Standards Development

Scope

This document specifies the requirements for the materials, design, fabrication, erection, testing and inspection of site built, vertical, cylindrical, flat bottomed, above ground, welded, steel tanks for the storage of liquids at ambient temperatures and above.

It is concerned with the structural design of the basic tank structure and does not provide requirements for considering process design, operational issues, safety and firefighting facilities, in-service inspection, maintenance, or repair.

This document is intended for use in conjunction with EN 1993-4-2 and so adheres the general principles and performance requirements for the structural design and serviceability limit states of those tank components. Specific requirements are addressed in EN 14015.

It is applicable to:

–      closed-top tanks, with and without internal floating roofs;

–      open-top tanks, with and without floating roofs;

–      tanks for which:

a)   the design pressure is not greater than 60 mbar;

b)   the design internal negative pressure is not lower than 6,0 mbar;

c)   the design metal temperature is between –40 °C and +300 °C;

d)   the maximum design liquid level is not higher than the top of the cylindrical shell;

e)   the maximum allowable stress does not exceed 260 N/mm2.

The limits of application of this document terminate at the following locations:

–      face of the first flange in a bolted flange connection;

–      first threaded joint on the pipe or coupling outside of the tank shell, roof or bottom;

–      first circumferential joint in a pipe not having a flange connection.

This document does not apply to tanks where the product is refrigerated to maintain it as a liquid at atmospheric pressure.