Industrial valves - Metallic butterfly valves

This European Standard specifies minimum general requirements for butterfly valves having metallic bodies for use with all type of pipe end connections (e.g. wafer, lug, flange, butt welding) and used for isolating, regulating or control applications.
The PN and Class ranges are:
-   PN 2,5; PN 6; PN 10; PN 16; PN 25; PN 40; PN 63; PN 100; PN 160;
-   Class 150; Class 300; Class 600; Class 900.
The size range is:
-   DN 20; DN 25; DN 32; DN 40; DN 50; DN 65; DN 80; DN 100; DN 125; DN 150; DN 200; DN 250; DN 300; DN 350; DN 400; DN 450; DN 500; DN 600; DN 700; DN 750; DN 800; DN 900; DN 1 000; DN 1 050; DN 1 100; DN 1 200; DN 1 400; DN 1 500; DN 1 600; DN 1 800; DN 2 000; DN 2 200; DN 2 400; DN 2 600; DN 2 800; DN 3 000; DN 3 200; DN 3 400; DN 3 600; DN 3 800; DN 4 000.
DN 750 and DN 1 050 are used only for Class 150 and Class 300.
Intermediate DNs are allowed upon agreement between manufacturer and customer.
For valves subject to European legislation on pressure equipment, EN 16668 applies together with this European Standard.
For industrial process control valves, EN 1349 and EN 60534 2 1 apply together with this European Standard.
For water supply application, EN 1074 1 and EN 1074 2 apply together with this European Standard.
NOTE 1   Butterfly valves for water supply application do not comply with Annex ZA and are not CE marked because they are excluded from the pressure equipment European legislation.
NOTE 2   The range of DN, applicable to each PN, for wafer and wafer lug valve types is as given in the appropriate part of EN 1092 for Type 11 flanges for the applicable material. The range of DN, applicable to each PN, for flanged valve types is as given in the appropriate part of EN 1092 for Type 21 flanges for the applicable material.
The correspondence between DN and NPS is given for information in Annex D.

Industriearmaturen - Metallische Klappen

Dieses Dokument legt allgemeine Mindestanforderungen an Klappen mit metallischem Gehäuse fest, die für den Einbau in alle Typen von Rohrendverbindungen (Scheiben, Ösen, Flanschen, Anschweißenden) bestimmt sind und zum Absperren, Stellen oder Regeln benutzt werden.
Der PN- und Classbereich umfasst:
   PN 2,5; PN 6; PN 10; PN 16; PN 25; PN 40; PN 63; PN 100; PN 160;
   Class 150; Class 300; Class 600; Class 900.
Der Größenbereich umfasst:
   DN 20; DN 25; DN 32; DN 40; DN 50; DN 65; DN 80; DN 100; DN 125; DN 150; DN 200; DN 250; DN 300; DN 350; DN 400; DN 450; DN 500; DN 600; DN 700; DN 750; DN 800; DN 900; DN 1 000; DN 1 050; DN 1 100; DN 1 200; DN 1 400; DN 1 500; DN 1 600; DN 1 800; DN 2 000; DN 2 200; DN 2 400; DN 2 600; DN 2 800; DN 3 000; DN 3 200; DN 3 400; DN 3 600; DN 3 800; DN 4 000.
DN 750 und DN 1 050 werden nur für Class 150 und Class 300 verwendet.
Zwischen-Nennweiten sind zulässig bei Vereinbarung zwischen Hersteller und Kunde.
Dieses Dokument gilt für Klappen aus Metall, die für alle industriellen Anwendungsfälle verwendet werden. Zusätzliche Anforderungen der jeweiligen Anwendungsnormen können für Klappen gelten, die für spezifischere Anwendungen verwendet werden (z. B. Wasserwirtschaft, chemische und petrochemische Verfahrensindustrie, Gasverteilung).
ANMERKUNG 1   Industrielle Anwendungsfälle schließen Anwendungen in der Wasserversorgung mit ein.
Für Armaturen gemäß der Europäischen Gesetzgebung gilt EN 16668 zusammen mit diesem Dokument.
Für Regelarmaturen für die Prozessregelung gelten EN 1349 und EN 60534 2 1 zusammen mit diesem Dokument.
Bei Anwendungen in der Wasserversorgung gelten EN 1074 1 und EN 1074 2 zusammen mit diesem Dokument.
ANMERKUNG 2   Klappen für die Anwendung in der Wasserversorgung entsprechen nicht Anhang ZA und haben keine CE-Kennzeichnung, weil sie von der Europäischen Richtlinie über Druckgeräte ausgeschlossen sind.
ANMERKUNG 3   Der Nennweitenbereich für Einklemmklappen und Klappen mit Flanschaugen, der auf jede PN anwendbar ist, wird im entsprechenden Teil der EN 1092 für Flansche des Typs 11 für den anzuwendenden Werkstoff angegeben. Der Nennweitenbereich für Klappen mit Flansch, der auf jede PN anwendbar ist, wird im entsprechenden Teil der EN 1092 für Flansche des Typs 21 für den anzuwendenden Werkstoff angegeben.
Die Zuordnung zwischen DN und NPS ist als Information in Anhang D angegeben.

