Abstract: A combination manway cover and pressure relief apparatus (2) for a tank (4) having a manway opening (14) and containing a fluid. A body (12) covers the manway opening and is guided and biased along a substantially vertical, linear path (16). The body is guided along the path by bolts (18) which pass through a plurality body, gasket and flange bolt holes (22, 23, 24). The weight of the body biases the body along the path toward the manway opening. Pressure relief for the tank is provided when the fluid pressure within the tank moves the body away from the manway opening.

Abstract: A storage vault (2, 182) includes an inner tank (4,4',152,180) entombed within a concrete outer tank (8) by first erecting a pair of sidewall forms (51) on a base plate (44) to create an open-top enclosure (54). The inner tank (180) can include a plastic tank (152) enclosed within an external framework (154), the combination (150) housed within a steel tank (174). A layer of concrete (56) is poured onto the base plate, the inner tank is lowered onto the layer of concrete, and concrete is poured into the enclosure to entomb the inner tank while the bottom layer of concrete is still wet. Reinforced hold-down bars (86) extend over the top of the enclosure and have downwardly extending hold-down tubes (92) which engage the top of the inner tank and keep the inner tank positioned horizontally and vertically. The hold-down bars are fastened to the base plate to keep the inner tank properly positioned.

Abstract: A vault for dual containment of the fluids by an inner tank and an outer tank is produced by the apparatus described. The tendency of the inner tank to bob up in response to buoyancy from fluid concrete is countered by a hold-down assembly. The hold-down assembly produces downward pressure on the tank which is distributed over a region of the upper surface of the tank by a pressure distribution device which is left embedded in the concrete. An adjustment device is coupled to the form to permit pushing or pulling on the tank manway to move the manway down or up to provide the proper location.

Abstract: A storage vault (2, 182) includes an inner tank (4,4',152,180) emtombed within a concrete outer tank (8) by first erecting a pair of sidewall forms (51) on a base plate (44) to create an open-top enclosure (54). The inner tank (180) can include a plastic tank (152) enclosed within an external framework (154), the combination (150) housed within a steel tank (174). A layer of concrete (56) is poured onto the base plate, the inner tank is lowered onto the layer of concrete, and concrete is poured into the enclosure to entomb the inner tank while the bottom layer of concrete is stil wet. Reinforced hold-down bars (86) extend over the top of the enclosure and have downwardly extending hold-down tubes (92) which engage the top of the inner tank and keep the inner tank positioned horizontally and vertically. The hold-down bars are fastened to the base plate to keep the inner tank properly positioned.

Abstract: A tank stabilizer (6, 50) for an above ground liquid storage tank (8) of the type having one or more bottom supports or skids (10) to support the tank a distance above a support surface (16). The tank stabilizer includes lateral supports (20,56), preferably trough-like or U-shaped structures, which are secured to the support surface and configured so the bottom supports fits snugly therein. The tank stabilizer restricts horizontal movement of the tank relative to the support surface during an earthquake. The tank stabilizer may include an upwardly extending liquid barrier (34) circumscribing the lateral supports to help contain any spills or leaks.

Abstract: An above-ground liquid storage system (2) includes a steel inner container (4) encased within a layer (6) of reinforced concrete. The steel container has an upper opening (12) in an upper wall (10) thereof. An overfill reservoir (14) is positioned within the container below the upper opening so that the contents of the overfill reservoir are protected by virtue of being within, rather than outside of, the container. A fill pipe (18) extends through the overfill reservoir to permit user to introduce a liquid, such as gasoline or fuel, into the container. The fill pipe has an upper end (26) positioned above the upper opening and a lower end (22) positioned below the upper opening. An upper barrier (40), including a cylindrical wall (30) covered by a removable cover (34) to define an operating region (43) above the upper opening, is used to seal the upper opening.

Abstract: A storage vault includes an inner tank entombed within a concrete outer tank by first erecting a pair of sidewall forms on a base plate to create an open-top enclosure. The wall forms are securely clamped together. A layer of concrete is then poured onto the base plate and the inner tank is restrained by lowered onto the layer of concrete. Concrete is poured into the enclosure to entomb the inner tank while the bottom layer of concrete is still wet. The inner tank is a pair of reinforced hold-down bars extending over the top of the enclosure and having a pair of downwardly extending hold-down tubes which contact the top of the inner tank. Back hold-down bar is forced downwardly by a chain which passes over the hold-down bar and is fastened to the base plate. After the concrete has set sufficiently, the hold-down bars and tubes are removed and the holes created by the hold-down tubes are filled with concrete.

Abstract: A method for making a steel/concrete tank is provided. A steel interior tank is pressurized during or after pouring of a concrete outer tank around a steel inner tank. Pressurization is commenced before the concrete has set, and is maintained until substantial setting of the concrete. The resulting structure is less susceptible than previous structures to cracking of the exterior concrete upon pressure-testing of the structure for leaks.

Abstract: A storage vault includes an inner tank entombed within a concrete outer tank by first erecting a pair of sidewall forms on a base plate to create an open-top enclosure. The wall forms are securely clamped together. A layer of concrete is then poured onto the base plate and the inner tank is lowered onto the layer of concrete. Concrete is poured into the enclosure to entomb the inner tank while the bottom layer of concrete is still wet. The inner tank is restrained by a pair of reinforced hold-down bars extending over the top of the enclosure and having a pair of downwardly extending hold-down tubes which contact the top of the inner tank. A back hold-down bar is forced downwardly by a chain which passes over the hold-down bar and is fastened to the base plate. After the concrete has set sufficiently, the hold-down bars and tubes are removed and the holes created by the hold-down tubes are filled with concrete.