SIST EN ISO 27509:2021

Petroleum and natural gas industries - Compact flanged connections with IX seal ring (ISO 27509:2020)

This document specifies detailed manufacturing requirements for circular steel and nickel alloy
compact flanged connections and associated seal rings, for designated pressures and temperatures
in class designations CL 150 (PN 20) to CL 1500 (PN 260) for nominal sizes from DN 15 (NPS ½) to
DN 1200 (NPS 48), and for CL 2500 (PN 420) for nominal sizes from DN 15 (NPS ½) to DN 600 (NPS 24).
NOTE NPS is expressed in accordance with ASME B36.10M and ASME B36.19M.
This document is applicable to welding neck flanges, blind flanges, paddle spacers and spacer blinds
(paddle blanks), valve/equipment integral flanges, orifice spacers, reducing threaded flanges and rigid
interfaces for use in process piping for the petroleum, petrochemical and natural gas industries.
This document is applicable within a temperature range from −196 °C to +250 °C.
This document is not applicable for external pressure.

Erdöl- und Erdgasindustrie - Kompakte Flanschverbindungen mit IX Dichtungsring (ISO 27509:2020)

Industries du pétrole et du gaz naturel - Raccordements à brides compactes avec bague d'étanchéité IX (ISO 27509:2020)

Industrija za predelavo nafte in zemeljskega plina - Kompaktni prirobnični konektorji s tesnilnim obročem IX (ISO 27509:2020)

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN ISO 27509:2021
01-februar-2021
Nadomešča:
SIST EN ISO 27509:2014
SIST EN ISO 27509:2014/AC:2014
Industrija za predelavo nafte in zemeljskega plina - Kompaktni prirobnični
konektorji s tesnilnim obročem IX (ISO 27509:2020)

Petroleum and natural gas industries - Compact flanged connections with IX seal ring

(ISO 27509:2020)

Erdöl- und Erdgasindustrie - Kompakte Flanschverbindungen mit IX Dichtungsring (ISO

27509:2020)

Industries du pétrole et du gaz naturel - Raccordements à brides compactes avec bague

d'étanchéité IX (ISO 27509:2020)
Ta slovenski standard je istoveten z: EN ISO 27509:2020
ICS:
23.040.60 Prirobnice, oglavki in spojni Flanges, couplings and joints
elementi
75.180.01 Oprema za industrijo nafte in Equipment for petroleum and
zemeljskega plina na splošno natural gas industries in
general
SIST EN ISO 27509:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 27509:2021
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SIST EN ISO 27509:2021
EN ISO 27509
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2020
EUROPÄISCHE NORM
ICS 23.040.60 Supersedes EN ISO 27509:2012
English Version
Petroleum and natural gas industries - Compact flanged
connections with IX seal ring (ISO 27509:2020)
Industries du pétrole et du gaz naturel - Erdöl- und Erdgasindustrie - Kompakte

Raccordements à brides compactes avec bague Flanschverbindungen mit IX Dichtungsring (ISO

d'étanchéité IX (ISO 27509:2020) 27509:2020)
This European Standard was approved by CEN on 12 February 2020.

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, 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

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 27509:2020 E

worldwide for CEN national Members.
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SIST EN ISO 27509:2021
EN ISO 27509:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 27509:2021
EN ISO 27509:2020 (E)
European foreword

This document (EN ISO 27509:2020) has been prepared by Technical Committee ISO/TC 67 "Materials,

equipment and offshore structures for petroleum, petrochemical and natural gas industries" in

collaboration with Technical Committee CEN/TC 12 “Materials, equipment and offshore structures for

petroleum, petrochemical and natural gas industries” the secretariat of which is held by NEN.

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 June 2021, and conflicting national standards shall be

withdrawn at the latest by June 2021.

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 ISO 27509:2012.

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, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 27509:2020 has been approved by CEN as EN ISO 27509:2020 without any modification.

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SIST EN ISO 27509:2021
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SIST EN ISO 27509:2021
INTERNATIONAL ISO
STANDARD 27509
Second edition
2020-12
Petroleum and natural gas
industries — Compact flanged
connections with IX seal ring
Industries du pétrole et du gaz naturel — Raccordements à brides
compactes avec bague d'étanchéité IX
Reference number
ISO 27509:2020(E)
ISO 2020
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SIST EN ISO 27509:2021
ISO 27509:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
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SIST EN ISO 27509:2021
ISO 27509:2020(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ..............................................................................................................................................................................................................................vii

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3  Terms and definitions ..................................................................................................................................................................................... 2

4 Abbreviations and symbols ....................................................................................................................................................................... 2

4.1 Abbreviated terms ............................................................................................................................................................................... 2

4.2 Symbols ......................................................................................................................................................................................................... 3

5 Design .............................................................................................................................................................................................................................. 5

5.1 General ........................................................................................................................................................................................................... 5

5.2 Design principles ................................................................................................................................................................................... 6

5.3 Assembly requirements .................................................................................................................................................................. 8

