EN 13480-4:2024
(Main)Metallic industrial piping - Part 4: Fabrication and installation
Metallic industrial piping - Part 4: Fabrication and installation
This document specifies the requirements for fabrication and installation of piping systems, including supports, designed in accordance with EN 13480-3:2024.
Metallische industrielle Rohrleitungen - Teil 4: Fertigung und Verlegung
Dieses Dokument legt die Anforderungen an die Fertigung und Verlegung, einschließlich der Halterungen, von Rohrleitungssystemen, die nach EN 13480-3:2024 konstruiert sind, fest.
Tuyauteries industrielles métalliques - Partie 4: Fabrication et installation
Le présent document spécifie les exigences relatives à la fabrication et à l'installation des réseaux de tuyauteries, supports inclus, conçus conformément à l’EN 13480-3:2024.
Kovinski industrijski cevovodi - 4. del: Proizvodnja in vgradnja
Ta dokument določa zahteve za proizvodnjo in vgradnjo cevovodov, vključno z nosilci, ki so konstruirani v skladu s standardom EN 13480-3:2024.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2024
Nadomešča:
SIST EN 13480-4:2018
SIST EN 13480-4:2018/A1:2024
SIST EN 13480-4:2018/A2:2024
Kovinski industrijski cevovodi - 4. del: Proizvodnja in vgradnja
Metallic industrial piping - Part 4: Fabrication and installation
Metallische industrielle Rohrleitungen - Teil 4: Fertigung und Verlegung
Tuyauteries industrielles métalliques - Partie 4: Fabrication et installation
Ta slovenski standard je istoveten z: EN 13480-4:2024
ICS:
23.040.10 Železne in jeklene cevi Iron and steel pipes
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.
EN 13480-4
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2024
EUROPÄISCHE NORM
ICS 23.040.01 Supersedes EN 13480-4:2017
English Version
Metallic industrial piping - Part 4: Fabrication and
installation
Tuyauteries industrielles métalliques - Partie 4: Metallische industrielle Rohrleitungen - Teil 4:
Fabrication et installation Fertigung und Verlegung
This European Standard was approved by CEN on 9 July 2024.
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
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13480-4:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Symbols . 9
5 General . 9
5.1 Requirements on the manufacturer . 9
5.2 Requirements on fabricators and installers of piping and supports . 9
5.3 Requirements for fabrication and installation . 9
5.4 Classification of piping . 10
5.5 Material grouping . 10
5.6 Tolerances . 10
6 Cutting and bevelling . 10
6.1 General . 10
6.2 Identification of pressure parts . 10
7 Bending and other forming . 11
7.1 General . 11
7.2 Heat treatment after cold forming . 13
7.2.1 Flat products . 13
7.2.2 Pipes . 13
7.3 Heat treatment after hot forming . 15
7.3.1 Material groups 1, 3, 4, 5 and 6 . 15
7.3.2 Material groups 8.1 and 8.2 . 15
7.3.3 Heat treatment after hot forming for material group 10. 17
7.3.4 Heat treatment after hot forming for clad materials . 17
7.4 Tolerances . 17
7.4.1 Out-of-roundness of bends under internal pressure equal to, or greater than, the
external pressure . 17
7.4.2 Out-of-roundness of bends under external pressure and vacuum . 18
7.4.3 Waves at bends . 18
7.4.4 Start-up bulge of induction bends . 19
7.5 Surface finish . 19
8 Installation of piping . 19
8.1 Fixing and alignment . 19
8.2 Field run piping. 20
8.3 Flanged or similar mechanical connections . 21
8.3.1 Flange connections . 21
8.3.2 Threaded connections . 22
8.3.3 Couplings and compression fittings . 22
8.4 Protection of ends of piping components . 22
9 Welding . 22
9.1 Welding personnel . 22
9.2 Welding procedure specifications . 22
9.3 Welding procedures . 23
9.3.1 Verification of suitability. 23
9.3.2 Application . 24
9.4 Filler metals and auxiliary materials . 24
9.5 Climatic conditions . 24
9.6 Cleaning before and after welding . 24
9.7 Joint preparation . 25
9.8 Edge protection . 25
9.9 Assembly for welding . 25
9.10 Earthing . 25
9.11 Performance of welding . 26
9.11.1 Preheating . 26
9.11.2 Striking marks . 26
9.11.3 External welds . 26
9.11.4 Dissimilar joints . 26
9.12 Backing rings . 26
9.13 Attachments . 27
