EN 13480-3:2002

SLOVENSKI STANDARD
01-november-2002
.RYLQVNLLQGXVWULMVNLFHYRYRGLGHO.RQVWUXLUDQMHLQL]UDþXQ
Metallic industrial piping - Part 3: Design and calculation
Metallische industrielle Rohrleitungen - Teil 3: Konstruktion und Berechnung
Tuyauteries industrielles métalliques - Partie 3: Conception et calcul
Ta slovenski standard je istoveten z: EN 13480-3:2002
ICS:
77.140.75 Jeklene cevi in cevni profili Steel pipes and tubes for
za posebne namene specific use
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 13480-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2002
ICS 23.040.01
English version
Metallic industrial piping - Part 3: Design and calculation
Tuyauteries industrielles métalliques - Partie 3: Conception Metallische industrielle Rohrleitungen - Teil 3: Konstruktion
et calcul und Berechnung
This European Standard was approved by CEN on 23 May 2002.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13480-3:2002 E
worldwide for CEN national Members.

Issue 1 (2002-05)
Contents
Foreword.6
1 Scope .7
2 Normative references .7
3 Terms, definitions, symbols and units .8
3.1 Terms and definitions.8
3.2 Symbols and units .8
4 Basic design criteria.10
4.1 General.10
4.2 Loadings .10
4.2.1 General.10
4.2.2 Combination of loads .11
4.2.3 Loads for dimensioning .11
4.2.4 Other loads to be taken into account .12
4.2.5 Design conditions.13
4.3 Thickness.16
4.4 Tolerances .18
4.5 Joint coefficient.18
4.6 Dimensioning of piping components subject to pressure .18
5 Design stresses.19
5.1 General.19
5.2 Time-independent nominal design stress.19
5.2.1 Steels other than austenitic steels.19
5.2.2 Austenitic steels.20
5.2.3 Nickel and / or chromium alloy steels .20
5.2.4 Steels castings.20
5.2.5 Additional requirements for steels with no specific control .21
5.3 Time-dependent nominal design stress .21
5.3.1 General.21
5.3.2 Steels.21
5.3.3 Nickel and/or chromium alloy steels .22
6 Design of piping components under internal pressure.22
6.1 Straight pipes .22
6.2 Pipe bends and elbows .23
6.2.1 General.23
6.2.2 Symbols .23
6.2.3 Required wall thicknesses.23
6.3 Mitre bends.25
6.3.1 General.25
6.3.2 Symbols .25
6.3.3 Effective radius of mitre bend .26
6.3.4 Multiple mitre bends .27
6.3.5 Single mitre bends.27
6.3.6 Adjacent straight pipe sections of mitre bends.27
6.4 Reducers.27
6.4.1 Conditions of applicability.27
6.4.2 Specific definitions .28
6.4.3 Specific symbols and abbreviations.29
6.4.4 Conical shells.30
6.4.5 Junctions - general .30
6.4.6 Junction between the large end of a cone and a cylinder without a knuckle .31
6.4.7 Junction between the large end of a cone and a cylinder with a knuckle .34
Issue 1 (2002-05)
6.4.8 Junction between the small end of a cone and a cylinder .35
6.4.9 Offset reducers .37
6.4.10 Special forged reducers.37
6.5 Flexible piping components .38
6.5.1 General.38
6.5.2 Expansion joints .38
6.5.3 Corrugated metal hose assemblies .39
6.6 Bolted flange connections.40
7 Design of ends under internal pressure.41
7.1 Dished ends.41
7.1.1 Symbols .41
7.1.2 Hemispherical ends.41
7.1.3 Torispherical ends.42
7.1.4 Ellipsoidal ends.44


7.1.5 Calculation of .45
7.2 Circular flat ends.48
7.2.1 General.48
7.2.2 Symbols .48
7.2.3 Unstayed flat circular ends welded to cylindrical shells/pipes .50
7.2.4 Unstayed flat circular bolted ends.57
7.2.5 Reinforcements of openings in unstayed flat ends .63
8 Openings and branch connections.66
8.1 General.66
8.2 Symbols .66
8.3 Limitations.67
8.3.1 Thickness ratio.67
8.3.2 Openings in the vicinity of discontinuities .68
8.3.3 Types of reinforcement .70
8.3.4 Calculation method.71
8.3.5 Elliptical openings and oblique branch connections .71
8.3.6 Reinforcing pads.72
8.3.7 Dissimilar material of shell and reinforcements.73
8.3.8 Extruded outlets.73
8.3.9 Branches in bends or elbows.73
8.3.10 Screwed-in branches.73
8.4 Isolated openings .74
8.4.1 General.74
8.4.2 Unreinforced openings.77
d D
8.4.3 Reinforced openings with / < 0,8.77
i i
8.4.4 Reinforced single openings with 0,8 < d/D
1,0 .83
8.5 Adjacent openings.83
8.5.1 Unreinforced openings.83
8.5.2 Reinforced openings with d/D
0,8.83
8.6 Design of special piping components.84
8.6.1 Cylindrical Y-pieces.84
8.6.2 Spherical Y-pieces.85
8.6.3 Triform reinforced branches.86
9 Design of piping components under external pressure.87
9.1 General.87
9.2 Symbols and elastic stress limits .89
