EN 16668:2025

SLOVENSKI STANDARD
01-april-2025
Nadomešča:
SIST EN 16668:2016+A1:2018
Industrijski ventili - Zahteve in preskušanje kovinskih ventilov kot tlačnega pribora
Industrial valves - Requirements and testing for metallic valves as pressure accessories
Industriearmaturen - Anforderungen und Prüfungen für Metallarmaturen als
drucktragende Ausrüstungsteile
Robinetterie industrielle - Exigences et essais pour appareils de robinetterie métalliques
utilisés comme accessoires sous pression
Ta slovenski standard je istoveten z: EN 16668:2025
ICS:
23.060.01 Ventili na splošno Valves in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16668
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2025
EUROPÄISCHE NORM
ICS 23.060.01 Supersedes EN 16668:2016+A1:2018
English Version
Industrial valves - Requirements and testing for metallic
valves as pressure accessories
Robinetterie industrielle - Exigences et essais pour Industriearmaturen - Anforderungen und Prüfungen
appareils de robinetterie métalliques utilisés comme für Metallarmaturen als drucktragende
accessoires sous pression Ausrüstungsteile
This European Standard was approved by CEN on 22 December 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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16668:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 8
4 Category of valves . 9
5 Requirements . 9
5.1 Design . 9
5.1.1 General . 9
5.1.2 Shell design strength . 10
5.1.3 Protection against exceeding the allowable limits . 10
5.2 Materials . 10
5.2.1 General requirements . 10
5.2.2 European harmonized material standards. 10
5.2.3 European approval of materials (EAM) . 10
5.2.4 Particular Material Appraisal (PMA) . 11
5.2.5 Requirements for prevention of brittle fracture at low temperatures . 11
5.2.6 Selection of bolting material . 11
5.2.7 Material selection for parts other than shell . 11
5.3 Manufacturing . 12
5.3.1 Welding . 12
5.3.2 Heat treatment . 14
5.3.3 Traceability . 14
5.3.4 Qualification of non-destructive testing personnel . 14
5.4 Non-destructive testing (NDT) . 14
5.4.1 Non-destructive testing of steel castings . 14
5.4.2 Non-destructive testing of joint welding . 14
5.5 Final assessment . 14
5.6 Marking . 15
5.7 Surface and coating testing . 15
5.8 Documentation . 15
5.8.1 Documentation for final inspection. 15
5.8.2 Accompanying documents . 16
Annex A (normative) Classification of valves. 17
Annex B (informative) European harmonized standards for materials and components for
shell parts . 22
Annex C (informative) European Approval of Materials (EAM) . 24
Annex D (informative) European harmonized standards for valves . 25
Annex E (informative) Non-destructive testing of steel castings . 27
E.1 Terms and definitions . 27
E.2 Non-destructive testing of steel castings . 27
Annex F (normative) Non-destructive testing (NDT) of joint welding . 35
F.1 General . 35
F.2 Non-destructive testing (NDT) extent . 35
F.3 Selection of NDT-methods . 41
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2014/68/EU (Pressure Equipment Directive) aimed to be
covered . 42
Bibliography . 44
European foreword
This document (EN 16668:2025) has been prepared by Technical Committee CEN/TC 69 “Industrial
valves”, 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 August 2025, and conflicting national standards shall be
withdrawn at the latest by August 2025.
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 16668:2016+A1:2018.
This document includes the following significant technical changes with respect to
EN 16668:2016+A1:2018:
— the most important changes have been made in the following clauses and subclauses: Clause 4, 5.1.2,
5.1.3, 5.2.1, 5.2.4, 5.3.1.3, 5.3.1.4, 5.3.1.5, 5.3.1.6, 5.3.3, 5.3.4, 5.8.1, 5.8.2 and Annex A;
— the following tables have been modified: Table 2 and Table E.1;
— Annex ZA has been modified;
— dated references have been updated.
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.
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 organisations 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.
Introduction
This document is to be understood as an umbrella standard referencing European harmonized standards
for industrial metallic valves as pressure accessories for industrial applications. It covers the
requirements to meet the Essential Safety Requirements of the Pressure Equipment Directive.
