oSIST prEN 13121-3:2022

GRP tanks and vessels for use above ground - Part 3: Design and workmanship

This European Standard gives requirements for the design, fabrication, inspection, testing and verification of GRP tanks and vessels with or without thermoplastics lining for storage or processing of fluids, factory made or site built, non-pressurized or pressurized up to 10 bar, for use above ground. Further requirements are presented in normative Annex G.
The terms vessels and tanks as used in this part of EN 13121 include branches up to the point of connection to pipe work or other equipment by bolting and supports, brackets or other attachments bonded directly to the shell.
This part of EN 13121 covers vessels and tanks subject to temperatures between - 40 °C and 120 °C.
Excluded from this part of EN 13121 are:
-   tanks and vessels for the transport of fluids;
-   underground storage tanks;
-   spherical vessels;
-   vessels and tanks of irregular shape;
-   tanks and vessels with double containment where the double wall is considered structural;
-   tanks and vessels which are subject to the risk of explosion, or failure of which may cause an emission of radioactivity;
-   specification for fibre reinforced cisterns of one piece and sectional construction for the storage, above ground, of cold water (see EN 13280).

Oberirdische GFK-Tanks und -Behälter - Teil 3: Auslegung und Herstellung

Dieses Dokument legt Anforderungen für Auslegung, Fertigung, Prüfung und den Nachweis für oberirdische GFK-Tanks und –Behälter, mit oder ohne thermoplastische(r) Auskleidung fest, die im Werk oder auf der Baustelle gefertigt und drucklos oder bis zu 10 bar druckbeaufschlagt sind und zur Lagerung oder Verarbeitung von Fluiden dienen. Weitere Anforderungen sind im normativen Anhang G dargelegt.
Die Begriffe Behälter und Tank im Sinne dieses Dokuments umfassen auch Stutzen(Abzweige) bis zur Verbindung zu Rohrleitungen oder anderen Anlagenteilen, wie Verschraubungen, Unterstützkonstruktionen, Halterungen oder anderen Anbauteilen, die unmittelbar mit der Schale verbunden sind.
Dieses Dokument gilt für Behälter und Tanks, die Temperaturen zwischen −40 °C und 120 °C ausgesetzt sind.
Dieser Teil der EN 13121 gilt nicht für
   Tanks und Behälter für den Transport von Fluiden,
   unterirdische Lagertanks,
   kugelförmige Behälter,
   Behälter und Tanks mit unregelmäßiger Form,
   Tanks und Behälter in doppelwandiger Ausführung, bei denen die Doppelwandigkeit statisch berücksichtigt wird,
   Tanks und Behälter, die bei Explosion oder Undichtheit die Emission radioaktiver Strahlungen zur Folge haben können, und
   einteilige und mehrteilige oberirdische faserverstärkte Tanks für die Lagerung von Kaltwasser (siehe EN 13280).

Réservoirs et récipients en PRV pour applications hors sol - Partie 3 : Conception et fabrication

Nadzemni rezervoarji in posode iz umetnih mas, ojačanih s steklenimi vlakni - 3. del: Konstruiranje in izdelava

General Information

• Status: Not Published
• Public Enquiry End Date: 02-Nov-2022
• ICS: 23.020.10 - Stationary containers and tanks
• Technical Committee: TLP - Pressure vessels
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 01-Sep-2022
• Due Date: 19-Jan-2023
• Completion Date: 25-Nov-2022
• Directive: 2014/68/EU - Directive 2014/68/EU of the European Parliament and of the Council of 15 May 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of pressure equipment
• Mandate: M/071 - Mandate to CEN for standardization in the field of Pressure equipment
• Mandate: M/601 - COMMISSION IMPLEMENTING DECISION of 1.3.2024 on a standardisation request to the European Committee for Standardization and the European Committee for Electrotechnical Standardization as regards pressure equipment and assemblies in support of Directive 2014/68/EU of the European Parliament and of the Council
• Ref Project: FprEN 13121-3 - GRP tanks and vessels for use above ground - Part 3: Design and workmanship

Relations

• Revised: SIST EN 13121-3:2016 - GRP tanks and vessels for use above ground - Part 3: Design and workmanship
• Effective Date: 18-Jan-2023
• Revised: SIST EN 13121-3:2016 - GRP tanks and vessels for use above ground - Part 3: Design and workmanship
• Effective Date: 01-Oct-2022

Overview

FprEN 13121-3 - "GRP tanks and vessels for use above ground - Part 3: Design and workmanship" (CEN) sets requirements for the design, fabrication, inspection, testing and verification of glass reinforced plastics (GRP) tanks and vessels for above‑ground use. It applies to factory‑made or site‑built, non‑pressurized or pressurized vessels up to 10 bar, intended for service temperatures between −40 °C and 120 °C. The standard covers vessels with bonded supports and branches up to pipe connections and includes requirements for thermoplastic linings and resin‑based barriers. Further requirements appear in normative Annex G.