Robinetterie industrielle - Robinets métalliques à papillon

Le présent document spécifie les exigences minimales générales relatives aux robinets à papillon à corps métallique destinés à être utilisés avec tous les types de raccordements d’extrémités de tuyauterie (par exemple à insérer, à oreilles, à brides, à souder en bout) et utilisés pour des applications de sectionnement, réglage ou régulation.
Les gammes de PN et de Class sont:
   PN 2,5; PN 6; PN 10; PN 16; PN 25; PN 40; PN 63; PN 100; PN 160;
   Class 150; Class 300; Class 600; Class 900.
La gamme de dimension est:
   DN 20; DN 25; DN 32; DN 40; DN 50; DN 65; DN 80; DN 100; DN 125; DN 150; DN 200; DN 250; DN 300; DN 350; DN 400; DN 450; DN 500; DN 600; DN 700; DN 750; DN 800; DN 900; DN 1 000; DN 1 100; DN 1 200; DN 1 400; DN 1 500; DN 1 600; DN 1 800; DN 2 000; DN 2 200; DN 2 400; DN 2 600; DN 2 800; DN 3 000; DN 3 200; DN 3 400; DN 3 600; DN 3 800; DN 4 000.
Le DN 750 et le DN 1 050 sont utilisés uniquement pour les Class 150 et Class 300.
Des DNs intermédiaires sont autorisés soumis à accord entre fabricant et client.
Le présent document s'applique aux robinets métalliques à papillon utilisés dans toutes les applications industrielles. Des exigences supplémentaires données dans les normes d'application pertinentes peuvent s'appliquer aux robinets à papillon utilisés dans des applications plus spécifiques (par exemple dans le secteur de l'eau, dans l'industrie de procédés chimiques et pétrochimiques, dans l'industrie de distribution du gaz).
NOTE 1   Les applications industrielles couvre les applications pour l'eau.
Pour les appareils de robinetterie soumis à la règlementation européenne sur les équipements sous pression, l’EN 16668 s'applique en complément du présent document.
Pour les robinets de régulation des processus industriels, voir l’EN 1349 et l’EN 60534-2-1 qui s'appliquent en complément du présent document.
Pour les applications d'approvisionnement en eau, l'EN 1074-1 et l'EN 1074-2 s'appliquent en complément du présent document.
NOTE 2   Les robinets à papillon pour des applications d'approvisionnement en eau ne respectent pas l'Annexe ZA et ne sont pas marqués CE parce qu'ils sont exclus de la règlementation européenne sur les équipements sous pression.
NOTE 3   La gamme de DN, applicable à chaque PN, pour les types d'appareil de robinetterie à insérer et à oreilles, est telle que donnée dans la partie appropriée de l'EN 1092 pour les brides de type 11 pour le matériau approprié. La gamme de DN, applicable à chaque PN, pour les types d'appareil de robinetterie à brides, est telle que donnée dans la partie appropriée de l'EN 1092 pour les brides de type 21 pour le matériau approprié.
La correspondance entre DN et NPS est fournie pour information en Annexe D.

