EN 13445-1:2014/A2:2018

SLOVENSKI STANDARD
01-maj-2018
1HRJUHYDQHQHNXUMHQHWODþQHSRVRGHGHO6SORãQR'RSROQLOR$
Unfired pressure vessels - Part 1: General
Unbefeuerte Druckbehälter - Teil 1: Allgemeines
Récipients sous pression non soumis à la flamme - Partie 1 : généralités
Ta slovenski standard je istoveten z: EN 13445-1:2014/A2:2018
ICS:
23.020.32 7ODþQHSRVRGH Pressure vessels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13445-1:2014/A2
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2018
EUROPÄISCHE NORM
ICS 23.020.30
English Version
Unfired pressure vessels - Part 1: General
Récipients sous pression non soumis à la flamme - Unbefeuerte Druckbehälter - Teil 1: Allgemeines
Partie 1 : Généralités
This amendment A2 modifies the European Standard EN 13445-1:2014; it was approved by CEN on 25 November 2017.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of
this amendment into the relevant 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 amendment 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13445-1:2014/A2:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Modification to Clauses 1 to 3 (Scope, Normative references and Terms and
definitions) . 4
2 Addition of new Clause 6 . 7
3 Modification to Annex A . 9
4 Modification to Annex B . 22
5 Modification to Annex X . 45
6 Modification to Annex ZA . 50
7 Modification to the Bibliography . 52

European foreword
This document (EN 13445-1:2014/A2:2018) has been prepared by Technical Committee CEN/TC 54
“Unfired pressure vessels”, 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 September 2018, and conflicting national standards
shall be withdrawn at the latest by September 2018.
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 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 2014/68/EU.
For relationship with EU Directive 2014/68/EU, see informative Annex ZA, which is an integral part of
this document.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
1 Modification to Clauses 1 to 3 (Scope, Normative references and Terms and
definitions)
nd
Replace Clauses 1 to 3 with the following text [the former NOTE after the 2 paragraph was inserted into
Clause 6]:
“
1 Scope
This European Standard defines the terms, definitions, quantities, symbols and units that are used
throughout the EN 13445 series and gives general information on the design and manufacturing of
vessels under this standard.
It also contains instructions on how to use the standard (Annex A) as well as an index which covers the
whole standard (Annex B). This information is aimed to aid users of the EN 13445 series.
This European Standard applies to unfired pressure vessels with a maximum allowable pressure
greater than 0,5 bar gauge but may be used for vessels operating at lower pressures, including vacuum.
This European Standard is not applicable to pressure vessels of the following types:
— vessels of riveted construction;
— vessels of lamellar cast iron or any other materials not included in Parts 2, 6, or 8 of the standard;
— multilayered, autofrettaged or pre-stressed vessels.
This European standard can be applied to the following pressure vessels, provided that account is taken
of additional and/or alternative requirements resulting from the hazard analysis and from rules or
instructions specific for:
— transportable vessels;
— items specifically designed for nuclear use;
— pressure vessels with a risk of overheating.
NOTE EN 14222 covers electrically fired boilers made from stainless steel and can be used as an example of
additional requirements for such vessels.
Other European standards apply to industrial piping (EN 13480 series) and to water tube and shell
boilers (EN 12952 series and EN 12953 series).
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 764-1:2015+A1:2016, Pressure equipment — Part 1: Vocabulary
EN 764-2:2012, Pressure equipment — Part 2: Quantities, symbols and units
EN 13445-2:2014, Unfired pressure vessels — Part 2: Materials
EN 13445-3:2014, Unfired pressure vessels — Part 3: Design
EN 13445-4:2014, Unfired pressure vessels — Part 4: Fabrication
EN 13445-5:2014, Unfired pressure vessels — Part 5: Inspection and testing
EN 13445-6:2014, Unfired pressure vessels — Part 6: Requirements for the design and fabrication of
pressure vessels and pressure parts constructed from spheroidal graphite cast iron
EN 13445-8:2014, Unfired pressure vessels — Part 8: Additional requirements for pressure vessels of
aluminium and aluminium alloys
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 764-1:2015+A1:2016,
EN 764-2:2012 and the following apply.
NOTE To aid the user, some of the most important terms and definitions from EN 764-1 have been repeated
here.
3.1
assembly
several pieces of pressure equipment assembled by a manufacturer to constitute an integrated and
functional whole
3.2
fluid
gas, liquid and vapour in their pure phase as well as mixtures thereof
Note 1 to entry: A fluid may contain a suspension of solids.
