SIST EN 14620-4:2025
(Main)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 4: Insulation components
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 4: Insulation components
This document specifies the requirements for materials, design and installation of the insulation of refrigerated liquefied gas (RLG) storage tank systems.
RLG storage tank systems store liquefied gas with a low boiling point, i.e. below normal ambient temperature.
The concept of storing such products in liquid form and in non-pressurized tanks therefore depends on the combination of latent heat of vaporization and thermal insulation.
Consequently, thermal insulation for RLG storage tank systems is not an ancillary part of the containment system (as for most ambient atmospheric hydrocarbon tanks) but it is an essential component and the storage tank system cannot operate without a properly designed, installed and maintained insulation system.
The main functions of the insulation in RLG storage tank systems are:
- to maintain the boil off due to heat in-leak at or below the specified limits;
- to limit the thermal loading of the outer tank components, so to prevent both their sudden damage and premature ageing (e.g. due to external condensation and ice formation);
- to prevent damage by frost heave of the foundation/soil beneath the tank base slab (in combination with the slab heating system for tanks resting at grade);
- to minimize condensation and icing on the outer surfaces of the tank.
A wide range of insulation materials is available. However, the material properties differ greatly amongst the various generically different materials and also within the same generic group of materials.
Therefore, within the scope of this document, only general guidance on selection of materials is given.
NOTE For general guidance on selection of materials, see Annex A.
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.
Auslegung und Herstellung standortgefertigter, stehender, zylindrischer Flachboden-Tanksystemen für die Lagerung von tiefkalt verflüssigten Gasen bei Betriebstemperaturen zwischen 0 °C und -196 °C - Teil 4: Dämmung
Dieses Dokument legt die Anforderungen an Werkstoffe, Auslegung und Einbau der Dämmung für Tanksysteme zur Lagerung von tiefkalt verflüssigten Gasen (RLG, en: refrigerated liquefied gas) fest.
In RLG-Tanksystemen wird verflüssigtes Gas mit niedrigem Siedepunkt gelagert, d. h. unterhalb der üblichen Umgebungstemperatur.
Das Konzept zur Lagerung von flüssigem Lagergut in nicht unter Druck stehenden Tanks hängt daher von der geeigneten Kombination der latenten Verdampfungswärme und der Wärmedämmung ab.
Folglich ist die Wärmedämmung für RLG-Lagertanksysteme kein untergeordneter Bestandteil des von der Sicherheitshülle gebildeten Systems (wie bei den meisten unter Umgebungsbedingungen betriebenen Kohlenwasserstofftanks), sondern eine sehr wichtige Komponente, weil das Lagertanksystem nur betrieben werden kann, wenn das Dämmsystem vorschriftsmäßig ausgelegt, eingebaut und gewartet wird.
Die wichtigsten Funktionen der Dämmung in RLG-Lagertanksystemen sind:
- Beibehaltung der Verdampfungsrate (en: Boil-off) aufgrund von Wärmeaufnahme auf oder unterhalb der festgelegten Grenzwerte;
- Begrenzung der Wärmebelastung der Bauteile des Außentanks, um sowohl deren plötzliche Beschädigung als auch vorzeitige Alterung (z. B. aufgrund äußerer Kondensation und Eisbildung) zu verhindern;
- Verhinderung von Schäden durch Frosthub des Fundaments/des Erdreichs unter der Tankgrundplatte (in Kombination mit dem Plattenheizsystem für Tanks, die ebenerdig aufgestellt sind);
- Minimierung von Kondensation und Eisbildung an den Außenflächen des Tanks.
Es gibt eine große Bandbreite von Dämmstoffen. Die Eigenschaften der Werkstoffe, die sowohl unterschiedlichen als auch gleichen Werkstoffgruppen zuzuordnen sind, unterscheiden sich jedoch beträchtlich.
Daher wird im Rahmen dieses Dokuments nur eine allgemeine Anleitung zur Werkstoffauswahl gegeben.
ANMERKUNG Allgemeine Empfehlungen für die Werkstoffauswahl sind in Anhang A aufgeführt.
Dieses Dokument behandelt die Auslegung und Herstellung standortgefertigter, stehender, zylindrischer Flachboden-Tanksysteme für die Lagerung von tiefkalt verflüssigten Gasen mit Betriebstemperaturen zwischen 0 °C und −196 °C.
