Cylindrical steel tanks


ABOVEGROUND STEEL TANKS

 

Types of steel tanks

Stiffening of membrane of single deck floating roof

Methods of erection

Typical damages of aboveground steel tanks

Inspection of steel tanks

Realized projects of tanks

Typical drawings of tanks

Publications

About the author



first page

 

REALIZED PROJECTS


The author, Lyubomir A. Zdravkov, is structural engineer with emphasized interest in steel structures. He has participated in many projects for civil and industrial buildings in Bulgaria and around the world.
Aboveground steel tanks are significant part of realized projects. The team managed by Lyubomir Zdravkov finished design of many AST as follow:

1. In 2003 year is finished design of 10 tanks with 33 000 m3 capacity each one for Banias Refinery, Syria. These tanks are with single bottom and shell.
- 8 tanks for light oils products are with single deck floating roof. Diameter of the tanks D = 50,25 m and height of shell H = 17,88 m. Steel A573 Gr.70 is used for the shell and annular bottom plates. Steel A36 - for the floating roof and central bottom;
- 2 tanks are with supported cone roof.
Diameter of the tanks D = 50,25 m and height of shell H = 17,28 m. Steel A573 Gr.70 is used for the shell and steel A36 - for central bottom, roof structure and cover plates.
All tanks are designed, prefabricated and erected according to API Std. 650.

General view of tanks
Groups of AST in Banias Refinery

Structure of cone roof
Structure of supported cone roof

Spiral stairway
Spiral stairway
Floating roof and rolling ladder
Single deck floating roof and rolling ladder

2. In 2005 year is finished design of 38 aboveground steel tanks in Al-Jabalayn and Palogue, Sudan. These tanks are with single bottom and shell.
- 7 tanks are with single deck floating roof. They have 52 000 m3 capacity each one and are used for crude oil storage. Diameter of the tanks D = 60,0 m and height of shell H = 18,46 m. Steel A516 Gr.70 is used for the shell and annular bottom plates. Steel A283 Gr.C is used for the floating roof and central bottom;
- 31 smaller tanks
with fixed roofs. The bottoms, shells and roofs are made from steel A36. All of these tanks have been erected on earth type foundations.
All tanks are designed, prefabricated and erected according to API Std. 650.

General view
General view of site in Al-Jabalayn

Workers
Native workers

Erection of first shell course
Erection of first shell course
Damage by erection
Crushed tank by erection

3. The author has participated of design of group of 8 aboveground steel tanks for light oils with double shell and double bottoms for Kostinbrod, Bulgaria. Capacities V, diameters D and heights H of the tanks are different. They are designed according to standard EN 14015:2004 but shell and bottom are mounted by roll method. Roofs are cone supported, with one central column.
For more security all vertical joints of shells and catching basins are transposed on 600 mm.
All tanks have active vacuum system for leak detection and prevention of pollution of the environment.
Responsible elements like shell, bottom and structure are made from steel ВСт3пс5 (S235 J0).

Mounting of steel bottom
Mounting of steel bottom

Double steel bottom with separate net
Double steel bottom with separate net

Steel bridge between two aboveground steel tanks
Steel bridge between tanks
Group of aboveground steel tanks with double shell and double bottom
Group of steel tanks with double shell and bottom

4. In 2009 year is finished design of 7 aboveground steel tanks for diesel fuels, with 20000 m3 each one. They are situated in PB "Polykraiste", Bulgaria. Owner of these storage facilities is "ДРВВЗ". These tanks are characterized by:
- internal shell diameter D = 38,10 m and height of shell H = 19,46 m;
- single shell but with double steel bottom;
- all tanks are with single deck floating roof;
- the shell is stiffened at the top by wide stiffening ring. It acts as a service platform, too;
- ladder on shell is spiral, with hot-galvanized steps and gratings;
- continuous access to the roof is realized by rolling ladder, which is beared by supporting structure;
- rotation of the roof is limited by vertical antirotation devices;
- in the shell are mounted two manholes, which provide access into the tanks.

Standard for design of facilities - EN 14015:2004.
All tanks have active vacuum system for leak detection that watching for punches on steel bottoms.

Aboveground Steel tank
Aboveground steel tank during erection
Welding of central part of bottom
Welding of central bottom plates

Antirotation devices
Antirotation devices
and service platform

Floating roof and rolling ladder
Floating roof, rolling ladder
and supporting structure