Excluded are transport tanks, underground tanks, spherical or irregularly shaped vessels, structurally double‑contained tanks, vessels at explosion or radioactivity risk, and cold‑water cisterns covered by EN 13280.

Key Topics and Requirements

• Scope & documentation: Information manufacturers must obtain, prepare and supply; final documentation for verification.
• Materials: Selection of GRP resins, reinforcement, chemical protective barriers, thermoplastic and resin linings, flammability and electrical resistivity considerations.
• Laminate design: Laminate construction, required thickness, mechanical properties, inter‑laminar shear, peel strength and pull‑off strength; methods to derive laminate mechanical values.
• Design loads and strains: Definition of limit strains, limit laminate loadings and design strain calculations.
• External load cases: Snow, wind, seismic, insulation, agitation, venting/pressure buildup, personnel loads and temperature‑induced stresses.
• Verification methods: Partial factor method and (A·γ)‑factored loads for structural verification.
• Structural analysis: Detailed design and verification for cylindrical shells, buckling criteria, conical and dished ends, flat bottoms and skirts, circumferential seams, openings and branches.
• Fabrication & quality: Requirements for workmanship, inspection, testing and on‑site assembly (factory or site built).

Applications and Users

This standard is essential for:

• Design engineers specifying GRP tanks and vessels for chemical storage and processing.
• Manufacturers and fabricators of GRP tanks (factory‑made or site‑built).
• Inspectors, testing laboratories and certifying bodies performing verification, pressure testing and inspection.
• Plant owners, asset managers and procurement specialists who need compliant specifications for above‑ground fluid storage or process vessels. Typical applications include chemical and industrial storage, secondary process tanks, and lined vessels where corrosion resistance, lightweight construction and non‑metallic properties are required.

Related Standards

• EN 13280 (fibre reinforced cisterns for cold water) - exclusion reference for certain cisterns.
• This draft (prEN 13121-3:2022) is prepared by CEN/TC 210 and is intended to supersede EN 13121-3:2016 when finalized. For complete compliance, consult the full prEN 13121 series and normative Annex G.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2022
Nadzemni rezervoarji in posode iz umetnih mas, ojačanih s steklenimi vlakni - 3.
del: Konstruiranje in izdelava
GRP tanks and vessels for use above ground - Part 3: Design and workmanship
Oberirdische GFK-Tanks und -Behälter - Teil 3: Auslegung und Herstellung
Réservoirs et récipients en PRV pour applications hors sol - Partie 3 : Conception et
fabrication
Ta slovenski standard je istoveten z: prEN 13121-3
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
prEN 13121-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2022
ICS 23.020.10 Will supersede EN 13121-3:2016
English Version
GRP tanks and vessels for use above ground - Part 3:
Design and workmanship
Réservoirs et récipients en PRV pour applications hors Oberirdische GFK-Tanks und -Behälter - Teil 3:
sol - Partie 3 : Conception et fabrication Auslegung und Herstellung
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 210.
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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13121-3:2022 E
worldwide for CEN national Members.