Conception et fabrication de réservoirs à fond plat, verticaux, cylindriques, construits sur site, destinés au stockage des gaz réfrigérés, liquéfiés, dont les températures de service sont comprises entre 0 °C et 196 °C - Partie 4 : Constituants isolants
Le présent document spécifie les exigences pour les matériaux, la conception et l'installation du système d'isolation des réservoirs destinés au stockage des gaz liquéfiés réfrigérés (GLR).
Les réservoirs de stockage des GLR assurent le stockage de gaz liquéfiés à bas point d'ébullition, à savoir au-dessous de la température ambiante normale.
Le concept de stockage de tels produits en phase liquide et dans des réservoirs non pressurisés dépend alors de la combinaison entre la chaleur latente d'évaporation et l'isolation thermique.
Par conséquent, l'isolation thermique des réservoirs de stockage de GLR ne constitue pas un élément auxiliaire du système de confinement (comme c'est le cas pour la plupart des réservoirs de stockage d'hydrocarbures en air ambiant) mais en est un constituant essentiel ; le réservoir de stockage ne peut pas fonctionner sans un système d'isolation correctement conçu, installé et entretenu.
Les principales fonctions de l'isolation dans les réservoirs de stockage de GLR sont les suivantes :
- maintenir l'évaporation à un niveau égal ou inférieur aux limites spécifiées ;
- protéger les constituants du réservoir externe en les maintenant à une valeur égale ou supérieure à leur température minimale de conception ;
- prévenir les dommages consécutifs au soulèvement par le gel de la fondation/du sol sous la dalle de fondation du réservoir (en combinaison avec le système de réchauffage de la dalle pour les réservoirs sur sol) ;
- réduire le plus possible la condensation et la formation de givre sur les surfaces externes du réservoir.
Il existe une large gamme de matériaux isolants. Toutefois, les propriétés des matériaux diffèrent considérablement parmi la variété de différents matériaux génériques, voire également au sein d'un même groupe générique de matériaux.
Par conséquent, dans le cadre du domaine d'application de la présente Norme européenne, seules des indications d'ordre général sont données sur le choix des matériaux.
NOTE Pour obtenir des indications d'ordre général sur le choix des matériaux, voir l'Annexe A.
Le présent document traite de la conception et de la 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.
Konstruiranje in proizvodnja na mestu postavitve grajenih pokončnih, valjastih posod z ravnim dnom za shranjevanje hlajenih utekočinjenih plinov z delovnimi temperaturami med 0 °C in –196 °C - 4. del: Izolacijski deli
Ta dokument določa zahteve za materiale, konstruiranje in namestitev izolacije posod za shranjevanje hlajenega utekočinjenega plina (RLG). V posodah za shranjevanje hlajenega utekočinjenega plina se shranjuje utekočinjeni plin z nizkim vreliščem, tj. pod običajno temperaturo okolja. Koncept shranjevanja takšnih izdelkov v tekoči obliki in v posodah, ki niso pod tlakom, je zato odvisen od kombinacije latentne toplote izhlapevanja in toplotne izolacije. Posledično toplotna izolacija za posode za shranjevanje hlajenega utekočinjenega plina ni pomožni del sistema zadrževanja (kot pri večini rezervoarjev za ogljikovodike v zunanjem zraku), temveč je bistvena komponenta, posoda za shranjevanje pa ne more delovati brez pravilno načrtovanega, nameščenega in vzdrževanega izolacijskega sistema. Glavne funkcije izolacije v posodah za shranjevanje hlajenega utekočinjenega plina so: – vzdrževanje izhlapevanja zaradi uhajanja toplote pri določenih mejnih vrednostih ali pod njimi; – omejevanje toplotne obremenitve zunanjih komponent posode, da se preprečijo tako njihove nenadne poškodbe kot prezgodnje staranje (npr. zaradi zunanje kondenzacije in nastajanja ledu); – preprečevanje poškodb zaradi zmrzovanja temeljev/tal pod osnovno ploščo posode (v kombinaciji s sistemom ogrevanja plošče za posode, ki so na tleh); – zmanjšanje kondenzacije in zaledenitve na zunanjih površinah posode. Na voljo je širok nabor izolacijskih materialov, pri čemer se lahko lastnosti na splošno različnih materialov in tudi znotraj iste splošne skupine materialov zelo razlikujejo. Zato so v okviru tega dokumenta podana le splošna navodila za izbiro materialov. OPOMBA: Za splošna navodila v zvezi z izbiro materialov glej dodatek A. Ta dokument obravnava konstruiranje in proizvodnjo na mestu postavitve grajenih pokončnih, valjastih posod z ravnim dnom za shranjevanje hlajenih utekočinjenih plinov z delovnimi temperaturami med 0 °C in –196 °C.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2025
