Requirements for non-UN pressure receptacles not designed, constructed and tested according to referenced standards
To reflect scientific and technical progress or where no standard is referenced in 6.2.2 or 6.2.4, or to
deal with specific aspects not addressed in a standard referenced in 6.2.2 or 6.2.4, the competent
authority may recognize the use of a technical code providing the same level of safety.
In the type approval the issuing body shall specify the procedure for periodic inspections if the
standards referenced in 6.2.2 or 6.2.4 are not applicable or shall not be applied.
The competent authority shall transmit to the secretariat of UNECE a list of the technical codes that it
recognises. The list should include the following details: name and date of the code, purpose of the
code and details of where it may be obtained. The secretariat shall make this information publicly
available on its website.
A standard which has been adopted for reference in a future edition of the ADR may be approved by
the competent authority for use without notifying the secretariat of UNECE.
The requirements of 6.2.1, 6.2.3 and the following requirements however shall be met.
NOTE: For this section, the references to technical standards in 6.2.1 shall be considered as
references to technical codes.
The following provisions contain examples of materials that may be used to comply with
requirements for materials in 188.8.131.52:
(a) Carbon steel for compressed, liquefied, refrigerated liquefied gases and dissolved gases as
well as for substances not in Class 2 listed in Table 3 of packing instruction P200 of 184.108.40.206;
(b) Alloy steel (special steels), nickel, nickel alloy (such as monel) for compressed, liquefied,
refrigerated liquefied gases and dissolved gases as well as for substances not in Class 2 listed in
Table 3 of packing instruction P200 of 220.127.116.11;
(c) Copper for:
(i) gases of classification codes 1A, 1O, 1F and 1TF, whose filling pressure referred to
a temperature of 15 °C does not exceed 2 MPa (20 bar);
(ii) gases of classification code 2A and also UN No. 1033 dimethyl ether; UN No. 1037 ethyl
chloride; UN No. 1063 methyl chloride; UN No. 1079 sulphur dioxide;
UN No. 1085 vinyl bromide; UN No. 1086 vinyl chloride; and UN No. 3300
ethylene oxide and carbon dioxide mixture with more than 87% ethylene oxide;
(iii) gases of classification codes 3A, 3O and 3F;
(d) Aluminium alloy: see special requirement "a" of packing instruction P200 (10) of 18.104.22.168;
(e) Composite material for compressed, liquefied, refrigerated liquefied gases and dissolved
(f) Synthetic materials for refrigerated liquefied gases; and
(g) Glass for the refrigerated liquefied gases of classification code 3A other than UN No. 2187
carbon dioxide, refrigerated, liquid or mixtures thereof, and gases of classification code 3O.
Metal cylinders, tubes, pressure drums and bundles of cylinders
At the test pressure, the stress in the metal at the most severely stressed point of the pressure
receptacle shall not exceed 77% of the guaranteed minimum yield stress (Re).
"Yield stress" means the stress at which a permanent elongation of 2 per thousand (i.e. 0.2%) or, for
austenitic steels, 1% of the gauge length on the test-piece, has been produced.
NOTE: In the case of sheet-metal the axis of the tensile test-piece shall be at right angles to the
direction of rolling. The permanent elongation at fracture, shall be measured on a test-piece of
circular cross-section in which the gauge length "l" is equal to five times the diameter "d" (l = 5d); if
test pieces of rectangular cross-section are used, the gauge length "l" shall be calculated by the
where F0 indicates the initial cross-sectional area of the test-piece.
Pressure receptacles and their closures shall be made of suitable materials which shall be resistant to
brittle fracture and to stress corrosion cracking between –20 °C and +50 °C.
Welds shall be skilfully made and shall afford the fullest safety.
Additional provisions relating to aluminium-alloy pressure receptacles for compressed gases, liquefied gases, dissolved gases and non pressurized gases subject to special requirements (gas samples) as well as articles containing gas under pressure other than aerosol dispensers and small receptacles containing gas (gas cartridges)
The materials of aluminium-alloy pressure receptacles which are to be accepted shall satisfy the
Rm, in MPa (= N/mm2)
49 to 186
196 to 372
196 to 372
343 to 490
Yield stress, Re, in MPa (= N/mm2) (permanent
set = 0,2%)
10 to 167
59 to 314
137 to 334
206 to 412
Permanent elongation at fracture (l = 5d), in %
12 to 40
12 to 30
12 to 30
11 to 16
Bend test (diameter of former d = n e, where e is the thickness of the test piece)
n = 5 (Rm 98)
n = 6 (Rm > 98)
n = 6 (Rm 325)
n = 7 (Rm > 325)
n = 6 (Rm 325)
n = 7 (Rm > 325)
n = 7 (Rm 392)
n = 8 (Rm > 392)
Aluminium Association Series Number a
a See "Aluminium Standards and Data", Fifth edition, January 1976, published by the Aluminium Association,
