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: 02-Jun-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

prEN 14620-2 is a draft European Standard from CEN (European Committee for Standardization) for the metallic components of site-built, vertical, cylindrical, flat-bottomed tank systems used to store refrigerated liquefied gases. It specifies the material, design, fabrication, installation and weld examination rules for these tank components across the operating range from 0 °C to -196 °C. It is written for tank designers, fabricators, welders, purchasers and inspectors who need one technical basis for specifying and checking the metalwork.

What does prEN 14620-2 specify?

prEN 14620-2 specifies the general requirements for the metallic components of refrigerated liquefied gas tank systems. In practice, it covers the parts of the tank that carry load, contain product, or need to stay sound at cryogenic temperature, including shells, bottoms, roofs, nozzles, anchors, attachments and related welds.

The document is organized into clauses 1 to 9 and five informative annexes. Clause 1 gives the scope, Clause 2 lists normative references, Clause 3 gives terms and definitions, Clauses 4 to 9 cover materials, design, fabrication, welding procedures, welding, and weld examination.

Annex	What it covers
Annex A	Recommendations for drop-weight testing of HAZ and weld metal
Annex B	Wide-plate crack arrest testing
Annex C	Typical examples of combinations of actions
Annex D	Guidance for duties and responsibilities between parties
Annex E	Global test for membrane tanks

What are the key requirements of prEN 14620-2?

Materials and toughness

Clause 4 ties material selection to the minimum metal temperature that each component may see. For the primary and secondary liquid containers, the Thermal Protection System (TPS), roofs, vapor or purge gas parts, fasteners, mountings and piping components, the standard uses different rules depending on whether the part can see cryogenic liquid, cold vapor, warm vapor, or only ambient conditions.

For the main liquid-containing parts, Clause 4 sets out steel classification, maximum plate thickness, toughness requirements and alternative plate selection rules. It calls for impact testing, drop-weight testing and quasistatic fracture toughness where required, so the project can show that the material, weld metal and heat-affected zone will remain adequate at low temperature. For procurement and quality control, this means the buyer needs material certificates and test evidence that match the intended service conditions, not just the nominal grade on the order.

Clause 4.6 also links plate thickness tolerances to EN 10029. That matters because fabrication thickness affects both strength calculations and welding practice, so the ordered plate thickness has to suit how the design was based.

Design basis, loads and stresses

Clause 5 uses limit state design. prEN 14620-2 separates ultimate limit state and serviceability limit state checks, then defines actions and partial factors for persistent, transient, accidental and seismic design situations. For membrane tank systems, it also treats individual loads, static stability, progressive deformation, and fatigue behaviour.

This is important in practice because the designer must combine permanent loads, variable loads, thermal effects, pressure, test conditions and seismic actions in the right way for the chosen tank type. Annex C gives example combinations of actions, which helps a project team build consistent load cases for design verification and checking.

Clause 5 also sets stress limits for plates, weld metal, anchorage and welds. The standard uses these limits to control shell thickness, bottom design, roof design, and the local effects at nozzles, attachments and connections between containers. For a buyer or checker, this is the part that tells you what kind of structural proof the supplier must provide.

Tank details: bottom, shell, roof, nozzles and anchorage

Clause 5 gives detailed rules for the bottom, shell, roof, nozzles and anchor systems. It covers annular and center bottom plates, shell welds, plate arrangement, stiffeners, membrane tank outer containers, vapor and purge gas containment components, compression areas at roof-to-shell junctions, and suspended roofs.

These details matter because refrigerated tanks fail at local details as often as at global strength. The standard therefore controls weld type, plate overlap, joint spacing, attachment location, and the way loads enter the shell. It also requires suspended roofs to be designed for loss of a hanger, for pressure balance above and below the roof, and for thermal movement and seismic effects.

Clause 5.12 on tank anchorage is especially practical. It requires ductile anchorage, allowance for settlement and thermal movement, spacing around the circumference, corrosion protection where needed, and attachment through pads or brackets rather than directly to the shell. The aim is to keep the tank stable without making the anchor system brittle or impossible to inspect.

