oSIST prEN 1759-3:2022

SLOVENSKI STANDARD
oSIST prEN 1759-3:2022
01-januar-2022
Prirobnice in prirobnični spoji - Okrogle prirobnice za cevi, ventile, fitinge in pribor
z oznako Class - 3. del: Prirobnice iz bakrovih zlitin
Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories,
Class designated - Part 3: Copper alloy flanges
Flansche und ihre Verbindungen - Runde Flansche für Rohre, Armaturen, Formstücke
und Zubehörteile, nach Class bezeichnet - Teil 3: Flansche aus Kupferlegierungen
Brides et leurs assemblages - Brides circulaires pour tubes, appareils de robinetterie,
raccords et accessoires, désignées Class - Partie 3 : Brides en alliages de cuivre
Ta slovenski standard je istoveten z: prEN 1759-3
ICS:
23.040.60 Prirobnice, oglavki in spojni Flanges, couplings and joints
elementi
77.150.30 Bakreni izdelki Copper products
oSIST prEN 1759-3:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 1759-3:2022


DRAFT
EUROPEAN STANDARD
prEN 1759-3
NORME EUROPÉENNE

EUROPÄISCHE NORM

December 2021
ICS 23.040.60 Will supersede EN 1759-3:2003
English Version

Flanges and their joints - Circular flanges for pipes, valves,
fittings and accessories, Class designated - Part 3: Copper
alloy flanges
Brides et leurs assemblages - Brides circulaires pour Flansche und ihre Verbindungen - Runde Flansche für
tubes, appareils de robinetterie, raccords et Rohre, Armaturen, Formstücke und Zubehörteile, nach
accessoires, désignées Class - Partie 3 : Brides en Class bezeichnet - Teil 3: Flansche aus
alliages de cuivre Kupferlegierungen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 74.

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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1759-3:2021 E
worldwide for CEN national Members.

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Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 8
3 Terms and definitions . 8
4 Designation . 9
4.1 General. 9
4.2 Standard designation . 9
4.3 Information to be supplied by the equipment manufacturer . 10
5 General requirements . 10
5.1 Materials . 10
5.2 Repairs . 10
5.3 Bolting . 11
5.4 Gaskets . 11
5.5 Pressure/temperature (p/T) ratings. 11
5.5.1 General. 11
5.5.2 p/T ratings of flanged joints . 11
5.6 Dimensions. 12
5.6.1 Flanges . 12
5.6.2 Bolt holes . 12
5.7 Flange facings . 12
5.7.1 Types of facings . 12
5.7.2 Jointing face finish . 12
5.7.3 Rims . 13
5.7.4 Collars and loose flanges . 13
5.8 Spot facing or back facing . 13
5.9 Tolerances . 13
5.10 Marking . 13
5.10.1 Other than type 21 flanges . 13
5.10.2 Method of marking . 14
5.10.3 Omission of markings . 14
5.10.4 Declaration of compliance . 14
Annex A (informative) Information to be supplied by the equipment manufacturer . 29
Annex B (informative) Application and installation . 30
Annex C (informative) Use of metric bolting in lieu of imperial bolting . 31
C.1 General. 31
C.2 Gaskets . 31
C.3 Comparable nominal bolt sizes . 31
C.4 Imperial/metric bolt comparisons . 31
Annex D (informative) Approximate masses of flanges and collars . 33
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Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/68/EU aimed to be covered . 38
Bibliography . 40

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European foreword
This document (prEN 1759-3:2021) has been prepared by Technical Committee CEN/TC 74 “Flanges
and their joints”, the secretariat of which is held by DIN.
This document is currently submitted to CEN Enquiry.
This document will supersede EN 1759-3:2003 and EN 1759-3:2003/AC:2004.
The main changes compared to EN 1759-3:2003 and EN 1759-3:2003/AC:2004 are:
— update of Annex ZA.
This document has been prepared under a standardization request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of
1
EU Directive(s) .
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
document.
EN 1759 consists of the following parts:
— Flanges and their joint — Circular flanges for pipes, valves, fittings and accessories, Class
designated — Part 1: Steel flanges (draft stage;
— Flanges and their joint — Circular flanges for pipes, valves, fittings and accessories, Class
designated — Part 3: Copper alloy flanges (draft stage);
— Flanges and their joint — Circular flanges for pipes, valves, fittings and accessories, Class
designated — Part 4: Aluminium alloy flanges (draft stage).
The Annexes A, B, C, D and ZA are informative.