Industrijski ventili - Kovinske zaporne lopute

General Information

Status
Not Published
Public Enquiry End Date
19-Jan-2020
Current Stage
4020 - Public enquire (PE) (Adopted Project)
Start Date
07-Nov-2019
Due Date
26-Mar-2020
Completion Date
11-Feb-2020

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SLOVENSKI STANDARD
oSIST prEN 593:2020
01-januar-2020
Industrijski ventili - Kovinske zaporne lopute
Industrial valves - Metallic butterfly valves
Industriearmaturen - Metallische Klappen
Robinetterie industrielle - Robinets métalliques à papillon
Ta slovenski standard je istoveten z: prEN 593
ICS:
23.060.30 Zapirni ventili (zasuni) Gate valves
oSIST prEN 593:2020 en,fr,de

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

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oSIST prEN 593:2020
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oSIST prEN 593:2020
DRAFT
EUROPEAN STANDARD
prEN 593
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2019
ICS Will supersede EN 593:2017
English Version
Industrial valves - Metallic butterfly valves

Robinetterie industrielle - Robinets métalliques à Industriearmaturen - Metallische Klappen

papillon

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 69.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 593:2019 E

worldwide for CEN national Members.
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oSIST prEN 593:2020
prEN 593:2019 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms and definitions ................................................................................................................................... 8

4 Design requirements ..................................................................................................................................... 9

4.1 General ................................................................................................................................................................ 9

4.2 Shell ................................................................................................................................................................... 11

4.3 Body .................................................................................................................................................................. 11

4.3.1 General ............................................................................................................................................................. 11

4.3.2 End connections ............................................................................................................................................ 12

4.4 Obturator (disc) ............................................................................................................................................ 14

4.5 Seat seal ........................................................................................................................................................... 14

4.6 Driving shaft ................................................................................................................................................... 14

4.7 Shaft seal ......................................................................................................................................................... 15

4.8 Optional design features ........................................................................................................................... 15

4.9 Materials .......................................................................................................................................................... 16

4.9.1 Shell materials ............................................................................................................................................... 16

4.9.2 Trim materials .............................................................................................................................................. 16

4.9.3 Corrosion protection................................................................................................................................... 17

4.10 Pressure/temperature ratings ................................................................................................................ 17

4.11 Dimensions and tolerances ...................................................................................................................... 18

4.11.1 Face-to-face and end-to-end dimensions ............................................................................................ 18

4.11.2 Flange body ends .......................................................................................................................................... 18

4.11.3 Wafer bodies .................................................................................................................................................. 18

4.11.4 Butt welding ends ........................................................................................................................................ 18

4.12 Operation ........................................................................................................................................................ 18

4.12.1 Operational capability ................................................................................................................................ 18

4.12.2 Operating device .......................................................................................................................................... 18

4.13 Permanent joining ....................................................................................................................................... 20

4.13.1 Welding ............................................................................................................................................................ 20

4.13.2 Non-destructive tests .................................................................................................................................. 20

4.13.3 Heat treatment .............................................................................................................................................. 20

4.14 Functional characteristics and performances ................................................................................... 20

4.14.1 Application ..................................................................................................................................................... 20

4.14.2 Design strength ............................................................................................................................................. 20

4.14.3 Flow characteristics .................................................................................................................................... 21

4.15 Requirements for pressure equipment European legislation ..................................................... 21

5 Final assessment .......................................................................................................................................... 22

5.1 General ............................................................................................................................................................. 22

5.2 Additional tests ............................................................................................................................................. 22

5.2.1 Shell tightness ............................................................................................................................................... 22

5.2.2 Seat tightness ................................................................................................................................................. 22

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5.2.3 Optional tests ................................................................................................................................................. 23

5.3 Final assessment for pressure equipment European legislation ................................................ 23

6 Designation ..................................................................................................................................................... 23

7 Marking and preparation for storage and transportation ............................................................ 23

7.1 Marking ............................................................................................................................................................ 23

7.1.1 Mandatory marking ..................................................................................................................................... 23

7.1.2 Supplementary marking ............................................................................................................................ 23

7.2 Preparation for storage and transportation ....................................................................................... 24

8 Documentation .............................................................................................................................................. 24

8.1 General ............................................................................................................................................................. 24

8.2 Documentation for pressure equipment European legislation ................................................... 24

Annex A (informative) Information to be supplied by the customer ...................................................... 25