1 Scope
This document is applicable to metallic valves as pressure accessories for industrial applications with a
maximum allowable pressure PS greater than 0,5 bar in accordance with the European legislation for
pressure equipment and specifies requirements applicable to design, manufacture, testing, materials and
documentation.
All essential safety requirements of the European legislation for pressure equipment applicable to valves
have been taken into consideration and are addressed in this document.
This document does not apply to:
— safety valve and bursting disc (safety accessories),
— sight glass with its frames (component of a pressure equipment), and
— measurement chambers.
For other exclusions, refer to the European legislation for pressure equipment [60].
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 19:2023, Industrial valves — Marking of metallic valves
EN 736-1:2018, Valves — Terminology — Part 1: Definition of types of valves
EN 764-1:2015+A1:2016, Pressure equipment — Part 1: Vocabulary
EN 764-2:2012, Pressure equipment — Part 2: Quantities, symbols and units
EN 764-4:2014, Pressure equipment — Part 4: Establishment of technical delivery conditions for metallic
materials
EN 764-5:2014, Pressure equipment — Part 5: Inspection documentation of metallic materials and
compliance with the material specification
EN 764-7:2002, Pressure equipment — Part 7: Safety systems for unfired pressure equipment
EN 1349:2009, Industrial process control valves
EN 10269:2013, Steels and nickel alloys for fasteners with specified elevated and/or low temperature
properties
EN 12266-1:2012, Industrial valves — Testing of metallic valves — Part 1: Pressure tests, test procedures
and acceptance criteria — Mandatory requirements
EN 12266-2:2012, Industrial valves — Testing of metallic valves — Part 2: Tests, test procedures and
acceptance criteria — Supplementary requirements
EN 12516-1:2014+A1:2018, Industrial valves — Shell design strength — Part 1: Tabulation method for
steel valve shells
EN 12516-2:2014+A1:2021, Industrial valves — Shell design strength — Part 2: Calculation method for
steel valve shells
EN 12516-3:2002, Valves — Shell design strength — Part 3: Experimental method
EN 12516-4:2014+A1:2018, Industrial valves — Shell design strength — Part 4: Calculation method for
valve shells manufactured in metallic materials other than steel
EN 13445-2:2021+A1:2023, Unfired pressure vessels — Part 2: Materials
EN 13445-4:2021+A1:2023, Unfired pressure vessels — Part 4: Fabrication
EN 13445-5:2021+A1:2024, Unfired pressure vessels — Part 5: Inspection and testing
EN 13480-2:2024, Metallic industrial piping — Part 2: Materials
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 9606-2:2004, Qualification test of welders — Fusion welding — Part 2: Aluminium and aluminium
alloys (ISO 9606-2:2004)
EN ISO 9606-3:1999, Approval testing of welders — Fusion welding — Part 3: Copper and copper alloys
(ISO 9606-3:1999)
EN ISO 9606-4:1999, Approval testing of welders — Fusion welding — Part 4: Nickel and nickel alloys (ISO
9606-4:1999)
EN ISO 9606-5:2000, Approval testing of welders — Fusion welding — Part 5: Titanium and titanium alloys,
zirconium and zirconium alloys (ISO 9606-5:2000)
EN ISO 9712:2022, Non-destructive testing — Qualification and certification of NDT personnel (ISO
9712:2021)
EN ISO 11970:2016, Specification and qualification of welding procedures for production welding of steel
castings (ISO 11970:2016)
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 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, Corrected version 2017-10-01)
EN ISO 15614-2:2005, Specification and qualification of welding procedures for metallic materials —
Welding procedure test — Part 2: Arc welding of aluminium and its alloys (ISO 15614-2:2005)
EN ISO 15614-5:2024, Specification and qualification of welding procedures for metallic materials —
Welding procedure test — Part 5: Arc welding of titanium, zirconium and their alloys (ISO 15614-5:2024)
EN ISO 15614-6:2006, Specification and qualification of welding procedures for metallic materials —
Welding procedure test — Part 6: Arc and gas welding of copper and its alloys (ISO 15614-6:2006)
EN ISO 17635:2016, Non-destructive testing of welds — General rules for metallic materials (ISO
17635:2016)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 736-1:2018,
EN 764-1:2015+A1:2016, EN 764-2:2012, EN 764-4:2014, EN 764-5:2014, EN 764-7:2002 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
valve
piping component which influences the fluid flow by opening, closing or partially obstructing the passage
of the fluid flow or by diverting or mixing the fluid flow
Note 1 to entry: Typical valves are gate valves, globe valves, control valves, check valves, diaphragm valves,
butterfly valves, plug and ball valves as well as non-standard valves either manual or actuator operated and steam
traps, usually covered by a product standard.
