A plastic article useful as a riser assembly for a septic tank or as part of another structure is comprised of a multiplicity of identical shape conical wall plastic risers. The risers are attached to each other at joints by tabs which engage rim segments; each end of the riser has alternating tabs and rim segments. A riser assembly wall undulates in the lengthwise direction. The risers nest within each other for shipment or storage.

A collapsible storage silo having an expanded configuration includes: (a) a shell for circumscribing storage space and comprising a plurality of concentrically nested tubular members that are collapsible; (b) a lift system operable to slidably expand the plurality of concentrically nested tubular members to place the silo in its expanded configuration; and (c) a mast operable to support the lift system, The mast is pivotable between horizontal and vertical positions relative to a frame. A winch attaches to the mast and a cable extends between the winch and an outermost tubular member to expand the silo such that inwardly and outwardly projecting lips of nested members engage each other and a conical hopper engages an innermost tubular member. A flexible inner liner attaches between an outermost tubular member and the hopper. A collapsible roof has a flexible roof membrane and a plurality of radially extending foldable rib members.

A vertical fluid storage tank includes an oval-shaped body having a first end, a second end, and a sidewall extending between the first and second ends. The body defines an interior fluid storage cavity and has a major axis and a minor axis along a horizontal cross section through the body. The fluid storage tank further includes a top wall at the first end of the body, a bottom wall at the second end of the body, and a frame member connected to the sidewall of the body. The frame member includes a first portion that extends longitudinally along the sidewall of the body and a second portion that extends along the bottom wall and is connected to the first portion. The fluid storage tank further includes a connection port on the sidewall of the body adapted for connection to the connection port on an adjacent fluid storage tank.

A quasi-cylindrical cargo container is formed of a plurality of rigid, curved panels together forming first and second semi-cylindrical shells, and a plurality of rigid, flat extension panels bridging the first and second semi-cylindrical shells. A method of manufacturing the container includes forming the first and second semi-cylindrical shell from the curved panels, forming the quasi-cylindrical shell from the first and second semi-cylindrical shells and the flat extension panels, forming collars conformably encompassing the quasi-cylindrical shell, constricting the collars to compress joints formed at abutting edges of pairs of adjacent panels, rolling the shell and collars sequentially to bring the joints to a lower position, welding inside seams of the joints when at the lower position, removing the collars, rolling the shell sequentially to bring the joints to an upper position, and welding outside seams of the joints when at the upper position.

A safety door latch system is presented for a grain bin having a door frame. An inner door is connected to the door frame that is configured to move between an open position and a closed position. An outer door is connected to the door frame and is configured to move between an open position and a closed position. A safety mechanism is connected to the door frame and is configured to move between an open position and a closed position. When the inner door frame is moved to a closed position, a portion of the inner door engages the safety mechanism thereby causing the safety mechanism to move to the closed position. When the safety mechanism is in the closed position, the outer door may be latched to the safety mechanism. When the safety mechanism is in the open position, the outer door cannot latch to the safety mechanism.

A modular indefinite volume combined tank is provided, including a tank body module, a tank bottom module and an inflating module, wherein the tank body module is formed by splicing a plurality of wall plates and connectors, and the wall plates and the connectors form a tank body. The tank bottom module includes a strip-type steel plate, concrete cloth, annular steel plate and a cement foundation. The strip-type steel plate is paved on the cement foundation, the annular steel plate is arranged in the upper side of the outer edge of the strip-type steel plate, the annular steel plate is encircled by a plurality of arc-shaped steel sheets, a ring of annular edge is arranged in the annular steel plate to be connected to the upper tank body, and a layer of concrete cloth is arranged between the lower side of the annular steel plate and the strip-type steel plate.

A collapsible storage silo having an expanded configuration includes: (a) a shell for circumscribing storage space and comprising a plurality of concentrically nested tubular members that are collapsible; (b) a lift system operable to slidably expand the plurality of concentrically nested tubular members to place the silo in its expanded configuration; and (c) a mast operable to support the lift system. The mast is pivotable between horizontal and vertical positions relative to a frame. A winch attaches to the mast and a cable extends between the winch and an outermost tubular member to expand the silo such that inwardly and outwardly projecting lips of nested members engage each other and a conical hopper engages an innermost tubular member. A flexible inner liner attaches between an outermost tubular member and the hopper. A collapsible roof has a flexible roof membrane and a plurality of radially extending foldable rib members.

A tank for the storage of liquid or gaseous substances with a fiber-reinforced plastic sheathing, which limits at least one interior space for holding the materials to be stored. At least one circumferential section of the fiber-reinforced plastic sheathing comprises an evacuable sandwich structure, which completely encloses the circumferential section. As a result, the tank has a low weight with a high thermal insulation capacity. Furthermore, a reliable explosion protection of the tank is provided. Furthermore, a method for manufacturing a tank for the storage of liquid or gaseous substances is provided.

A modular indefinite volume combined tank is provided, including a tank body module, a tank bottom module and an inflating module, wherein the tank body module is formed by splicing a plurality of wall plates and connectors, and the wall plates and the connectors form a tank body. The tank bottom module includes a strip-type steel plate, concrete cloth, annular steel plate and a cement foundation. The strip-type steel plate is paved on the cement foundation, the annular steel plate is arranged in the upper side of the outer edge of the strip-type steel plate, the annular steel plate is encircled by a plurality of arc-shaped steel sheets, a ring of annular edge is arranged in the annular steel plate to be connected to the upper tank body, and a layer of concrete cloth is arranged between the lower side of the annular steel plate and the strip-type steel plate.

A safety door latch system is presented for a grain bin having a door frame. An inner door is connected to the door frame that is configured to move between an open position and a closed position. An outer door is connected to the door frame and is configured to move between an open position and a closed position. A safety mechanism is connected to the door frame and is configured to move between an open position and a closed position. When the inner door frame is moved to a closed position, a portion of the inner door engages the safety mechanism thereby causing the safety mechanism to move to the closed position. When the safety mechanism is in the closed position, the outer door may be latched to the safety mechanism. When the safety mechanism is in the open position, the outer door cannot latch to the safety mechanism.