An attachable flotation device for a fuel storage cap of a watercraft, the fuel storage cap including an outer surface, an inner surface, and an engagement portion that engages a corresponding portion of the watercraft to cover access to a fuel tank of the watercraft, comprising a floatable material including a top and a bottom; and an attachment mechanism on the bottom of the floatable material that is attachable to the outer surface of the fuel storage cap to attach the floatable material to the fuel storage cap, the floatable material providing sufficient buoyancy to enable the fuel storage cap to float in water when the fuel storage cap accidentally falls in the water during refueling, preventing the fuel storage cap from sinking, and allowing the fuel storage cap to be more readily located and retrieved.

A method for removing sludge from a crude oil storage tank comprising a bottom and a moveable roof configured to float on the top of a quantity of crude oil disposed in said storage tank, where the method includes reducing a volume of crude oil in the storage tank to about a level of a sludge sediment in the storage tank, measuring a topology of the sludge disposed on said bottom, reliquefying asphaltene deposits, pumping the reliquefying asphaltene deposits out of the storage tank, wherein the method is performed without the entry of one or more persons into said storage tank.

A method for removing sludge from a crude oil storage tank comprising a bottom and a moveable roof configured to float on the top of a quantity of crude oil disposed in said storage tank, where the method includes reducing a volume of crude oil in the storage tank to about a level of a sludge sediment in the storage tank, measuring a topology of the sludge disposed on said bottom, reliquefying asphaltene deposits, pumping the reliquefying asphaltene deposits out of the storage tank, wherein the method is performed without the entry of one or more persons into said storage tank.

A dome-based cyclic inert sealing system for an external floating roof tank includes the external floating roof tank, a dome structure, an inert sealing pipeline, and a gas source servo device; wherein the dome structure is formed by a top portion of a tank wall of the external floating roof tank for sealing; the dome structure together with an internal wall of the external floating roof tank, a floating plate and a sealing device form a gas phase space which is isolated from atmosphere, so as to fill the gas phase space with an inert sealing medium; the inert sealing medium is a gas fire-fighting medium used in a suffocation fire-fighting method; the gas source servo device is connected to the gas phase space through the inert sealing pipeline and communicates through a valve for feedback-controlling states of the inert sealing medium in the gas phase space.

A dome-based cyclic inert sealing system for an external floating roof tank includes the external floating roof tank, a dome structure, an inert sealing pipeline, and a gas source servo device; wherein the dome structure is formed by a top portion of a tank wall of the external floating roof tank for sealing; the dome structure together with an internal wall of the external floating roof tank, a floating plate and a sealing device form a gas phase space which is isolated from atmosphere, so as to fill the gas phase space with an inert sealing medium; the inert sealing medium is a gas fire-fighting medium used in a suffocation fire-fighting method; the gas source servo device is connected to the gas phase space through the inert sealing pipeline and communicates through a valve for feedback-controlling states of the inert sealing medium in the gas phase space.

A roof panel of a sealed floating roof for a storage tank includes a first frame segment and a second frame segment. Each of the first and second frame segments includes a first depression configured to abut an adjacent top depression of a respective frame segment of a respective adjacent roof panel to form a walled trough to guide an automatic welder along a weld joint during a welding process. The roof panel also includes a panel component. The panel component includes a top sheet and a pan-shaped bottom sheet coupled to the top sheet. The pan-shaped bottom sheet is coupled to a respective upper lip of each of the first and second frame segments.

A roof panel of a sealed floating roof for a storage tank includes a first frame segment and a second frame segment. Each of the first and second frame segments includes a first depression configured to abut an adjacent top depression of a respective frame segment of a respective adjacent roof panel to form a walled trough to guide an automatic welder along a weld joint during a welding process. The roof panel also includes a panel component. The panel component includes a top sheet and a pan-shaped bottom sheet coupled to the top sheet. The pan-shaped bottom sheet is coupled to a respective upper lip of each of the first and second frame segments.

An internal floating roof for a storage tank includes a rim, a first plurality of girders, including a first girder, a second plurality of girders, including a second girder, a deck sheet, a first cap channel, a second cap channel, and a pontoon coupled to the first girder. The first plurality of girders extend in a first direction across the rim, wherein the first plurality of girders comprises a first girder. The second plurality of girders extend in a second direction, cross-wise to the first direction. The deck sheet is disposed on a first top surface of the first girder and a second top surface of the second girder. The first cap channel is coupled to a first top channel of the first girder. The first cap channel comprises a first foot configured to press a first edge of the deck sheet against the first top surface of the first girder. The first foot is welded to the deck sheet along a first length of the first cap channel. The second cap channel is coupled to a second top channel of the second girder, wherein the second cap channel comprises a second foot configured to press a second edge of the deck sheet against the second top surface of the second girder. The second foot is welded to the deck sheet along a second length of the second cap channel.

An internal floating roof for a storage tank includes a rim, a first plurality of girders, including a first girder, a second plurality of girders, including a second girder, a deck sheet, a first cap channel, a second cap channel, and a pontoon coupled to the first girder. The first plurality of girders extend in a first direction across the rim, wherein the first plurality of girders comprises a first girder. The second plurality of girders extend in a second direction, cross-wise to the first direction. The deck sheet is disposed on a first top surface of the first girder and a second top surface of the second girder. The first cap channel is coupled to a first top channel of the first girder. The first cap channel comprises a first foot configured to press a first edge of the deck sheet against the first top surface of the first girder. The first foot is welded to the deck sheet along a first length of the first cap channel. The second cap channel is coupled to a second top channel of the second girder, wherein the second cap channel comprises a second foot configured to press a second edge of the deck sheet against the second top surface of the second girder. The second foot is welded to the deck sheet along a second length of the second cap channel.

A floating cover system for a container with an open top includes a plurality of floating cover sections with cover connector devices spaced along a periphery of each at a connector spacing. A ballast tube has tube connector devices spaced along the exterior thereof at the same connector spacing. The ballast tube is open at each end and longer ballast tubes also define access holes along a length thereof. Water enters an interior of the ballast tube through the open ends thereof and the access holes, if any. When all the cover sections are installed in the container, the open top of the container is substantially covered by cover sections joined together at seams where adjacent cover connector devices are connected together, and the tube connectors are connected to the cover connectors along a ballast seam such that the ballast tube is located under the ballast seam.