1 Directive 97/23 EC of the European Parliament and of the Council of 29 May 1997 on the approximation of the
Laws of the Member States concerning pressure equipment; OIEC L 181.
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Introduction
This document is related, but not identical, to ISO 7005-3 in respect of flanges having designations
Class 150 and Class 300. Outside diameters and mating dimensions are in accordance with ANSI B16.24.
Information on the use of metric bolting in lieu of imperial bolting which can be used with these flanges
is given in an informative annex.
The mating dimensions of the flanges of this standard are compatible with Class designated flanges of
other materials in accordance with the other parts of EN 1759.

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1 Scope
This document specifies requirements for circular copper alloy flanges and copper alloy collars
combined with loose steel plate flanges in Class designations Class 150 and Class 300 and nominal sizes
from DN 10 to DN 900 (NPS 1/2 to NPS 36) in the types shown in Table 1.
This document also specifies dimensions and tolerances, materials and their associated
pressure/temperature (p/T) ratings, flange facings and related surface finish, weld repairs and marking
together with information on bolting, gaskets, application and installation and approximate flange
masses.
The flanges specified, with the exception of integral (type 21) flanges, are for attachment to copper or
copper alloy tubes in accordance with EN 12449.
NOTE 1 The size of copper and copper alloy tubes is designated by reference to the outside diameter in
millimetres.
NOTE 2 See also Annex B.
NOTE 3 Non-gasketed pipe joints are outside the scope of this document.
Table 1 — Types of flanges and collars
Type No. Description
01 Plate flange in copper alloy for brazing or welding
04 Loose plate flange in steel with a weld-neck collar (type 34) in copper alloy, for welding
05 Blank flange in copper alloy
05C Blank flange in steel clad with a copper alloy jointing face
07 Loose plate flange in steel with a slip-on collar (type 37) in copper alloy, for soft soldering,
brazing or welding
11 Weld-neck flange in copper alloy for welding
12 Hubbed slip-on flange in copper alloy, for soft soldering, brazing or welding
14 Hubbed slip-on flange in copper alloy supplied with tube stops, for soft soldering, brazing
or welding
21 Integral flange in copper alloy as part of some other equipment or component
34 Weld-neck collar in copper alloy
37 Slip-on collar in copper alloy

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Type 01 Type 04, 34 Type 05, 05C
Plate flange in copper alloy for Loose plate flange in steel with a 05 Blank flange in copper alloy
brazing or welding weld-neck collar(type 34) in
05C Blank flange in steel clad
copper alloy, for welding
with a copper alloy jointing face

Type 07, 37 Type 11 Type 12
Loose plate flange in steel with a Weld-neck flange in copper alloy Hubbed slip- on flange in copper
slip-on collar (type 37) in copper for welding alloy, for soft soldering, brazing
alloy, for soft soldering, brazing or welding
or welding


Type 14 Type 21
Hubbed slip-on flange in copper Integral flange in copper alloy as
alloy supplied with tube stops, part of some other equipment or
for soft soldering, brazing or component
welding
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Key
Steel component