750 Third Avenue, New York.
The actual properties will depend on the composition of the alloy concerned and on the final treatment
of the pressure receptacle, but whatever alloy is used the thickness of the pressure receptacle shall be
calculated by one of the following formulae:
e = minimum thickness of pressure receptacle wall, in mm
PMPa = test pressure, in MPa
Pbar = test pressure, in bar
D = nominal external diameter of the pressure receptacle, in mm and
Re = guaranteed minimum proof stress with 0.2% proof stress, in MPa (= N/mm2)
In addition, the value of the minimum guaranteed proof stress (Re) introduced into the formula is in
no case to be greater than 0.85 times the guaranteed minimum tensile strength (Rm), whatever the
type of alloy used.
NOTE 1: The above characteristics are based on previous experience with the following
materials used for pressure receptacles:
Column A: Aluminium, unalloyed, 99.5% pure;
Column B: Alloys of aluminium and magnesium;
Column C: Alloys of aluminium, silicon and magnesium, such as ISO/R209-Al-Si-Mg
(Aluminium Association 6351);
Column D: Alloys of aluminium, copper and magnesium.
NOTE 2: The permanent elongation at fracture is measured by means of test-pieces of circular
cross-section in which the gauge length "l" is equal to five times the diameter "d" (l = 5d); if
test-pieces of rectangular section are used the gauge length shall be calculated by the formula:
where Fo is the initial cross-section area of the test-piece.
NOTE 3: (a) The bend test (see diagram) shall be carried out on specimens obtained by
cutting into two equal parts of width 3e, but in no case less than 25 mm, an
annular section of a cylinder. The specimens shall not be machined elsewhere
than on the edges;
(b) The bend test shall be carried out between a mandrel of diameter (d) and two
circular supports separated by a distance of (d + 3e). During the test the inner
faces shall be separated by a distance not greater than the diameter of the
(c) The specimen shall not exhibit cracks when it has been bent inwards around the
mandrel until the inner faces are separated by a distance not greater than the
diameter of the mandrel;
(d) The ratio (n) between the diameter of the mandrel and the thickness of the
specimen shall conform to the values given in the table.
A lower minimum elongation value is acceptable on condition that an additional test approved by the
competent authority of the country in which the pressure receptacles are made proves that safety of
carriage is ensured to the same extent as in the case of pressure receptacles constructed to comply with
the characteristics given in the table in 22.214.171.124.1 (see also EN 1975:1999 + A1:2003).
The wall thickness of the pressure receptacles at the thinnest point shall be the following:
- Where the diameter of the pressure receptacle is less than 50 mm: not less than 1.5 mm;
- Where the diameter of the pressure receptacle is from 50 to 150 mm: not less than 2 mm; and
- Where the diameter of the pressure receptacle is more than 150 mm: not less than 3 mm.
The ends of the pressure receptacles shall have a semicircular, elliptical or "basket-handle" section;
they shall afford the same degree of safety as the body of the pressure receptacle.
Pressure receptacles in composite materials
For composite cylinders, tubes, pressure drums and bundles of cylinders which make use of
composite materials, the construction shall be such that a minimum burst ratio (burst pressure divided
by test pressure) is:
- 1.67 for hoop wrapped pressure receptacles;
- 2.00 for fully wrapped pressure receptacles.
Closed cryogenic receptacles
The following requirements apply to the construction of closed cryogenic receptacles for refrigerated
If non-metallic materials are used, they shall resist brittle fracture at the lowest working temperature
of the pressure receptacle and its fittings.
The pressure relief devices shall be so constructed as to work perfectly even at their lowest working
temperature. Their reliability of functioning at that temperature shall be established and checked by
testing each device or a sample of devices of the same type of construction.
The vents and pressure relief devices of pressure receptacles shall be so designed as to prevent the
liquid from splashing out.
General requirements for aerosol dispensers, small receptacles containing gas (gas cartridges) and fuel cell cartridges containing liquefied flammable gas