Holding times for tank-containers carrying refrigerated liquefied gases

                                                            
The reference holding time for tank-containers carrying
refrigerated liquefied gases shall be determined on the
basis of the following:
(a) The effectiveness of the insulation system,
determined in accordance with 6.8.3.4.11;
b) The lowest set pressure of the pressure limiting
device(s);
(c) The initial filling conditions;
(d) An assumed ambient temperature of 30 °C;
(e) The physical properties of the individual
refrigerated liquefied gas intended to be carried.

 

                                                                                
The effectiveness of the insulation system (heat influx in
Watts) shall be determined by type testing the tankcontainers.
This test shall consist of either:
(a) A constant pressure test (for example at atmospheric
pressure) during which the loss of refrigerated
liquefied gas is measured over a period of time; or
(b) A closed system test during which the rise in
pressure in the shell is measured over a period of
time.
When performing the constant pressure test, variations
in atmospheric pressure shall be taken into account.
When performing either test corrections shall be made
for any variation of the ambient temperature from the
assumed ambient temperature reference value of 30 °C.
NOTE: ISO 21014:2006 "Cryogenic vessels —
Cryogenic insulation performance" details methods of
determining the insulation performance of cryogenic
vessels and provides a method of calculating the holding
time.

 

Inspections and tests for battery-vehicles and MEGCs

The elements and items of equipment of each battery-vehicle or MEGC shall be inspected and tested
either together or separately before being put into service for the first time (initial inspection and test).
Thereafter battery-vehicles or MEGCs the elements of which are receptacles shall be inspected at not
more than five-year intervals. Battery-vehicles and MEGCs the elements of which are tanks shall be
inspected according to 6.8.3.4.6. An exceptional inspection and test shall be performed regardless of
the last periodic inspection and test when necessary according to 6.8.3.4.16.

The initial inspection shall include:
- a check of conformity to the approved type;
- a check of the design characteristics;
- an examination of the internal and external conditions;
- a hydraulic pressure test10 at the test pressure indicated on the plate prescribed in 6.8.3.5.10;
- a leakproofness test at the maximum working pressure; and
- a check of satisfactory operation of the equipment.
 
When the elements and their fittings have been pressure-tested separately, they shall be subjected
together after assembly to a leakproofness test.
 
10 In special cases and with the agreement of the expert approved by the competent authority, the hydraulic
pressure test may be replaced by a pressure test using another liquid or gas, where such an operation does not present
any danger.

Cylinders, tubes and pressure drums and cylinders as part of bundles of cylinders shall be tested
according to packing instruction P200 or P203 in 4.1.4.1.
The test pressure of the manifold of the battery-vehicle or MEGC shall be the same as that of the
elements of the battery-vehicle or MEGC. The pressure test of the manifold may be performed as a
hydraulic test or by using another liquid or gas with the agreement of the competent authority or its
authorised body. By derogation from this requirement, the test pressure for the manifold of batteryvehicle
or MEGC shall not be less than 300 bar for UN No. 1001 acetylene, dissolved.

The periodic inspection shall include a leakproofness test at the maximum working pressure and an
external examination of the structure, the elements and the service equipment without disassembling.
The elements and the piping shall be tested at the periodicity defined in packing instruction P200 of
4.1.4.1 and in accordance with the requirements of 6.2.1.6 and 6.2.3.5 respectively. When the
elements and equipment have been pressure-tested separately, they shall be subjected together after
assembly to a leakproofness test.

An exceptional inspection and test is necessary when the battery-vehicle or MEGC shows evidence of
damaged or corroded areas, or leakage, or any other conditions, that indicate a deficiency that could
affect the integrity of the battery-vehicle or MEGC. The extent of the exceptional inspection and test
and, if deemed necessary, the disassembling of elements shall depend on the amount of damage or
deterioration of the battery-vehicle or MEGC. It shall include at least the examinations required under
6.8.3.4.17.

The examinations shall ensure that:
(a) The elements are inspected externally for pitting, corrosion, or abrasions, dents, distortions,
defects in welds or any other conditions, including leakage, that might render the batteryvehicles
or MEGCs unsafe for transport;
(b) The piping, valves, and gaskets are inspected for corroded areas, defects, and other conditions,
including leakage, that might render battery-vehicles or MEGCs unsafe for filling, discharge or
transport;
(c) Missing or loose bolts or nuts on any flanged connection or blank flange are replaced or
tightened;
(d) All emergency devices and valves are free from corrosion, distortion and any damage or defect
that could prevent their normal operation. Remote closure devices and self-closing stop-valves
shall be operated to demonstrate proper operation;
(e) Required marks on the battery-vehicles or MEGCs are legible and in accordance with the
applicable requirements; and
(f) Any framework, supports and arrangements for lifting the battery-vehicles or MEGCs are in
satisfactory condition.

The tests, inspections and checks in accordance with 6.8.3.4.12 to 6.8.3.4.17 shall be carried out by
the expert approved by the competent authority. Certificates shall be issued showing the results of
these operations, even in the case of negative results.
These certificates shall refer to the list of the substances permitted for carriage in this battery-vehicle
or MEGC in accordance with 6.8.2.3.1.
A copy of these certificates shall be attached to the tank record of each tank, battery-vehicle or MEGC
tested (see 4.3.2.1.7).

Marking

The following additional particulars shall be marked by stamping or by any other similar method on
the plate prescribed in 6.8.2.5.1, or directly on the walls of the shell itself if the walls are so reinforced
that the strength of the tank is not impaired.

On tanks intended for the carriage of only one substance:
- the proper shipping name of the gas and, in addition for gases classified under an n.o.s. entry,
the technical name16;
This indication shall be supplemented:
- in the case of tanks intended for the carriage of compressed gases filled by volume (pressure),
by an indication of the maximum filling pressure at 15 °C permitted for the tank; and
- in the case of tanks intended for the carriage of compressed gases filled by mass, and of
liquefied gases, refrigerated liquefied gases or dissolved gases by an indication of the
maximum permissible load mass in kg and of the filling temperature if below
–20 °C.

On multipurpose tanks:
- the proper shipping names of the gases and, in addition for gases classified under an n.o.s.
entry, the technical name of the gases 16 for whose carriage the tank is approved.
These particulars shall be supplemented by an indication of the maximum permissible load mass in kg
for each gas.

On tanks intended for the carriage of refrigerated liquefied gases:
- the maximum working pressure allowed.
 
                                                                            
- reference holding time (in days or hours)
for each gas 13;
- the associated initial pressures (in bar
gauge or kPa gauge)13

 

On tanks equipped with thermal insulation:
- the inscription "thermally insulated" or "thermally insulated by vacuum".
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