Each element, including each individual cylinder of a bundle, intended for the carriage of toxic gases,
shall be capable of being isolated by a shut-off valve.

Battery-vehicles or MEGCs intended for the carriage of toxic gases shall not have safety valves,
unless the safety valves are preceded by a bursting disc. In the latter case, the arrangement of the
bursting disc and safety valve shall be satisfactory to the competent authority.

When battery-vehicles or MEGCs are intended for carriage by sea, the requirements of 6.8.3.2.26
shall not prohibit the fitting of safety valves conforming to the IMDG Code.

Receptacles which are elements of a battery-vehicle or MEGC intended for the carriage of flammable
gases shall be combined in groups of not more than 5 000 litres which are capable of being isolated by
a shut-off valve.
Each element of a battery-vehicle or MEGC intended for the carriage of flammable gases, when
consisting of tanks conforming to this Chapter, shall be capable of being isolated by a shut-off valve.

Type approval

No special requirements.

Inspections and tests

The materials of every welded shell with the exception of cylinders, tubes, pressure drums and
cylinders as part of bundles of cylinders which are elements of a battery-vehicle or of a MEGC shall
be tested according to the method described in 6.8.5.

The basic requirements for the test pressure are given in 4.3.3.2.1 to 4.3.3.2.4 and the minimum test
pressures are given in the table of gases and gas mixtures in 4.3.3.2.5.

The first hydraulic pressure test shall be carried out before thermal insulation is placed in position.
When the shell, its fittings, piping and items of equipment have been tested separately, the tank shall
be subjected to a leakproofness test after assembly.

The capacity of each shell intended for the carriage of compressed gases filled by mass, liquefied
gases or dissolved gases shall be determined, under the supervision of an expert approved by the
competent authority, by weighing or volumetric measurement of the quantity of water which fills the
shell; the measurement of shell capacity shall be accurate to within 1%. Determination by a
calculation based on the dimensions of the shell is not permitted. The maximum filling masses
allowed in accordance with packing instruction P200 or P203 in 4.1.4.1 as well as 4.3.3.2.2 and
4.3.3.2.3 shall be prescribed by an approved expert.

Checking of the welds shall be carried out in accordance with the λ=1 requirements of 6.8.2.1.23.

By derogation from the requirements of 6.8.2.4.2, the periodic inspections shall take place:

at least after six years at least after eight years
 
of service and thereafter at least every 12 years in the case of tanks intended for the carriage of
refrigerated liquefied gases.
 
The intermediate inspections according                  
to 6.8.2.4.3 shall be carried out at least
six years after each periodic inspection.
A leakproofness test or an intermediate inspection
according to 6.8.2.4.3 may be performed, at the request
of the competent authority, between any two successive
periodic inspections.

 

In the case of vacuum-insulated tanks, the hydraulic-pressure test and the check of the internal
condition may, with the consent of the approved expert, be replaced by a leakproofness test and
measurement of the vacuum.

If, at the time of periodic inspections, openings have been made in shells intended for the carriage of
refrigerated liquefied gases, the method by which they are hermetically closed before the shells are
returned to service shall be approved by the approved expert and shall ensure the integrity of the shell.

Leakproofness tests of tanks intended for the carriage of gases shall be performed at a pressure of not
less than:
- For compressed gases, liquefied gases and dissolved gases: 20% of the test pressure;
- For refrigerated liquefied gases: 90% of the maximum working pressure.
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