[SOURCE: EN 736-1:2018, 3.1, modified — The Note 1 to entry was added here.]
3.2
production welding
welding carried out during manufacturing before final delivery to the purchaser including joint welding
and finishing welding
3.2.1
joint welding
welding used to weld components in order to obtain an integral unit

As impacted by EN ISO 15614-1:2017/A1:2019.
3.2.2
finishing welding
production welding carried out in order to ensure the agreed quality of the casting
[SOURCE: EN ISO 11970:2016, 3.1.2]
3.3
repair welding
welding carried out after delivery to the end user, i.e. after the casting has been in service
[SOURCE: EN ISO 11970:2016, 3.2]
3.4
sample
set of one or more units taken from a batch and intended to provide information on the batch
Note 1 to entry: This definition is based on ISO 2859-1.
3.5
material manufacturer
person or organization (like founder, forge-, welding shop) which provides material to the responsible
valve manufacturer
4 Category of valves
A classification under the use of DN and PS and fluid groups 1 and 2 leads to maximum Category III. A
method of classification of valves is provided in Annex A.
Valves classified in Article 4 (3) of the European legislation for pressure equipment shall be designed,
manufactured and tested in accordance with the “sound engineering practice” requirement of a member
state and are excluded from conformance to the requirements of this document except 5.6, 5.8.1 and 5.8.2.
NOTE Valves complying with the requirements of the relevant product standard are considered to comply with
the “sound engineering practice” requirement.
5 Requirements
5.1 Design
5.1.1 General
Valves shall meet the design requirements of this document.
NOTE Annex D contains a summary of European harmonized standards for valves.
A hazard analysis shall be conducted for the intended use and for the reasonably foreseeable conditions.
It is recommended to have this hazard analysis documented.
If hazards are identified which apply to the valve, appropriate measures in order to reduce or eliminate
the hazard identified shall be taken into account.
5.1.2 Shell design strength
5.1.2.1 The shell design strength shall be determined by one or more of the following standards:
a) for steel valves designed by the tabulation method: according to EN 12516-1:2014+A1:2018;
b) for steel valves designed by calculation solely: according to EN 12516-2:2014+A1:2021;
c) for copper alloy, aluminium and cast iron valves: according to EN 12516-4:2014+A1:2018;
d) an experimental method provided that sole use of an experimental method is only permitted when
the maximum allowable pressure at room temperature, PS, multiplied by the DN-number is less than
3 000 bar: according to EN 12516-3:2002. This standard is used to supplement the tabulation
method a), and the calculation method b) without limit.
The valve obturator normally is not part of the shell – except if an “end of line service” is agreed. In this
case, all requirements related to the European legislation for pressure equipment apply to the obturator
as well.
5.1.2.2 Appropriate calculation methods other than those specified in the relevant European
harmonized standards giving same level of safety may be applied.
5.1.3 Protection against exceeding the allowable limits
A means to protect against excessive pressure increase in isolated cavities shall be provided when the
analysis of hazards and risks identifies this as a risk.
Some valves trap fluid inside cavities that become isolated during service. When this occurs, an increase
in temperature could result in an excessive rise in pressure and the allowable limits being exceeded.
5.2 Materials
5.2.1 General requirements
Shell materials shall be selected in accordance with EN 12516-1:2014+A1:2018,
EN 12516-4:2014+A1:2018 or EN 13445-2:2021+A1:2023.
