prEN 14620-2

• Abstract:

  This document specifies general requirements for the materials, design, construction and installation of the metallic components of refrigerated liquefied gas tank systems.; This document deals with the design and manufacture of site built, vertical, cylindrical, flat-bottomed tank systems for the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -196 °C.

• Status: Not Published
• Publication Date: 07-Jul-2026
• ICS: 23.020.10 - Stationary containers and tanks
• Technical Committee: CEN/TC 265 - Site built metallic tanks for the storage of liquids
• Drafting Committee: CEN/TC 265/WG 10 - Revision of EN 14620
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 10-Sep-2026
• Due Date: 22-Jan-2025
• Completion Date: 10-Sep-2026
• Ref Project: oSIST prEN 14620-2:2026 - Design and manufacture of site built, vertical, cylindrical, flat-bottomed tank systems for the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -196 °C - Part 2: Metallic components

• Referred By: EN ISO 21420:2020 - Protective gloves - General requirements and test methods (ISO 21420:2020)
• Effective Date: 28-Jan-2026
• Referred By: EN ISO 13688:2013 - Protective clothing - General requirements (ISO 13688:2013)
• Effective Date: 28-Jan-2026
• Revises: EN 14620-2:2006 - Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -165 °C - Part 2: Metallic components
• Effective Date: 28-Jan-2023

Overview

prEN 14620-2: Design and manufacture of site built, vertical, cylindrical, flat-bottomed tank systems for the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -196 °C - Part 2: Metallic components is a draft European Standard developed by CEN/TC 265. This standard specifies the general requirements for the materials, design, fabrication, and installation of the metallic components of tank systems designed for the storage of refrigerated, liquefied gases. It applies to site-built, vertical, cylindrical, flat-bottomed tanks, which operate at low temperatures and are commonly used in sectors such as energy, chemicals, and industrial gases.

This document aligns with relevant Eurocodes, especially EN 1993 (Eurocode 3) for steel structures, ensuring consistency in structural safety and performance across the industry.

Key Topics

prEN 14620-2 covers the following essential areas for metallic refrigerated liquefied gas storage tanks:

• Materials Selection: Detailed requirements for steel and aluminium grades, material toughness for cryogenic applications, maximum plate thickness, and quality certification.
• Design Principles: Comprehensive guidance on limit state design, including considerations for containment type, stress limits, and actions (loads) for single, double, full containment, and membrane tanks.
• Component Specification: Guidance on the design of tank shells, bases, roofs (including self-supported and suspended types), nozzles, and other attachments.
• Fabrication: Requirements for plate processing, tolerances, alignments, and the handling and assembly of metallic components.
• Welding and Examination: Specifications for welding procedures, welder qualifications, weld testing (including visual, radiographic, ultrasonic, and leak tests), and acceptance criteria to ensure the integrity of welded joints.
• Inspection and Quality Assurance: Detailing non-destructive examination (NDE) methods, record-keeping, and relevant documentation as per European and international references.

Applications

This standard is widely applicable for safe and efficient storage solutions involving cryogenic and refrigerated liquefied gases such as LNG (liquefied natural gas), ethylene, and ammonia. Key uses include:

• Energy Sector: Storage of LNG and other fuels at import/export terminals and power generation facilities.
• Petrochemical and Chemical Industries: On-site storage of raw materials and intermediates.
• Industrial Gas Production: Storage for gases like nitrogen and oxygen in liquefied form.
• Infrastructure Projects: Large-scale storage solutions for various low-temperature applications.

By specifying harmonized guidelines for the use and performance of metallic components, prEN 14620-2 helps ensure the structural integrity, durability, and safety of these critical storage tanks, supporting reliability in downstream applications.

Related Standards

prEN 14620-2 is part of the broader EN 14620 series, which addresses the design and construction of tank systems for refrigerated, liquefied gases. Related standards and references include:

• EN 14620-1: General requirements for site-built tank systems
• EN 14620-3: Concrete components for storage tanks
• EN 1993 (Eurocode 3): Design of steel structures
• EN 1998-4: Seismic design for tanks and similar structures
• EN ISO 15614-1, EN 1011-2: Qualification of welding procedures

Supporting references include specifications for material quality, welding, inspection, and structural design, such as EN 10025, EN 13445, and ASTM E208.