9.2.1 Symbols .89
9.2.2 Elastic stress limits .90
9.3 Cylindrical pipes, elbows and mitre bends.90
9.3.1 Determination of lengths .90
9.3.2 Interstiffener collapse.92
9.3.3 Overall collapse of stiffened pipes .94
9.3.4 Stiffener stability.95
9.3.5 Heating/cooling channels .98
9.4 Reducers (conical shells) .99
9.5 Dished ends.101
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9.5.1 Hemispherical ends .101
9.5.2 Torispherical ends .102
9.5.3 Ellipsoidal ends.102
10 Design for cyclic loading .102
10.1 General.102
10.2 Exemption from detailed fatigue analysis.102
10.3 Fatigue design for cyclic pressure.103
10.3.1 Equivalent full load cycles.103
10.3.2 Simplified fatigue analysis.103
10.4 Fatigue design for thermal gradients .117
10.4.1 General.117
10.4.2 Design guidance .117
10.5 Fatigue design for combined loads .117
11 Integral attachments.118
11.1 General.118
11.2 Allowable stresses.118
11.3 Analysis methods for welded attachments on piping.119
11.3.1 General.119
11.3.2 Symbols .119
11.3.3 Limitations.120
11.3.4 Preliminary calculations.121
11.3.5 Analysis of attachments welded to pipe with a full penetration weld.124
11.3.6 Analysis of attachments welded to pipe with fillet or partial penetration weld .125
11.3.7 Stress analysis of the run pipe.125
11.4 Alternative calculation methods.126
12 Flexibility analysis and acceptance criteria.126
12.1 Basic conditions .126
12.1.1 General.126
12.1.2 Loading conditions.127
12.1.3 Allowable stresses.127
12.2 Piping flexibility.128
12.2.1 General.128
12.2.2 Basic conditions .129
12.2.3 Displacement strains.129
12.2.4 Displacement stresses .130
12.2.5 Stress range .131
12.2.6 Cold spring .131
12.2.7 Properties for flexibility analysis.131
12.2.8 Supporting conditions.132
12.2.9 Expansion joints .133
12.2.10 Flexibility analysis .133
12.3 Flexibility analysis .135
12.3.1 General.135
12.3.2 Stress due to sustained loads.136
12.3.3 Stress due to sustained and occasional or exceptional loads .136
12.3.4 Stress range due to thermal expansion and alternating loads.137
12.3.5 Additional conditions for the creep range .138
12.3.6 Stresses due to a single non-repeated support movement .138
12.3.7 Determination of resultant moments .138
12.3.8 Reactions.141
12.4 Fatigue analysis .141
13 Supports .141
13.1 General requirements.141
13.1.1 General.141
13.1.2 Classification of supports.141
13.1.3 Additional definitions .142
Boundaries .142
13.1.5 Welded support attachments.144
13.2 Material requirements.146
13.3 Design .146
Issue 1 (2002-05)
13.3.1 General.146
13.3.2 Design temperatures for support components .147
13.3.3 Detail design.148
13.3.4 Buckling.149
13.3.5 Vibration .149
13.3.6 Support location .150
13.3.7 Determination of component sizes.150
13.4 Connections .151
13.4.1 Welded connections.151
13.4.2 Bolted connections.152
13.5 Design requirements for special components .152
13.5.1 Constant load hangers and supports.152
13.5.2 Variable load spring supports .153
13.5.3 Rigid struts .155
13.5.4 Shock arrestors.155
13.5.5 Sliding supports.156
13.5.6 Anchors .156
13.6 Documentation of supports.157
13.7 Marking of supports .157
Annex A (informative)  Dynamic analysis.158
Annex B (normative)   More accurate calculation of bends and elbows.171
Annex C (informative)  Expansion joints .179
Annex D (normative)   Flanges .194
Annex E (normative)   Design of branch connections in piping accessories.229
Annex F (informative)  Testing during operation in the case of cyclic loading.234
Annex G (informative)  Physical properties of steels.235
Annex H (normative)   Flexibility characteristics, flexibility and stress intensification factors and
section moduli of piping components and geometrical discontinuities .242
Annex I (informative)   Production testing of spring supports and shock arrestors .250
Annex J (normative)   Type testing of support components.255
Annex K (informative)  Attachment of supports to structures .256
Annex L (informative)  Buckling of linear type supports .258
Annex M (informative)  Design guidance for structural components.261
Annex ZA (informative) Clauses of this European Standard addressing essential requirements or other
provisions of the PED.266
Bibliography .268
Issue 1 (2002-05)
Foreword
This document (EN 13480-3:2002) has been prepared by Technical Committee CEN /TC 267, "Industrial piping
and pipelines", the secretariat of which is held by AFNOR.