Copper alloy component

Figure 1 — Types of flanges and collars
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 1652, Copper and copper alloys — Plate, sheet, strip and circles for general purposes
EN 10028-2, Flat products made of steels for pressure purposes — Part 2: Non-alloy and alloy steels with
specified elevated temperature properties
EN 10222-2, Steel forgings for pressure purposes — Part 2: Ferritic and martensitic steels with specified
elevated temperature properties
EN 12420, Copper and copper alloys — Forgings
EN 12449, Copper and copper alloys — Seamless round tubes for general purposes
EN ISO 887, Plain washers for metric bolts, screws and nuts for general purposes — General plan
(ISO 887:2000)
EN ISO 4287, Geometrical Product Specification (GPS) — Surface texture: Profile method — Terms,
definitions and surface texture parameters (ISO 4287:1997)
EN ISO 6708:1995, Pipework components — Definition and selection of DN (nominal size)
(ISO 6708:1995)
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 https://www.electropedia.org/
3.1
Class
alphanumeric designation used for reference purposes related to a combination of mechanical and
dimensional characteristics of a component of a pipework system. It comprises the word Class followed
by a dimensionless whole number
Note 1 to entry: The number following the word Class does not represent a measurable value and should not be
used for calculation purposes except where specified in the relevant standard.
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Note 2 to entry: The designation Class is not meaningful unless it is related to the relevant component standard
number.
Note 3 to entry: It is intended that all components with the same Class and NPS (see below) designations have the
same mating dimensions for compatible flange types.
3.2
DN
see EN ISO 6708:1995
3.3
NPS
alphanumeric designation of size for components of a pipework system, which is used for reference
purposes. It comprises, for the purpose of Class designated flanges according to this document, the
letters NPS followed by a dimensionless number which is indirectly related to the physical size of the
bore or outside diameter of the end connections
Note 1 to entry: The number following the letters NPS does not represent a measurable value and should not be
used for calculation purposes except where specified in the relevant standard. See EN ISO 6708.
4 Designation
4.1 General
The types of flanges and their reference numbers are given in Table 1 and the range of DN applicable to
each flange type and to each Class shall be as given in Table 3.
NOTE 1 Flanges, which are identified and/or marked by NPS additionally or alternatively to DN, are deemed to
comply with this document.
NOTE 2 The relationship between DN and NPS is given for reference purposes in Tables 3, 4, 5 and 6.
4.2 Standard designation
Flanges and collars in accordance with this standard shall be designated by the following:
a) designation, e.g. flange or collar;
b) number of this standard, EN 1759-3;
c) number of flange type in accordance with Figure 1;
d) Class designation, Class . (the word Class may be omitted);
e) nominal size, DN . (and/or NPS .);
f) material number or symbol (see Tables 7 and 8) (for type 05C flanges it is necessary to specify both
the material of the flange and the material of the cladding).
EXAMPLE 1 Designation of a plate flange type 01 in Class 150 and DN 600 (NPS 24) and in material symbol
CuAl8Fe3:
Flange EN 1759-3/01/Class 150/DN 600/CW303G
or
Flange EN 1759-3/01/150/NPS 24/CW303G
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EXAMPLE 2 Designation of a loose flange type 07 in Class 150 and DN 50 (NPS 2) and in material symbol
S235JR:
Flange EN 1759-3/07/Class 150/DN 50/S235JR
or
Flange EN 1759-3/07/150/NPS 6/S235JR
EXAMPLE 3 Designation of a slip-on collar type 37 in Class 150 and DN 50 (NPS 2) and in material symbol
CuZn20Al2As:
Collar EN 1759-3/37/Class 150/DN 50/CW702R
or
Collar EN 1759-3/37/150/NPS 2/CW702R
EXAMPLE 4 Designation of a blank flange type 05C with clad jointing face, in Class 300 and DN 150 (NPS 6)
and in materials symbols, S235JR (for blank flange) and CuNi30Mn1Fe (for cladding):
Flange EN 1759-3/05C/Class 300/DN 150/S235JR-CW354H
or
Flange EN 1759-3/05C/300/NPS 6/S235JR-CW354H
4.3 Information to be supplied by the equipment manufacturer
For information to be supplied by the equipment manufacturer see Annex A.
5 General requirements
5.1 Materials
Flanges and collars shall be manufactured from the materials specified in Tables 7 and 8 except for
type 21 flanges where the flange manufacturer may use other materials by agreement with the
equipment manufacturer.
The flange manufacturer shall provide means of identifying the material of the flange. An equipment
manufacturer may require a certificate in accordance with EN 10204 which is suitable for the category
of the equipment to which the flange is fitted.
NOTE If a protective coating such as zinc coating or painting is required on steel components, the equipment
manufacturer should state this on the enquiry and/or order.
5.2 Repairs
5.2.1 Repairs by welding are permitted when there is a proven method and where not otherwise
prohibited by the applicable material standard. All welding shall be carried out in accordance with a
written procedure.
NOTE For approval of welding procedures, see EN 288-1. For approval of welders, see EN 287-1.
5.2.2 Any filler rod used for weld repairs shall be such as to produce a weld having characteristics at