3.3
hazard
potential source of harm
3.4
hazard category
category of the pressure vessel taking into account the potential hazards
3.5
joint coefficient
reduction coefficient, which is applied to the nominal design stress
Note 1 to entry: E.g. used for a welded joint and related to the testing group.
3.6
main pressure bearing parts
parts which constitute the envelope under pressure, essential for the integrity of the equipment
3.7
manufacturer
individual or organization responsible for the design, fabrication, testing, installation where relevant,
and compliance with the requirements of the relevant product standard, whether executed by him or a
subcontractor
Note 1 to entry: The manufacturer can subcontract one or more of the above mentioned tasks under its
responsibility.
3.8
material manufacturer
individual or organization that produces material in the basic product form used in the manufacture of
pressure components
3.9
maximum allowable pressure
PS
maximum pressure for which the pressure vessel is designed as specified by the manufacturer
3.10
maximum allowable temperature
TS
max
maximum temperature for which the pressure vessel is designed as specified by the manufacturer
3.11
minimum allowable temperature
TS
min
minimum temperature for which the pressure vessel is designed as specified by the manufacturer
3.12
pipelines
piping or system of piping designed for the conveyance of any fluid or substance to or from an
installation (onshore or offshore) starting from and including the first isolation device located within
the installation and including all the annexed equipment designed specifically for pipelines
3.13
piping
tubing, fittings, expansion joints, hoses or other pressure-bearing components, intended for the
transport of fluid, connected together and integrated into a pressure system
3.14
pressure vessel
housing and its direct attachments up to the coupling point connecting it to other equipment, designed
and built to contain fluids under pressure
Note 1 to entry: A vessel may be composed of more than one chamber.
3.15
required thickness
thickness excluding corrosion or any other allowances specified in the EN 13445 series
Note 1 to entry: The minimum thickness that the component can have in service to fulfil the standard.
3.16
risk
combination of the probability of occurrence of harm and the severity of that harm
3.17
significant hazard
hazard which has been identified as associated with the pressure vessel and which requires specific
action by the designer to eliminate or to reduce the risk according to the risk assessment
3.18
testing factor
reduction factor taking into account the amount of NDT testing in castings, applied on the nominal
design stress to take account of possible manufacturing deficiencies
3.19
testing group
grouping which determines the appropriate level of non-destructive testing (NDT) on a welded joint
Note 1 to entry: The testing group of a vessel is not linked to the hazard category.
3.20
weldment
weld metal, heat affected zone and adjacent base material(s)
”.
2 Addition of new Clause 6
Add the following new Clause 6:
“
6 Risk assessment and handling
6.1 Hazards
Pressure vessels according to this European Standard shall be designed, constructed, installed and
equipped under consideration of all significant hazards and risks that may arise when the vessel is
erected, tested and operated in accordance with the manufacturer’s instructions or else are reasonably
foreseeable.
Such hazards shall be analysed by the manufacturer prior to designing the vessel. Apart from normal
hazards connected to the operation of the vessel (see EN 13445-3:2014, 5.3), the following hazards
shall be considered (as applicable):
— corrosion and chemical attack;
— wear;
— external fire;
— reasonably foreseeable misuse of the vessel.
6.2 Hazard removal and risk reduction
6.2.1 General
As far as practically feasible, the vessel shall be designed as to remove or reduce the respective risk. If
removal of a certain hazard is not feasible, the vessel shall be designed and equipped to protect against
the respective risk or (as a final measure) information be given on the hazard and what measures are to
be taken to reduce the risks from the hazard. Such information shall be given through warning signs
and in the operating instructions.
NOTE The procedure to follow is outlined in Figure 6.2–1.
6.2.2 Design considerations
If it is envisaged that safety accessories will have to be fitted to the vessel, the vessel shall be equipped
with the necessary connections for such accessories.
NOTE The selection, application and installation of safety related accessories intended to protect pressure
vessels during operation are covered in EN 764-7:2002.

Figure 6.2-1 — Hazard consideration
”.
3 Modification to Annex A
Replace the current Annex A with the following:
"
Annex A
(informative)
Using the standard
A.1 Purpose
The EN 13445 series is a standard which in many places uses other design, fabrication, inspection, and
testing philosophies than other pressure vessel standards. This annex is designed to facilitate the
introduction to the use of the standard.
