Packing Instruction 200

For cylinders, the general packing requirements of 4;1.1 and 4;4.1.1 must be met.

Cylinders, constructed as specified in Part 6, Chapter 5 are authorized for the transport of a specific substance when specified in the following tables (Table 1 and Table 2). Cylinders other than UN marked and certified cylinders may be used if the design, construction, testing, approval and marks conform to the requirements of the appropriate national authority in which they are approved and filled. The substances contained must be permitted in cylinders and permitted for air transport according to these Instructions. Cylinders for which prescribed periodic tests have become due must not be charged and offered for transport until such retests have been successfully completed. Valves must be suitably protected or must be designed and constructed in such a manner that they are able to withstand damage without leakage as specified in Annex B of ISO 10297:1999. Cylinders with capacities of one litre or less must be packaged in outer packaging constructed of suitable material of adequate strength and design in relation to the packaging capacity and its intended use, and secured or cushioned so as to prevent significant movement within the outer packaging during normal conditions of transport. For some substances, the special packing provisions may prohibit a particular type of cylinder. The following requirements must be met:

1) Pressure relief devices must be fitted on cylinders used for the transport of UN 1013 Carbon dioxide and UN 1070 Nitrous oxide. Other cylinders must be fitted with a pressure relief device if specified by the appropriate national authority of the country of use. The type of pressure relief device, the set to discharge pressure and relief capacity of pressure relief devices, if required, must be specified by the appropriate national authority of the country of use. Manifolding of cylinders is not permitted.

2) The following two tables cover compressed gases (Table 1) and liquefied and dissolved gases (Table 2). They provide:

 a) the UN number, name and description, and classification of the substance;

 b) the LC50 for toxic substances;

 c) the types of cylinders authorized for the substance, shown by the letter "X";

 d) the maximum test period for periodic inspection of the cylinders;

 Note.- For cylinders which make use of composite materials, the maximum test period must be five years. The test period may be extended to that specified in Tables 1 and 2 (i.e. up to ten years), if approved by the appropriate national authority of the country of use.

 e) the minimum test pressure of the cylinders;

 f) the maximum working pressure of the cylinders for compressed gases (where no value is given, the working pressure must not exceed two thirds of the test pressure) or the maximum filling ratio(s) dependent on the test pressure(s) for liquefied and dissolved gases;

 g) special packing provisions that are specific to a substance.

3) In no case must cylinders be filled in excess of the limit permitted in the following requirements:

 a) For compressed gases, the working pressure must be not more than two thirds of the test pressure of the cylinders. Restrictions to this upper limit on working pressure are imposed by special packing provision "o". In no case must the internal pressure at 65C exceed the test pressure.

 b) For high pressure liquefied gases, the filling ratio must be such that the settled pressure at 65C does not exceed the test pressure of the cylinders.

The use of test pressures and filling ratios other than those in the table is permitted provided that the above criterion is met, except where special packing provision "o" applies.

For high pressure liquefied gases and gas mixtures for which relevant data are not proavailable, the maximum filling ratio (FR) must be determined as follows:

FR = 8.5  10-4  dg  Ph

where
FR = maximum filling ratio 
dg = gas density (at 15 C, 1 bar)(in g/l)
Ph = minimum test pressure (in bar)

If the density of the gas is unknown, the maximum filling ratio must be determined as follows:

     Ph * MM * 10E-3
FR = ----------------
         R * 338
where
FR = maximum filling ratio
Ph = minimum test pressure (in bar)
MM = molecular mass (in g/mol)
R = 8.31451 x 10-2 bar.l/mol.K (gas constant)

For gas mixtures, the average molecular mass is to be taken, taking into account the volumetric concentrations of the various components.

 c) For low pressure liquefied gases, the maximum mass of contents per litre of water capacity must equal 0.95 times the density of the liquid phase at 50C; in addition, the liquid phase must not fill the cylinder at any temperature up to 60C. The test pressure of the cylinder must be at least equal to the vapour pressure (absolute) of the liquid at 65C, minus 100 kPa (1 bar).

For low pressure liquefied gases for which filling data is not provided in the table, the maximum filling ratio must be determined as follows:

FR = (0.0032  BP - 0.24)  d1

where
FR = maximum filling ratio
BP = boiling point (in Kelvin)
d1 = density of the liquid at boiling point (in kg/l)

 d) For UN 1001, Acetylene, dissolved, and UN 3374 Acetylene, solvent free, see p).

 e) For liquefied gases charged with compressed gases, both components - the liquefied gas and the compressed gas - have to be taken into consideration in the calculation of the internal pressure in the cylinder.

The maximum mass of contents per litre of water capacity must not exceed 0.95 times the density of the liquid phase at 50C; in addition, theliquid phase must not completely fill the cylinder at any temperature upto 60C.

When filled, the internal pressure at 65C must not exceed the testpressure of the cylinders. The vapour pressures and volumetric expansionsof all substances in the cylinders must be considered. When experimentaldata is not available, the following steps must be carried out:

    i)   Calculation of the vapour pressure of the liquefied gas and of the partial pressure of the compressed gas at 15C (filling temperature);

   ii)  Calculation of the volumetric expansion of the liquid phase resulting from the heating from 15C to 65C and calculation of the remaining volume for the gaseous phase;

  iii) Calculation of the partial pressure of the compressed gas at 65C considering the volumetric expansion of the liquid phase;

  Note.- The compressibility factor of the compressed gas at 15C and 65C must be considered.

   iv)  Calculation of the vapour pressure of the liquefied gas at 65C;

    v)   The total pressure is the sum of the vapour pressure of the liquefied gas and the partial pressure of the compressed gas at 65C;

   vi)  Consideration of the solubility of the compressed gas at 65C in the liquid phase;

The test pressure of the cylinder must not be less than the calculated total pressure minus 100 kPa (1bar).

