ISO 21009-1:2008

INTERNATIONAL ISO
STANDARD 21009-1
First edition
2008-09-01
Corrected version
2008-12-01


Cryogenic vessels — Static vacuum-
insulated vessels —
Part 1:
Design, fabrication, inspection and tests
Récipients cryogéniques — Récipients isolés sous vide statiques —
Partie 1: Exigences de conception de fabrication, d'inspection, et
d'essais




Reference number
ISO 21009-1:2008(E)
©
ISO 2008

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ISO 21009-1:2008(E)
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ISO 21009-1:2008(E)
Contents Page
Foreword. v
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Symbols .5
5 General requirements.7
6 Mechanical loads .7
6.1 General.7
6.2 Load during the pressure test.7
7 Chemical effects .8
8 Thermal conditions.8
9 Material .8
9.1 Selection of materials.8
9.2 Inspection certificate.9
9.3 Materials for outer jackets and service equipment.9
10 Design .9
10.1 Design options.9
10.2 Common design requirements.9
10.3 Design by calculation.16
11 Fabrication.43
11.1 General.43
11.2 Cutting .43
11.3 Cold forming.47
11.4 Hot forming.49
11.5 Manufacturing tolerances .50
11.6 Welding .53
11.7 Non-welded permanent joints .54
12 Inspection and testing.54
12.1 Quality plan .54
12.2 Production control test plates.56
12.3 Non-destructive testing.57
12.4 Rectification .60
12.5 Pressure testing.60
13 Marking and labelling .61
14 Final assessment.62
15 Periodic inspection.62
Annex A (normative)  Elastic stress analysis .63
Annex B (normative)  Additional requirements for 9 % Ni steel .72
Annex C (normative) Pressure strengthening of vessels from austenitic stainless steels .74
Annex D (informative) Pressure limiting systems .85
Annex E (normative) Further use of the material cold properties to resist pressure loads.86
Annex F (informative) Specific weld details .90
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ISO 21009-1:2008(E)
Annex G (normative) Additional requirements for flammable fluids . 94
Annex H (informative) Relief devices. 95
Annex I (normative) Outer jacket relief devices . 96
Annex J (informative) Increased material property for austenitic stainless steel . 97
Annex K (normative) Base materials. 98
Annex L (normative) Cylindrical shells subject to external pressure (pressure on the convex
surface) — Calculation . 107
Annex M (normative) Design of openings in cylinders, spheres and cones — Calculation . 112
Annex N (normative) Design of ends for internal pressure . 122
Bibliography . 124

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ISO 21009-1:2008(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has
been established has the right to be represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 21009-1 was prepared by Technical Committee ISO/TC 220, Cryogenic vessels.
ISO 21009 consists of the following parts, under the general title Cryogenic vessels — Static vacuum-
insulated vessels:
⎯ Part 1: Design, fabrication, inspection and tests
⎯ Part 2: Operational requirements:
This corrected version incorporates the following corrections:
⎯ a single safety factor is given for the knuckle-region;
⎯ the straight flange length requirement is expressed in terms of s;
⎯ the formulae specifying cones which come under the field of application have been corrected;
⎯ the cone angle is specified for internal pressure calculation;
⎯ the formulae used for internal pressure calculation have been corrected;
⎯ the formulae used for external pressure calculation have been corrected;
⎯ the symbols used to denote wall thickness in Figure 7 have been changed;
⎯ the Greek symbols used in Figures 10.1 to 10.8 (with the exception of ϕ) have been replaced by Latin
symbols;
⎯ the relationship to the pressure vessel code has specified with regard to calculations made for austenitic
stainless steels;
⎯ the cross-references in Annex G have been corrected;
⎯ the formula for calculating moment of inertia, I, in relation to stiffening rings has been corrected;
⎯ the formulae for calculating limits of reinforcement normal to the vessel wall by increased nozzle
thickness have been corrected.

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INTERNATIONAL STANDARD ISO 21009-1:2008(E)