This annex only gives a general overview of the requirements of the standard. Reference shall always be
made to the standard text itself, and not all requirements are necessarily mentioned in this annex.
A.2 General
The standard is harmonized under the Pressure Equipment Directive (2014/68/EU). This means that if
an unfired pressure vessel meets the requirements of the standard, this pressure vessel can be
presumed to conform to those essential safety requirements in Annex I of the Directive which are listed
in the Annexes ZA of the individual parts of the standard.
NOTE 1 A compilation of all Annexes ZA can be found as Annex X of this Part 1.
In this connection, it should be understood that the standard is indivisible. The design and manufacture
of unfired pressure vessels requires the application of all relevant Parts of the standard for the
requirements of the standard to be fulfilled. Only in the case that the standard gives no information to
specific parts of pressure vessels other standards may be used exceptionally. In such a case, special
attention should be paid to ensure that application of such other standard(s) is made consistent with
the safety philosophy and the general safety requirements of EN 13445 (i.e. same nominal design
stresses, same safety margins, etc.).
NOTE 2 Part 7 and Part 9 are not mandatory parts of the standard in this sense.
This standard applies to unfired pressure vessels with the limitations and exclusions stated in Clause 1
of this Part 1.
A.3 Prerequisites
Prior to designing and manufacturing a pressure vessel under the standard, the manufacturer shall
establish a number of prerequisites:
— The conditions under which the vessel will be operating.
— Load cases to be considered are enumerated in EN 13445-3:2014, 5.3.1 to 5.3.2 and also in Clause 6
of this Part 1.
— The category of the vessel (I to IV) as defined in Directive CR 13445-7:2002, 4.2 and
CR 13445-7:2002, Annex A shows how the category of a vessel is to be established.
NOTE 1 The category determines the type of inspection document required for the materials of the main
pressure-bearing parts, as stated in Annex I, Section 4.3 of the Directive (Inspection Documents are defined in
EN 10204:2004). The category may also influence how particular material appraisals (see A.4.2) are to be
performed.
— The assessment module (as defined in the Directive) to be used. CR 13445-7:2002, 4.3 and
CR 13445-7:2002, Annex B describe the different assessment modules and which assessment
modules can be used for the different categories.
The choice of module may affect the participation of a notified body and/or a recognized third party
organization or user inspectorate in the inspection and testing of the vessel as enumerated in
CR 13445-7:2002, Annex C. (It should be noted that the use of user inspectorates may not be permitted
in all member states).
— The testing group of the vessel according to EN 13445-5:2014, 6.6.1.2. The available testing groups
depend upon the material group, thickness, and welding method. Category 4 is further limited with
regards to pressure, temperature, content, number of cycles, design stress, and dimensions.
NOTE 2 The testing group affects not only the testing requirements but also design and manufacturing aspects,
e.g. joint coefficient, permitted weld details and required weld production tests.
Although the same testing group normally applies to the whole vessel, it is (with the exception of Group
4) permissible to have different testing groups apply to different parts (e.g. welds).
A.4 Materials
A.4.1 General
Specific requirements for steels are given in Part 2.
Specific rules for spheroidal graphite cast iron, aluminium, and nickel/nickel alloys are given in
EN 13445-6:2014 (see A.8 in this annex), EN 13445-8:2014 (see A.9 in this annex), and
EN 13445-10:2015 (see A.10 in this annex), respectively. In some instances, references may be made
from these parts to EN 13445-2:2014.
A.4.2 Permitted materials
Only materials which are qualified for pressure equipment may be used. Qualification of materials can
be made in three different ways
— Materials from European harmonized Standards, see EN 13445-2:2014, 4.3.1.
Certain materials supplied in accordance with European material Standards are accepted as
qualified for use in pressure-bearing parts. These materials are enumerated in
EN 13445-2:2014, Table E.2-1.
— Materials with a European Approval for Materials (EAM), see EN 13445-2:2014, 4.3.2;
Materials with an EAM, which states that they can be used for products under the PED, are qualified
for use in relevant products according to this standard.
EAMs are published in the Official Journal, and the European Commission maintains a list of EAMs
there.
— Materials with a Particular Material Appraisal (PMA), see EN 13445-2:2014, 4.3.3.
Materials, which have been subject to a PMA are qualified. This appraisal is carried out by the
manufacturer (and in certain cases checked by a Notified Body).
NOTE The European Commission and Member States have in November 2006 agreed on ”Guiding Principles
for the contents of Particular Materials Appraisals”. The document is published on
https://ec.europa.eu/commission/index_en (Search for Particular Materials Appraisal).