Annex B (informative) Trim material list ......................................................................................................... 27

Annex C (informative) Environmental corrosion protection .................................................................... 28

Annex D (informative) Correspondence between DN and NPS ................................................................. 29

Annex E (informative) Example for valve shaft calculation ....................................................................... 30

E.1 General ............................................................................................................................................................. 30

E.2 Calculation....................................................................................................................................................... 31

E.2.1 Shear stress ..................................................................................................................................................... 31

E.2.2 Combined shear stress (at valve bearing) (section 2-2)................................................................. 31

E.2.3 Combined tensile stress at seating due to torsion and bending (section 2-2) ....................... 31

E.2.4 Shear stress at reduced area (sections 1-1, 3-3, 4-4) ....................................................................... 32

E.3 Examples of influence of flow velocity/hydrodynamic torques for shaft sizing ................... 32

Annex ZA (informative) Relationship between this European Standard and the essential

requirements of Directive 2014/68/EU (Pressure Equipment Directive) aimed to be

covered ............................................................................................................................................................. 35

Bibliography ................................................................................................................................................................. 37

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oSIST prEN 593:2020
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European foreword

This document (prEN 593:2019) has been prepared by Technical Committee CEN/TC 69 “Industrial

valves”, the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 593:2017.

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, see informative Annex ZA, which is an integral part of this document.

The main technical changes compared to the previous edition are:
a) inclusion of an introduction to explain the reason of this revision;

b) the inclusion of a sentence in the scope to clarify that this document applies to all industrial

applications;

c) addition of new 4.15 and 5.3 on the design requirements and final assessment for pressure

equipment European legislation;
d) addition of a new Clause 8 for the documentation;
e) update of Annex ZA.
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Introduction

This document was revised to refer to EN 16668:2016+A1:2018 for all requirements related to pressure

equipment European legislation.

Annex ZA of this document is identical to Annex ZA of EN 16668:2016+A1:2018, for those requirements

applicable to butterfly valves.
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1 Scope

This document specifies minimum general requirements for butterfly valves having metallic bodies for

use with all type of pipe end connections (e.g. wafer, lug, flange, butt welding) and used for isolating,

regulating or control applications.
The PN and Class ranges are:
— PN 2,5; PN 6; PN 10; PN 16; PN 25; PN 40; PN 63; PN 100; PN 160;
— Class 150; Class 300; Class 600; Class 900.
The size range is:

— DN 20; DN 25; DN 32; DN 40; DN 50; DN 65; DN 80; DN 100; DN 125; DN 150; DN 200; DN 250;

DN 300; DN 350; DN 400; DN 450; DN 500; DN 600; DN 700; DN 750; DN 800; DN 900; DN 1 000;

DN 1 050; DN 1 100; DN 1 200; DN 1 400; DN 1 500; DN 1 600; DN 1 800; DN 2 000; DN 2 200;

DN 2 400; DN 2 600; DN 2 800; DN 3 000; DN 3 200; DN 3 400; DN 3 600; DN 3 800; DN 4 000.

DN 750 and DN 1 050 are used only for Class 150 and Class 300.
Intermediate DNs are allowed upon agreement between manufacturer and customer.

This document applies to metallic butterfly valves used for all industrial applications. Additional

requirements given in the relevant application standards may apply to butterfly valves used for more

specific applications (e.g. for the water industry, the chemical and petrochemical process industry, the

gas distribution industry).
NOTE 1 Industrial applications cover water applications.

For valves subject to European legislation on pressure equipment, EN 16668 applies together with this

document.

For industrial process control valves, EN 1349 and EN 60534-2-1 apply together with this document.

For water supply application, EN 1074-1 and EN 1074-2 apply together with this document.

NOTE 2 Butterfly valves for water supply application do not comply with Annex ZA and are not CE marked

because they are excluded from the pressure equipment European legislation.

NOTE 3 The range of DN, applicable to each PN, for wafer and wafer lug valve types is as given in the appropriate

part of EN 1092 for Type 11 flanges for the applicable material. The range of DN, applicable to each PN, for flanged

valve types is as given in the appropriate part of EN 1092 for Type 21 flanges for the applicable material.