Cryogenic vessels — Static vacuum-insulated vessels —
Part 1:
Design, fabrication, inspection and tests
1 Scope
This part of ISO 21009 specifies requirements for the design, fabrication, inspection and testing of static
vacuum-insulated cryogenic vessels designed for a maximum allowable pressure of more than 0,5 bar.
This part of ISO 21009 applies to static vacuum-insulated cryogenic vessels for fluids as specified in 3.4 and
does not apply to vessels designed for toxic fluids.
For static vacuum-insulated cryogenic vessels designed for a maximum allowable pressure of not more than
0,5 bar this International Standard may be used as a guide.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 4126-2, Safety devices for protection against excessive pressure — Part 2: Bursting disc safety devices
ISO 4136, Destructive tests on welds in metallic materials — Transverse tensile test
ISO 9016, Destructive tests on welds in metallic materials — Impact tests — Test specimen location, notch
orientation and examination
ISO 9606-1, Approval testing of welders — Fusion welding — Part 1: Steels
ISO 9606-2, Qualification test of welders — Fusion welding — Part 2: Aluminium and aluminium alloys
ISO 9712, Non-destructive testing — Qualification and certification of personnel
ISO 10474, Steel and steel products — Inspection documents
ISO 14732, Welding personnel — Approval testing of welding operators for fusion welding and of resistance
weld setters for fully mechanized and automatic welding of metallic materials
ISO 15607, Specification and qualification of welding procedures for metallic materials — General rules
ISO 15613, Specification and qualification of welding procedures for metallic materials — Qualification based
on pre-production welding test
ISO 15614-1, Specification and qualification of welding procedures for metallic materials — Welding
procedures test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys
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ISO 21009-1:2008(E)
ISO 15614-2, Specification and qualification of welding procedures for metallic materials — Welding
procedure test — Part 2: Arc welding of aluminium and its alloys
ISO 17636, Non-destructive testing of welds — Radiographic testing of fusion-welded joints
ISO 21010, Cryogenic vessels — Gas/materials compatibility
ISO 21013-3, Cryogenic vessels — Pressure-relief accessories for cryogenic service — Part 3: Sizing and
capacity determination
ISO 21028-1 Cryogenic vessels — Toughness requirements for materials at cryogenic temperature — Part 1:
Temperatures below -80 °C
ISO 21028-2 Cryogenic vessels — Toughness requirements for materials at cryogenic temperature — Part 2:
Temperatures between -80 °C and -20 °C
ISO 23208, Cryogenic vessels — Cleanliness for cryogenic service
ISO 21009-2, Cryogenic vessels — Static vacuum insulated vessels — Part 2: Operational requirements
ISO 21011, Cryogenic vessels — Valves for cryogenic service
EN 10028-7, Flat products made of steels for pressure purposes — Part 7: Stainless steels
EN 13068-3, Non-destructive testing – Radioscopic testing — Part 3: General principles of radioscopic testing
of metallic materials by X- and gamma rays
ASME Boiler and Pressure Vessel Code, Section V: Nondestructive Examination
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
accessories
service equipment which has a safety related function with respect to pressure containment and/or control
EXAMPLE Accessories include protective or limiting devices, controlling and monitoring devices, valves and
indicators.
3.2
automatic welding
welding in which the parameters are automatically controlled
NOTE Some of these parameters may be adjusted to a limited extent, either manually or automatically, during
welding to maintain the specified welding conditions.
3.3
bursting disc device
non-reclosing pressure relief device ruptured by differential pressure
NOTE The bursting disc device is the complete assembly of installed components including, where appropriate, the
bursting disc holder.
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ISO 21009-1:2008(E)
3.4
cryogenic fluid
refrigerated liquefied gas
gas which is partially liquid because of its low temperature
NOTE This includes totally evaporated liquids and supercritical fluids.
EXAMPLE In ISO 21009, the (refrigerated, but) non-toxic gases, and mixtures of them, shown in Table 1, are
referred to as cryogenic fluids.
Table 1 — Refrigerated but non toxic gases
classification
Identification number, name and description
code
3° A Asphyxiant gases
1913 Neon, refrigerated liquid
1951 Argon, refrigerated liquid
1963 Helium, refrigerated liquid
1970 Krypton, refrigerated liquid
1977 Nitrogen, refrigerated liquid
2187 Carbon dioxide, refrigerated liquid
2591 Xenon, refrigerated liquid
3136 Trifluoromethane, refrigerated liquid
3158 Gas, refrigerated liquid, not otherwise specified (NOS)
3° O Oxidizing gases
1003 Air, refrigerated liquid
1073 Oxygen, refrigerated liquid
2201 Nitrous oxide, refrigerated liquid, oxidizing
3311 Gas, refrigerated liquid, oxidizing, NOS
3° F Flammable gases
1038 Ethylene, refrigerated liquid
1961 Ethane, refrigerated liquid
1966 Hydrogen, refrigerated liquid
1972 Methane, refrigerated liquid or natural gas, refrigerated liquid, with high methane content
3138 Ethylene, acetylene and propylene mixture, refrigerated liquid, containing at least 71,5 %