NOTE Other metallic shell materials can be used providing they are covered by an EAM or PMA.
The inspection documents of material shall be in accordance with EN 764-5:2014.
EAM or PMA is not required for valves classified in Article 4 (3) of the European legislation for pressure
equipment.
5.2.2 European harmonized material standards
A summary of European Harmonized Material Standards for shell parts is given in Annex B.
5.2.3 European approval of materials (EAM)
EAM for materials are intended for repeated use. They are established in accordance with EN 764-4:2014
and apply to materials or treatment condition and product forms or dimensions not covered in a
European Harmonized Standard.
Annex C contains a link to OJEU Website for European approval of materials (EAM).
5.2.4 Particular Material Appraisal (PMA)
If a material grade or a product form or a thickness is not covered by a harmonized European material
standard or EAM, a particular material appraisal (PMA) shall be performed. PMA shall be established in
accordance with EN 764-4:2014.
For valves in categories III or IV, a specific assessment and confirmation of the PMA shall be performed
by a competent authority.
A PMA shall also be performed for a material specified in a harmonized European material Standard or
EAM for materials for pressure equipment, which is intended in an exceptional case for service conditions
outside its specified range of application.
Table 1 lists EN material standards covering materials for which it is required to obtain a PMA when used
as shell material.
Table 1 — EN material standards for which a PMA is required
Main material group European Standard / Material
Steels specified in European EN 10025-2:2019 (S235JR, S235JRG2 and S355J2G3)
standards
EN 10222-2:2017+A1:2021 (P250GH)
Cast irons EN 1561:2023
EN 545:2010
Copper EN 1982:2024
EN 12449:2023
EN 12163:2024
EN 12164:2024
5.2.5 Requirements for prevention of brittle fracture at low temperatures
Appropriate methods for the prevention of brittle fracture at low temperatures shall be applied.
Temperature limits as given in EN 12516-1:2014+A1:2018 and EN 12516-4:2014+A1:2018 shall be
considered.
The methods to prevent brittle fracture at low temperatures described in EN 13480-2:2024 and
EN 13445-2:2021+A1:2023, Annex B shall be applied.
5.2.6 Selection of bolting material
Material selection for bolting shall be in accordance with EN 10269:2013.
NOTE 1 Other bolting materials can be used providing they are covered by an EAM or PMA.
NOTE 2 EN 1515-4:2021 provides a possible selection of bolting for pressure equipment.
5.2.7 Material selection for parts other than shell
Material selection for parts other than shell shall be listed or specified.
The stuffing box packing shall not cause corrosion on a stem, shaft or pivot.
5.3 Manufacturing
5.3.1 Welding
5.3.1.1 General requirements
Welding of the shell itself or on components of shell shall only be undertaken if the following conditions
are satisfied:
a) a welding procedure specification is held by the manufacturer;
b) the welding procedures selected by the manufacturer are qualified for the field of application;
c) the welders and welding operators are qualified for the work allocated to them and their approval is
valid.
Welding of high-alloy martensitic chromium steels (>13 % Cr) requires particular qualification, except
casting production welds at the foundry.
General rules for the specification and qualification of welding procedures for metallic materials specified
in EN ISO 15607:2019 shall be taken into account.
NOTE The provision of the fabrication drawings with welding data (weld details, welding procedure and
welding fillers) including information on type and extent of non-destructive testing of welding seams, parts lists
and copies of the welding procedure qualifications can be subject to agreement.
5.3.1.2 Welding procedure specification (WPS)
Welding procedure specifications shall be compiled in accordance with EN ISO 15609-1:2019 for all
welds.
5.3.1.3 Qualification of welding procedure specifications (WPQR)
Welding procedure specifications to be used shall be qualified by reference to an appropriate WPQR.
