prEN 1759-4

SLOVENSKI STANDARD
01-januar-2022
Prirobnice in prirobnični spoji - Okrogle prirobnice za cevi, ventile, fitinge in pribor
z oznako Class - 4. del: Prirobnice iz aluminijevih zlitin
Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories,
Class designated - Part 4: Aluminium alloy flanges
Flansche und ihre Verbindungen - Runde Flansche für Rohre, Armaturen, Formstücke
und Zubehörteile, nach Class bezeichnet - Teil 4: Flansche aus Aluminiumlegierungen
Brides et leurs assemblages - Brides circulaires pour tubes, appareils de robinetterie,
raccords et accessoires, désignés Class - Partie 4 : Brides en alliages d’aluminium
Ta slovenski standard je istoveten z: prEN 1759-4
ICS:
23.040.60 Prirobnice, oglavki in spojni Flanges, couplings and joints
elementi
77.150.10 Aluminijski izdelki Aluminium products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2021
ICS 23.040.60 Will supersede EN 1759-4:2003
English Version
Flanges and their joints - Circular flanges for pipes, valves,
fittings and accessories, Class designated - Part 4:
Aluminium 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, désignés Class - Partie 4 : Brides en Class bezeichnet - Teil 4: Flansche aus
alliages d'aluminium Aluminiumlegierungen
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 1759-4:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Designations . 5
4.1 Range of nominal sizes . 5
4.2 Range of Class designations . 5
4.3 Types of flanges . 5
4.4 Designation of flanges . 6
5 General requirements . 6
5.1 Flange materials . 6
5.2 Repairs . 6
5.3 Bolting . 6
5.4 Gaskets . 7
5.5 Pressure/temperature (p/T) ratings. 7
5.6 Dimensions. 7
5.7 Flange facings . 7
5.7.1 Types of jointing faces . 7
5.7.2 Jointing face finish . 7
5.8 Spot facing and back facing of flanges . 7
5.9 Tolerances . 8
5.10 Marking . 8
Annex A (informative) Masses of flanges . 16
Annex B (informative) Comparison of metric bolting to imperial bolting . 17
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/68/EU . 18
Bibliography . 20

European foreword
This document (prEN 1759-4:2021) 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 1759-4:2003.
The main changes compared to EN 1759-4:2003 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
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).
Annexes A and B 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.
1 Scope
This document specifies requirements for Class designated circular flanges for pipes, valves, fittings and
accessories made from aluminium alloy in the range of DN 15 to DN 600 (NPS 1/2 to NPS 24) and
Class 150 to Class 300 (see Table 1).
This document specifies the types of flanges and their facings, dimensions and tolerances, bolt sizes,
surface finish of jointing faces, marking and materials together with associated pressure temperature
(p/T) ratings.
The flanges are intended to be used for piping as well as for pressure vessels.
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 1515-1, Flanges and their joints — Bolting — Part 1: Selection of bolting
EN ISO 4287:1998, Geometrical product specifications (GPS) — Surface texture: Profile method — Terms,
definitions and surface texture parameters (ISO 4287:1997)
EN 12392, Aluminium and aluminium alloys — Wrought products and cast products — Special
requirements for products intended for the production of pressure equipment
EN 12560 (series), Flanges and their joints — Gaskets for Class-designated flanges
EN ISO 4287:1998, 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
DN
see EN ISO 6708:1995
3.2
Nominal pipe size
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.
Note 2 to entry: The relationship between DN and NPS is given in the tables.
3.3
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.
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 designations shall have the same
mating dimensions for compatible flange types.
3.4
R , R
a z
see EN ISO 4287:1998
3.5
maximum allowable pressure
PS
PS means the maximum pressure for which the equipment is designed, as specified by the equipment
manufacturer
3.6
maximum allowable temperature
TS
TS means the maximum temperature for which the equipment is designed, as specified by the
equipment manufacturer
4 Designations
4.1 Range of nominal sizes
The range of DN (NPS) applicable to each Class shall be as given in Table 1.
4.2 Range of Class designations
The range of Class designations shall be as given in Table 1.
4.3 Types of flanges
Figure 1 illustrates flanges identified according to type:
a) Type 05 Blank flange;
b) Type 11 Weld-neck flange.
4.4 Designation of flanges
The designation of the flanges shall contain the following information:
a) description (flange);
b) number of this standard (EN 1759-4);
c) flange type (11, 05 resp.);
d) flange facing type (e.g. C);
e) DN or NPS (e.g. DN 300);
f) for type 11 flanges only, neck diameter, A and neck thickness, S (e.g. 324 × 5);
g) Class (e.g. Class 150);
h) material (e.g. EN AW-5083-O).
EXAMPLE 1 For a type 11 flange:
Flange EN 1759-4 — 11 — C — DN 300 — 324 × 5 — Class 150 — EN AW-5083-O
EXAMPLE 2 For a type 05 flange:
Flange EN 1759-4 — 05 — C — DN 300 — Class 150 — EN AW-5083-O
5 General requirements
5.1 Flange materials
Flanges shall be manufactured from the material grades EN AW-5083 (AlMg4,5Mn0,7) -O or EN AW-
6061 (AlMg1SiCu) -T6 according to EN 12392. Other materials may be used. For the p/T ratings see 5.5.
Weld-neck flanges shall be forged or made from extruded bars; blank flanges shall be forged or made
from plate.
5.2 Repairs
Repai
...