Nadomešča:
SIST EN 14620-4:2007
Konstruiranje in proizvodnja na mestu postavitve grajenih pokončnih, valjastih
posod z ravnim dnom za shranjevanje hlajenih utekočinjenih plinov z delovnimi
temperaturami med 0 °C in –196 °C - 4. del: Izolacijski 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 4: Insulation components
Auslegung und Herstellung standortgefertigter, stehender, zylindrischer Flachboden-
Tanksystemen für die Lagerung von tiefkalt verflüssigten Gasen bei
Betriebstemperaturen zwischen 0 °C und -196 °C - Teil 4: Dämmung
Conception et fabrication de réservoirs à fond plat, verticaux, cylindriques, construits sur
site, destinés au stockage des gaz réfrigérés, liquéfiés, dont les températures de service
sont comprises entre 0 °C et 196 °C - Partie 4 : Constituants isolants
Ta slovenski standard je istoveten z: EN 14620-4:2025
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.
EN 14620-4
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2025
EUROPÄISCHE NORM
ICS 23.020.10 Supersedes EN 14620-4:2006
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 4: Insulation components
Conception et fabrication de réservoirs à fond plat, Auslegung und Herstellung standortgefertigter,
verticaux, cylindriques, construits sur site, destinés au stehender, zylindrischer Flachboden-Tanksystemen 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 4 : Constituants isolants 4: Dämmung
This European Standard was approved by CEN on 27 January 2025.
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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14620-4:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 7
4 Design requirements, performance characteristics, testing and selection of insulating
materials . 7
4.1 General. 7
4.2 Analysis of design requirements . 8
4.2.1 General. 8
4.2.2 Thermal resistance . 8
4.2.3 Structural and tightness requirements . 8
4.2.4 Ageing and deterioration . 9
4.2.5 Specific design requirements . 9
4.3 Assessment of the performance characteristics . 9
4.3.1 General. 9
4.3.2 Thermal resistance . 9
4.3.3 Mechanical properties . 9
4.3.4 Temperature resistance . 10
4.3.5 Resistance to water and water vapour . 10
4.3.6 Influences of stored product . 10
4.3.7 Chemical properties . 10
4.3.8 Fire behaviour . 11
4.4 Testing of materials and systems . 12
4.4.1 General. 12
4.4.2 Test methods . 12
5 Protection of insulation – vapour barrier . 13
5.1 General. 13
5.2 Protective structure formed by the outer tank . 13
5.3 Protective cover for external insulation . 13
6 Design of insulation system . 14
6.1 General. 14
6.2 Thermal design . 14
6.3 Structural design . 15
6.3.1 General. 15
6.3.2 Load bearing insulation/compressive action . 15
6.3.3 Other load bearing insulation materials . 17
6.3.4 Load bearing insulation/other actions . 17
6.4 Insulation for each tank component . 17
6.4.1 General. 17
6.4.2 Supporting ringbeam. 18
6.4.3 Bottom insulation . 18
6.4.4 Shell insulation (external) . 19
6.4.5 Shell/wall insulation (internal) . 20
6.4.6 Roof insulation (external) . 22
6.4.7 Roof insulation on suspended roof . 22
6.4.8 Insulation for penetrations and internal piping . 22
7 Installation . 23
7.1 General . 23
7.2 Requirements . 23
7.2.1 Materials . 23
7.2.2 Conditions of work on site . 23
7.2.3 Anti-corrosive protection . 24
7.2.4 Construction tolerances . 24
7.2.5 Prevention of damage . 24
7.3 Inspection and testing . 25
Annex A (informative) Insulation materials . 26
Annex B (normative) Test methods . 29
Annex C (informative) Recommendations for qualification compressive strength testing of
tank insulation system made of brittle material . 31
Annex D (normative) Non-metallic Liquid barrier of the Thermal Protection System . 32
D.1 General . 32
D.2 Performance requirements . 32
D.3 Materials . 33
D.4 Model Testing . 33
D.5 Installation . 33
D.6 Examination and tests . 33
Annex E (informative) . 35
Bibliography . 36
European foreword
This document (EN 14620-4:2025) 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 European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2025, and conflicting national standards shall
be withdrawn at the latest by October 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 14620-4:2006.