For the pressure retaining welds on a shell of a valve, the welding procedure qualification tests shall be
performed in accordance with one of the applicable standards:
a) EN ISO 15614-1:2017, whereby level 2 of welding procedure qualification tests shall be fulfilled;
NOTE For valves classified in Article 4 (3), the level of welding procedure qualification tests is determined by
the valve manufacturer.
b) EN ISO 15614-2:2005;
c) EN ISO 15614-5:2024;
d) EN ISO 15614-6:2006;
e) EN ISO 15613:2004 (by preproduction tests).
The additional requirements which may be applied to welding procedure qualification testing outlined
in EN 13445-4:2021+A1:2023, 8.3 shall be taken into account.
Pressure retaining welds performed on the shells of valves in categories II, III and IV shall be performed
in accordance with a welding procedure as specified in EN ISO 15614-1:2017 and this clause.
For all test coupons it is permissible for a manufacturer to subcontract preparation of test pieces and
their testing but not the welding of the test pieces.
For welds other than pressure retaining welds, that are directly attached to a shell, welding procedure
specifications may be acceptable by holding welding procedure approval records carried out in
accordance with EN ISO 15611:2024 and EN ISO 15612:2018.
5.3.1.4 Qualification of welders and welding operators
Welders shall be qualified in accordance with the respective applicable part of EN ISO 9606-1:2017,
EN ISO 9606-2:2004, EN ISO 9606-3:1999, EN ISO 9606-4:1999 and EN ISO 9606-5:2000.
Welding operators shall be qualified according to EN ISO 14732:2013.
Pressure retaining welds performed on the shells of valves in categories II, III and IV shall be examined
in accordance with EN ISO 14732:2013. For valves of category II, III and IV re-validation in accordance
with EN ISO 14732:2013, 5.3 c), is not permitted.
In the context of qualification of welders and welding operators EN 13445-4:2021+A1:2023, 8.4 outlines
additional requirements that shall be taken into account.
5.3.1.5 Finishing welding on castings
Finishing welding is only permissible on steel castings in accordance with EN ISO 11970:2016. When
carrying out finishing welding on defective areas of steel castings, the defective area shall be completely
rectified and tested to ensure that it is free from inadmissible imperfections.
Finishing welding shall be performed in accordance with a written procedure specifying the
requirements for imperfection removal, welding, heat treatment and non-destructive testing.
Undocumented finishing welding prior to PWHT is permissible provided the imperfection depth does not
exceed 40 % of the wall thickness.
Undocumented finishing welding after PWHT is permissible, provided that the imperfection depth does
not exceed 20 % of the wall thickness or 25 mm, whichever is the smallest value.
Depressions resulting from the removal of imperfections shall be 100 % surface tested in order to ensure
the complete removal of the imperfection. For the surface testing, magnetic particle testing (MT) or
penetrant testing (PT) shall be applied as appropriate.
The requirements for the specification and approval of welding procedures for the production of steel
castings stated in EN ISO 11970:2016 shall be followed.
5.3.1.6 Repair of joint weld imperfections
Repair of joint weld imperfections shall be carried out in accordance with EN 13445-4:2021+A1:2023,
12.2. Repair work on the welds and NDE results shall be documented and made available to the purchaser
on request.
All unacceptable imperfections shall be removed, either by mechanical means (such as grinding or
machining) or by thermal means (such as arc air gouging or thermal gouging) or by a combination of
thermal and mechanical means. It is the responsibility of the manufacturer to decide how unacceptable
imperfections shall be removed. This may be by local means or by removal of the weld from the joint
followed by rewelding.
When thermal gouging/arc air gouging is used on austenitic steels, care shall be taken to remove any
contamination of the remaining weld or material. Similarly, when gouging with carbon electrodes is used
on ferritic steels, the affected surface shall be removed by mechanical means to a minimum depth of
0,3 mm.
Thermal gouging methods shall not be used for martensitic creep-resisting steel.
When unacceptable imperfections are removed and are not followed by welding, all the remaining
thickness shall be greater than the minimum thickness necessary to satisfy the design unless the local
area satisfies the conditions of 5.3.2. The area shall have a taper with the adjoining surfaces, and blend
smoothly.
Repairs by welding shall be carried out in accordance with a WPS which has been qualified in accordance
with 5.3.1.3.