5.4 Standard components ....................................................................................................................................................................... 8

5.5 Units of measurements .................................................................................................................................................................... 9

5.6 Rounding ...................................................................................................................................................................................................... 9

5.7 Conformance with piping design codes ............................................................................................................................ 9

5.8 Conformance with this document .......................................................................................................................................10

6 Designation .............................................................................................................................................................................................................10

6.1 Designation of flanges ....................................................................................................................................................................10

6.2 Designation of seal rings .............................................................................................................................................................10

7 Materials ....................................................................................................................................................................................................................11

7.1 General ........................................................................................................................................................................................................11

7.2 Flange materials..................................................................................................................................................................................11

7.3 Bolting materials ................................................................................................................................................................................11

7.4 Seal ring materials ............................................................................................................................................................................12

8 Strength, pressure/temperature ratings and leak tightness ..............................................................................13

8.1 General ........................................................................................................................................................................................................13

8.2 Pressure/temperature ratings ...............................................................................................................................................13

8.3 Pressure testing and leak tightness ...................................................................................................................................14

9  Dimensions of flanges ..................................................................................................................................................................................14

9.1 General ........................................................................................................................................................................................................14

9.2 Weld neck dimensions ...................................................................................................................................................................15

9.3 Blind flange (BL) dimensions ..................................................................................................................................................23

9.4 Integral flange (IF) dimensions .............................................................................................................................................26

9.5 Rigid interface dimensions ........................................................................................................................................................37

9.6 Dimensions of paddle blanks (PB) and paddle spacers (PS) .......................................................................39

9.7 Handle and lifting lugs ...................................................................................................................................................................41

9.8 Dimensions of orifice spacers (OS) ....................................................................................................................................42

9.9 Dimensions of reducing threaded flanges ...................................................................................................................44

9.10 Auxiliary connections .....................................................................................................................................................................45

9.11 Flange tolerances ...............................................................................................................................................................................45

9.12 Surface finish .........................................................................................................................................................................................47

10  Marking of flanges............................................................................................................................................................................................48

10.1 Flanges other than integral flanges ....................................................................................................................................48

10.2 Manufacturer's name or trademark ..................................................................................................................................48

10.3 Nominal size ...........................................................................................................................................................................................48

10.4 Pressure class designation .........................................................................................................................................................48

10.5 Pipe dimensions ..................................................................................................................................................................................48

10.6 Material identification ...................................................................................................................................................................48

10.7 Identification of internally threaded flanges .............................................................................................................49

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SIST EN ISO 27509:2021
ISO 27509:2020(E)

10.8 Material traceability ........................................................................................................................................................................49

10.9 Marking examples .............................................................................................................................................................................49

10.10 Stamping ....................................................................................................................................................................................................49

11 Dimensions of seal rings ...........................................................................................................................................................................49

12 Manufacture, testing and inspection of IX seal rings ...................................................................................................53

13 Coating and colour coding .......................................................................................................................................................................53

14 Marking of seal rings .....................................................................................................................................................................................54

15 Quality management systems ..............................................................................................................................................................54

16 Bolt dimensions and masses .................................................................................................................................................................54

Annex A (normative) Pressure temperature ratings and load capacity .......................................................................55

Annex B (normative) Integral flange angle selection .......................................................................................................................59

Annex C (normative) Bolt dimensions and masses ............................................................................................................................70

Annex D (normative) Handling, installation, assembly and repair of flanges .......................................................77

Annex E (informative) Mass of flanges .............................................................................................................................................................90

Annex F (informative) Metric bolting ...........................................................................................................................................................100

Annex G (informative) Additional information on bibliographical references ................................................102

Bibliography .........................................................................................................................................................................................................................104

iv © ISO 2020 – All rights reserved
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SIST EN ISO 27509:2021
ISO 27509:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore

structures for petroleum, petrochemical and natural gas industries, Subcommittee SC 6, Processing

equipment and systems, in collaboration with the European Committee for Standardization (CEN)

Technical Committee CEN/TC 12, Materials, equipment and offshore structures for petroleum,

petrochemical and natural gas industries, in accordance with the Agreement on technical cooperation

between ISO and CEN (Vienna Agreement).

This second edition cancels and replaces the first edition (ISO 27509:2012), which has been technically

revised. It also incorporates the Technical Corrigendum ISO 27509:2012/Cor.1:2013. The main changes

compared to the previous edition are as follows:
— Annexes B and D (Annex E in previous edition) have become normative annexes;

— more stringent quality requirements regarding manufacture of products and assembly instructions

have been introduced. These include

a) ultrasonic testing of products in accordance with new requirements in ASME VIII div. 2 (in