— General editorial update;
— Normative reference updated;
— Recent insulating materials European standards introduced and Annex B updated;
— Aspects related to insulating materials fire behaviour developed and clarified;
— Brittle material compressive behaviour clarified with the use of interleaving material;
— Requirements for Insulation for penetrations and internal piping introduced;
— New Annex C added about the recommendations for qualification compressive strength testing of
tank insulation system made of brittle material;
— New Annex D for non-metallic TPS added;
— Annex about limit state theory for tank bottom insulation removed;
— New Annex E added, providing guidance for defining duties and responsibilities between various
parties involved.
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.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: 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 the United
Kingdom.
1 Scope
This document specifies the requirements for materials, design and installation of the insulation of
refrigerated liquefied gas (RLG) storage tank systems.
RLG storage tank systems store liquefied gas with a low boiling point, i.e. below normal ambient
temperature.
The concept of storing such products in liquid form and in non-pressurized tanks therefore depends on
the combination of latent heat of vaporization and thermal insulation.
Consequently, thermal insulation for RLG storage tank systems is not an ancillary part of the containment
system (as for most ambient atmospheric hydrocarbon tanks) but it is an essential component and the
storage tank system cannot operate without a properly designed, installed and maintained insulation
system.
The main functions of the insulation in RLG storage tank systems are:
— to maintain the boil off due to heat in-leak at or below the specified limits;
— to limit the thermal loading of the outer tank components, so to prevent both their sudden damage
and premature ageing (e.g. due to external condensation and ice formation);
— to prevent damage by frost heave of the foundation/soil beneath the tank base slab (in combination
with the slab heating system for tanks resting at grade);
— to minimize condensation and icing on the outer surfaces of the tank.
A wide range of insulation materials is available. However, the material properties differ greatly amongst
the various generically different materials and also within the same generic group of materials.
Therefore, within the scope of this document, only general guidance on selection of materials is given.
NOTE For general guidance on selection of materials, see Annex A.
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.
EN 1363-1, Fire resistance tests — Part 1: General requirements
EN 1363-2, Fire resistance tests — Part 2: Alternative and additional procedures
EN 1993-1-2, Eurocode 3 — Design of steel structures — Part 1-2: Structural fire design
EN 13501-1, Fire classification of construction products and building elements — Part 1: Classification
using data from reaction to fire tests
EN 13501-2, Fire classification of construction products and building elements — Part 2: Classification
using data from fire resistance and/or smoke control tests, excluding ventilation services
EN 13381-4, Test methods for determining the contribution to the fire resistance of structural members —
Part 4: Applied passive protection to steel members
EN 14303, Thermal insulation products for building equipment and industrial installations — Factory made
mineral wool (MW) products — Specification
EN 14305:2015, Thermal insulation products for building equipment and industrial installations — Factory
made cellular glass (CG) products — Specification
EN 14307, Thermal insulation products for building equipment and industrial installations — Factory made
extruded polystyrene foam (XPS) products — Specification
EN 14308, Thermal insulation products for building equipment and industrial installations — Factory made
rigid polyurethane foam (PUR) and polyisocyanurate foam (PIR) products — Specification
EN 14309, Thermal insulation products for building equipment and industrial installations — Factory made
products of expanded polystyrene (EPS) — Specification
EN 14314, Thermal insulation products for building equipment and industrial installations — Factory made
phenolic foam (PF) products — Specification
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 14620-3:2006, 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
3: Concrete components
EN 15599-1, Thermal insulation products for building equipment and industrial installations — In-situ
thermal insulation formed from expanded perlite (EP) products — Part 1: Specification for bonded and
loose-fill products before installation
EN ISO 1182, Reaction to fire tests for products — Non-combustibility test (ISO 1182)
EN ISO 1716, Reaction to fire tests for products — Determination of the gross heat of combustion (calorific
value) (ISO 1716)
EN ISO 12624, Thermal insulating products for building equipment and industrial installations —
Determination of trace quantities of water-soluble chloride, fluoride, silicate, sodium ions and pH (ISO
12624)
EN ISO 16534, Thermal insulating products for building applications — Determination of compressive
creep (ISO 16534)
EN ISO 16535, Thermal insulating products for building applications — Determination of long-term water
absorption by immersion (ISO 16535)
EN ISO 29469:2022, Thermal insulating products for building applications — Determination of
compression behaviour (ISO 29469:2022)
ISO 3951-1, Sampling procedures for inspection by variables — Part 1: Specification for single sampling
plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a single quality characteristic
and a single AQL
ASTM E84, Standard Test Method for Surface Burning Characteristics of Building Materials
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 terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
compressive strength
σm
ratio of the maximum compressive force, F , reached when the strain, ε, at yield or rupture is less than
m
10 %, to the initial cross-sectional area of the test specimen
[SOURCE: ISO 29469:2022, 3.2]
3.2
compressive stress at 10% strain
σ
ratio of the compressive force, F , at 10 % strain, ε , to the initial cross-section of the test specimen for
10 10
products presenting 10 % strain before possible yield or rupture
[SOURCE: ISO 29469:2022, 3.3]
4 Design requirements, performance characteristics, testing and selection of
insulating materials
4.1 General
The selection of the appropriate insulation system and materials shall be based on the following:
— analysis of design requirements (see 4.2);
— assessment of the performance characteristics of the materials (see 4.3);
— environmental aspects.