The correspondence between DN and NPS is given for information in Annex D.
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 19:2016, Industrial valves - Marking of metallic valves

EN 558:2017, Industrial valves - Face-to-face and centre-to-face dimensions of metal valves for use in

flanged pipe systems - PN and Class designated valves
EN 736-1:2018, Valves - Terminology - Part 1: Definition of types of valves
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EN 736-2:2016, Valves - Terminology - Part 2: Definition of components of valves
EN 736-3:2008, Valves - Terminology - Part 3: Definition of terms

EN 1074-2:2000, Valves for water supply - Fitness for purpose requirements and appropriate verification

tests - Part 2: Isolating valves

EN 1092-1:2018, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, PN

designated - Part 1: Steel flanges

EN 1092-2:1997, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, PN

designated - Part 2: Cast iron flanges

EN 1092-3:2003, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, PN

designated - Part 3: Copper alloy flanges

EN 1092-4:2002, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, PN

designated - Part 4: Aluminium alloy flanges

EN 1267:2012, Industrial valves - Test of flow resistance using water as test fluid

EN 1759-1:2004, Flanges and their joint - Circular flanges for pipes, valves, fittings and accessories, Class

designated - Part 1: Steel flanges, NPS 1/2 to 24

EN 1759-3:2003, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, Class

designated - Part 3: Copper alloy flanges

EN 1759-4:2003, Flanges and their joint - Circular flanges for pipes, valves, fittings and accessories, class

designated - Part 4: Aluminium alloy flanges

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, 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 12570:2000, Industrial valves - Method for sizing the operating element
EN 12627:2017, Industrial valves — Butt welding ends for steel valves

EN 12982:2009, Industrial valves - End-to-end and centre-to-end dimensions for butt welding end valves

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EN 16668:2016+A1:2018, Industrial valves - Requirements and testing for metallic valves as pressure

accessories

EN 60534-2-3:2016, Industrial-process control valves - Part 2-3: Flow capacity - Test procedures

EN ISO 1043-1:2011, Plastics - Symbols and abbreviated terms - Part 1: Basic polymers and their special

characteristics (ISO 1043-1:2011)

EN ISO 5211:2017, Industrial valves - Part-turn actuator attachments (ISO 5211:2017)

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 10497:2010, Testing of valves - Fire type-testing requirements (ISO 10497:2010)

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 15607:2003, Specification and qualification of welding procedures for metallic materials - General

rules (ISO 15607:2003)
ISO 1629:2013, Rubber and latices — Nomenclature
3 Terms and definitions

For the purposes of this document the terms and definitions given in EN 736-1, EN 736-2, EN 736-3,

EN 16668 and the following 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
maximum allowable pressure

maximum pressure for which the pressure equipment is designed as specified by the manufacturer

[SOURCE: EN 764-1:2015+A1:2016, 3.2.87]
3.2
maximum allowable temperature
max

maximum temperature for which the pressure equipment is designed as specified by the manufacturer

[SOURCE: EN 764-1:2015+A1:2016, 3.1.9]
3.3
end of line service

condition that occurs when the downstream side of the valve is opened to atmosphere

3.4
driving shaft

shaft connected to the obturator to operate the valve in the case of a multi-shaft valve

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3.5
trim
parts in contact with the fluid
3.6
eccentration
offset

deviation of the operating axes in respect to the reference axes of the pipe/valve

4 Design requirements
4.1 General

The valve shall be of either concentric design (see Figure 1) or eccentric design (see Figures 2 to 4). The

offset may be single, double or triple.
A first offset is an axial offset of the shaft to the seat contact.

A second offset is an offset from the pipe centreline to the valve obturator centerline.

In the triple offset design, the seat and seal contact surface centreline is inclined in respect to the pipe /

valve centreline, whatever the form of the contact.
Figure 1 — Concentric design
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Key
e eccentricity 1
Figure 2 — Single eccentric design (single offset)
Key
e1 eccentricity 1
e eccentricity 2
Figure 3 — Double eccentric design (double offset)
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Key
e eccentricity 1
e eccentricity 2
e3 eccentricity 3
Figure 4 — Triple eccentric design (triple offset)
The design details are the responsibility of the manufacturer.
The butterfly valve may be:
— soft sealing; or
— metallic sealing.