prEN 13121-3:2022 (E)
Contents
European foreword . 9
Introduction . 10
1 Scope . 11
2 Normative references . 11
3 Terms and definitions . 13
4 Symbols and abbreviations . 15
5 Information and requirements to be supplied and documented . 17
5.1 General . 17
5.2 Information to be obtained by the manufacturer . 17
5.3 Information to be prepared by the manufacturer . 18
5.4 Final documentation . 19
6 Material . 19
6.1 General . 19
6.2 Chemical protective barrier . 19
6.2.1 General . 19
6.2.2 Thermoplastics linings . 19
6.2.3 Resin based linings . 19
6.3 Flammability . 19
6.4 Electrical resistivity . 19
7 Mechanical properties . 20
7.1 General . 20
7.2 Heat deflection temperature. 20
7.3 Laminate construction . 20
7.4 Laminate thickness . 22
7.5 Laminate properties . 22
7.6 Inter-laminar shear strength . 22
7.6.1 Laminate . 22
7.6.2 Thermoplastics linings . 22
7.7 Peel strength of laminates . 23
7.8 Pull-off strength of laminates and thermoplastic liner . 23
7.9 Selection of physical properties of materials and allowable design factors . 23
7.9.1 General . 23
7.9.2 Basic design . 23
7.9.3 Advanced design . 24
7.9.4 Design factors . 25
7.9.5 Overall design factors K and F . 25
8 Determination of design strain and loadings . 28
8.1 General . 28
8.2 Limit design strains . 28
8.2.1 General . 28
8.2.2 Limit resin strain ε . 28
ar
8.2.3 Limit strain for laminate or lamina ε . 28
lim
8.2.4 Limit test strain ε . 29
test
8.3 Limit design laminate loadings . 29
8.4 Determination of the mechanical values from laminates . 29
8.4.1 General . 29
8.4.2 Calculation of laminate values without experimental test data . 30
8.4.3 Laminate with experimental data . 30
8.5 Laminate thickness . 30
prEN 13121-3:2022 (E)
9 Design . 31
9.1 Introduction . 31
9.2 Determination of external loads . 31
9.2.1 Snow loads . 31
9.2.2 Wind loads . 31
9.2.3 Seismic loads . 32
9.2.4 Insulation loads . 34
9.2.5 Loads resulting from connections . 34
9.2.6 Agitation . 34
9.2.7 Pressure due to inadequate venting . 34
9.2.8 Personnel loading . 34
9.2.9 Internal stresses in vessels and tanks due temperatures . 35
9.3 Verification by the partial factor method . 35
9.3.1 General . 35
9.3.2 Dimensioning by using (A ⋅γ )-factored loads. 40
F,i
9.4 Drawings and design calculations . 41
9.5 Design details . 41
9.5.1 Design temperature TS . 41
9.5.2 Pressure . 41
10 Design analysis . 42
10.1 Symbols and units . 42
10.2 Vertical vessels or tanks, cylinders under loads (t < 0,01∙D) . 45
10.2.1 Circumferential loadings . 45
10.2.2 Combined axial loading . 45
10.3 Cylindrical shells subject to compressive loadings — critical buckling criteria. 46
10.3.1 General . 46
10.3.2 Critical axial buckling load . 46
10.3.3 Critical circumferential buckling pressure . 47
10.3.4 Combined axial and radial compressive loadings . 47
10.3.5 Critical buckling pressure for cylindrical shell stiffened with external or internal rings. 48
10.4 Conical shells . 50
10.4.1 General requirements. 50
10.4.2 Shallow conical ends . 51
10.4.3 Conical ends subject to internal pressure . 52
10.4.4 Conical ends subject to external pressure . 53
10.4.5 Shell conical covers . 55
10.5 Dished end . 56
10.5.1 General requirements. 56
10.5.2 Dished ends subject to internal pressure . 57
10.5.3 Stability for dished ends subject to external pressure . 58
10.6 Design of flat bottoms and skirts for vertical tanks and vessels . 59
10.6.1 Definitions . 59
10.6.2 Fully supported, flat bottom tanks . 59
10.6.3 Vessels with flat bases subjected to pressure . 66
10.6.4 Dished bottom and conical bottom configurations . 66
10.7 Circumferential seams for cylindrical joints . 75
10.7.1 General . 75
10.7.2 Construction without thermoplastics liner . 78
10.7.3 Construction with thermoplastics liner . 78
10.8 Openings, branches and compensating laminate . 78
10.8.1 General . 78
10.8.2 Symbols . 79
10.8.3 Compensation requirements for openings . 79
10.8.4 Pull out load from nozzles . 86
10.8.5 Prevention of failure in peel . 86
10.8.6 Pad connections . 86
prEN 13121-3:2022 (E)
10.8.7 Screwed connections . 88
10.8.8 Access and inspecting openings . 88
10.8.9 Gusset on branches . 88
10.9 Flat Panels or Blind flanges . 88
10.9.1 General . 88
10.9.2 Symbols . 89
10.9.3 Circular panels . 89
10.10 Horizontal tanks and vessels . 92
10.10.1Types of supports . 92
10.10.2Symbols . 94
10.10.3Unit loads of the cylindrical shell . 95
10.10.4Unit loads on saddle position. 101
10.10.5Unit loads for horizontal loads at the vessel . 108
10.11 Large diameter pipes and pipe fittings . 109
10.11.1General . 109
10.11.2Joints . 109
10.11.3Elbows . 110
10.11.4Large cut-outs and Tees . 110
11 Bolted flange connections . 113
11.1 General . 113
11.2 Full face flanges design . 119
11.2.1 General . 119