Practical Value

Using prEN 14620-2 ensures that tank systems for refrigerated, liquefied gas storage are built to the latest European best practices. This standard:

• Minimizes risks associated with low-temperature storage
• Ensures compliance with regulatory requirements
• Facilitates interoperability and safety across the supply chain
• Provides robust guidance for construction, welding, and inspection of metallic tank components

Organizations implementing this standard benefit from improved safety, lower maintenance costs, and enhanced performance in their cryogenic storage operations.

SLOVENSKI STANDARD
01-oktober-2026
Načrtovanje in proizvodnja na mestu postavitve grajenih navpičnih, valjastih
jeklenih posod z ravnim dnom za shranjevanje hlajenih utekočinjenih plinov z
delovnimi temperaturami med 0 °C in –196 °C - 2. del: Kovinski deli
Design and manufacture of site built, vertical, cylindrical, flat-bottomed tank systems for
the storage of refrigerated, liquefied gases with operating temperatures between 0 °C
and -196 °C - Part 2: Metallic components
Auslegung und Herstellung standortgefertigter, stehender, zylindrischer Flachboden-
Tanksysteme für die Lagerung von tiefkalt verflüssigten Gasen bei Betriebstemperaturen
zwischen 0 °C und -196 °C - Teil 2: Metallische Bauteile
Conception et fabrication de réservoirs cylindriques fond plat, verticaux, construits sur
site, destinés au stockage des gaz réfrigérés, liquéfiés, dont les températures de service
sont comprises entre 0 °C et -196 °C - Partie 2 : Constituants métalliques
Ta slovenski standard je istoveten z: prEN 14620-2
ICS:
23.020.10 Nepremične posode in Stationary containers and
rezervoarji tanks
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2026
ICS 23.020.10 Will supersede EN 14620-2:2006
English Version
Design and manufacture of site built, vertical, cylindrical,
flat-bottomed tank systems for the storage of refrigerated,
liquefied gases with operating temperatures between 0 °C
and -196 °C - Part 2: Metallic components
Conception et fabrication de réservoirs cylindriques Auslegung und Herstellung standortgefertigter,
fond plat, verticaux, construits sur site, destinés au stehender, zylindrischer Flachboden-Tanksysteme für
stockage des gaz réfrigérés, liquéfiés, dont les die Lagerung von tiefkalt verflüssigten Gasen bei
températures de service sont comprises entre 0 °C et - Betriebstemperaturen zwischen 0 °C und -196 °C - Teil
196 °C - Partie 2 : Constituants métalliques 2: Metallische Bauteile
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 265.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14620-2:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 10
4 Materials . 11
4.1 Temperatures. 11
4.1.1 General. 11
4.1.2 Temperatures for materials to contain cryogenic liquid or gas products . 11
4.1.3 Temperatures for warm vapour container or purged gas container and other
structures not to contain cryogenic liquid or cryogenic gas products . 12
4.1.4 Maximum design metal temperature . 12
4.2 Primary and secondary liquid container, membrane tank outer container and
thermal protection system (TPS) . 12
4.2.1 General. 12
4.2.2 Steel classification . 12
4.2.3 General requirements . 13
4.2.4 Maximum plate thickness . 13
4.2.5 Toughness requirements . 14
4.2.6 Alternative plate material selection for components of primary and secondary liquid
containers and thermal protection system (TPS) . 16
4.2.7 Certification . 17
4.3 Refrigerated temperature roofs and suspended roofs . 18
4.3.1 Steel. 18
4.3.2 Aluminium . 18
4.3.3 Certification . 18
4.4 Structures not designed to contain cryogenic liquid or gas products . 18
4.4.1 Steel. 18