9.13.1 General . 27
9.13.2 Temporary attachments . 27
9.13.3 Permanent attachments . 27
9.14 Post-weld heat treatment . 27
9.14.1 General . 27
9.14.2 Equipment . 31
9.14.3 Temperature measurements . 31
9.14.4 Controlling thickness . 31
9.14.5 Rate of heating . 33
9.14.6 Local heat treatment . 33
9.14.7 Insulation . 34
9.15 Weld identification. 34
10 Adjustment and repair. 34
10.1 General . 34
10.2 Adjustment . 34
10.2.1 Cold hammering . 34
10.2.2 Adjustments by means of heat . 34
10.2.3 Adjustment by welding . 35
10.2.4 Adjustment by local forging . 35
10.3 Weld repair . 35
11 Marking and documentation . 35
11.1 Marking of spools and components for installation . 35
11.2 Marking and identification of installed piping . 35
11.2.1 General . 35
11.2.2 CE Marking of installed piping . 36
11.2.3 Technical identification of installed piping . 36
12 Additional requirements . 37
12.1 Cleaning . 37
12.2 Temporary preservation . 37
12.3 External corrosion protection . 37
12.4 Thermal and acoustic insulation . 37
12.5 Connections for static electricity . 38
Annex A (informative) Contamination and surface quality of stainless steel. 39
A.1 Introduction . 39
A.2 Protection . 39
A.2.1 Handling . 39
A.2.2 During fabrication and installation . 39
A.3 Controlled cleaning methods . 40
A.4 Chemical treatments . 40
A.4.1 Acid pickling . 40
A.4.2 Decontamination, passivation . 40
A.5 Preparing for shipment. 41
Annex B (normative) Dimensional tolerances for fabricated spools . 42
Annex C (informative) Example for the extension of the P value . 44
Annex Y (informative) History of EN 13480-4 . 46
Y.1 Differences between EN 13480-4:2017 and EN 13480-4:2024 . 46
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/68/EU aimed to be covered. 47
Bibliography . 49
European foreword
This document (EN 13480-4:2024) has been prepared by Technical Committee CEN/TC 267 “Industrial piping
and pipelines”, the secretariat of which is held by AFNOR.
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 December 2024, and conflicting national standards shall be withdrawn
at the latest by December 2024.
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 13480-4:2017.
This new edition incorporates the Amendments which have been approved previously by CEN members, and
the corrected pages up to Issue 1 without any further technical change. Annex Y provides details of significant
technical changes between this European Standard and the previous edition.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this document.
This European Standard EN 13480 for metallic industrial piping consists of eight interdependent and not
dissociable 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;
Part 8: Additional requirements for aluminium and aluminium alloy piping.
Although these Parts may be obtained separately, it should be recognized that the Parts are inter-dependant.
As such the manufacture of metallic industrial piping requires the application of all the relevant Parts in order
for the requirements of the Standard to be satisfactorily fulfilled.
This European Standard will be maintained by a Maintenance MHD working group whose scope of working is
limited to corrections and interpretations related to EN 13480. The contact to submit queries can be found at
https://unm.fr/en/maintenance-agencies/maintenance-agency-en-13480/.
A form for submitting questions can be downloaded from the link to the MHD website. After subject experts
have agreed an answer, the answer will be communicated to the questioner. Interpretation sheets will be
posted on the website of the MHD.
Amendments to this new edition may be issued from time to time and then used immediately as alternatives
to rules contained herein. These amendments will be consolidated within EN 13480:2024 in accordance with
the maintenance system of EN 13480 series approved by CEN/BT Decision C172/2021.
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 organizations 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 fabrication and installation of piping systems, including
supports, designed in accordance with EN 13480-3:2024.