Fabrication, welding and heat treatment

Clause 6 controls handling, storage, preparation and tolerances. Materials for primary and secondary liquid containers must be kept separate and traceable, stainless steel must be protected from contamination, and the heat numbers of tank plates and nozzle parts must be transferred into the as-built traceability record.

Clause 6 also limits cold forming strain and says when stress relieving becomes necessary. That matters because cryogenic tank steel can lose toughness if it is formed too aggressively without the right follow-up treatment. The clause also addresses temporary attachments, temporary openings, roof erection stability and fabrication quality class.

Clause 7 requires a Welding Procedure Specification (WPS) and a Welding Procedure Qualification Record (WPQR) for all welding, including repair and tack welding. It also sets out impact testing of weld metal and HAZ, welding qualification for welders and welding operators, and production test plates. For 9 % Nickel steel, the clause gives extra testing requirements because this material is central to low-temperature tank service.

Clause 8 then controls the welding operation itself. It covers tack welds, weather protection, preheating, and post-weld heat treatment (PWHT). Shell nozzles and manholes in Type 1 and Type 2 steels often need PWHT before installation, and the clause gives the conditions under which that treatment can be waived. For fabrication teams, this is the section that turns the procedure into shop-floor practice.

Weld examination and leak testing

Clause 9 sets out the examination regime. It requires qualified non-destructive testing (NDT) personnel, independent examination work, written procedures, and a sequence of visual, surface and volumetric examination methods as appropriate. Visual examination is required for each completed weld, and the acceptance levels vary according to whether the weld is liquid tight, vapor tight or another type.

The clause also includes dye penetrant examination, magnetic particle examination, vacuum box examination, tracer gas tightness testing for membrane tanks, global testing, radiographic examination and ultrasonic examination. This matters because the standard does not stop at making the weld - it also tells the project how to verify tightness and soundness before the tank enters service.

What terms does prEN 14620-2 define?

• Amplitude of strain - one half of the range of strains in cyclic loading.
• Examination - testing carried out in line with applicable non-destructive examination standards.
• Inspection - the activity used to ensure compliance with this document.
• Minimum specified ultimate tensile strength (f_u) - the lower of the steel or weld material ultimate tensile strength at room temperature.
• Minimum specified yield strength (f_y) - the lower of the steel or weld material yield strength at room temperature.
• Mounting - a nozzle or permanent attachment to the pressure-containing elements of the tank system.
• Nominal thickness - the ordered thickness of the material, including any corrosion allowance where applicable.
• Range of strain - the difference between the maximum and minimum values in the cyclic strain curves.

Who uses prEN 14620-2?

prEN 14620-2 is used by the people who specify, design, build, inspect and accept refrigerated liquefied gas tanks.

• Tank owners and purchasers use it to define the technical basis of a project and to check that suppliers have qualified materials and weld procedures.
• Structural and mechanical designers use it for shell, bottom, roof, nozzle, anchor and membrane design.
• Fabrication and erection contractors use it for plate handling, tolerances, welding, PWHT and traceability.
• Welding coordinators, welders and welding operators use it for WPS, WPQR and qualification requirements.
• NDT and quality personnel use it for examination methods, acceptance criteria and test records.
• It is relevant to projects for refrigerated liquefied gas storage where the tank is built on site and the metal components must perform at very low temperature.

What changed in prEN 14620-2 from the previous edition?

prEN 14620-2 states that it will supersede EN 14620-2:2006. The foreword lists these main changes:

• general editorial update
• terms and definitions adjusted
• normative references updated
• material requirements extended to temperatures down to -196 °C
• steel classification updated so it is independent of containment type
• toughness requirements updated
• design moved to limit state theory with Eurocode references where appropriate
• nozzle details completely revised
• the section title changed from “inspection” to “weld examination”
• membrane testing updated
• weld examination acceptance criteria updated
• informative annexes on membrane actions and load or fatigue curves deleted from the annexes and incorporated into the main text
• new informative annexes added for HAZ and weld metal drop-weight testing, wide-plate crack arrest testing, and typical combinations of actions
• bibliography updated

Which standards are used with prEN 14620-2?