4.4.2 Aluminium . 18
4.4.3 Certification . 18
4.5 Other components . 18
4.5.1 Fasteners . 18
4.5.2 Mountings . 19
4.5.3 Piping components . 19
4.6 Plate thickness tolerances . 19
5 Design . 19
5.1 General. 19
5.1.1 General. 19
5.1.2 Ultimate limit state . 19
5.1.3 Serviceability limit state . 20
5.2 Definition of actions for Single, Double and Full containment tanks and membrane
tank outer container . 20
5.2.1 Actions and partial factors . 20
5.2.2 Combinations of actions . 24
5.3 Definition of actions for membrane of the membrane containment tank systems . 25
5.3.1 Individual loads . 25
5.3.2 Load combinations . 26
5.4 Limits of design stress. 27
5.4.1 Plates and weld metal . 27
5.4.2 Anchorage. 28
5.4.3 Stresses in welds . 29
5.5 Primary and secondary liquid container, membrane and membrane tank outer
container . 29
5.5.1 Single, double and full containment tanks . 29
5.5.2 Membrane of membrane containment tank system . 36
5.5.3 Membrane tank outer container . 43
5.6 Vapor and purge gas containment components . 43
5.6.1 Single, double and full containment tanks . 43
5.6.2 Membrane tank . 44
5.7 Roof . 44
5.7.1 General . 44
5.7.2 Minimum nominal plate thickness . 45
5.7.3 Self-supported roof with framing . 45
5.7.4 Self-supported roof without framing . 45
5.7.5 Compression area . 46
5.8 Suspended roof . 49
5.9 Nozzles . 49
5.9.1 Nozzle design . 49
5.9.2 Shell manholes and nozzles . 49
5.9.3 Roof manholes and nozzles . 52
5.9.4 Nozzle welding details . 52
5.9.5 Flange drilling . 58
5.9.6 Post-weld heat treatment of nozzles . 58
5.10 Primary and secondary containment, bottom connections . 59
5.11 Connections between containers . 59
5.12 Tank anchorage . 59
5.13 Structural attachments . 60
5.14 Design of aluminium structures . 60
6 Fabrication . 61
6.1 Handling of materials . 61
6.2 Plate preparation and tolerances . 61
6.2.1 Shell plates . 61
6.2.2 Annular bottom plates . 61
6.2.3 Nozzles . 61
6.2.4 Reinforcing plates . 62
6.3 Tolerances . 62
6.3.1 Foundation peripheral tolerances . 62
6.3.2 Other foundation surface tolerances . 62
6.3.3 Bottom plate tolerances . 62
6.3.4 Shell to bottom connection . 62
6.3.5 Ovality . 62
6.3.6 Local deformation in plates . 62
6.3.7 Local deformation at welds . 63
6.3.8 Vertical tolerance . 64
6.3.9 Tolerances on alignment of plates . 64
6.3.10 Fabrication quality class according to design . 64
6.3.11 Tolerance for membrane system . 65
6.3.12 Roof tolerances . 65
6.4 Roof . 65
6.5 Temporary attachments . 65
6.6 Temporary openings . 65
6.6.1 Temporary construction and access openings. 65
6.6.2 Openings after hydrostatic test . 66
6.7 Limits for cold formed strain . 66
6.8 Fabrication of aluminium structures . 67
7 Welding procedures . 67
7.1 General. 67
7.2 WPQR requirements . 67
7.3 Impact testing . 68
7.4 9 % Nickel steel . 68
7.5 Welders and welding operators . 68
7.5.1 Single, double and full containment tanks . 68
7.5.2 Membrane . 68
7.6 Production test plates . 69
7.6.1 Single, double and full containment tanks . 69
7.6.2 Membrane tanks . 69
7.7 Welding procedures of aluminium structures . 69
8 Welding . 69
8.1 Tack and temporary welds . 69
8.2 Atmospheric conditions . 70
8.3 Preheating . 70
8.4 Post-weld heat treatment . 70
8.5 Welding of aluminium structures . 71
9 Weld examination . 71
9.1 Qualification of NDE personnel . 71
9.2 Examination procedures . 71
9.3 Type of examinations . 72
9.3.1 Examination of materials . 72
9.3.2 Extent of weld examination . 72
9.4 Visual examination . 77
9.5 Dye penetrant examination . 78
9.6 Magnetic particle examination . 78
9.7 Vacuum box examination . 78
9.8 Tracer gas tightness test for membrane tanks . 78
9.8.1 General. 78
9.8.2 Ammonia test . 79
9.8.3 Helium test . 79
9.9 Global test for membrane tanks . 80
9.10 Soap bubble examination . 80
9.10.1 General. 80
9.10.2 Shell to bottom with double fillet weld . 80
9.10.3 Reinforcement plates . 80
9.10.4 Roof . 80
9.11 Radiographic examination . 81
9.12 Ultrasonic examination . 81
9.13 Acceptance criteria. 81
9.13.1 Radiographic examination . 81
9.13.2 Ultrasonic examination . 81
9.14 Unacceptable defects in welds . 82
9.14.1 General. 82
9.14.2 Automatic welding . 82
9.14.3 Manual welding . 82
9.15 Acceptable thinning after grinding . 83
9.16 Weld examination of aluminium structures . 83
Annex A (informative) Recommendations for drop-weight testing of heat-affected zone
(HAZ) and weld metal . 84
Annex B (informative) Wide-plate crack arrest testing . 86
Annex C (informative) Typical Examples Combinations of Actions . 87
C.1 General . 87
C.2 Combination of actions for persistent or transient design situation. 87
C.3 Combination of actions for accidental design combinations . 87
C.4 Combination of actions for seismic design combinations. 88
Annex D (informative) Guidance for duties and responsibilities between parties . 89
Annex E (informative) Global test for membrane tanks . 90
E.1 General . 90
E.2 Intermediate monitoring . 90
E.3 Test phases . 90
E.3.1 Concrete outer tank . 90
E.3.2 Steel outer tank . 91
Bibliography . 93