This European Standard has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this European
Standard.
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 November 2002, and conflicting national standards shall be withdrawn at the latest
by November 2002.
In this European Standard the Annexes A, C, D, E, H, I, J, K and N are informative and the Annexes B, F, G, L and
M are normative.
This European Standard EN 13480 for metallic industrial piping is the third part of a set of seven interdependent
Parts which are:
 Part 1: General.
 Part 2: Materials.
 Part 3: Design and calculation.
 Part 4: Fabrication and installation.
 Part 5: Inspection and testing;
 Part 6: Additional requirements for buried piping.
 CEN/TR 13480-7: Guidance on the use of conformity assessment procedures.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland and the United Kingdom.
Issue 1 (2002-05)
1 Scope
This Part of this European Standard specifies the design and calculation of industrial metallic piping systems,
including supports, covered by EN 13480.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
EN 287-1, Approval testing for welders – Fusion welding – Part 1: Steels.EN 288, Specification and approval of
welding procedures for metallic materials .
EN 1591-1, Flanges and their joints – Design rules for gasketed circular flange connections – Part 1: Calculation
method.
EN 10204:1991, Metallic materials – Types of inspection documents.
EN 12953-3, Shell boilers - Part 3: Design and calculation
EN 25817:1992, Arc-welded joints in steel – Guidance on quality levels for imperfections (ISO 5817: 1992).
EN 13445-3:2002, Unfired pressure vessels – Part 3: Design.
EN 13480-1, Metallic industrial piping – Part 1: General.
EN 13480-2, Metallic industrial piping – Part 2: Materials.
EN 13480-4:2002, Metallic industrial piping – Part 4: Fabrication and installation.
EN 13480-5:2002, Metallic industrial piping – Part 5: Inspection and testing.
ENV 1993, Eurocode 3: Design of steel structures
Issue 1 (2002-05)
3 Terms, definitions, symbols and units
3.1 Terms and definitions
For the purposes of this Part of this European Standard, the terms and definitions given in EN 13480-1 apply.
3.2 Symbols and units
For the purposes of this Part of this European Standard, the symbols and units given in EN 13480-1 and in Table 3.2-
1 apply.
Specific symbols are defined in the relevant sub-clauses.
Issue 1 (2002-05)
Table 3.2-1 — General symbols and units
Symbol Description Unit
a
PS maximum allowable pressure bar
b
R, r radii mm
R minimum specified value of upper yield strength at calculation temperature when this N/mm² (MPa)
eH t
temperature is greater than the room temperature
S
mean value of the stress which leads to a 1 % creep elongation in 100 000 h N/mm² (MPa)
S mean value of the stress which leads to a 1 % creep elongation in 200 000 h N/mm² (MPa)
S mean value of creep rupture strength as indicated by the standards, for the material in N/mm² (MPa)
t
R T
question at the considered temperature, t, and for the considered lifetime T (in hours)
whereby the dispersion band of the results does not deviate by more than 20 % from the
mean value.