Clause 7),

b) requirements to material strength and machining strictly in accordance with given tolerances

for IX seal rings (in Clause 12),

c) new and better coating requirements for IX seal rings (in Clause 13 and Annex D),

d) excluding use of IX seal rings to assist alignment by transfer of significant shear load during

assembly (in Annex D),

e) more comprehensive and detailed guidelines on the evaluation of damages to products and the

repair of such damages (in Annex D),

f) more comprehensive requirements to qualification of bolt tensioning procedures (in Annex D),

and
© ISO 2020 – All rights reserved v
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SIST EN ISO 27509:2021
ISO 27509:2020(E)

g) the elastoplastic deformation of flanges by first assembly has been better explained in 5.3

and in Annex D, in order to prevent unnecessary re-machining or rejection when flange bevel

angles have changed.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
vi © ISO 2020 – All rights reserved
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SIST EN ISO 27509:2021
ISO 27509:2020(E)
Introduction

This document, which is originally based on NORSOK L-005, has been developed to provide an

International Standard for compact flanged connections that constitutes an alternative to conventional

flanges as specified in ASME standards, European standards and other standards, with reduced mass

and smaller overall dimensions, as well as increased reliability in leak tightness by means of its inherent

design features and make up procedures. CFCs can also provide an alternative to other types of clamp

and hub type mechanical connectors.

The use of load carrying sealing elements, traditionally referred to as "gaskets", does not conform with

the requirements of this document.

This document has been developed for use in process piping systems, which are designed in accordance

with codes for pressure piping, e.g. ASME B31.3. See 5.7 for more details.

The flange designs have been selected to achieve a minimum safety factor of 2,0 when subjected to a

design pressure equal to ASME B16.5 pressure temperature ratings within the temperature limits of

this document.

The main body of this document contains all necessary information on how to manufacture and supply

flange and seal ring materials, such as
— flange dimensions and material requirements,
— seal ring dimensions and material requirements,
— bolting dimensions and material requirements,
— requirements to tolerances and surface finish, and
— requirements to designation and marking of finished products.
Annexes A, B, C and D cover the following topics:
— structural capacity equations for flange assemblies;

— how to apply the flanges to special geometries of valves and equipment nozzles;

— bolt dimensions and masses;

— installation and assembly instructions, and guidelines on how to repair damage and irregularities

on sealing surfaces.
Annexes E, F and G cover the following topics:
— masses of all standard components;
— suitable dimensions of alternative metric bolting;
— additional information on bibliographical references.
In this document, the following verbal forms are used:
— "shall" indicates a requirement;
— "should" indicates a recommendation;
— "may" indicates a permission;
— "can" indicates a possibility or a capability.
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SIST EN ISO 27509:2021
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SIST EN ISO 27509:2021
INTERNATIONAL STANDARD ISO 27509:2020(E)
Petroleum and natural gas industries — Compact flanged
connections with IX seal ring
1 Scope

This document specifies detailed manufacturing requirements for circular steel and nickel alloy

compact flanged connections and associated seal rings, for designated pressures and temperatures

in class designations CL 150 (PN 20) to CL 1500 (PN 260) for nominal sizes from DN 15 (NPS ½) to

DN 1200 (NPS 48), and for CL 2500 (PN 420) for nominal sizes from DN 15 (NPS ½) to DN 600 (NPS 24).

NOTE NPS is expressed in accordance with ASME B36.10M and ASME B36.19M.

This document is applicable to welding neck flanges, blind flanges, paddle spacers and spacer blinds

(paddle blanks), valve/equipment integral flanges, orifice spacers, reducing threaded flanges and rigid

interfaces for use in process piping for the petroleum, petrochemical and natural gas industries.

This document is applicable within a temperature range from −196 °C to +250 °C.
This document is not applicable for external pressure.
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.

ISO 2768-1, General tolerances — Part 1: Tolerances for linear and angular dimensions without individual

tolerance indications

ISO 4287, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions

and surface texture parameters

ISO 4288, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Rules and

procedures for the assessment of surface texture

ISO 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-

section conduits running full — Part 1: General principles and requirements

ISO 5167-2:2003, Measurement of fluid flow by means of pressure differential devices inserted in circular

cross-section conduits running full — Part 2: Orifice plates

ISO 14313, Petroleum and natural gas industries — Pipeline transportation systems — Pipeline valves

ISO 80000-1:2009, Quantities and units — Part 1: General

EN 1591-4, Flanges and their joints — Part 4: Qualification of personnel competency in the assembly of the

bolted connections of critical service pressurized systems

EN 1779, Non-destructive testing — Leak testing — Criteria for method and technique selection

ASME B16.5, Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard

ASME B16.34, Valves — Flanged, Threaded and Welding End
ASME B1.20.1, Pipe Threads, General Purpose (Inch)
ASME B31.3:2018, Process Piping
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SIST EN ISO 27509:2021
ISO 27509:2020(E)

ASTM B568, Standard Test Method for Measurement of Coating Thickness by X-Ray Spectrometry

ASTM B571, Standard Practice for Qualitative Adhesion Testing of Metallic Coatings

ASME VIII Div. 2: Boiler and Pressure Vessel Code — Alternative Rules
3  Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
class
pressure class in accordance with specific values

Note 1 to entry: The values shall be in accordance with ASME B16.5 and ASME B16.34

3.2
compact flanged con
...