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 10204:2004, Metallic products — Types of inspection documents
EN 12952-5:2021, Water-tube boilers and auxiliary installations — Part 5: Workmanship and construction of
pressure parts of the boiler
EN 13480-1:2024, Metallic industrial piping — Part 1: General
EN 13480-2:2024, Metallic industrial piping — Part 2: Materials
EN 13480-3:2024, Metallic industrial piping — Part 3: Design and calculation
EN 13480-5:2024, Metallic industrial piping — Part 5: Inspection and testing
EN ISO 3834-3:2021, Quality requirements for fusion welding of metallic materials — Part 3: Standard quality
requirements (ISO 3834-3:2021)
EN ISO 4063:2023, Welding, brazing, soldering and cutting — Nomenclature of processes and reference
numbers (ISO 4063:2023)
EN ISO 5817:2023, Welding — Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding
excluded) — Quality levels for imperfections (ISO 5817:2023)
EN ISO 9606-1:2017, Qualification testing of welders — Fusion welding — Part 1: Steels
(ISO 9606-1:2012, including Cor 1:2012 and Cor 2:2013)
EN ISO 13920:1996, Welding — General tolerances for welded constructions — Dimensions for lengths and
angles — Shape and position (ISO 13920:1996)
EN ISO 14732:2013, Welding personnel — Qualification testing of welding operators and weld setters for
mechanized and automatic welding of metallic materials (ISO 14732:2013)
EN ISO 15609-1:2019, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 1: Arc welding (ISO 15609-1:2019)
EN ISO 15609-2:2019, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 2: Gas welding (ISO 15609-2:2019)
EN ISO 15609-3:2004, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 3: Electron beam welding (ISO 15609-3:2004)
EN ISO 15609-4:2009, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 4: Laser beam welding (ISO 15609-4:2009)
EN ISO 15609-5:2011, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 5: Resistance welding (ISO 15609-5:2011, Corrected version
2011-12-01)
EN ISO 15609-6:2013, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 6: Laser-arc hybrid welding (ISO 15609-6:2013)
EN ISO 15610:2024, Specification and qualification of welding procedures for metallic materials — Qualification
based on tested welding consumables (ISO 15610:2024)
EN ISO 15611:2024, Specification and qualification of welding procedures for metallic materials — Qualification
based on previous welding experience (ISO 15611:2024)
EN ISO 15612:2018, Specification and qualification of welding procedures for metallic materials — Qualification
by adoption of a standard welding procedure specification (ISO 15612:2018)
EN ISO 15613:2004, Specification and qualification of welding procedures for metallic materials — Qualification
based on pre-production welding test (ISO 15613:2004)
EN ISO 15614-1:2017, Specification and qualification of welding procedures for metallic materials - Welding
procedure test - Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys (ISO 15614-
1:2017)
EN ISO 17663:2009, Welding — Quality requirements for heat treatment in connection with welding and allied
processes (ISO 17663:2009)
CEN ISO/TR 15608:2017, Welding — Guidelines for a metallic materials grouping system
(ISO/TR 15608:2017)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13480-1:2024 and the following
apply.
3.1
field run piping
piping installed without preplanning by drawings of the piping routing and the support points
Note 1 to entry: Typical dimensions are DN 50 or smaller.
3.2
spool (with or without overlength)
prefabricated assembly of components which forms part of a piping system
3.3
cold forming
forming at ambient temperature, but not below + 5 °C
3.4
hot forming
for ferritic steels, forming at temperatures at or above the maximum permissible temperature for post-weld
heat treatment; for austenitic and austenitic-ferritic steels at temperatures above 300 °C
As impacted by EN ISO 15614-1:2017/A1:2019.
4 Symbols
For the purposes of this document, the symbols given in EN 13480-1:2024 apply. Additional symbols are
defined in appropriate clauses of this Part.
5 General
5.1 Requirements on the manufacturer
The manufacturer shall be responsible for the fabrication and the installation, even if this work will be
sub-contracted to other fabricators and/or installers.
5.2 Requirements on fabricators and installers of piping and supports
5.2.1 The fabricators and/or installers shall ensure the correct transport, handling, storage, fabrication,
installation and testing of all piping components including supports.
5.2.2 The fabricators and installers shall have access to facilities which enable them to handle the piping
components including supports correctly and to carry out the required tests.
5.2.3 The fabricators and/or installers shall employ their own responsible supervisors and competent
personnel. If sub-contractors are employed, the fabricator and/or installer remain responsible for their
competence and the compliance with this European Standard.