If the solubility of the compressed gas in the liquefied phase is not known for the calculation, the test pressure can be calculated without taking the gas solubility (sub-paragraph (vi)) into account.

4) Gas mixtures containing any of the following gases must not be offered for transport in aluminium alloy cylinders unless approved by the appropriate national authority of the State of Origin:

UN 1037 Ethyl chloride
UN 1063 Methyl chloride
UN 1063 Refrigerant gas R 40
UN 1085 Vinyl bromide, stabilized
UN 1086 Vinyl chloride, stabilized
UN 1860 Vinyl fluoride, stabilized
UN 1912 Methyl chloride and methylene chloride mixture

5) The filling of cylinders must be carried out by qualified staff usingappropriate equipment and procedures. The procedures should include checksof:

 a) The conformity of cylinders and accessories with these Instructions;

 b) Their compatibility with the product to be transported;

 c) The absence of damage which might affect safety;

 d) Compliance with the degree or pressure of filling, as appropriate;

 e) Marks and identification.

These requirements are deemed to be met if the following standards are applied:

ISO 10691: 2004 Gas cylinders - Refillable welded steel cylinders for liquefied petroleum gas (LPG) - Procedures for checking before, during and after filling.

ISO 11372: 2011 Gas cylinders - Acetylene cylinders - Filling conditions and filling inspection

ISO 11755: 2005 Gas cylinders - Cylinder bundles for compressed and liquefied gases (excluding acetylene) - Inspection at time of filling

ISO 13088: 2011 + AMD. 1:2020 Gas cylinders - Acetylene cylinder bundles - Filling conditions and filling inspection

ISO 24431:2016 Gas cylinders - Seamless, welded and composite cylinders for compressed and liquefied gases (excluding acetylene) - Inspection at time of filling

6) "Special packing provisions":

Material compatibility

 a) Aluminium alloy cylinders are forbidden.

 b) Copper valves are forbidden.

 c) Metal parts in contact with the contents must not contain more than 65 per cent copper.

 d) When steel cylinders or composite cylinders with steel liners are used, only those bearing the "H" mark in accordance with 6;5.2.7.4 p) are permitted.

Gas specific provisions:

 l) UN 1040 Ethylene oxide may also be packed in hermetically sealed glass ampoules or metal inner packagings suitably cushioned in fibreboard, wooden or metal boxes meeting the Packing Group I performance level. The maximum quantity permitted in any glass inner packaging is 30 g, and the maximum quantity permitted in any metal inner packaging is 200 g. After filling, each inner packaging must be determined to be leak-tight by placing the inner packaging in a hot water bath at a temperature, and for a period of time, sufficient to ensure that an internal pressure equal to the vapour pressure of ethylene oxide at 55C is achieved. The maximum net mass in any outer packaging must not exceed 2.5 kg. When cylinders are used, they must be of the seamless or welded steel types that are equipped with suitable pressure relief devices. Each cylinder must be tested for leakage with an inert gas before each refilling and must be insulated with three coats of heat retardant paint or in any equally efficient manner. The maximum net quantity per cylinder must not exceed 25 kg.

 m) Cylinders must be filled to a working pressure not exceeding 5 bar.

 o) In no case must the working pressure or filling ratio shown in the table be exceeded.

 p) For UN 1001 Acetylene, dissolved, and UN 3374 Acetylene, solvent free: cylinders must be filled with a homogeneous monolithic porous mass; the working pressure and the quantity of acetylene must not exceed the values prescribed in the approval or in ISO 3807-1:2000, ISO 3807-2:2000 or ISO 3807:2013, as applicable.

For UN 1001 Acetylene, dissolved, cylinders must contain a quantity of acetone or suitable solvent as specified in the approval (see ISO 3807-1:2000, ISO 3807-2:2000 or ISO 3807-2013, as applicable); cylinders fitted with pressure relief devices must be transported vertically.

The test pressure of 52 bar applies only to cylinders fitted with a fusible plug.

 ra) Ethyl chloride may be carried in securely sealed glass ampoules containing not more than 5 g of ethyl chloride and filled with an ullage of not less than 7.5 per cent at 21C. Ampoules must be cushioned with efficient non-combustible material in partitioned cartons to the extent of not more than 12 ampoules per carton. The cartons must be tightly packed to prevent movement in wooden boxes (4C1, 4C2), plywood boxes (4D), reconstituted wood boxes (4F), fibreboard boxes (4G) or plastic boxes (4H1, 4H2) that meet the performance testing requirements of 6;4 at the Packing Group II performance level. Not more than 300 g of ethyl chloride is permitted per package.

 s) Aluminium alloy cylinders must be:

  a) Equipped only with brass or stainless steel valves; and

  b) Cleaned in accordance with ISO 11621:1997 and not contaminated with oil.

Periodic inspection:

 u) The interval between periodic tests may be extended to 10 years for aluminium alloy cylinders when the alloy of the cylinder has been subjected to stress corrosion testing as specified in ISO 7866:2012 + Cor 1:2014.

 v) The interval between periodic inspections for steel cylinders may be extended to 15 years if approved by the appropriate national authority of the country of use.

Requirements for N.O.S. descriptions and for mixtures:

 z) The construction materials of the cylinders and their accessories must be compatible with the contents and must not react to form harmful or dangerous compounds therewith.

The test pressure and filling ratio must be calculated in accordance with the relevant requirements of PI 200.

The necessary steps must be taken to prevent dangerous reactions (i.e. polymerization or decomposition) during transport. If necessary, stabilization or addition of an inhibitor must be required.

 Note.- For the carriage of oxygen to provide life support to aquatic animals, see Note 7 of the Introductory Notes to this Part.