P203

P203	PACKING INSTRUCTION	P203
This instruction applies to Class 2 refrigerated liquefied gases.
Requirements for closed cryogenic receptacles:
(1) The special packing provisions of 4.1.6 shall be met.
(2) The requirements of Chapter 6.2 shall be met.
(3) The closed cryogenic receptacles shall be so insulated that they do not become coated with frost.
(4) Test pressure Refrigerated liquids shall be filled in closed cryogenic receptacles with the following minimum test pressures:
(a) For closed cryogenic receptacles with vacuum insulation, the test pressure shall not be less than 1.3 times the sum of the maximum internal pressure of the filled receptacle, including during filling and discharge, plus 100 kPa (1 bar);
(b) For other closed cryogenic receptacles, the test pressure shall be not less than 1.3 times the maximum internal pressure of the filled receptacle, taking into account the pressure developed during filling and discharge.
(5) Degree of filling For non-flammable, non-toxic refrigerated liquefied gases (classification codes 3A and 3O) the volume of liquid phase at the filling temperature and at a pressure of 100 kPa (1 bar) shall not exceed 98% of the water capacity of the pressure receptacle. For flammable refrigerated liquefied gases (classification code 3F) the degree of filling shall remain below the level at which, if the contents were raised to the temperature at which the vapour pressure equalled the opening pressure of the relief valve, the volume of the liquid phase would reach 98% of the water capacity at that temperature.
(6) Pressure-relief devices Closed cryogenic receptacles shall be fitted with at least one pressure-relief device.
(7) Compatibility Materials used to ensure the leakproofness of the joints or for the maintenance of the closures shall be compatible with the contents. In the case of receptacles intended for the carriage of oxidizing gases (classification code 3O), these materials shall not react with these gases in a dangerous manner.
Periodic inspection The periodic inspection and test frequencies of pressure relief valves in accordance with 6.2.1.6.3 shall not exceed five years. The periodic inspection and test frequencies of non-UN closed cryogenic receptacles in accordance with 6.2.3.5.2 shall not exceed 10 years.

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P203	PACKING INSTRUCTION (cont'd)	P203
Requirements for open cryogenic receptacles: Only the following non oxidizing refrigerated liquefied gases of classification code 3A may be carried in open cryogenic receptacles: UN Nos. 1913, 1951, 1963, 1970, 1977, 2591, 3136 and 3158.
Open cryogenic receptacles shall be constructed to meet the following requirements:
(1) The receptacles shall be designed, manufactured, tested and equipped in such a way as to withstand all conditions, including fatigue, to which they will be subjected during their normal use and during normal conditions of carriage.
(2) The capacity shall be not more than 450 litres.
(3) The receptacle shall have a double wall construction with the space between the inner and outer wall being evacuated (vacuum insulation). The insulation shall prevent the formation of hoar frost on the exterior of the receptacle.
(4) The materials of construction shall have suitable mechanical properties at the service temperature.
(5) Materials which are in direct contact with the dangerous goods shall not be affected or weakened by the dangerous goods intended to be carried and shall not cause a dangerous effect, e.g. catalysing a reaction or reacting with the dangerous goods.
(6) Receptacles of glass double wall construction shall have an outer packaging with suitable cushioning or absorbent materials which withstand the pressures and impacts liable to occur under normal conditions of carriage.
(7) The receptacle shall be designed to remain in an upright position during carriage, e.g. have a base whose smaller horizontal dimension is greater than the height of the centre of gravity when filled to capacity or be mounted on gimbals.
(8) The openings of the receptacles shall be fitted with devices allowing gases to escape, preventing any splashing out of liquid, and so configured that they remain in place during carriage.
Open cryogenic receptacles shall bear the following marks permanently affixed e.g. by stamping, engraving or etching: The manufacturer’s name and address; The model number or name; The serial or batch number; The UN number and proper shipping name of gases for which the receptacle is intended; The capacity of the receptacle in litres.