Embodiments of methods and systems for replacing a fixed roof of a storage tank. An embodiment of a method includes pre-assembling a roof on a floor of a tank basin in the form of modules, assembling the modules on a top of the tank, and welding the modules together to form the roof of the tank. An embodiment of a system for replacing the fixed roof of a storage tank includes a template, a coil support, a plurality of roof modules, a plurality of eyelets, a walking beam, and a hauler.

A system for covering two or more containers and associated methods are provided. In some embodiments, the system includes (1) one or more corner components configured to be positioned at corners of the two or more containers; (2) one or more elongated components configured to be positioned between sides of the two or more containers; and (3) one or more side supporting components positioned at the sides of the two or more containers. At least one of the one or more elongated component is formed with a socket configured to accommodate an extension of at least one of the one or more side supporting components such that the at least one elongated component and the at least one side supporting component are securely connected.

Embodiments of methods and systems for replacing a fixed roof of a storage tank. An embodiment of a method includes pre-assembling a roof on a floor of a tank basin in the form of modules, assembling the modules on a top of the tank, and welding the modules together to form the roof of the tank. An embodiment of a system for replacing the fixed roof of a storage tank includes a template, a coil support, a plurality of roof modules, a plurality of eyelets, a walking beam, and a hauler.

A container for the transport and storage of liquids comprises at least one upwardly open socket at the top of an inner container. A clamping disk has an internal thread that can be screwed onto an external thread of the socket, thereby clamping a container top at the edge of its opening. A screw lock interacts with the external thread of the socket and the internal thread of the clamping disk and prevents unintentional loosening of the clamping disk and the socket.

A hatch cover includes spring-loaded exhaust and suction valves to regulate internal tank pressure with respect to outside pressure. The valves are disposed in a ring housing. The cover further includes a spring-loaded locking bolt configured to engage the hatch base and thereby provide a retaining force between the housing and the hatch base. The exhaust-valve springs may be selectively preloaded to establish a target exhaust pressure. The locking-bolt spring may be selectively disengaged or overcome to release engagement of the bolt from the hatch base.

A storage tank hatch isolation system for a storage tank having a vertical riser attached to a top of the storage tank and having a cover with an aperture, a connecting member extending from a side of the vertical riser, a distal end of the connecting member being attached to a tank hatch, and a valve assembly assessable through the aperture in the cover, the valve assembly configured to be moved from an open position in which flow through the vertical riser to the connecting member is not obstructed, and a closed position in which flow through the vertical riser to the connecting member is obstructed.