs of the secondary wall. In the alternative embodiment, the rib-bearing wall is the tertiary wall, and the walls and annular materials of the tank are formed within a female mold. In either case, a tank prepared from integral ribs, with superior robustness and strength, is provided with triple containment.
摘要:
A method for calculating underground storage tank (UST) buoyancy and buoyancy safety factors defines boundaries of side areas such that the boundaries do not overlap for multiple tank installations. Installation plan information may be input over a medium such as the Internet. The computer calculates the buoyancy and buoyancy safety factor and returns this information to the requesting party over the same medium. This technique allows installers to verify the adequacy of installation plans quickly. Records of the information provided by the installer may be kept so the recipient of the information (typically the UST manufacturer) can reconcile differences between the actual installation and the installation plan in the event of UST flotation. The information may be provided on a paper form supplied by the installer. In preferred embodiments, the calculations are tailored to installation guidelines (often provided by the UST manufacturer), which may specify such parameters as spacing between tanks in multi-tank installations, some or all deadman dimensions, slab dimensions, etc. Preferred embodiments generate a form letter that includes the installation plan information and the results of the buoyancy and/or buoyancy safety factor calculations.
摘要:
A triple-walled underground storage tank is provided with primary, secondary and tertiary walls. Between each two adjacent walls, an annular space is provided. The annular space is continuous throughout, and permits the flow of liquid therein. Monitors may provided separately for each annulus, to detect the formation of leaks, or a lack of containment, in either wall defining the annular space. In one embodiment, the tertiary wall is a smooth cylinder formed about the circumferential ribs of the secondary wall. In the alternative embodiment, the rib-bearing wall is the tertiary wall, and the walls and annular materials of the tank are formed within a female mold. In either case, a tank prepared from integral ribs, with superior robustness and strength, is provided with triple containment.
摘要:
A retaining system in which straps are provided with hooks that remain engaged with retaining loops even when tension on the straps is released and in which the tightening mechanism includes rods which are located partially below a rib surface on which the straps are placed such that the ends of the rods are near the plane of the strap ends, thereby greatly reducing the bending moment applied to the strap ends and threaded rods. The hook preferably includes a cavity opposite the hook end that will engage the retaining loop when no tension is on the line. In some embodiments, the hook includes a spring-loaded retaining clip to further ensure that the hook does not become disengaged from the retaining loop. The tightening mechanism includes two rods, each of which is positioned to one side of a rib on which the straps rest.
摘要:
A double walled riser sump has an annular space between the two walls. The provision of the annular space provides for monitoring the integrity of the two walls of the sump. The two walls of the sump are preferably separated by a thin film or a distance fabric that allows the passage of fluids, and preferably liquids. The annular space may be in fluid communication with a reservoir holding a monitoring fluid and positioned near the top of the sump to be easily accessible. In some embodiments, a top of the riser sump is also double walled and the top annular space is in fluid communication with the annular space between the vertical walls. If a leak develops in either wall of the sump, a corresponding drop in the fluid level of the reservoir will occur.
摘要:
A female-molded double-walled underground storage tank is provided with an annulus of reduced thickness, defined by a plastic film. The film separates the inner and outer walls of the tank, providing an annulus which can be monitored to monitor the tank for failure of either the inner or the outer tank, before contamination of the exterior environment. The tank is formed of fiberglass reinforced plastic, the inner and outer walls thereof being tied together by fiberglass reinforced plastic which holds the annular film in place. The domes of the outer and inner shell are separated due to a layer of wax and alcohol applied to the inner surface of the dome of the exterior tank prior to formation of the interior tank. The spaces between the flats of the two tanks, the domes of the two tanks, and the interior of the ribs of the exterior tank are placed in fluid communication by gutters running along the length of the tank.
摘要:
A steel rib, designed for affixation to the interior of an underground storage tank, provides improved compression characteristics, with a reduction in cost of preparation and materials. The rib is provided with diametrically opposed vents, which may be formed by cutting a portion of a hollow, rectangular rib, rotating it 90.degree. in a direction orthogonal to the plane of the rib, and reaffixing it, so as to occlude the interior of the rib. When used to reinforce a double-walled tank, the rib allows the strengthening of the outer wall to enhance resistance to penetration and damage frequently incurred in handling, and reduce installation costs.
摘要:
A wet well apparatus, and installation method therefore, that includes a cylindrical body extending between a first end and a second end along a body axis defining an interior material holding volume and a base form closing the first end of the cylindrical body to define a base interior volume adjacent the interior material holding volume of the cylindrical body. The base form is configured to receive a flowable fill material in the base interior volume.