NOTE The task and responsibilities of a welding co-ordinator are described in EN ISO 14731:2019.
5.2.4 All stages of fabrication and installation shall be supervised in such a way as to maintain the design
integrity of the finished system.
5.2.5 Co-ordination between those responsible for design and those responsible for fabrication and/or
installation and testing shall be maintained at all times, to ensure that fabrication, installation and testing is
carried out in accordance with the design specification.
5.2.6 The fabricator and/or installer of the piping shall fulfil the requirements of
EN ISO 3834-3:2021.
5.3 Requirements for fabrication and installation
5.3.1 Prior to any operation, a check shall be made to ensure that the spools and components supplied are
in accordance with the relevant documents (specifications, drawings, certificates etc.).
5.3.2 Prefabricated spools and components shall be protected during handling, transport, and storage.
5.3.3 When joining spools or components, they shall not be strained nor deformed other than as may be
required by the design. Designer's installation instructions, if any, shall be observed.
NOTE 5.3.3 is deemed to be fulfilled, when the quality characteristics of the material are not impaired by cold or hot
forming, e.g. by cutting, grinding, straightening or bending, of the components and when the different components have
been joined such that stresses and deformations which can impair the safety of the piping are excluded.
5.3.4 Any temporary supports or restraints used as an aid during transport, installation or testing shall be
removed prior to commissioning.
5.3.5 Appropriate measures shall be taken to avoid corrosion-inducing contamination of stainless steel and
non-ferrous materials. If contamination occurs, it shall be properly removed as soon as practicable,
notwithstanding any final treatment.
NOTE Recommended methods for the prevention and removal of contamination on stainless steel are given in
Annex A.
5.3.6 Piping for fluids which are likely to cause condensation shall be installed with adequate slopes and
traps.
5.4 Classification of piping
The piping systems shall be classified into different categories depending on the fluid carried, diameter and
pressure. These are given in EN 13480-1:2024.
5.5 Material grouping
Material grouping is given in EN 13480-2:2024.
5.6 Tolerances
Tolerances shall comply with EN ISO 13920:1996, class C and class G, except where other classes are specified
in this European Standard or by design.
Angular tolerances for fabricated pipework shall be determined by the dimensional tolerance for the terminal
points of the finished part.
Alternative tolerances for fabrication and installation of pipework shall be determined and in all cases these
shall be identified in the specification. Dimensional tolerances for fabricated spools shall comply with Annex B.
6 Cutting and bevelling
6.1 General
Cutting and bevelling by machining shall be permitted for all materials.
Flame cutting shall be permitted for material groups 1, 2, 3, 4 and 5 only with preheating as specified for
welding.
NOTE Flame cutting for material groups 1 and 2 can be used for bevelling, if the required bevel forms and tolerances
can be achieved and the heat affected zone has no detrimental effects on the quality of the weld.
For material groups 3, 4 and 5, the heat affected zone shall be removed by machining or grinding.
Plasma cutting shall be permitted for all material groups given in this European Standard. Plasma cutting shall
be preceded by preheating, as specified for welding.
Other cutting and bevelling processes are permitted, provided their suitability is demonstrated.
6.2 Identification of pressure parts
For pressure parts, identification of materials shall remain possible, either by retaining or by transferring the
mark stipulated by the product standard, or by using a unique code kept in the records of the piping fabricator.
Stamping shall not introduce a notching effect, therefore low-stress stamping is recommended.
If any method of marking other than hard-stamping, edging or engraving (vibrograph) is used, the fabricator
shall ensure that confusion between different materials is not possible.
7 Bending and other forming
7.1 General
7.1.1 Fabricators of formed pressure parts shall have adequate procedures, equipment and tools for the
forming and the subsequent heat treatment.
The procedure for bending shall be qualified according to EN 12952-5:2021, Annex A, with regard to
examination and range of qualification.
Pipes with internal coating such as glass, rubber or plastics shall not be formed unless it has been
demonstrated that the forming process is not detrimental to the lining.
NOTE There are two kinds of forming within the scope of this European Standard: cold forming and hot forming.
The thickness after bending or forming shall be not less than that required by the design.