NOTE 1 Refer to EN 14620-1:2024, Clause 6.2.
Information on typical material selection may be found in Annex A.
Selected material shall comply with the relevant European Standards as follows (non exhaustive list):
— Expanded Perlite: EN 15599-1;
— Mineral Wool: EN 14303;
— Cellular Glass: EN 14305:2015;
— Extruded Polystyrene: EN 14307;
— Rigid Polyurethane (PUR) and Polyisocyanurate (PIR) foam: EN 14308;
— Expanded Polystyrene: EN 14309;
— Phenolic foam: EN 14314.
Other insulating materials can be used providing they meet design requirements and performance
characteristics specified in this document.
For the specific application of this document, refer also to 4.3 and Annex B for the assessment of
performance characteristics. For insulation materials where the product standards do not specify testing
methods to assess performance characteristics required by 4.3, the testing methods specified in the
product standard for the similar insulation materials may be used (e.g. methods specified in EN 14308
can be used for PVC foam performance assessment). Otherwise, the testing methods to be suggested or
developed.
NOTE 2 See Annex E.
4.2 Analysis of design requirements
4.2.1 General
The thermal insulation system as a whole, and each component of it separately, shall be designed taking
into account the following design requirements.
4.2.2 Thermal resistance
4.2.2.1 Normal operation of the tank
All factors contributing to heat in-leak through the insulation system shall be considered, such as:
— product temperature;
— external ambient temperature and other climatic conditions (solar radiation, wind velocity,
humidity, etc.);
— thermal conductivity of the relevant materials, including influences of the environment they are
exposed to and potential degradation through ageing;
— thermal convection;
— thermal radiation;
— thermal bridging (as due to nozzles, TPS, anchors, deck rods, etc).
4.2.2.2 Accidental conditions
Each insulation component shall provide appropriate behaviour for all specified accidental conditions.
The required performance characteristics shall be retained for the duration of the accidental conditions
and not decay after it.
4.2.3 Structural and tightness requirements
The insulation system shall be designed to resist all applicable static and dynamic actions for both normal
and accidental conditions, unless the insulation is not intended to provide the structural resistance.
The insulation system shall provide liquid tightness and vapour tightness, if specified.
4.2.4 Ageing and deterioration
The insulation shall be resistant to deterioration from environmental conditions, ageing and product
exposure:
— There shall be no reduction in insulation thermal or mechanical performance due to ageing and no
deterioration from the exposure to substances insulation may be in contact during its lifetime.
— Ageing and deterioration shall not affect performance of the insulation support and attachment
systems.
— If such deterioration in insulation thermal or mechanical performance due to ageing is possible, those
shall be accounted in the insulation design.
4.2.5 Specific design requirements
In addition to the above requirements, the tank insulation design shall fulfil all the specific design
requirements that are inherent with the selected specific insulation system, material, installation method
and type of containment. These shall be specified on a case-by-case basis.
4.3 Assessment of the performance characteristics
4.3.1 General
Based on the design requirements, the required performance characteristics of the insulation materials
in the operating temperature range shall be determined. As a minimum, the subjects described in 4.3.2
to 4.3.8 shall be considered.