Whichever method of qualification is used, the qualification does not necessarily cover the suitability of
the material with regards to the environment and content of the vessel, i.e. corrosion, erosion, etc. The
manufacturer will always have to evaluate the material's resistance to such action.
Whichever way the material has been qualified, all other rules in Part 2 will have to be fulfilled.
A.4.3 Prevention of brittle fracture
Rules for prevention against brittle fracture are given in EN 13445-2:2014, Annex B.
Three different routes are allowed:
— Code of practice (EN 13445-2:2014, B.2.2).
— More flexible approach based on fracture mechanics and operating experience (EN 13445-2:2014,
B.2.3).
— Application of fracture mechanics analysis (EN 13445-2:2014, B.2.4).
The first two methods are limited to certain materials and thickness.
The third method requires detailed work in fracture mechanics, and the standard only contains
guidance on it. It can only be used after agreement between the concerned parties.
A.4.4 Material grouping
Materials are grouped in EN 13445-2:2014, Table A-1 with respect to major chemical elements,
specified minimum tensile test data. This grouping is used throughout the standard to decide design,
manufacturing, and inspection aspects.
A.5 Design
A.5.1 General
Most of the requirements for design are to be found in Part 3.
NOTE Specific design rules for vessels manufactured from spheroidal graphite cast iron, aluminium, and
nickel/nickel alloys are given in EN 13445-6:2014 (see A.8 in this annex),EN 13445-8:2014 (see A.9 in this annex),
and EN 13445-10:2015 (see A.10 in this annex), respectively.
A.5.2 Design for static loads
There are four different methods for design, which can be used either separately or in combination with
each other
— Design by formulas (DBF).
These rules are contained in EN 13445-3:2014, Clauses 7 to 16, 20 to 22 and Annexes F, G, GA and J.
For simple geometries such as cylinders and spheres, formulas can be given where pressure and
geometrical dimensions give the required minimum thicknesses directly.
For more complicated geometries, a trial-and-error approach shall be used in most cases. The
designer will have to assume the analysis thickness(es), and use the formulas to compute the
stresses and/or the load ratios as applicable. These stresses and/or load ratios are then compared
with allowable values. EN 13445-3:2014, Figure 5-1 shows the relations between different
thickness definitions.
In the design formulas of components having a governing weld, the weakening effect of that weld is
accounted for by means of a joint coefficient z. The maximum allowed value of this coefficient
depends upon the testing group of the weld as specified in EN 13445-3:2014, Table 5.6-1 and
EN 13445-5:2014, Table 6.6.1-1.
NOTE Governing welds are listed in EN 13445-3:2014, 5.6.
For two types of components, flange connections and heat exchanger tubesheets, multiple sets of
rules are given (in EN 13445-3:2014, Clause 11, Annex G, and Annex GA, and in EN 13445-3:2014,
Clause 13 and Annex J, respectively). The alternative rules of EN 13445-3:2014, Annexes G, GA and J
are based on more advanced methods than their corresponding main clause, and are expected to
lead to more appropriate and less conservative designs. Either set can be used at the designer's
option within the limitations given for each set.
Annex G is recommended for the design of flange connections where the flanges are subject to
strong leak-tightness requirements, significant thermal cycling, and/or significant additional loads
(forces or moments). It implies that the bolt stress is controlled by the use of a defined tightening
procedure.
Annex GA is a further development of Annex G. It may be used particularly for flange connections in
vessels containing gases or vapours, for which it is necessary to fix a maximum allowable leak rate.
Annex J is recommended for the design of heat exchanger tubesheets subject to relatively low cyclic
loading.
— Design by analysis using direct assessment of failure modes (DBA - Direct Route).
These rules are contained in EN 13445-3:2014, Annex B.
For each failure mode a specific assessment method is provided (e.g.: limit analysis for assessment
of gross plastic deformation, shakedown analysis for progressive deformation).
— Design by analysis using stress categorization (DBA – Method based on stress categories).
These rules are contained in EN 13445-3:2014, Annex C.
Stresses shall be computed (in most cases using finite element methods) and divided into different
categories. The stresses in each category are then compared to allowable values for the respective
category.
— Design by experiment (DBE).
These rules are contained in EN 13445-3:2014, Annex T.
Design by experiment always includes a burst test and may be supplemented by control of
deformation and a fatigue test. It can either be used separately (with limitations given in
EN 13445-3:2014, T.4.1) or as a verification of DBF or DBA calculations.
