This application discloses a new type of suction leg, an offshore caisson, a sit-on-bottom supporting platform. The suction leg includes a sealing long pile, this sealing long pile including a tubular pipe and a top head connected tightly to the tubular pipe to form cylindrical integral structure with sealing top and opening bottom. The top head has at least one opening to be able to open or close. The sealing long pile can be penetrated into the seabed by a gravity penetration method or/and a suction pile penetration method, or pulled out from the seabed by a buoyancy uplift method or/and a suction pile uplift method.

A steel plate and concrete composite tank unit, tank groups and offshore platforms with new type of tank units are disclosed. The tank unit comprises an outer concrete tank that comprises an outer tank shell, two heads and ring shell connections at both ends, an inner steel tank that comprises an inner tank shell, epitaxial structures at both ends of the inner steel tank. Inner tank shell is connected to the outer tank shell by epitaxial structures, and an isolation layer that is formed from the gap between the outer concrete tank and the inner steel tank where it is filled with isolation medium.

A steel plate and concrete composite tank unit, tank groups and offshore platforms with new type of tank units are disclosed. The tank unit comprises an outer concrete tank that comprises an outer tank shell, two heads and ring shell connections at both ends, an inner steel tank that comprises an inner tank shell, epitaxial structures at both ends of the inner steel tank. Inner tank shell is connected to the outer tank shell by epitaxial structures, and an isolation layer that is formed from the gap between the outer concrete tank and the inner steel tank where it is filled with isolation medium.

A test cell (10) for containing equipment (12) subject to pressure testing comprises a plurality of metal plate wall panels (14) and a mesh roof panel (16) formed from mesh strands (26) of a high strength material. Each wall panel has a lapped connection (18) with an adjacent wall panel. The mesh panel (16) may be formed from a ballistic fabric, and the mesh strands (26) may be wire, rope and braid of steel, metal, plastic, natural or composite fibre, or a combination thereof. In the event of a pressure failure of the equipment (12) under test, the roof panel (16) captures fragments of the equipment while allowing the dissipation of pressure shock waves through the apertures (28) in the mesh. The lapped connections (18) between wall panels (14) result in increased friction between adjacent wall panels (14) and thus an increase in the strength of the connection when subject to pressure shock waves.

A test cell (10) for containing equipment (12) subject to pressure testing comprises a plurality of metal plate wall panels (14) and a mesh roof panel (16) formed from mesh strands (26) of a high strength material. Each wall panel has a lapped connection (18) with an adjacent wall panel. The mesh panel (16) may be formed from a ballistic fabric, and the mesh strands (26) may be wire, rope and braid of steel, metal, plastic, natural or composite fibre, or a combination thereof. In the event of a pressure failure of the equipment (12) under test, the roof panel (16) captures fragments of the equipment while allowing the dissipation of pressure shock waves through the apertures (28) in the mesh. The lapped connections (18) between wall panels (14) result in increased friction between adjacent wall panels (14) and thus an increase in the strength of the connection when subject to pressure shock waves.

A method for constructing a triple shell tank including an inner tank, an intermediate tank, and an outer tank each having a roof and a side plate includes the following procedure. As construction entrances, a first construction opening is opened in an outer tank side plate, a second construction opening is opened in an inner tank side plate, and a third construction opening is opened in an intermediate tank side plate, each during the installation of the corresponding side plate. The construction openings are opened so as to partially overlap with one another in a circumferential direction and a height direction of the triple shell tank. The first construction opening and the second construction opening are opened so as to satisfy a relationship AR1AR2, where AR1 is an opening area of the first construction opening and AR2 is an opening area of the second construction opening.

The invention is directed to a method of insulating tanks having a capacity between 200 m.sup.3 and 20,000 m.sup.3 used for storage of oil and oil products. In the method, foundation elements, including tank bottom heat insulation, are prepared. The tank is mounted on the prepared foundation, then insulation of the tank walls and roof is installed. Supporting relieving skirts are mounted on the tank walls and roof, forming tiers. The tiers are filled with foam glass blocks having expansion joints. A top coat of metal sheets is mounted on the outer surface of the blocks. Foam glass blocks in the lower tier are made to be removable to provide access to a wall-bottom corner weld joint, and the blocks of the remaining tiers are fixed to the tank surface and interconnected with an adhesive material.

The invention is directed to a method of insulating tanks having a capacity between 200 m.sup.3 and 20,000 m.sup.3 used for storage of oil and oil products. In the method, foundation elements, including tank bottom heat insulation, are prepared. The tank is mounted on the prepared foundation, then insulation of the tank walls and roof is installed. Supporting relieving skirts are mounted on the tank walls and roof, forming tiers. The tiers are filled with foam glass blocks having expansion joints. A top coat of metal sheets is mounted on the outer surface of the blocks. Foam glass blocks in the lower tier are made to be removable to provide access to a wall-bottom corner weld joint, and the blocks of the remaining tiers are fixed to the tank surface and interconnected with an adhesive material.

A composite elevated storage tank for smaller capacities having an improved anchorage connecting the steel tank to the reinforced concrete pedestal. The anchorage includes tank anchor assemblies and an insulator at a top surface of the concrete pedestal, with anchors embedded in the concrete. The steel tank includes a skirt and base plates welded to a bottom cone section of the tank. The skirt, base plates, and tank anchor assemblies enable the steel tank and the reinforced concrete pedestal to be constructed on-site simultaneously.

A composite elevated storage tank for smaller capacities having an improved anchorage connecting the steel tank to the reinforced concrete pedestal. The anchorage includes tank anchor assemblies and an insulator at a top surface of the concrete pedestal, with anchors embedded in the concrete. The steel tank includes a skirt and base plates welded to a bottom cone section of the tank. The skirt, base plates, and tank anchor assemblies enable the steel tank and the reinforced concrete pedestal to be constructed on-site simultaneously.