European foreword
This document (prEN 14620-2:2026) has been prepared by Technical Committee CEN/TC 265 “Metallic
tanks for the storage of liquids”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document is intended for use in conjunction with relevant parts of EN 1993 and so adheres the
general rules for the structural design of any tank component within the scope of Eurocode 3.
EN 14620-2:2006:
— general editorial update;
— terms and definitions adjusted;
— normative references updated;
— material requirements extended to temperatures down to −196 °C;
— steel classification updated to be independent on containment type;
— toughness requirements updated;
— design based on limit state theory and reference to Eurocodes added where appropriate;
— nozzle details completely revised;
— change of section title “inspection” to “weld examination”;
— testing for membrane tanks updated;
— acceptance criteria for weld examination updated;
— informative annexes about actions on membrane and determination of the load and fatigue curves
for membrane deleted and incorporated into main part;
— new informative annex with recommendations for drop-weight testing of heat-affected zone (HAZ)
and weld metal added;
— new informative annex for wide-plate crack arrest testing added;
— new informative annex with typical combinations of actions added;
— bibliography updated.
A list of all parts in the EN 14620 series, “Design and manufacture of site built, vertical, cylindrical, flat-
bottomed tank systems for the storage of refrigerated, liquefied gases with operating temperatures
between 0 °C and −196 °C”, can be found on the CEN website.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
1 Scope
This document specifies general requirements for the materials, design, construction and installation of
the metallic components of refrigerated liquefied gas tank systems.
This document deals with the design and manufacture of site built, vertical, cylindrical, flat-bottomed
tank systems for the storage of refrigerated, liquefied gases with operating temperatures between 0 °C
and −196 °C.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ASTM E208, Standard Test Methods for Conducting Drop-Weight Test of Ferritic Steels
EN 1593, Non-destructive testing — Leak testing — Bubble emission technique
EN 1759-1, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, Class
designated — Part 1: Steel flanges, NPS 1/2 to 24
EN 1990, Eurocode — Basis of structural and geotechnical design
EN 1991-1-4, Eurocode 1 — Actions on structures — Part 1-4: Wind actions
EN 1991-1-6, Eurocode 1 — Actions on structures — Part 1-6: Actions during execution
EN 1993-1-1, Eurocode 3 — Design of steel structures — Part 1-1: General rules and rules for buildings
EN 1993-1-6, Eurocode 3 — Design of steel structures — Part 1-6: Strength and stability of shell
structures
EN 1993-1-8, Eurocode 3 — Design of steel structures — Part 1-8: Joints
EN 1993-1-9, Eurocode 3 — Design of steel structures — Part 1-9: Fatigue
EN 1993-1-10, Eurocode 3 — Design of steel structures — Part 1-10: Material toughness and through-
thickness properties
EN 1998-4, Eurocode 8 — Design of structures for earthquake resistance — Part 4: Silos, tanks, pipelines,
towers, masts and chimneys
EN 1999-1-1, Eurocode 9 — Design of aluminium structures — Part 1-1: General rules
EN 10025, Hot rolled products of structural steels
EN 10028-1, Flat products made of steels for pressure purposes — Parts 1: General requirements
EN 10028-2, Flat products made of steels for pressure purposes — Parts 2: Non-alloy and alloy steels with
specified elevated temperature properties
EN 10028-3, Flat products made of steels for pressure purposes — Parts 3: Weldable fine grain steels,
normalized
EN 10028-4, Flat products made of steels for pressure purposes — Parts 4: Nickel alloy steels with
specified low temperature properties
EN 10028-5, Flat products made of steels for pressure purposes — Parts 5: Weldable fine grain steels,
thermomechanically rolled
EN 10028-6, Flat products made of steels for pressure purposes — Parts 6: Weldable fine grain steels,