ethylene with not more than 22,5 % acetylene and not more than 6 % propylene
3312 Gas, refrigerated liquid, flammable, NOS
The flammable gases and mixtures of them may be mixed with: helium, neon, nitrogen, argon, carbon dioxide.
Oxidizing and flammable gases may not be mixed.
NOTE The classification code, identification number, name and description are according to UN codes.
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ISO 21009-1:2008(E)
3.5
documentation
technical documents delivered by the manufacturer to the owner consisting of:
⎯ all certificates establishing the conformity with this part of ISO 21009 (e.g. material, pressure test,
cleanliness, safety devices);
⎯ a short description of the vessel (including characteristic data, etc.);
⎯ a list of fluids and their net mass for which the cryogenic vessel is designed;
⎯ an operating manual (for the user) that contains
⎯ a short description of the vessel (including characteristic data, etc.),
⎯ a statement that the vessel is in conformity with this part of ISO 21009, and
⎯ the instructions for normal operation.
3.6
gross volume of the inner vessel
internal volume of the inner vessel , excluding nozzles, pipes etc. determined at minimum design temperature
and atmospheric pressure
3.7
handling loads
loads exerted on the static cryogenic vessel in all normal transport operations including loading, unloading,
pressure loading during transportation, installation, etc.
3.8
inner vessel
pressure vessel intended to contain the cryogenic fluid to be stored
3.9
manufacturer of the static cryogenic vessel
company that carries out the final assembly, including the final acceptance test, of the static cryogenic vessel
3.10
maximum allowable pressure
maximum pressure permissible at the top of the vessel in its normal operating position
3.11
net volume of the inner vessel
volume of the inner vessel, below the inlet to the relief devices, excluding nozzles, pipes etc., determined at
minimum design temperature and atmospheric pressure
3.12
normal operation
intended operation of the vessel either up to the maximum allowable pressure or subjected to handling
loads
3.13
outer jacket
gas-tight enclosure which contains the inner vessel and enables the vacuum to be established
3.14
piping system
tubes, pipes and associated components which can come in contact with cryogenic fluids including valves,
fittings, pressure relief devices, and their supports
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ISO 21009-1:2008(E)
3.15
pressure
gauge pressure
pressure relative to atmospheric pressure
3.16
relief plate
plate retained by atmospheric pressure which allows relief of excess internal pressure, generally from the
vacuum jacket
3.17
relief plug
plug retained by atmospheric pressure which allows relief of excess internal pressure, generally from the
vacuum jacket
3.18
service equipment
measuring instruments, filling, discharge, venting, safety, pressurizing, cooling and thermal insulation devices
3.19
static cryogenic vessels
thermally insulated vessel intended for use with one or more cryogenic fluids in a stationary condition
NOTE Static cryogenic vessels consist of inner vessel(s), an outer jacket and the piping system.
3.20
thermal insulation
vacuum inter-space between the inner vessel and the outer jacket
NOTE The space may or may not be filled with material to reduce the heat transfer between the inner vessel and the
outer jacket.
3.21
year built
date of the final acceptance test of the final assembled cryogenic vessel at the manufacturer
4 Symbols
For the purposes of this document, the following symbols apply:
c allowances for corrosion mm
d diameter of opening mm
i
d outside diameter of tube or nozzle mm
a
f narrow side of rectangular or elliptical plate mm
l buckling length mm
b
n number —
p design pressure as defined by 10.2.3.2.1 and 10.3.3.2 bar
p allowable external pressure limited by elastic buckling bar
e
p strengthening pressure bar
k
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ISO 21009-1:2008(E)
p allowable external pressure limited by plastic deformation bar
p
p maximum allowable gauge pressure bar
s
p test pressure [see 10.2.3.2.3] bar
T
r radius e.g. inside knuckle radius of dished end and cones mm
s minimum wall thickness mm
s actual wall thickness mm
e
v factor indicative of the utilisation of the permissible design stress in joints
or factor allowing for weakenings —
x (decay-length zone) distance over which governing stress is assumed to act mm
2
A cross sectional area of reinforcing element mm
A elongation at fracture %
s
C design factors —
β
D shell diameter mm
D outside diameter e.g. of a cylindrical shell mm
a
D internal diameter e.g. of a cylindrical shell mm
i
2
E Young's modulus N/mm
H Safety coefficient for pressure test —
4
I moment of inertia of reinforcing element mm
2
K material property used for design (see 10.3.2.3.1) N/mm
2
Kt material property at t °C used for design (e.g. K for material property at 20 °C) N/mm
20
(see 10.3.2.3.2)
R radius of curvature e.g. inside crown radius of dished end mm
S safety factor at design pressure —
S safety factor against elastic buckling at design pressure —
k
S safety factor against plastic deformation at design pressure —
p
S safety factor against plastic deformation at proof test pressure —
T
Z auxiliary value —
ν Poisson ratio —
u out-of-roundness —
2
σ design stress value N/mm
k