DBF is the most common and simple way to design vessels. All DBF rules cover pressure. Some kinds of
non-pressure loads can be taken into account through use of EN 13445-3:2014, Clauses 16 and 22.
DBA is used to assess structural shapes and load configurations not covered by DBF. It may also be used
as an alternative to DBF. Between the two possible DBA routes, that in EN 13445-3:2014, Annex B is
expected to be less conservative or more realistic than that in EN 13445-3:2014, Annex C, as being
based on more advanced methods.
A.5.3 Design in the creep range
— Design by Formulae.
The rules contained in EN 13445-3:2014, Clause 19 allow the design of vessels or vessel parts for
loading of predominantly non-cyclic nature (less than 500 equivalent full pressure cycles or the
number of equivalent full pressures cycles, given by the alternative rule stated in
EN 13445-3:2014, 17.5.4).
The DBA rules in EN 13445-3:2014, Annex B may be used when interaction between creep and
fatigue occurs.
Different sets of rules are used depending on whether the vessel is subjected to a single creep load
case (use EN 13445-3:2014, 19.8.1) or multiple creep load cases (use EN 13445-3:2014, 19.8.2).
In both cases, the joint factor is modified by the weld creep strength reduction factor according to
EN 13445-3:2014, 19.6.
NOTE A procedure for the determination of the weld creep strength reduction factor by tests is given in
EN 13445-2:2014, Annex C.
— Design by Analysis – Direct Route.
Design by Analysis in the creep range is covered in EN 13445-3:2014, Annex B. The design checks
to be considered (in addition to those for operation below the creep range listed in
EN 13445-3:2014, B.5.1) are:
— Creep Rupture Design Check, see EN 13445-3:2014, B.9.4,
— Excessive Creep Strain Design Check, see EN 13445-3:2014, B.9.5,
— Creep Fatigue Interaction Design Check, see EN 13445-3:2014, B.9.6.
A.5.4 Design for cyclic loads (fatigue)
Each vessel which is subjected to more than a certain number (given in
EN 13445-3:2014, Formula (5.4-1) or by the alternative rule of EN 13445-3:2014, 17.5.4) of equivalent
full pressure cycles shall be checked against fatigue. The standard provides two methods, and either
method can be used at the designer's option.
— A simplified fatigue analysis (EN 13445-3:2014, Clause 17).
This simplified method uses coefficients for different geometries and different weld details to
compute the maximum number of fatigue cycles allowed. It is essentially applicable to vessels
predominantly subject to pressure fluctuations, with however some provisions to account (to a
certain extent) for other load fluctuations.
It will normally give more conservative results than a detailed fatigue analysis.
— A detailed fatigue analysis (EN 13445-3:2014, Clause 18).
This method presumes a detailed stress analysis at all critical points (in practice mostly using finite
element methods).
In both analyses, the intensity of the fatigue loading is measured, at any vessel point, by a “damage
factor” from which the “critical areas” of the vessel can be found. In these areas, more NDT is required,
as defined in EN 13445-5:2014, Annex G.
A.5.5 Nominal design stresses
The nominal design stress f to be introduced into the formulas giving the minimum required thickness
or to be used to calculate the allowable stresses shall be computed as detailed in
EN 13445-3:2014, Clause 6 (except for operation in the creep range where EN 13445-3:2014, 19.5 is to
be used, which gives different values depending on whether lifetime monitoring is used).
NOTE 1 The concept of nominal design stress is not used within EN 13445-3:2014, Annex B. In this annex,
allowable loads are directly derived from the material characteristics.
NOTE 2 For non-austenitic steels there are two alternative sets of design stresses, the normal one in
EN 13445-3:2014, 6.2 and the Alternative Route in EN 13445-3:2014, 6.3, which permits higher stresses under
certain conditions.
A.5.6 Weld details
Butt welds are preferred for all welded joints, but joggle joints, joints with permanent backing strips,
and lap joints are permitted for certain circumferential joints, provided that the restrictions given in
EN 13445-3:2014, 5.7 are observed.
Allowable weld designs with material and geometry limitations are listed in EN 13445-3:2014, Annex A.
A.5.7 Access openings
The standard specifies a minimum number and size of access openings which are detailed in
EN 13445-5:2014, C.2 to C.4.
Rules for closing mechanisms and locking devices are given in EN 13445-5:2014, C.5.