quenched and tempered
EN 10028-7, Flat products made of steels for pressure purposes — Parts 7: Stainless steels
EN 10029, Hot-rolled steel plates 3 mm thick or above — Tolerances on dimensions and shape
EN 1011-2, Welding — Recommendations for welding of metallic materials — Part 2: Arc welding of
ferritic steels
EN 10160, Ultrasonic testing of steel flat product of thickness equal or greater than 6 mm (reflection
method)
EN 10204, Metallic products — Types of inspection documents
EN 10216-1, Seamless steel tubes for pressure purposes — Technical delivery conditions — Part 1: Non-
alloy steel tubes with specified room temperature properties
EN 10216-2, Seamless steel tubes for pressure purposes — Technical delivery conditions — Part 2: Non-
alloy and alloy steel tubes with specified elevated temperature properties
EN 10216-3, Seamless steel tubes for pressure purposes — Technical delivery conditions — Part 3: Alloy
fine grain steel tubes
EN 10216-4, Seamless steel tubes for pressure purposes — Technical delivery conditions — Part 4: Non-
alloy and alloy steel tubes with specified low temperature properties
EN 10216-5, Seamless steel tubes for pressure purposes — Technical delivery conditions — Part 5:
Stainless steel tubes
EN 10217-1, Welded steel tubes for pressure purposes — Technical delivery conditions — Part 1: Electric
welded and submerged arc welded non-alloy steel tubes with specified room temperature properties
EN 10217-2, Welded steel tubes for pressure purposes — Technical delivery conditions — Part 2: Electric
welded non-alloy and alloy steel tubes with specified elevated temperature properties
EN 10217-3, Welded steel tubes for pressure purposes — Technical delivery conditions — Part 3: Electric
welded and submerged arc welded alloy fine grain steel tubes with specified room, elevated and low
temperature properties
EN 10217-4, Welded steel tubes for pressure purposes — Technical delivery conditions — Part 4: Electric
welded non-alloy steel tubes with specified low temperature properties
EN 10217-5, Welded steel tubes for pressure purposes — Technical delivery conditions — Part 5:
Submerged arc welded non-alloy and alloy steel tubes with specified elevated temperature properties
EN 10217-6, Welded steel tubes for pressure purposes — Technical delivery conditions — Part 6:
Submerged arc welded non-alloy steel tubes with specified low temperature properties
EN 10217-7, Welded steel tubes for pressure purposes — Technical delivery conditions — Part 7: Stainless
steel tubes
EN 1090-3:2019, Execution of steel structures and aluminium structures — Part 3: Technical
requirements for aluminium structures
EN 1092-1, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN
designated — Part 1: Steel flanges
EN 13445-2, Unfired pressure vessels — Part 2: Materials
EN 13445-3, Unfired pressure vessels — Part 3: Design
EN 14620-1:2024, Design and manufacture of site built, vertical, cylindrical, flat-bottomed tank systems
for the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -196 °C —
Part 1: General
EN 14620-3, Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the
storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -165 °C — Part 3:
Concrete components
EN ISO 14732, Welding personnel — Qualification testing of welding operators and weld setters for
mechanized and automatic welding of metallic materials (ISO 14732)
EN ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method (ISO 148-1)
EN ISO 15607, Specification and qualification of welding procedures for metallic materials — General
rules (ISO 15607)
EN ISO 15609-1, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 1: Arc welding (ISO 15609-1)
EN ISO 15614-1, Specification and qualification of welding procedures for metallic materials — Welding
procedure test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys (ISO
15614-1)
EN ISO 17635, Non-destructive testing of welds — General rules for metallic materials (ISO 17635)
EN ISO 17636-1, Non-destructive testing of welds — Radiographic testing — X- and gamma-ray