This may be the same WPS as the one used for making the joint originally or a specific qualified repair
procedure.
Repairs shall be carried out by qualified welders or operators in accordance with 5.3.1.4. Weld repaired
areas shall be non-destructively examined in accordance with EN 13445-5:2021+A1:2024.
When repair welding is carried out after post weld heat treatment or hydraulic test these operations shall
be repeated. Any further post weld heat treatment carried out in accordance with 5.3.2 shall be
considered in terms of its effect on material and weld properties.
5.3.1.7 Filler metals and auxiliary materials
Filler metals and auxiliary materials shall be in accordance with EN 13445-4:2021+A1:2023, 8.5.
5.3.2 Heat treatment
Heat treatment shall be performed whenever this is required to achieve the required mechanical
properties of the materials used for shell parts.
Requirements regarding post weld heat treatment (PWHT) shall be in accordance with
EN 13445-4:2021+A1:2023.
5.3.3 Traceability
An identification system, e. g. Positive Material Identification (PMI) or Color Coding system for the
Material, shall be created and maintained for materials used in fabrication, so that all material subject to
stress due to pressure and those welded thereto in the completed work can be traced to its origin. This
shall also include the use of welding consumables.
5.3.4 Qualification of non-destructive testing personnel
Non-destructive testing personnel shall be qualified and certified in accordance with EN ISO 9712:2022
except for visual inspection for which personnel shall be qualified but need not be certified.
Non-destructive testing personnel shall hold an appropriate certificate of competence (e.g. personnel
certification on non-destructive testing level 1, 2 or 3 as appropriate).
5.4 Non-destructive testing (NDT)
5.4.1 Non-destructive testing of steel castings
For non-destructive testing of steel castings, guidance is given in Annex E.
5.4.2 Non-destructive testing of joint welding
Non-destructive testing of joint welding shall be in accordance with Annex F.
5.5 Final assessment
Valves shall meet the requirements given in Table 2 and Table 3 below.
As appropriate the final inspection shall be carried out internally and externally on every part of the valve,
in the course of manufacture (e.g. where testing during the final inspection is no longer possible).
Table 2 — Inspection
Assessment Subject Requirements
Visual assessment Type of valve Compliance to order specification
Material Compliance to order specification
Marking Compliance to 5.6
Surface and coating Compliance to 5.7
Documentation As appropriate Compliance to 5.8
Table 3 — Testing
Requirements Testing and Inspection - Remarks
1  Shell strength EN 12266-1:2012, Annex A, A.2, Test P10;
Process control valves shall also comply
with EN 1349:2009, 6.1
2  Shell tightness EN 12266-1:2012, Annex A, A.3, Test P11;
If the result of hazard analyses identifies the need for shell Process control valves shall also comply
tightness, then P11 test is required. with EN 1349:2009, 6.1
3  Seat tightness EN 12266-1:2012, Annex A, A.4, Test P12;
If the result of hazard analyses identifies the need for seat For Process control valves EN 1349:2009,
tightness test, then P12 test is required. 6.3 shall be applied.
4  Obturator strength EN 12266-2:2012, Annex A, A.2, Test P 20
If a pressure related hazard is identified in relation with
the obturator of the valve (for example in valves used as
end of line service), P 20 Test of EN 12266-2:2012 is
required in addition.
5.6 Marking
Marking shall be in accordance with EN 19:2023 and the relevant harmonized European product
standards.
5.7 Surface and coating testing
Protective coating or special surface treatment shall be inspected or tested in accordance with the order
specification.
5.8 Documentation
5.8.1 Documentation for final inspection
The following documents shall be available as appropriate:
— evidence of qualification of NDT personnel relevant to the equipment category;
— evidence of qualification of permanent joining personnel relevant to the equipment category;
— data dealing with heat treatment (e.g. diagram of temperatures);
— inspection documents for base materials and welding consumables;
— procedures for assuring material traceability;
— NDT test reports, including radiographic films;
— test reports of destructive tests (e.g. test coupons);
— reports on imperfections or deviations arising during manufacture;
— data related to the preparation of component parts (e.g. forming chamfering);
— evidence of qualification of permanent joining procedures;
— reports on testing according to EN 12266-1 and EN 12266-2 (as applicable).