TS maximum allowable temperature °C
Z section modulus for a pipe mm
c corrosion or erosion allowance (see Figure 4.3-1) mm
c absolute value of the negative tolerance taken from the material standard (see mm
Figure 4.3-1)
c
thinning allowance for possible thinning during manufacturing process (see Figure 4.3-1) mm
e analysis thickness of a component used for the check of the strength (see Figure 4.3-1) mm
a
e nominal thickness on drawings (see Figure 4.3-1) mm
n
e ordered thickness (see Figure 4.3-1) mm
ord
e minimum required thickness with allowances and tolerances (see mm
r
Figure 4.3-1)
f
design stress (see clause 5) N/mm² (MPa)
f
CR Design stress in the creep range N/mm² (MPa)
p
calculation pressure (see 4.2.3.4) N/mm² (MPa)
c
p operating pressure (see 4.2.3.1) N/mm² (MPa)
o
t calculation temperature (see 4.2.3.5) °C
c
t operating temperature (see 4.2.3.2) °C
o
z joint coefficient (see 4.5) -
additional thickness resulting from the selection of the ordered thickness (see mm

Figure 4.3-1)
a
All pressures for calculation purposes are in N/mm² (MPa) and PS is in bar.
b
The following subscripts apply :
iinside
mmean
o outside
Issue 1 (2002-05)
4 Basic design criteria
4.1 General
The calculation rules in this Part shall apply for operating and testing conditions as well as preset, cold spring
conditions, flushing and cleaning conditions.
The scope of each of the calculation rules is limited on a case by case basis by geometrical characteristics which
shall be taken into account for each component, loading, failure mode and material property.
NOTE Where this European Standard does not indicate a calculation rule, it is the designer's responsibility to use widely
acknowledged calculation rules, or experimental methods to justify the dimensions and thicknesses selected.
Elastic calculation methods shall be used in this Part, although some components might exhibit plastic behaviour.
If shaping and assembly techniques specific to the pressure vessel industry are used for large diameter pipes, the
rules applicable to such techniques shall be those relating to the design of shells for pressure vessels. For the
general stability, the requirements of EN 13480 remain applicable if the structure, as a whole, behaves according to
the beam theory.
For temporary piping, e.g. flushing, cleaning and blow-through systems, the nominal design stress for the design
conditions shall be used.
4.2 Loadings
4.2.1 General
Any piping system is subjected to a number of loadings during its lifetime. These loadings can be one or a
combination of the following loads:
 internal and/or external pressure;
 temperature;
 weight of piping and contents;
 climatic loads;
 dynamic effects of the fluid;
 movements of the ground and buildings;
 vibrations;
 earthquakes.
NOTE 1 This list is not exhaustive.
NOTE 2 Explanations of these loads are given in 4.2.3 and 4.2.4.
Issue 1 (2002-05)
4.2.2 Combination of loads
The loads and their possible combinations, given in 4.2.5.1 to 4.2.5.4, shall be taken into account at the design
stage of the piping system and its supports. Some unlikely combinations may be ruled out following a study
considering both the likelihood of their occurrence, failure of the fluid containment boundary and the health and
safety consequences.
Where a piping system is subjected to more than one pressure/temperature condition, the greatest calculated
thickness determined for these conditions shall be used.
4.2.3 Loads for dimensioning
4.2.3.1 Operating pressure
The operating pressure, p , shall be below the maximum allowable pressure, PS, specified for the piping system.
o
4.2.3.2 Operating temperature
The operating temperature, t , shall be below the maximum allowable temperature, TS, specified for the piping
o
system.
4.2.3.3 Sets
The set (p t ) to be considered shall correspond to the most severe conditions of coincident pressure and
o, o
temperature which may prevail in the piping system over a long time.
For a piping system under steady state conditions, the maximum transient conditions shall be considered in
accordance with clause 10.
NOTE The calculated stress resulting from such variations in pressure and/or temperature may exceed the maximum
allowable stress by 10 % if the transient event occurs for less than 10 % of any 24 h operating period.
4.2.3.4 Calculation pressure
The calculation pressure, p , shall be determined for the pressure temperature conditions (p t ) specified in
c o, o
4.2.3.3.
The calculation pressure p shall be not less than the associated operating pressure p . The conditions (p t )
c 0 ,
o o
resulting in the greatest wall thickness shall be considered with the following minimum conditions:
1) p = p = PS with the associated t as defined in 4.2.3.5;
c o c
2) t as defined in 4.2.3.5 for t =TS with
...