Scope

The requirements across the whole width of the page apply both to fixed tanks (tank-vehicles), to
demountable tanks and battery-vehicles, and to tank-containers, tank swap bodies and MEGCs. Those
contained in a single column apply only:
- to fixed tanks (tank-vehicles), to demountable tanks and battery-vehicles (left hand column);
- to tank-containers, tank swap bodies and MEGCs (right hand column).

These requirements shall apply to:

fixed tanks (tank-vehicles), demountable tanks
and battery-vehicles
tank-containers, tank swap bodies and MEGCs

used for the carriage of gaseous, liquid, powdery or granular substances.

Section 6.8.2 sets out the requirements applicable to fixed tanks (tank-vehicles), to demountable tanks,
tank-containers, tank swap bodies intended for the carriage of substances of all classes and batteryvehicles
and MEGCs for gases of Class 2. Sections 6.8.3 to 6.8.5 contain special requirements
supplementing or modifying the requirements of section 6.8.2.

For provisions concerning use of these tanks, see Chapter 4.3.

Requirements applicable to all classes

Construction

Basic principles

Shells, their attachments and their service and structural equipment shall be designed to withstand
without loss of contents (other than quantities of gas escaping through any degassing vents):
- static and dynamic stresses in normal conditions of carriage as defined in 6.8.2.1.2 and
6.8.2.1.13;
- prescribed minimum stresses as defined in 6.8.2.1.15.

The tanks and their fastenings shall be capable of
absorbing, under the maximum permissible load,
the forces exerted by:
- in the direction of travel: twice the total
mass;
- at right angles to the direction of travel: the
total mass;
- vertically upwards: the total mass;
- vertically downwards: twice the total mass.
Tank-containers and their fastenings shall,
under the maximum permissible load be
capable of absorbing the forces equal to those
exerted by:
- in the direction of travel: twice the total
mass;
- horizontally at right angles to the direction
of travel: the total mass; (where the
direction of travel is not clearly
determined, twice the total mass in each
direction);
- vertically upwards: the total mass;
- vertically downwards: twice the total
mass.

 

The walls of the shells shall have at least the thickness specified in

6.8.2.1.17 to 6.8.2.1.21 6.8.2.1.17 to 6.8.2.1.20.

 

Shells shall be designed and constructed in accordance with the requirements of standards listed in
6.8.2.6 or of a technical code recognized by the competent authority, in accordance with 6.8.2.7, in
which the material is chosen and the shell thickness determined taking into account maximum and
minimum filling and working temperatures, but the following minimum requirements of 6.8.2.1.6 to
6.8.2.1.26 shall be met.

Tanks intended to contain certain dangerous substances shall be provided with additional protection.
This may take the form of additional thickness of the shell (increased calculation pressure) determined
in the light of the dangers inherent in the substances concerned or of a protective device (see the
special provisions of 6.8.4).

Welds shall be skilfully made and shall afford the fullest safety. The execution and checking of welds
shall comply with the requirements of 6.8.2.1.23.

Measures shall be taken to protect shells against the risk of deformation as a result of a negative
internal pressure. Shells, other than shells according to 6.8.2.2.6, designed to be equipped with
vacuum valves shall be able to withstand, without permanent deformation, an external pressure of not
less than 21 kPa (0.21 bar) above the internal pressure. Shells used for the carriage of solid substances
(powdery or granular) of packing groups II or III only, which do not liquefy during carriage, may be
designed for a lower external pressure but not less than 5 kPa (0.05 bar). The vacuum valves shall be
set to relieve at a vacuum setting not greater than the tank's design vacuum pressure. Shells, which are
not designed to be equipped with a vacuum valve shall be able to withstand, without permanent
deformation an external pressure of not less than 40 kPa (0.4 bar) above the internal pressure.

Materials for shells

Shells shall be made of suitable metallic materials which, unless other temperature ranges are
prescribed in the various classes, shall be resistant to brittle fracture and to stress corrosion cracking
between -20 °C and +50 °C.
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