A buoyant cover has a planar body, the body having a first buoyant insulating layer, a second tensile layer overlaying the first buoyant insulating layer, the planar body having a periphery configured based on the tank perimeter to provide a limited gap with the tank perimeter, and the body defining a plurality of peripheral holes positioned about the periphery and proximate the periphery. The second tensile layer may be wrapped about an edge of the first buoyant insulating layer. There may be an underlying portion of the second tensile layer near the periphery. A peripheral seam may be sewn through the underlying portion and the first buoyant insulating layer. The peripheral holes may penetrate the underlying portion. There may be grommets defining the peripheral holes. The planar body may have a circular periphery.

A scarifying rig may be mounted on the surface of a floating roof to move about the perimeter of the roof. The rig comprises a trolley, one or more support rails fixed on the trolley, and a horizontal arm mounted on the support rails for controlled movement along the support rails. A vertical rail is attached substantially to the end of the horizontal arm for reciprocating vertical movement (up and down) about the end of the horizontal arm. A nozzle assembly is mounted to the vertical rail.

A scarifying rig may be mounted on the surface of a floating roof to move about the perimeter of the roof. The rig comprises a trolley, one or more support rails fixed on the trolley, and a horizontal arm mounted on the support rails for controlled movement along the support rails. A vertical rail is attached substantially to the end of the horizontal arm for reciprocating vertical movement (up and down) about the end of the horizontal arm. A nozzle assembly is mounted to the vertical rail.

A number of implementations of an apparatus for supporting a floating roof in a storage tank are described. In one implementation, the apparatus includes at least two vertical support members coupled together at the top and bottom by spans members.

A number of implementations of an apparatus for supporting a floating roof in a storage tank are described. In one implementation, the apparatus includes at least two vertical support members coupled together at the top and bottom by spans members.

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 method of determining a status of a floating roof of a storage tank using a radar level gauge system arranged above the floating roof, the radar level gauge system being controllable to selectively evaluate reflected energy traveling towards the radar level gauge system in each propagation direction of a plurality of different propagation directions, the method comprising the steps of: radiating, by the radar level gauge system, an electromagnetic transmit signal towards the floating roof; receiving, by the radar level gauge system, an electromagnetic reflection signal resulting from reflection of the transmit signal at the floating roof; selectively evaluating, by the radar level gauge system based on the reflection signal, reflected energy traveling from the floating roof towards the radar level gauge system in each propagation direction of the plurality of different propagation directions; and determining the status of the floating roof based on the selective evaluation.

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.