least equal to the parent metal. Flanges shall be heat treated after repair welding when the material
standard requires such treatment.
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5.3 Bolting
Flanges shall be suitable for use with the nominal size and number of bolts specified in Tables 4 and
5 as appropriate.
The bolting material shall be chosen by the equipment manufacturer according to the pressure,
temperature, flange material and the selected gasket so that the flanged joint remains tight under the
expected operating conditions.
NOTE 1 For information on bolting, see EN 1515-1 and EN 1515-2 and Annexes B and C.
NOTE 2 For flange types 01, 05, 11, 12, 14 and 21, where copper alloy bolting is used, the recommended
bolting materials are EN 12420 Alloy Nos. CW306G or CW307G for temperatures up to and including 120 °C.
For flange types 04, 05C and 07, steel bolting should be used and reference should be made to
EN 1515-1, EN 1515-2 and Annex C.
5.4 Gaskets
The various gasket types, dimensions, design characteristics and material used are not within the scope
of this document. Dimensions of gaskets are given in the relevant parts of EN 12560.
5.5 Pressure/temperature (p/T) ratings
5.5.1 General
The p/T ratings of the flanges manufactured from the materials specified in Tables 7 and 8 are given in
Tables 9, 10 and 11.
The p/T ratings indicate the relationship between the maximum allowable pressure, PS and the
maximum allowable temperature, TS.
Linear interpolation is permitted for intermediate temperatures.
NOTE 1 See EN 764 for terminology.
NOTE 2 When type 21 flanges are supplied as part of another component (for example, a valve or pump) in a
material other than those listed in Table 7, reference should be made to the relevant product or application
standard for the appropriate p/T ratings.
NOTE 3 The p/T rating of a flange is not necessarily the p/T rating of the whole pipework system. Gasket
materials can also impose a limitation of the p/T rating of a flanged joint and the gasket manufacturer should be
consulted when selecting the material of the gasket.
5.5.2 p/T ratings of flanged joints
When two flanges in a flanged joint do not have the same p/T rating at any temperature, then the lower
of the two flange p/T ratings at that temperature shall apply.
NOTE 1 For any p/T rating, the temperature shown is considered to be the same as that of the contained fluid.
Use at a pressure corresponding to a temperature other than that of the contained fluid is the responsibility of the
user.
NOTE 2 Application of the p/T ratings given in this document to flange joints should take into consideration the
risks of leakage due to forces and moments developed in the connecting pipework, see Annex B.
NOTE 3 These notes on service considerations are not intended to be exhaustive.
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5.6 Dimensions
5.6.1 Flanges
Dimensions of flanges shall be in accordance with the following tables and figures as appropriate:
— Class 150 flanges: Table 4 and Figure 2;
— Class 300 flanges: Table 5 and Figure 3.
NOTE 1 The bore sizes of type 21 flanges are usually equal to the nominal size of the pipe, valve or fitting of
which they form a part and the actual bore sizes are usually given in the appropriate standard(s) for the pipe,
valve or fitting.
NOTE 2 When type 07, 12 and 14 flanges are for use with soft soldering techniques only, then reference should
be made to EN 1254-1 for socket depths.
NOTE 3 For type 34 collars and type 11 flanges the recommended weld preparation angle is 37,5 ± 2,5° when
butt welding to pipe with thickness of 3 mm and greater.
5.6.2 Bolt holes
Bolt holes shall be equally spaced on the pitch circle diameter. In the case of type 21 flanges, the bolt
holes shall be positioned such that they are symmetrical to the principle axes and such that no holes fall
on these axes, i.e. positioned “off-centre”, see Figures 2 and 3.
5.7 Flange facings
5.7.1 Types of facings
Types 01, 05, 11, 12, 14 and 21 flanges in copper alloy shall be provided with flat face.
NOTE 1 Flanges with flat face facings are suitable for bolting to flat face mating flanges using a full face gasket.
Types 04, 05C and 07 flanges have a raised face formed by the face of the collar or the cladding, for
bolting to raised face mating flanges using an inside bolt circle gasket.
NOTE 2 The bolting of these flanges to a flat face iron or steel mating flange using full face or inside bolt circle
gaskets is not precluded.
5.7.2 Jointing face finish
All flange jointing faces shall be machine finished and when compared by visual or tactile means with
reference specimens, shall be in accordance with Table 2.
NOTE 1 It is not intended that instrument measurements are taken on the flange faces, and the Ra and Rz
values as defined in EN ISO 4287 relate to the reference specimens.
NOTE 2 Other finishes may be agreed between the flange manufacturer and equipment manufacturer.
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Table 2 — Surface finish of jointing faces
a a
R R
a z
Method of machining
µm µm
min. max. min. max.
b
3,2 12,5 12,5 50
Turning
Machining processes other than turning are permissible provided that they give a surface finish in
accordance with the R and R values specified.
a z
a
R and R are defined in EN ISO 4287.
a z
b
Turning covers any method of machining operation producing either serrated concentric or serrated spiral
grooves.