11.2.2 Symbols . 120
11.2.3 Pipe loads on flanges. 122
11.2.4 Gasket load and bolt torque . 122
11.2.5 Summary of loads . 123
11.2.6 Total bending moment . 123
11.2.7 Flange design . 123
11.2.8 Flange slope . 125
11.3 Stub flange design with backing ring . 131
11.3.1 General . 131
11.3.2 Loads, bending moment and design for backing ring made of steel or GRP . 132
11.3.3 Stub flange loadings . 133
11.3.4 Stub shear interface design . 133
11.3.5 Stub end or flange design . 133
11.3.6 Seating stress . 134
11.4 Butt and strap jointed flanges at vessels or tanks. 136
12 Supports for vessels and tanks . 136
12.1 General . 136
12.2 Supports and mountings for tanks and vessels . 137
12.2.1 General considerations for supports . 137
12.2.2 Supports for vertical vessels . 137
13 Seismic loading . 143
14 Design calculation for tank and vessel anchorage . 143
14.1 General . 143
14.2 Design for uplift . 143
14.3 Design for anchor bolts . 143
15 Structures and fittings . 147
15.1 General . 147
15.2 Internal structures and fittings . 147
15.3 External structures and fittings . 147
15.4 Lifting devices . 147
16 Local load analysis . 152
17 Quality Control . 152
prEN 13121-3:2022 (E)
17.1 General . 152
17.2 Works requirements . 152
17.2.1 General . 152
17.2.2 Raw materials storage . 152
17.2.3 Manufacturing area . 152
17.2.4 Conditions for laminating . 152
17.3 Documentation to be prepared by the manufacturer . 153
17.3.1 Technical documentation . 153
17.3.2 Records and documentation requirements for raw materials . 153
17.3.3 Manufacturing documentation requirements . 154
17.3.4 Quality control documentation requirements . 154
17.4 Manufacture . 160
17.4.1 General . 160
17.4.2 Fabrication of thermoplastics liners . 160
17.4.3 Fabrication of laminates . 160
17.4.4 Imperfections in laminates . 161
17.4.5 Curing . 161
17.5 Inspection and testing after completion of fabrication . 161
17.5.1 Visual and dimensional inspection . 161
17.5.2 Physical test to be carried out . 162
17.5.3 Coupon testing . 162
17.6 Experimental Design Verification Method for pressure vessel . 163
17.6.1 General . 163
17.6.2 Manufacture of the prototype vessel . 163
17.6.3 Tests to be applied to prototype vessels . 164
18 Marking . 165
Annex A (informative) Product testing for serial or batch production process . 166
A.1 Initial type testing (ITT) . 166
A.2 Testing of samples . 166
A.2.1 General . 166
A.2.2 Batch release tests (BRT) . 166
A.2.2.1 General . 166
A.2.2.2 Retesting procedures for batch release tests . 167
A.2.3 Process control tests . 167
A.3 Inspection and test records . 167
A.3.1 General . 167
A.3.2 Marking . 167
A.3.3 Delivery, installation, maintenance . 167
Annex B (informative) Derivation of laminate properties from laminate properties . 168
B.1 General . 168
B.2 Lamina/laminate thickness . 168
B.3 Laminate modulus . 169
B.4 Determination of laminate flexural stiffness . 170
B.5 Determination of laminate strains from load resultants . 170
Annex C (normative) Pressure and leak testing . 172
C.1 General . 172
prEN 13121-3:2022 (E)
C.2 Open top tanks . 172
C.3 Tests of pressure less tanks and vessels . 173
C.3.1 Contents having a specific gravity up to 1,0 . 173
C.3.2 Contents having a specific gravity greater than 1,0 . 173
C.4 Hydraulic pressure test by pressure vessels . 173
C.4.1 Test done in the working attitude . 173
C.4.2 Pneumatic testing . 174
C.4.3 Vacuum test . 174
Annex D (normative) Methods of tests . 175
D.1 General . 175
D.1.1 Tests . 175
D.1.2 Accuracy of test equipment . 175
D.2 Loss on ignition . 176
D.3 Tensile strength of thermoplastics welds . 176
D.4 Bend test for thermoplastics welds . 176
D.4.1 Introduction . 176
D.4.2 Test arrangement . 176
D.4.3 Test pieces . 177
D.4.4 Method of test . 177
D.4.5 Requirements from flexural test . 177
D.4.6 Test report . 177
D.5 Ultimate tensile unit strength of laminates . 178
D.5.1 Test pieces and procedure . 178
D.5.2 Simple laminates . 178
D.5.3 Combined laminates . 178
D.6 Unit tensile modulus of laminates . 179
D.7 Inter laminar shear strength of laminates . 181
D.7.1 Form of test specimen . 181
D.7.2 Number of test specimens . 181
D.7.3 Procedure . 181
D.7.4 Results . 181
D.7.5 Report . 181
D.8 Lap shear strength of bond between thermoplastics lining and laminate or between
laminates . 182
D.8.1 Form of the test specimen . 182
D.8.2 Number of test specimens . 182
D.8.3 Procedure . 182
D.8.4 Report . 183
D.9 Peel strength of bond between laminate layers . 183
prEN 13121-3:2022 (E)
D.9.1 Form of the specimen . 183
D.9.2 Number of specimens. 183
D.9.3 Procedure . 184
D.9.4 Report . 184
D.10 Flexural short-term creep test (flexural modulus E and E test) . 186
1h 24h
D.10.1 General
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