4.3.2 Thermal resistance
The following shall be considered:
a) thermal conductivity:
1) over the required temperature range;
2) in the intended environment, external and internal (product vapour space, purged space, contact
with liquid product);
3) taking into account ageing effects over the tank design lifetime;
b) possible heat in-leak through radiation;
c) possible heat in-leak through convection (permeability of the insulation material and of the complete
insulation system);
d) heat in-leak through cold bridges.
4.3.3 Mechanical properties
The following shall be considered:
— compressive properties both at short- and at long-term (creep);
— tensile and shear properties for insulation on which lateral forces may act (e.g. earthquake);
NOTE Tensile properties can also be required for assessment of thermo-mechanical loads and thermal
stresses.
— adhesive strength for insulation systems, which are installed by adhesion.
4.3.4 Temperature resistance
The insulation shall withstand the temperatures (maximum and minimum service temperatures) and
temperature variations to which it may be exposed. Therefore, shrinkage, expansion and possible
cracking effects, including but not limited to thermal gradient within the insulation material, shall be
determined, taking into account:
— coefficient of thermal expansion, contraction;
— tensile strength, tensile modulus in the designed temperature ranges;
— restraints for the insulation component free movement.
4.3.5 Resistance to water and water vapour
To assess the possible negative effects of water and water vapour on the insulation, the following
characteristics shall be considered:
— closed cell content;
— permeability for water vapour;
— water absorption.
In addition, the consequential effects of water and water vapour penetration shall be assessed:
— reduction of thermal resistance;
— possible structural damage to the insulation by liquid water or by the process of freezing (possibly
freeze/thaw cycles).
4.3.6 Influences of stored product
The following characteristics shall be assessed:
— closed cell content (as indication of open/closed cellular structure);
— absorption of product vapours and effect on other material properties (thermal conductivity,
mechanical properties, fire resistance);
— absorption of/and permeability for liquid product;
— effects of long term liquid absorption on other material properties;
— desorption behaviour: time/percentage.
NOTE The influence of the stored product on an internal insulation system is critical, as it is often continuously
in contact with product vapours and it can come in direct contact with the liquid product in case of an accidental
leakage.
For testing of material behaviour in presence of product, see Table B.1.
4.3.7 Chemical properties
An assessment shall be made of the compatibility between and/or possible chemical reactions of:
a) insulation system, including all its constituents:
1) insulation materials;
2) ancillary products (paints, adhesives, mastics, sealants, coatings etc.);
3) its protective layer (cladding and fastening);
b) its environment:
1) for external insulation: ambient conditions, water, water vapour, contaminants in air and water;
2) for internal insulation: the product vapours and liquid, inerting/purging gas;
c) tank material and/or its coating in contact with the insulation system.
Typical chemical characteristics to be assessed shall be:
d) for external insulation:
1) resistance to corrosion of the insulation system itself (or parts of it) in conditions representative
for the site location, e.g.: marine atmosphere, atmosphere polluted by chemical industries;
2) corrosion protective or corrosion activating properties of the insulation, e.g.: possibility of
dissolving or leaching out corrosive products from the insulation, corrosion protection in case
of waterproof insulation system;
e) for internal insulation:
1) chemical resistance of the insulation system against the product vapours/liquids in the tank;
2) insulation to be inert for the products stored in the tank (absence of contaminants, chemical
reagents).
For methods of assessing the chemical properties, see Table B.2.
4.3.8 Fire behaviour
As a minimum, the following important aspects related to fire shall be considered in the risk assessment:
— fire risk during operation;
— fire risk during construction;
— fire risk during and after decommissioning for repair or complete dismantling;
— behaviour in case of an external fire;
— risk to personnel due to emission of toxic fumes or non-toxic smoke in case of insulation fire or
exposure to heat sources.
In view of this, the following minimum requirements shall be met:
— when using combustible insulation materials, prevention measures to exclude the possibility of
ignition shall be provided;
— load bearing insulation shall maintain its load carrying capacity required by design as exposed to
heat caused by fire, unless the containment system can accommodate it. After the fire, if the load
bearing capacity is reduced, the tank shall be taken out of service for inspection of insulation system;
NOTE 1 Some combustible closed cell insulation materials (e.g. close cell foam insulations) exposed to product
vapours in service can absorb those vapours. At decommissioning these materials cannot be fully purged and can
release flammable vapours. Also, material combustibility can increase due to product vapour absorption.