NOTE The choice of design and material depends on the design working temperature and the physical and

chemical characteristics of the fluid.
4.2 Shell
The shell is the combination of all pressure retaining part:
— the body,
— the retaining elements of the shaft seal ring or the stuffing box;
— the cover and the cover bolting if any,
— if used as end of line, the obturator and the shaft.
4.3 Body
4.3.1 General

Flanges of double flanged valves and single flange wafer valves shall have bolt holes in accordance with

the relevant standard as specified in 4.11.2. Threaded holes can be provided where the design of the valve

precludes through flange bolting.
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Flangeless wafer valves (see Figure 6) are intended for clamping between pipe flanges using through

bolting. The shape of wafer valve bodies shall be such that centring of the valves within the appropriate

flange bolt circle is ensured. Where through bolting is not practicable due to the valve design, e.g. close

to shaft passages, threaded holes can be provided for individual bolting.

Lugged or single flange wafer valves (see Figure 7) are supplied with threaded or through holes for

installation between two flanged components or at the end of a pipeline (i.e. end of line service or

downstream dismantling).

Threaded holes shall allow full thread engagement to a depth at least equal to the nominal bolt diameter

and at least 0,67 of the bolt diameter when the bolt hole is adjacent to the valve shaft.

For Class designed valves threaded body flange holes for bolts 1 inch or less in diameter shall be drilled

and tapped in accordance with UNC coarse thread series, Class 2B (see ASME B1.1). For bolts 1 1/8 inches

or more in diameter, such holes shall be drilled and tapped in accordance with UN 8 thread series,

Class 2B (see ASME B1.1). Other threads shall be specified.

The manufacturer's literature shall be consulted to determine if through bolting or/and end of line

assembly is possible. Any limitation regarding end of line service condition shall be indicated.

Elastomeric or plastic linings and liners can be extended over the flange faces of the body to form a gasket

for the flange.
4.3.2 End connections
End connections shall be either one of the following.

a) Double flanged butterfly valve: butterfly valve having double flanged body ends for connection to

flanges of adjacent components by individual bolting (see Figure 5).

b) Wafer butterfly valve: butterfly valve intended for clamping between flanges of adjacent

components.
NOTE Different body shapes are possible: see Figures 6 and 7 a) to g).

c) Butt welding end butterfly valve: butterfly valve intended for butt welding into a pipeline

(see Figure 8).

d) Mechanical connection for loose flange connection: butterfly valve with one or both loose flanges for

compensation of piping alignment (see Figure 9). The loose flange shall be pullout proof.

e) Mechanical connection: butterfly valve with one or two interfaces for connection of piping

(see Figures 10 and 11). The connection shall be spigot end or socket end. Requirements and test

methods of mechanical joints are described in EN 545. The connection may be pullout proof.

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Figure 5 — Double flanged body Figure 6 — Flangeless wafer body
a) Valve with central lugs b) Central single flange valve

c) Valve with lugs with internally threaded holes d) Single-flange valve with internally threaded

holes
e) Valve with lugs with drilled holes f) Single-flange valve with drilled holes
g) Valve with U-section
Figure 7 — Wafer valve bodies bolting configurations
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Figure 8 — Butt welding end body

Figure 9 — Loose-flange design Figure 10 — Socket-socket Figure 11 — Spigot-socket

design design
4.4 Obturator (disc)
The obturator (often named disc) can be with or without seal.

The valve manufacturer's technical documentation shall specify all necessary dimensions showing the

protrusion of the obturator in the open position beyond the faces of the valve.
4.5 Seat seal

In its technical documentation, the valve manufacturer shall specify whether the seat seal

— is a body liner by design, or
— is located in the body or on the obturator.

The liner/lining may have additional functions, including sealing the driving shaft and flange.

The valve documentation shall specify the seat materials and if the sealing element is replaceable or not.

4.6 Driving shaft

The external end of the driving shaft shall indicate the orientation of the obturator.

The choice of the shaft material depends on the design working temperature and the physical and

chemical characteristics of the fluid.

Valve shafts shall be sized for the maximum design torque at seating operation and at obturator position

of highest combined dynamic and bearing torques with a safety factor. The value of this safety factor

depends on the calculation method of the driving shaft. An example of calculation method is given in

Annex E.
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