Longitudinal welds should be located at the neutral zone. The range of the neutral zone after bending is given
in Figure 7.1.1-1.
Key
1 extrados
2 intrados
(a) optimal range for the longitudinal weld at bending
(b) weld
Figure 7.1.1-1 — Optimal range for the longitudinal weld at bending
7.1.2 The forming and post-forming heat treatment of thermomechanical steels shall be given individual
consideration. Account shall be taken of the recommendations of the steelmakers.
Pipes whose properties have been generated by thermomechanical means such as controlled rolling can be
formed by cold methods. Such materials may be substantially changed by the forming process and require
particular consideration to ensure that the specified properties are recovered after forming.
7.1.3 The following formulae shall be used for the calculation of the percentage deformation for cold formed
cylinders and cone products made by rolling (see Figure 7.1.3-1):
a) For cylinders and cones rolled from flat materials (see Figures 7.1.3-1a) and 7.1.3-1c)):
50 e
ord
(7.1.3-1)
V =
d
r
mf
b) For cylinders and cones rolled from intermediate product (see Figures 7.1.3-1b) and 7.1.3-1c)):
50 e r
int
mf
V = 1− (7.1.3-2)
d
r r
mf mi
where
e is the ordered thickness;
ord
e is the thickness of the intermediate product;
int
r is the average radius of the finished product;
mf
r is the average radius of the intermediate product;
mi
V is the deformation as a percentage.
d
NOTE If no intermediate quality heat treatment is applied between individual forming steps, the deformation is the
total amount of deformation of the individual steps. If intermediate quality heat treatment is applied between
the forming steps, the deformation is that deformation applied after the last treatment.
a) Initial product b) Intermediate product c) Finished product
Figure 7.1.3-1 — Forming of cylinders and cones
7.1.4 Tools and equipment used for forming shall be maintained to ensure a smooth profile free from stress-
raising defects, e.g. scores.
7.1.5 Heat treatment after forming shall be in accordance with the respective material standard.
7.1.6 Welding on to formed areas shall not be performed until heat treatment is complete.
7.2 Heat treatment after cold forming
7.2.1 Flat products
Flat products shall be heat treated after cold forming as required in Table 7.2.1-1.
For special design reasons, for example cyclic loading or stress corrosion cracking, heat treatment in excess of
that in Table 7.2.1-1 may be specified after cold forming.
No heat treatment for austenitic steels is required:
a) For austenitic steels having a documented minimum value of elongation after fracture (rupture) A equal
to or greater than 30 %, a maximum level of 15 % cold deformation shall be acceptable.
A greater deformation may be accepted if the evidence is supplied that there is a minimum elongation
after fracture (rupture) of 15 % after cold forming.
Such evidence shall be deemed supplied, if the acceptance certificate shows that elongation after fracture
(rupture) A is not less than 30 %. This shall be applicable only in cases where there is no risk of stress
corrosion cracking;
b) For austenitic steels having a required minimum value of elongation after fracture (rupture) A less than
30 %, evidence shall be supplied that there is a minimum elongation of 15 % after cold forming;
c) Deformation shall not exceed 10 % if the working temperature is below -196 °C.
Table 7.2.1-1 — Heat treatment after cold forming of flat products
Material groups according to Deformation Heat treatment
CEN ISO/TR 15608:2017
a b b
1.1, 1.2, 1.3, 2.1, 2.2 , 3, 4 , 5.1, 5.2 , ≤ 5 % no
b b b
5.3 , 5.4 , 6 ,
> 5 % yes
7.1, 7.2, 7.3, 9.1, 9.2, 10
c d
8.1, 8.2
a
If not heat treated, qualification tests are required to demonstrate that the material
properties are not impaired.
b
Heat treatment required in accordance with the material standards where the
minimum metal temperature is below - 10 °C.
c
See 7.2.1 a), b) and c).
d
Solution annealed and quenched or stabilised materials do not require heat
treatment after cold forming.
7.2.2 Pipes
Pipes shall be heat treated after cold forming in accordance with Table 7.2.2-1.
For special reasons, for example cyclic loading or stress corrosion, heat treatment may be specified after cold
forming.