The risks during tank decommissioning due to increased insulation combustibility and possible gas
desorption, should be fully understood and evaluated during the risk assessment process, in case the
insulation system from combustible not fully purgeable materials exposed to product vapours is selected.
NOTE 2 See Annex E
The following characteristics of the insulation system components shall be considered:
— maximum temperature limits of the material: melting temperature, decomposition temperature,
ignition temperature;
— reduction in load carrying capacity at elevated temperature (for load bearing insulation);
— fire resistance properties of the insulation (in case the thermal insulation is designed also for the dual
role of fire protection).
Only certified materials shall be used, and fire behaviour properties shall be stated on test certificates.
For methods of assessing fire behaviour, see Table B.3.
4.4 Testing of materials and systems
4.4.1 General
The performance characteristics of the insulation materials shall be demonstrated by:
— laboratory testing;
— mock-up testing of an insulation system;
NOTE 1 For evaluating the behaviour of a tank insulation system under a combination of various actions, the
testing of single material properties is not always sufficient. Mock-up testing is an alternative solution.
or
— complete installed tank insulation system.
NOTE 2 Finite element calculations can provide additional information.
4.4.2 Test methods
Whenever available, standardized testing methods shall be in accordance with Annex B and the insulation
product standards referenced in 4.1.
NOTE 1 Annex B deals with testing of performance characteristics of insulation materials/insulation systems.
Other tests, used only for specific products, are not covered e.g. measurements of density, dimensions, etc. The
insulation material manufacturer normally provides them.
NOTE 2 The selection of materials complying with the relevant European Standards as listed in 4.1 implies the
adoption of standard test methods for performance characteristics as: thermal resistance (4.3.2), mechanical
properties (4.3.3), temperature resistance (4.3.4) and resistance to water and water vapour (4.3.5), not addressed
in Annex B.
5 Protection of insulation – vapour barrier
5.1 General
As the insulation system is not a self-standing structural component of the tank, the insulation shall be
fixed against, placed upon, poured in between or supported by other structural components.
Furthermore insulation materials shall be protected against various types of possible deterioration and
damage, such as:
— mechanical damages;
— water absorption by rain, snow, etc.;
— deterioration by other climatic factors such as wind, hail, UV;
— water absorption and ice formation by penetration of water vapour;
— fire damage.
For this protection a protective cover shall be provided.
5.2 Protective structure formed by the outer tank
In many containment types, the outer tank provides the protection and the supporting structure for the
insulation and, in this case, it shall be confirmed that the outer tank provides sufficient tightness.
In cases where the outer tank is made of concrete, which is permeable for water vapour and product
vapour, the necessary measures shall be taken to make the concrete water vapour and product vapour
tight.
Water vapour and product vapour tightness shall be achieved by:
— either a metallic liner;
— or a Polymeric Vapour Barrier (PVB).
NOTE See also EN 14620-1:2024, 7.1.5 and EN 14620-3:2006, 10.3.
5.3 Protective cover for external insulation
Where the insulation is placed externally, an appropriate cover shall be provided. This cover shall give
protection against all factors that could adversely affect the quality/efficiency and lifetime of the
insulation.
The following factors shall be considered:
a) weather factors:
1) water vapour;
2) rain, snow, hail;
3) wind, storm;
4) solar radiation, UV;
b) other atmospheric factors:
1) pollution;
2) corrosion;
c) mechanical damages by humans, birds, etc.;
d) fire damage.
Since for cold insulation, the most detrimental “aggressor”, being invisible and acting continuously, is
water vapour, the penetration of water vapour shall be prevented/minimized. For most insulation
systems, a good Water Vapour Barrier (WVB) shall be installed on the outside of the insulation to
eliminate/minimize water vapour penetration. This WVB shall either be designed separately or as part
of the protective cover.
The maximum WVB transmission rate shall be 0,5 g/m 24 h under the average water vapour pressure
differential of the area where the project is located.
The protective cover and water vapour barrier of external tank insulation shall be:
— metallic (insulation cladding), or
— non-metallic (polymeric vapour barrier, vapour barrier mastics), or
— a combination of both.
NOTE The need for this WVB can be waived for certain insulation systems if it is sufficiently proven that the
insulation system itself is and remains water vapour tight.
6 Design of insulation system
6.1 General
In general, the design of the tank insulation system shall be based on structural and thermal
requirements. In addition, the installation method and the commissioning and decommissioning
(purging, gas freeing) requirements shall be taken into account.