A.6 Manufacturing
A.6.1 General
Most of the requirements for manufacturing are to be found in EN 13445-4:2014.
NOTE Specific rules for vessels manufactured from spheroidal graphite cast iron, aluminium, and
nickel/nickel alloys are given in EN 13445-6:2014 (see A.8 in this annex), EN 13445-8:2014 (see A.9 in this
annex), and EN 13445-10:2015 (see A.10 in this annex), respectively.
A.6.2 Tolerances
The standard specifies manufacturing tolerances both for vessel parts themselves and for welds:
— Permitted shape tolerances for vessels under internal pressure are specified in 5.4 of
EN 13445-4:2014.
Shape tolerances for vessels under external pressure shall not exceed those given for internal
pressure, but they shall also fulfill the requirements of EN 13445-3:2014, 8.5.1 (cylindrical and
conical shells) and EN 13445-3:2014, 8.7.2 (spherical shells). Larger shape deviations may be
accepted, but lead to reduced allowable external pressures. The rules for computing these reduced
pressures are given in EN 13445-3:2014, Annex F.
The rules cited above are absolute requirements of the standard. For other measurements,
recommended maximum tolerances are given in EN 13445-4:2014, Annex A.
EN 13445-3:2014, Annexes D and E give directions for measuring shape deviations in vessels under
external pressure.
— There are two sets of requirements on alignment at welds, for middle-line alignment
(EN 13445-4:2014, 5.2) and for surface alignment (EN 13445-4:2014, 5.3). Both sets shall be
observed simultaneously.
A.6.3 Forming
The standard covers both cold forming and hot forming, and EN 13445-4:2014, 9.3 specifies the
temperatures (depending upon material) at which forming shall be performed.
Formed parts may have to be heat-treated after forming. For cold-formed parts this requirement
depends both on the material group and on the amount of deformation during forming. Formulas to
compute this deformation are given in EN 13445-4:2014, 9.2.
The requirements for heat treatment after hot forming depend on the material group and on the
product form (see EN 13445-4:2014, 9.4).
If heat treatment is performed, the standard (depending on material group and heat treatment
condition) requires tests on test coupons. The samples, the type of coupons and tests are specified in
EN 13445-4:2014, 9.6.
A.6.4 Welding
The welding rules are to be found in EN 13445-4:2014, Clauses 6, 7, and 11 (the last one covers
repairs). The standard specifies three prerequisites for welding:
— the manufacturer shall have a welding procedure specification (WPS), see EN 13445-4:2014, 7.2;
— the welding procedure shall have been qualified (WPQR), see EN 13445-4:2014, 7.3;
— the welder or welding operator shall have been qualified, see EN 13445-4:2014, 7.4.
The requirements generally refer to other European Standards, with the addition of some extra
requirements regarding mechanical testing of welding procedure qualification tests.
A.6.5 Production tests on welds
In many cases, production tests are required on governing welds (longitudinal and circumferential
welds where membrane stresses govern the thickness) as defined in EN 13445-4:2014, Clause 8. The
amount of required production tests is specified in EN 13445-4:2014, 8.2 (for some special welds in
EN 13445-3:2014, 5.7.4) and depends upon material group, testing group, welding method and material
thickness and vary widely from no tests at all to one test per 100 m of weld or one test per vessel. When
a specified number of tests have passed successfully, the standard allows a reduction in the frequency of
the production tests.
The actual testing and the acceptance criteria are given in EN 13445-4:2014, 8.3 and 8.4.
A.6.6 PWHT (Post Weld Heat Treatment)
In some cases, the welding procedure will require that a PWHT be carried out after welding as defined
in EN 13445-4:2014, Clause 10. Holding times and holding temperatures are specified in
EN 13445-4:2014, Table 10.1-1 and depend upon material group and nominal thickness. For some
material groups, PWHT is waived for low thicknesses, but may still be desirable, e.g. when there is risk
of stress corrosion. For materials submitted to PWHT, which are not listed in this table, this treatment
shall be performed according to a procedure established in agreement with the material manufacturer,
or in conformity with other recognized codes.
If the PWHT temperature is too close to the maximum tempering temperature or the holding time
exceeds a certain number, the effect of the PWHT on the mechanical properties shall be demonstrated
either on test coupons heat treated with the vessel or test coupons subjected to a simulated PWHT.
Heat treatment shall be documented according to EN 13445-5:2014, 6.8.
A.6.7 Other types of joints
Procedures and operators for mechanical roller expansion shall have been qualified,
see EN 13445-4:2014, Annex C.