Table 7.2.2-1 — Heat treatment after cold forming of pipes
Material groups Mean bending
Outside Heat
according to radius of the pipe diameter of treatment
the pipe
CEN ISO/TR
15608:2017
r d
m o
1.1, 1.2, 1.3,
2.1,
r ≤ 1,3 d
all diameters yes
m o
b
2.2 ,
b
3 ,
d ≤ 142 mm
no
a
o
4 ,
1,3 d < r < 2,5 d
o m o
a a a
5.1, 5.2 , 5.3 , 5.4 ,
a
6 ,
c
d > 142 mm
yes
o
7,
8,
2,5 d ≤ r
9, all diameters no
o m
NOTE For d and r , see Figure 7.2.2-1.
o m
a
Heat treatment required in accordance with the material standards where the
minimum metal temperature is below -10 °C.
b
If not heat treated, qualification tests are required to demonstrate that the material
properties are not impaired.
c
Not required for material groups 8.1, 8.2.
Figure 7.2.2-1 — Pipe bending
7.3 Heat treatment after hot forming
7.3.1 Material groups 1, 3, 4, 5 and 6
After hot forming, including induction bending, the parts shall be heat treated (normalising, normalising and
tempering, quenching and tempering or annealing as appropriate) in accordance with the material
specification to ensure that the properties meet those required by the material standard, or other appropriate
specification. Special consideration shall be given to materials designed to operate at elevated or sub-zero
temperatures or other special conditions.
If the hot forming of materials of groups 1, 3, 5 up to 2 % Cr has been started and ended within the temperature
range fixed in the material specification:
a) normalised steels need not be renormalized;
b) quenched and tempered steels need only be tempered provided that they have been rapidly cooled by
water or air from the forming temperature.
Pipes bent using the incremental induction heating method (induction bends) may undergo thermal treatment
during bending by the application of water or air quenches.
Non-alloy steels (C, C-Mn) formed using the induction bending process with air or water quenching may be
suitable in the as-bent condition for applications where high impact resistance and ductility are not required.
Such bends may be supplied without post-bending heat treatment provided that bend hardness does not
exceed 285 HV.
Heat treatments for high alloyed ferritic material should follow as soon after forming as practicable, to
minimise the risk of hydrogen induced cracking.
The manufacturer shall demonstrate that the requisite properties are achieved in the final product by the
examination and testing of one or more sample bends. These bends shall be made in accordance with all the
relevant parameters to be used in production bends. These parameters include, but are not limited to,
chemical composition, forming temperature, forming rate (speed), forming coolant supply, forming
dimensions (e.g. bend radius and r / d ) and post-forming heat treatment.
m o
7.3.2 Material groups 8.1 and 8.2
Austenitic steels which have been rapidly cooled from above the solution annealing temperature using water
or air during the forming process shall not require post-forming heat treatment. Stabilised austenitic steels
formed above the solution annealing temperature shall be subjected to post-forming stabilising treatment.
Stabilised austenitic steels formed in the stabilising temperature range, shall not require subsequent
treatment.
Heat treatment shall be carried out in accordance with Table 7.3.2-1.
Table 7.3.2-1 — Heat treatment of austenitic steels after hot forming
Material type Typical steel grades Conditions under which post-forming Temperature range for heat Solution
heat treatment may be waived a annealing
treatment when stabilising
temperature
b,c
Name Number Non-welded parts Welded parts Non-welded parts Welded parts
°C °C °C
900 ± 20 920 ± 20 ≥ 1 020
Stabilised steels X 6 CrNiTi 18-10 1.4541
c
non-Mo-alloyed X 6 CrNiNb 18-10 1.4550
(L)
X 6 CrNiMoTi 17-12-2 1.4571 d d
not permitted not permitted
X 6 CrNiMoNb 17-12-2 1.4580
Mo-alloyed
e
≥ 1 050
1.4505
(X 4 NiCrMoCuNb 20-18)
Forming started at 1 000 °C to
Forming started at
1 150 °C and finished at
non stabilised 900 ± 20 920 ± 20
f
1 000 °C to 1 150 °C
> 750 °C (fastest possible
steels X 2 CrNi 19-11 1.4306
c c, g
(L) (L)
and finished at > 750 °C ≥ 1 000
Cooling) and stabilised fillers
low C-content/ X 2 CrNiN 18-10 1.4311
...
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