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ISO 21009-1:2008(E)
5 General requirements
5.1 The static cryogenic vessel shall safely withstand the mechanical and thermal loads and the chemical
effects encountered during pressure test and normal operation. These requirements are deemed to be
satisfied if Clauses 6 to 11 are fulfilled. The vessel shall be tested in accordance with Clause 12, marked in
accordance with Clause 13, and operated in accordance with ISO 21009-2.
5.2 Static cryogenic vessels shall be equipped with valves, pressure relief devices, etc. configured and
installed in such a way that the vessel can be operated safely. The number of openings in the inner vessel for
this equipment shall be kept to a minimum.
5.3 The static cryogenic vessel shall be clean for the intended service in accordance with ISO 23208.
5.4 The manufacturer shall retain the documents referred to in 3.5, and all supporting documentation
(including that from his subcontractors if any), for a period required by regulation(s) (e.g. product liability). In
addition the manufacturer shall retain all supporting and background documentation (including that from his
subcontractors if any) which establishes that the vessel conforms to this part of ISO 21009.
6 Mechanical loads
6.1 General
The static cryogenic vessel shall resist the mechanical loads mentioned in Clause 6 without such deformation
which could affect safety and which could lead to leakage.
The mechanical loads to be considered are:
⎯ loads exerted during the pressure test as specified in 6.2;
⎯ loads imposed during installation and removal of the vessel;
⎯ dynamic loads during transport of the vessel.
The following loads shall be considered to act in combination where relevant:
⎯ a pressure equal to the maximum allowable pressure in the inner vessel and pipework;
⎯ the pressure exerted by the liquid when filled to capacity;
⎯ loads produced by the thermal movement of the inner vessel, outer jacket and inter-space piping;
⎯ full vacuum in the outer jacket;
⎯ a pressure in the outer jacket equal to the set pressure of the relief device protecting the outer jacket;
⎯ wind loads and other site conditions (e.g. seismic loads, thermal loads) to the vessel when filled to
capacity.
6.2 Load during the pressure test
The load exerted during the pressure test used for calculation shall be:
p W H (p + 1)
T s
where
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ISO 21009-1:2008(E)
p is the test pressure (in bar);
T
H is 1,43 in Europe and 1,3 in North America and for other parts of the world, a value consistent with
the applicable pressure vessel code;
p is the maximum allowable gauge pressure (in bar);
s
+ 1 is the allowance for external vacuum (in bar).
7 Chemical effects
Due to operating temperatures and the materials of construction, the possibility of chemical action on the inner
surfaces in contact with the cryogenic fluids can be discounted.
Due to the fact that the inner vessel is inside an evacuated outer jacket, neither external corrosion of the inner
vessel, nor corrosion on the inner surfaces of the outer jacket will occur. Therefore inspection openings are
not required in the inner vessel or the outer jacket.
Corrosion allowance is also not required on surfaces in contact with the operating fluid or exposed to the
vacuum inter-space between the inner vessel and the outer jacket.
The material and the protection for the surfaces exposed to the atmosphere shall be suitable for intended use
(e.g. resistant to industrial and marine atmospheres).
8 Thermal conditions
The following thermal conditions shall be taken into account:
a) for the inner vessel and its associated equipment the full range of temperatures expected;
b) for the outer jacket and equipment thereof [other equipment than covered by a)]:
⎯ a minimum working temperature of −20 °C, unless otherwise specified and marked in accordance
with Clause 13;
⎯ a maximum working temperature of 50 °C.
9 Material
The materials used to manufacture the inner vessels and associated equipment shall meet the requirements
defined in 9.1 to 9.2.
9.1 Selection of materials
9.1.1 Materials which are or might be in contact with cryogenic fluids shall be in accordance with
ISO 21010.
9.1.2 Materials used at low temperatures shall follow the requirements of the relevant ISO 21028; for non-
metallic materials low temperature suitability shall be validated by an experimental method, taking into
account operating temperatures.
9.1.3 The base materials, listed in Annex K, subject to meeting the extra requirements given in the main
body of this part of ISO 21009, are suitable for and may be employed in the manufacture of the cryogenic
vessels conforming to ISO 21009-1.
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ISO 21009-1:2008(E)
9.2 Inspection certificate
9.2.1 The head and shell material shall be according to ISO 21028-1 or ISO 21028-2 and shall be declared
by an inspection certificate 3.1.B in accordance with ISO 10474.
9.2.2 The material manufactured to a recognised international standard shall meet the testing requirements
according to ISO 21028-1 or ISO 21028-2 and be declared by an inspection certificate 3.1.B in accordance
with ISO 10474.
9.3 Materials for outer jackets and service equipment
The outer jacket and the service equipment not subjected to cryogenic temperature shall be manufactured
from material suitable for th
...