References for the required qualification of procedures and operators for brazing are given in
EN 13445-4:2014, 7.10.3.
A.7 Inspection and testing
A.7.1 General
Most of the requirements for inspection and testing are to be found in EN 13445-5:2014.
NOTE Specific rules for vessels manufactured from spheroidal graphite cast iron, aluminium, and
nickel/nickel alloys are given in EN 13445-6:2014 (see A.8 in this annex), EN 13445-8:2014 (see A.9 in this
annex), and EN 13445-10:2015 (see A.10 in this annex), respectively.
A.7.2 Technical documentation
The contents of the technical documentation for the vessel are specified in detail in EN 13445-5:2014,
Clause 5. Subclause 5.3 specifies how the design review of these documents shall be performed.
NOTE Depending upon the assessment module selected for the vessel, this review is carried out by the
manufacturer only or by the manufacturer and the responsible notified body (or user inspectorate).
The required amount of dimensional details is given in EN 13445-5:2014, Annex B.
A.7.3 Non-destructive testing of welds
EN 13445-5:2014, 6.6.2 specifies the extent of NDT for different types of welds as a function of the
testing group. The testing group determines the value of the joint coefficient used for calculation of the
component's governing welds.
For the performance of NDT, EN 13445-5:2014, 6.6.3 specifies the method to be used, depending upon
the type of welded joint, but for details about NDT methods, techniques, characterization, and
acceptance criteria, reference is mainly made to other specified European Standards with some
additional requirements.
Special requirements when NDT is subcontracted are given in EN 13445-5:2014, 7.3.
Critical areas of vessels operating in cyclic service shall be subjected to more extended NDT as specified
in EN 13445-5:2014, Annex G.
NOTE Critical areas in fatigue are defined in EN 13445-3:2014, Clauses 17 and 18.
A.7.4 Final assessment
EN 13445-5:2014, Clause 10 specifies how final assessment shall be performed. Detailed rules are given
for the performance of the proof test, including the calculation of the test pressure. Annex H shows the
form to be used for declaration of compliance with the standard.
NOTE Depending upon the module selected for the assessment of the vessel, this assessment is carried out by
the manufacturer only or by the manufacturer and the responsible notified body (or user inspectorate).
All measurement and test equipment shall be calibrated in accordance with EN 13445-5:2014, Clause 9.
A.7.5 Marking and records
EN 13445-5:2014, Clauses 11 and 12 specify the minimum requirements of marking on the vessel and
of the records to be kept for the vessel, respectively.
A.8 Pressure vessels constructed from spheroidal graphite cast iron
A.8.1 General
EN 13445-6:2014 covers such vessels within the limits in EN 13445-6:2014, Clauses 1 and 4.2. In many
cases, EN 13445-6:2014 refers to the general rules in EN 13445-1:2014 to EN 13445-5:2014.
A.8.2 Materials
The ferritic and austenitic spheroidal graphite cast iron materials, which are permitted in pressure
vessels built to the standard, are listed in EN 13445-6:2014, 5.1 together with the corresponding design
temperature limits. Material testing is specified in EN 13445-6:2014, Clause 6.
A.8.3 Design
Design can follow either the DBF rules (with some modifications stated in EN 13445-6:2014, 5.2.2.3 to
5.2.2.5) or any of the two sets of DBA rules (with some modifications stated in
EN 13445-6:2014, Annex E) in EN 13445-3:2014. The nominal design stress shall be calculated
according to special rules in EN 13445-6:2014, 5.2.2.2, which include special temperature coefficients,
as well as testing and safety factors, which depend upon the amount of NDT.
EN 13445-6:2014, Annex G gives DBF formulas for common casting geometries.
DBE by means of burst tests can also be used, either as sole design method (if the pressure-volume
product is less than 6 000 bar litres) or as a complement to the other methods. EN 13445-6:2014
contains its own DBE rules in Subclauses 5.2.2.1.2.3 to 5.2.2.1.2.4.
Fatigue shall be considered for vessels with more than a certain number of full pressure cycles, this
number depending upon testing factor and stress concentration factors as shown in
EN 13445-6:2014, Table 4.1-1. The available methods are simplified and detailed assessments,
according to rules in EN 13445-6:2014, Annex D, and experimental assessment, according to rules in
EN 13445-6:2014, Annex H.
Fillet radii are limited by rules in EN 13445-6:2014, 5.2.2.6.
