SIST EN 14917:2021

SLOVENSKI STANDARD
oSIST prEN 14917:2020
01-april-2020
Kompenzatorji s kovinskimi mehovi v tlačnih cevovodih
Metal bellows expansion joints for pressure applications
Kompensatoren mit metallischen Bälgen für Druckanwendungen
Compensateurs de dilatation à soufflets métalliques pour appareils à pression
Ta slovenski standard je istoveten z: prEN 14917
ICS:
23.040.99 Drugi sestavni deli za Other pipeline components
cevovode
oSIST prEN 14917:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 14917:2020

---------------------- Page: 2 ----------------------
oSIST prEN 14917:2020


DRAFT
EUROPEAN STANDARD
prEN 14917
NORME EUROPÉENNE

EUROPÄISCHE NORM

February 2020
ICS 23.040.99 Will supersede EN 14917:2009+A1:2012
English Version

Metal bellows expansion joints for pressure applications
Compensateurs de dilatation à soufflets métalliques Kompensatoren mit metallischen Bälgen für
pour appareils à pression Druckanwendungen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 342.

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, Turkey 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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14917:2020 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------
oSIST prEN 14917:2020
prEN 14917:2020 (E)
Contents Page
European foreword . 8
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 13
4 Classification . 15
4.1 Classification of expansion joints . 15
4.1.1 General . 15
4.1.2 Axial . 15
4.1.3 Angular . 16
4.1.4 Lateral . 16
4.1.5 Universal . 16
4.1.6 Pressure balanced designs (axial or universal) . 16
4.2 Classification of the parts of expansion joints . 19
4.2.1 Main pressure-bearing parts (A) . 19
4.2.2 Pressure parts other than main pressure-bearing parts (B) . 19
4.2.3 Attachments to main pressure-bearing parts and to pressure parts (C) . 19
4.2.4 Other parts (D) . 19
5 Materials . 21
5.1 General . 21
5.1.1 Materials for pressure-bearing parts . 21
5.1.2 Materials for parts attached to pressure-bearing parts . 21
21
5.1.3 Materials for non-pressure parts .
5.1.4 Documentation . 21
5.2 Pressure-bearing parts . 21
5.2.1 Bellows . 21
5.2.2 Other pressure-bearing parts . 22
5.2.3 Ductility . 22
5.2.4 Brittle fracture . 22
5.3 Material documentation . 26
6 Design . 27
6.1 General . 27
6.1.1 Symbols . 27
6.1.2 Basic design criteria . 33
6.1.3 Allowable stresses . 34
6.1.4 Additional loadings . 36
6.2 Bellows design . 37
6.2.1 Purpose . 37
6.2.2 Conditions of applicability . 37
6.2.3 Design of U-shaped unreinforced bellows . 55
6.2.4 Design of U-shaped reinforced bellows . 70
6.2.5 Design of toroidal bellows . 73
6.2.6 Fatigue . 80
6.2.7 Bellows under the influence of movements . 84
6.2.8 Equivalent axial displacement per corrugation . 89
6.2.9 Forces and moments on pressurized expansion joints . 94
6.2.10 Torsion acting on bellows (unreinforced or reinforced) . 105
2

---------------------- Page: 4 ----------------------
oSIST prEN 14917:2020
prEN 14917:2020 (E)
6.3 Internal sleeve . 106
6.3.1 Scope . 106
6.3.2 Additional symbols . 106
6.3.3 Flow velocity . 107
6.3.4 Design conditions . 109
6.4 Hardware . 110
6.4.1 General . 110
6.4.2 Design parameters . 110
6.4.3 Hardware parts . 112
6.4.4 Permanent joints . 113
7 Manufacturing . 116
7.1 General . 116
7.2 Materials . 116
7.2.1 General . 116
7.2.2 Material traceability . 116
7.3 Permanent joints . 116
7.3.1 General . 116
7.3.2 Process and personal . 116
7.3.3 Repair and rework during manufacturing . 117
7.4 Forming of the bellows . 117
7.4.1 Forming processes . 117
7.4.2 Heat treatment . 119
7.5 Tolerances . 119
7.5.1 General . 119
7.5.2 Bellows . 119
7.5.3 Expansion joint . 120
7.6 Production tests . 121
8 Testing, inspection and documentation . 121
8.1 General . 121
8.2 Abbreviations . 121
8.3 Documents . 122
8.4 In-process inspection and testing . 122
8.4.1 General . 122
8.4.2 Materials . 122
8.4.3 Permanent joints . 123
8.4.4 Non-destructive testing of welds . 124
8.5 NDT methods . 131
8.5.1 Quality level . 131
8.5.2 Acceptance levels and testing techniques . 131
8.5.3 Non-destructive testing Personnel qualifications and approval . 131
8.5.4 Non-destructive testing documentation . 132
8.6 Final assessment and documentation . 134
8.6.1 General . 134
8.6.2 Final inspection . 134
8.7 Documentation . 137
8.7.1 Final documentation package . 137
8.7.2 Declaration/certification . 137
8.7.3 Operating instructions . 137
9 Marking and labelling . 137
10 Handling and installation . 138
10.1 General instructions . 138
3