techniques with film (ISO 17636-1)
EN ISO 17637, Non-destructive testing of welds — Visual testing of fusion-welded joints (ISO 17637)
EN ISO 17638, Non-destructive testing of welds — Magnetic particle testing (ISO 17638)
EN ISO 17640, Non-destructive testing of welds — Ultrasonic testing — Techniques, testing levels, and
assessment (ISO 17640)
EN ISO 20485, Non-destructive testing — Leak testing — Tracer gas method (ISO 20485)
EN ISO 3452 (all parts), Non-destructive testing — Pentrant testing (ISO 3452)
EN ISO 9016, Destructive tests on welds in metallic materials — Impact tests — Test specimen location,
notch orientation and examination (ISO 9016)
EN ISO 9606-1, Qualification testing of welders — Fusion welding — Part 1: Steels (ISO 9606-1)
EN ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel (ISO 9712)
ISO 12135, Metallic materials — Unified method of test for the determination of quasistatic fracture
toughness
ISO 15653, Metallic materials — Method of test for the determination of quasistatic fracture toughness of
welds
ISO 23277, Non-destructive testing of welds — Penetrant testing — Evaluation of indications
ISO 23278, Non-destructive testing of welds — Magnetic particle testing — Acceptance levels
ISO 5817, Welding — Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding
excluded) — Quality levels for imperfections
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14620-1:2024 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
amplitude of strain
one half of the range of strains
3.2
examination
testing in compliance with applicable standards for non-destructive examination
3.3
inspection
activity to ensure compliance with this document
3.4
minimum specified ultimate tensile strength (f )
u
minimum specified ultimate tensile strength of steel or weld material at room temperature whichever is
lesser
3.5
minimum specified yield strength (f )
y
minimum specified yield strength of steel or weld material at room temperature whichever is lesser
Note 1 to entry: For steels, other than austenitic steels the yield strength or 0,2 % proof strength shall be
applicable. For austenitic stainless steels the 1,0 % proof strength shall be applicable.
3.6
mounting
nozzle or permanent attachment to the pressure containing elements of the tank system
3.7
nominal thickness
ordered thickness of the material
Note 1 to entry: This thickness includes any corrosion allowance and is used for determination of PWHT
requirements, weld spacing, minimum and maximum thickness limitations, etc.
3.8
range of strain
difference between the maximum and minimum values in the cyclic strain curves
3.9
shell
self-standing cylindrical wall of a liquid, vapor or purge gas container or a membrane tank outer
container
4 Materials
4.1 Temperatures
4.1.1 General
The temperature to which the steel may be exposed under all conditions shall be determined.
4.1.2 Temperatures for materials to contain cryogenic liquid or gas products
4.1.2.1 Primary liquid container
The design metal temperature shall be the minimum design temperature according to
EN 14620-1:2024.
In cold regions, where the lowest one-day average ambient temperature (lodmat) according to
EN 14620-1:2024 is lower than the minimum design temperature, the design metal temperature shall
be lowered by 3 K.
4.1.2.2 Secondary liquid container and thermal protection system (TPS)
The design metal temperature shall be the lower of either the minimum design temperature or the
lodmat according to EN 14620-1:2024.
4.1.2.3 Refrigerated temperature roofs and suspended roofs
The design metal temperature shall be in accordance with 4.1.2.1.
4.1.2.4 Warm vapor or purge gas container components designed for accidental contact with
cryogenic liquid due to leakage
Design metal temperature for warm vapour container and purge case container components which are
designed to be potentially exposed to cold liquid product due to accidental leak in process piping should
be from material in accordance with 4.1.2.2 unless those components are protected against cold
product expos
...