A.8.4 Welding
No production or repair welding, only finishing welding, is allowed.
A.8.5 Testing and final assessment
Requirements for NDT and final assessment are given in EN 13445-6:2014, Clauses 6 to 7. Special rules
apply to critical zones which are defined in EN 13445-6:2014, 3.1.1.
A.9 Pressure vessels constructed from aluminium and aluminium alloys
A.9.1 General
Special requirements for such vessels are to be found in EN 13445-8:2014, which contains additions to
and exceptions from the general rules in EN 13445-1:2014 to EN 13445-5:2014.
A.9.2 Materials
EN 13445-8:2014, Clause 5 contains deviations from the rules in EN 13445-2:2014 for elongation,
prevention of brittle fracture and lamellar tearing, as well as special limits on the contents of lead and
hydrogen contents. EN 13445-8:2014, Tables 5.6-1 and A.2 show the special material grouping system
to be used for aluminium and aluminium alloys as well as the allowable material grades.
A.9.3 Design
In general, design follows the rules in EN 13445-3:2014, but EN 13445-8:2014, 6.4 contains alternative
rules for thick-walled pipes. The nominal design stress and maximum design temperatures shall be
calculated as shown in EN 13445-8:2014, Tables 6.3-1 and 6.3-2.
The rules are at present limited to vessels with less than 500 full equivalent pressure cycles.
Restrictions of certain welds and other design details as well as DBE rules are given in
EN 13445-8:2014 6.6.
A.9.4 Manufacturing
In general, the rules in EN 13445-2:2014 apply, but with a large number of deviations as outlined in
Table A.9-1.
Table A.9–1 — Deviations in EN 13445-8:2014 from EN 13445-4:2014
Reference in Modifying reference
Subject
EN 13445-4:2014 in EN 13445-8:2014
Tolerances 5.4 7.3
Welding procedures 7.2 7.4
Qualification of welding procedures 7.3 7.5
Qualification of welders 7.4 7.6
Joint preparation 7.6 7.7
Preheating 7.9 7.8
Production tests, reference criteria 8.2 7.9
Extent of testing Table 8.3–1 Table 7.10–1
Performance of tests and acceptance
8.4 7.11
criteria
Forming procedures 9.3 7.12
Heat treatment after forming 9.4 7.13
Sampling of formed products 9.5 7.14
Tests 9.6 7.15
Post weld heat treatment 10 7.16
A.9.5 Inspection and testing
In general, the rules in EN 13445-5:2014 apply, but with a number of deviations as outlined in
Table A.9-2.
Table A.9–2 — Deviations in EN 13445-8:2014 from EN 13445-5:2014 rules
Reference in Modifying reference
Subject
EN 13445-5:2014 in EN 13445-8:2014
Testing groups Table 6.6.1–1 Table 8.2–1
Demonstration of satisfactory
6.6.1.1.4 8.2.2
experience
Extent of NDT 6.6.2 and Table 6.6.2–1 8.3 and Table 8.3–1
Performance of NDT 6.6.3 to 6.6.7 8.4 to 8.5
Hydrostatic test 10.2.3.3 8.6
Pneumatic testing 10.2.3.4 8.7
Model approval of serially produced
A.2 9.1
vessels
Cyclically loaded vessels Annex G Not applicable, see 9.2

A.10 Pressure vessels constructed from nickel and nickel alloys
A.10.1 General
Special requirements for such vessels are to be found in EN 13445-10:2015, which contains additions to
and exceptions from the general rules in EN 13445-1:2014 to EN 13445-5:2014.
A.10.2 Materials
EN 13445-10:2015, Clause 5 contains deviations from the rules in EN 13445-2:2014 for elongation as
well as prevention of brittle fracture and lamellar tearing. EN 13445-10:2015, Annex A shows the
special material grouping system to be used for nickel and nickel alloys as well as material grades.
Physical properties of nickel and nickel alloys are shown in EN 13445-10:2015, Annex B.
In general, design follows the rules in EN 13445-3:2014, but EN 13445-10:2015, 6.4 contains
alternative rules for shells under external pressure. The nominal design stress and maximum design
temperatures shall be calculated as shown in EN 13445-10:2015, Table 6.2-1.
Restrictions on design for creep and fatigue are given in EN 13445-10:2015, 6.3 and 6.5.
A.10.3 Manufacturing
In general, the rules in EN 13445-2:2014 apply, but with a large number of deviations as outlined in
Table A.10-1.
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