---------------------- Page: 5 ----------------------
oSIST prEN 14917:2020
prEN 14917:2020 (E)
10.2 Packaging and storage . 138
10.3 Installation . 138
10.4 Unrestrained expansion joints . 139
10.5 Restrained expansions joints. 139
Annex A (informative) Categories of expansion joints . 140
A.1 General . 140
A.2 Determination of expansion joints categories . 140
A.3 Fluid groups . 140
A.3.1 General . 140
A.3.2 Group 1. 140
A.3.3 Group 2. 141
A.4 Technical requirements. 141
A.4.1 Expansion joints for vessels . 141
A.4.2 Expansion joints for piping . 141
A.4.3 Sound engineering practice (SEP) . 142
Expansion joint category . 142
Annex B (normative) Specification for materials 1.4828, 1.4876, 2.4360 and 2.4858 . 144
Annex C (informative) Incorporation of expansion joints into piping or pressure vessels . 151
C.1 Introduction . 151
C.2 Specific symbols and definitions . 151
C.3 Application criteria for expansion joints in piping . 153
C.3.1 General . 153
C.3.2 Use of axial expansion joints . 153
C.3.3 Use of restraint expansion joints . 159
C.3.4 Use of universal expansion joints . 165
C.3.5 Indeterminate configurations of expansion joints . 167
C.4 Application criteria for expansion joints in pressure vessels . 170
C.4.1 General . 170
C.4.2 Axial expansion joint installed in the shell . 170
C.4.3 Axial expansion joint installed at the floating head . 171
Annex D (informative) Calculation methods for systems of pipes containing expansion joints . 172
D.1 General . 172
D.1.1 Preliminary remarks . 172
D.1.2 Determining movement values . 172
D.1.3 Thermal expansion . 172
D.2 Approximate calculation of bellows movement . 174
D.2.1 General . 174
4

---------------------- Page: 6 ----------------------
oSIST prEN 14917:2020
prEN 14917:2020 (E)
D.2.2 Hinged systems . 175
D.2.3 Definitions . 175
D.3 Exact calculation of bellows movement . 179
D.3.1 Two hinges in a plane system (Z-system) . 179
D.3.2 Two gimbals in a three-dimensional system (Z-system) . 180
D.3.3 Three hinges in a plane system (U-system) . 181
D.3.4 Three hinges in a plane system (L-system) . 182
D.3.5 Three hinges in a three-dimensional system (Z-system) . 184
D.4 Calculation of forces and moments . 186
Annex E (informative) Explanatory notes on the design of expansion bellows . 188
E.1 General . 188
E.2 Calculation design . 188
E.3 Types of bellows . 189
E.3.1 Corrugation shape . 189
E.3.2 Number of plies . 189
E.4 Fatigue life expectancy . 189
E.5 Instability . 190
E.5.1 General . 190
E.5.2 Column instability . 190
E.5.3 In-plane instability . 190
E.5.4 Buckling . 190
E.6 Bellows spring rate . 191
Annex F (informative) Procedure for setting-up a design fatigue curve . 193
F.1 General . 193
F.2 Procedure for setting up a design fatigue curve for expansion bellows . 193
F.2.1 General . 193
F.2.2 Number of tests . 193
F.2.3 Extrapolation range . 193
F.2.4 Manufacturing methods . 193
F.2.5 Bellows material . 194
F.3 Tests . 194
F.3.1 Movement . 194
F.3.2 Test pressure . 194
F.3.3 Other test conditions . 194
F.3.4 Fatigue test equipment . 195
F.4 Evaluation of the test results .
...