5.7.3 Rims
Rims of flanges and collars may be machined or un-machined.
5.7.4 Collars and loose flanges
Collars and loose flanges shall be machine finished, or have a surface equivalent to that obtained by
machining on all locating diameters, bores and abutment faces. The abutment faces shall be flat and
square to the bore axis.
5.8 Spot facing or back facing
Any spot facing or back facing required shall not reduce the flange thickness to less than the minimum
specified.
When spot facing is used, the diameter shall be large enough to accommodate the outside diameter of
the equivalent normal series of washers complying with EN ISO 887 for the bolt size being fitted.
When a flange is back faced, it is permissible for the fillet radius to be reduced but it shall not be
eliminated entirely. The bearing surfaces for the bolting shall be parallel to the flange jointing face
within the limits given in Table 6.
5.9 Tolerances
Tolerances on dimensions shall be as specified in Table 6.
5.10 Marking
5.10.1 Other than type 21 flanges
All flanges and collars shall be marked as follows:
a) number of this standard, i.e. EN 1759-3;
b) flange type number, e.g. 05;
c) Class designation, e.g. Class 150 or 150;
d) DN and/or NPS, e.g. DN 100 and/or NPS 4;
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e) material designation. The alloy designation number given in Tables 7 and 8 shall be used, as
appropriate;
f) flange manufacturer’s name or trademark.
EXAMPLE 1 Copper alloy flanges:
EN 1759-3 — 12 — 150 — DN 300 (and/or NPS 12) — CW352H — XYZ
EXAMPLE 2 Copper alloy collars:
EN 1759-3 — 37 — 300 — DN 50 (and/or NPS 2) — CC491K — XYZ
EXAMPLE 3 Steel components:
EN 1759-3 — 07 — 300 — DN 50 (and/or NPS 2) — A105 — XYZ
5.10.2 Method of marking
Copper alloy flanges shall be clearly and permanently marked by a method other than stamping with
steel stamps.
NOTE 1 The flange manufacturer’s name or trademark together with other relevant marking may be produced
during casting or forging for both copper alloy and steel components.
NOTE 2 Steel flanges may be marked round the rim of the
...