For valves under Article 4 (3) of the European legislation for pressure equipment documentation as listed
above should be available and if agreed upon a “statement of conformity” of sound engineering practice
shall be made available.
5.8.2 Accompanying documents
5.8.2.1 Operating instructions shall be supplied for every valve detailing information required for the
safe installation, operation and maintenance:
a) safe operating limits and design basis;
b) where applicable, features of the design relevant to the life of the valve including recommended
maintenance requirements;
c) residual risks and hazards not prevented by design or protective measures, that might arise from
reasonably foreseeable misuse;
d) documents, drawings and diagrams necessary for a full understanding of the operating instructions;
e) information about replaceable parts and repair recommendations.
5.8.2.2 Valves under Article 4 (3) of the European legislation for pressure equipment shall be
accompanied by an adequate instruction for use containing the information 5.8.2 a) to 5.8.2 e).
Annex A
(normative)
Classification of valves
For all valves covered by the product standards listed in Table A.1 nominal size (DN), maximum allowable
pressure (PS) and the fluid group shall be used for valve classification. Consequently, the maximum
category for these valves ends up in category III even when installed in a higher categorized pressure
equipment.
For valves not covered by product standards listed in Table A.1, either the volume (V) or the nominal size
(DN) is to be considered for the classification of the valve. In case a valve is used as safety accessory or
part of, category IV is sometimes requested.
’The value PS (maximum allowable pressure) is the value specified in EN 12516-1:2014+A1:2018 or by
the valve technical documentation. For PN designated valves PS is equal to PN.
The classification results shown in Tables A.2 to A.5 are based on the above-mentioned conditions.
Valves, which are intended to be used both for liquid and for gaseous fluids, shall be classified for gaseous
fluids.
Valves, which are intended to be used both for fluids of Fluid Group 1 and fluids of Fluid Group 2, shall be
classified in Fluid Group 1.
Table A.1 — Harmonized product standards
Reference and title of the European harmonized product standard
EN 593:2017, Industrial valves — Metallic butterfly valves
EN 1171:2015, Industrial valves — Cast iron gate valves
EN 1349:2009, Industrial process control valves
EN 1983:2013, Industrial valves — Steel ball valves
EN 1984:2010, Industrial valves — Steel gate valves
EN 12288:2010, Industrial valves — Copper alloy gate valves
EN 13397:2001, Industrial valves — Diaphragm valves made of metallic materials
EN 13709:2010, Industrial valves — Steel globe and globe stop and check valves
EN 13789:2010, Industrial valves — Cast iron globe valves
EN 13547:2013, Industrial valves — Copper alloy ball valves
EN 16767:2020, Industrial valves — Metallic check valves
NOTE The following tables are based on Table 6 to 9 of Annex II of the European legislation for pressure equipment.
Table A.2 — Fluid Group 1 – Gas
PN Class DN 25 DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN
32 40 50 65 80 100 125 150 200 250 300 350 400 450 500 600 700 750 800 900 1 000
2,5
6    Category I
40              Category III
300    Category II
63  Art. 4 (3)
1 500
2 500
4 500
Exceptionally, valves intended for unstable gasses and falling within Categories I or II shall be classified in Category III.
Table A.3 — Fluid Group 1 – Liquid
PN Class DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN
25 32 40 50 65 80 100 125 150 200 250 300 350 400 450 500 600 700 750 800 900 1 000
2,5
6     Art. 4 (3)
10               Category I
63           Category II
1 500
2 500
4 500        Category III
Valves with a PN 2.5 and a DN > DN 800 shall be classified in Category I.
Table A.4 — Fluid Group 2 – Gas
PN Class DN 25 DN 32 DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN DN
40 50 65 80 100 125 150 200 250 300 350 400 450 500 600 700 750 800 900 1 000
2,5
10   Art. 4 (3)
...