NOTE The insulation design can differ substantially, based on the type of containment selected and on the part
of the tank under consideration (bottom, wall, roof). It is difficult to specify for each type of containment each subject
to be considered and the approach has been taken that only general requirements are mentioned below.
As part of the total tank insulation design, all additional requirements inherent with the specific type of
containment, part of the tank under consideration, insulation material selected and other project
inherent factors shall be clearly specified in the project specification.
6.2 Thermal design
The thermal design shall take account of the requirements specified:
— maximum allowed boil off due to heat in-leak;
— minimum temperature condition of the outer tank components;
— prevention of icing/condensation on external surfaces of the tank;
— prevention of soil freezing.
For boil-off, the maximum allowed boil-off per day and the external climatic conditions that shall be taken
into account shall be specified.
NOTE See Annex E
The thermal design shall result in an insulation system that, by spreading the total allowed heat in-leak
over the various parts of the tank, shall satisfy all the above requirements.
If in the thermal design of the tank, in addition to the thermal resistance offered by the insulation system,
allowance is also made for the thermal resistance of other parts of the tank such as constructional parts
(concrete) or vapour spaces inside the tank, this shall only be done in as far as the thermal resistance of
these components in the respective position in the tank and in the relevant temperature range is proven.
6.3 Structural design
6.3.1 General
The structural design of the load bearing insulation system shall be based on the allowable stress theory.
The load transfer from the inner tank to the outer tank through the load bearing insulation shall be
demonstrated.
All reinforced concrete components (including the concrete ringbeam) are designed according to the
limit state theory, as per the requirements of EN 14620-3:2006.
6.3.2 Load bearing insulation/compressive action
6.3.2.1 General
Certain parts of the tank insulation are subjected to compressive loads:
— tank bottom insulation for all types of containment;
— tank bottom and tank wall for membrane tanks;
— TPS for bottom and wall.
6.3.2.2 Allowable stress theory
6.3.2.2.1 For brittle materials (e.g. cellular glass)
The minimum overall safety factors, between compressive strength and design compressive stress shall
be as follows:
normal operation: 3,00 relative to σ
n
hydrostatic test: 2,25 relative to σ
n
earthquake (OBE): 1,25 relative to σ
min
earthquake (SSE): 1,00 relative to σ
min
NOTE 1 The overall safety factor makes allowance for influences of column effect, installation, variation on
materials and difference of testing; coexisting shear load is not covered.
The nominal compressive strength σ shall be determined as follows:
n
— compressive strength shall be measured in accordance with EN ISO 29469:2022, Annex A. The
results are expressed as compressive strength σ . Creep tests shall not be required if it is proven that
m
the material is not subject to creep;
— average value of a statistically sufficient number of such tests is called the nominal compressive
strength σ of this material; the manufacturer shall declare this value;
n
— average value less two times the standard deviation of σ results per above shall be compared with
m
the lower specification limit σ or declared level for compressive strength of this material; if any of
min
those values is lower than 67 % of σ , then the σ shall be adjusted as 1,5 times this minimum value.
n n
If in actual installation interleaving material is different than used in factory testing, the effect of the
intended interleaving material on cellular glass compressive strength shall be determined by test. The
compressive strength values used for the design shall be adjusted accordingly in case the tests indicate
reduction in the compressive strength. No increase in compressive strength over the values declared by
the material manufacturer is allowed.
For cellular glass products, the minimum extent of testing shall be as specified in ISO 3951-1. An s-method
acceptance sampling plan shall be used based on fabrication lot size, and the general inspection level shall
be at least Level I. The number of samples shall be chosen based on acceptance quality limit (AQL) of
1,0 %, and reduced inspection shall be chosen as a minimum.
NOTE 2 Recommendations for qualification of compressive strength for tank insulation system made of brittle
material are provided in Annex C.
6.3.2.2.2 For materials susceptible to creep (plastic foam)
PU material as a minimum have to follow EN 14308.
Compressive creep shall be measured in accordance with EN ISO 16534.
The compressive stress applied during the creep tests shall be determined as the nominal compressive
strength σ multiplied with the permissible load factor (PLDF).
n
The nominal compressive strength σ shall be determined as follows by short term compressive test:
n
— compressive strength shall be measured in accordance with EN ISO 29469:2022; the results
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...