Clause 2 makes the following documents normative, with dated references applying as cited and undated references using the latest edition.

Standard	What it contributes to prEN 14620-2
ASTM E208	Drop-weight testing method for ferritic steels
EN 1593	Bubble emission leak testing
EN 1759-1	Circular steel flanges, Class designated
EN 1990	Basis of structural and geotechnical design
EN 1991-1-4	Wind actions
EN 1991-1-6	Actions during execution
EN 1993-1-1	General rules for steel structures
EN 1993-1-6	Strength and stability of shell structures
EN 1993-1-8	Joints
EN 1993-1-9	Fatigue
EN 1993-1-10	Material toughness and through-thickness properties
EN 1998-4	Seismic design for tanks and similar structures
EN 1999-1-1	General rules for aluminium structures
EN 10025	Hot rolled structural steels
EN 10028-1 to EN 10028-7	Plate steels for pressure purposes, including low-temperature and stainless grades
EN 10029	Plate thickness and shape tolerances
EN 1011-2	Welding recommendations for ferritic steels
EN 10160	Ultrasonic testing of steel flat product
EN 10204	Inspection documents for metallic products
EN 10216-1 to EN 10216-5	Seamless steel tubes for pressure purposes
EN 10217-1 to EN 10217-7	Welded steel tubes for pressure purposes
EN 1090-3:2019	Execution requirements for aluminium structures
EN 1092-1	Steel flanges, PN designated
EN 13445-2	Materials for unfired pressure vessels
EN 13445-3	Design rules for unfired pressure vessels
EN 14620-1:2024	General rules for the tank series and connections between containers
EN 14620-3	Concrete components in the tank series
EN ISO 14732	Qualification of welding operators and weld setters
EN ISO 148-1	Charpy pendulum impact test method
EN ISO 15607	General rules for welding procedure qualification
EN ISO 15609-1	Welding procedure specification for arc welding
EN ISO 15614-1	Welding procedure test for steels and nickel alloys
EN ISO 17635	General rules for non-destructive testing of welds
EN ISO 17636-1	Radiographic testing of welds
EN ISO 17637	Visual testing of fusion-welded joints
EN ISO 17638	Magnetic particle testing of welds
EN ISO 17640	Ultrasonic testing of welds
EN ISO 20485	Tracer gas leak testing
EN ISO 3452 (all parts)	Penetrant testing
EN ISO 9016	Impact test specimen location and orientation for welds
EN ISO 9606-1	Welder qualification for fusion welding of steels
EN ISO 9712	Qualification and certification of NDT personnel
ISO 12135	Quasistatic fracture toughness of metallic materials
ISO 15653	Quasistatic fracture toughness of welds
ISO 23277	Penetrant testing acceptance levels
ISO 23278	Magnetic particle testing acceptance levels
ISO 5817	Quality levels for weld imperfections

What does the prEN 14620-2 document contain?

The document contains detailed material, design, fabrication and inspection rules for the metallic parts of refrigerated liquefied gas tank systems. It includes design equations and figures for bottom layouts, shell courses, roof compression areas, nozzles, anchorage and membrane behaviour, as well as testing and acceptance rules for welds and leak tightness.

It also contains supporting tables and procedures that are used for project design, fabrication control and verification. Annex C gives example load combinations, Annex E gives the test phases for the global membrane test, and Table 14 supports the statistical treatment of membrane fatigue test results.

The figures are practical rather than descriptive: they show typical details for annular plates, bottom joints, shell-to-bottom welds, nozzle connections, roof compression areas and anchor straps. For a project team, that means the standard is not only a list of requirements - it is also a design and verification guide for the critical details that control safety and integrity.

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
...