Aboveground Storage Tanks, Fixed Roof and Floating Roof Tanks

Aboveground Storage Tanks, Fixed Roof and Floating Roof Tanks

Aboveground Storage Tanks, Fixed Roof & Floating Roof Tanks

Essentially there are TWO types of above ground vertical tanks included in API 650 and other similar tank guidelines: Fixed Roof Tank, Floating Roof Tanks

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There are Two types of Fixed Roof Tanks:
Cone Roof Tank
Dome Roof Tank
and
One Type of External Floating Roof Tank 
CONE ROOF TANKS:-
Main Differences between CONE ROOF & Dome Roof normally store product at atmospheric pressure and ambient temperature can be “self supporting” or “supported ”
If “supported then internal columns support the roof structure - depending upon the tank diameter several columns required have roof plates generally in the order of 6 mm thick have roof plates that are flat and not formed usually the more cost effective option for a basic tank sometimes called “umbrella” type have outside rafters
 
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Main Differences between Cone Roof & DOME ROOF
DOME ROOF TANKS:-
normal design for a tanks used to store product above atmospheric pressure - however such tanks are pressure tight and not free vented termed as “self supporting” they have roof plates that are generally thicker and formed to a dome profile
more expensive option
The Aluminum Geodesic Dome Roof is a “self supporting” dome roof
 
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Summary Tank Types
Two types of Vertical Storage Tanks
  • Fixed Roof
  • External Floating Roof Tanks Two types of Fixed Roof Tanks
  • Dome Roof
  • Cone Roof One type of External Floating Roof Tank Roof on a Fixed Roof Tank has only One purpose - to protect the Stored Product from the atmosphere Roof on an External Floating Roof Tank has TWO purposes - to protect the Stored Product from the atmosphere AND control Evaporation

ALUMINUM DOME ROOF
Aluminum and Aluminum Alloy is one of the world’s most commonly used metals
Lightness - Strength - Corrosion Resistance
The aluminum dome roof is a system of:-
• triangular lightweight extruded profiles
• connected through node points
• transmitting all the roof loads laterally to the integral tension ring
• then through sliding or fixed supports to the tank shell and the tank foundation
The framework is covered with a 1.2 mm thick aluminum sheeting
All bolted structure and no welding is required at site for its assembly and erection
Complies with the requirements of API 650 App. G.
Totally supported on the tank shell without any need for internal supports
The standard aluminum dome roof is fitted with Sliding Supports and an Integral Tension Ring. This reduces the forces being transmitted to the tank shell and generally means that there is no significant modification required to the tank
Aluminum dome roof do not require painting – EVER
Maintenance free for the entire lifetime of the tank
 
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The following features normally included in a in a standard design:

• Integral Tension Ring
• Sliding Supports
• Free Vent
Any equipment that you have on a conventional steel dome or cone roof tank can be fitted on the aluminium dome roof and without any significant modification to the equipment or the roof
The dome roof ratio (dome height : tank diameter) is about 1:6
The aluminum dome roof can be designed to support a suspended aluminum internal floating roof

Main advantages of the Aluminum Dome Roof
• aluminium dome roof is a self-supporting structure
• aluminium dome roof is a lightweight structure and when fitting on an existing external floating roof tank it is not normally necessary to reinforce the tank shell
• aluminium dome roof is fitted with an Integral Tension Ring to avoid any additional stiffening requirement of the tank shell
• aluminium dome roof does not require painting, EVER - in this respect it can be considered as maintenance free for the entire lifetime of the tank

Aluminum Dome Roofs
Geodesic – means the shortest line between two points on a curved surface
Mr Buckminister Fuller from USA developed the principal of the geodesic dome in the 1940’s primarily for social housing
Dome was developed for storage tanks in the 1980's
South Pole Research Station had an aluminum dome roof
 
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