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

This European Standard specifies dimensions, tolerances, materials, P/T ratings and technical conditions of delivery for steel flanges with bore size DN 15 to DN 600, Class designated; based on ANSI-B 16.5-1988 + Addenda 1992.

Flansche und ihre Verbindungen - Runde Flansche für Rohre, Armaturen, Formstücke und Zubehörteile, nach Class bezeichnet - Teil 1: Stahlflansche, NPS 1/2 bis 24

Diese Europäische Norm für ein einheitliches System von Flanschen legt Anforderungen fest für runde Stahl-
flansche, in den Class-Stufen Class 150 bis Class 2 500 und den Nennweiten NPS 1/2 bis NPS 24.
ANMERKUNG Die Beziehung zwischen Nennweite (DN) und Nennweite (NPS) ist für Referenzzwecke angegeben in
den Tabellen 9 bis 14.
Diese Norm legt Typen für Stahlflansche und ihre Dichtflächenformen, Maße, Toleranzen, Gewinde,
Schraubengrößen, Oberflächenbeschaffenheit der Dichtflächen, Kennzeichnung, Werkstoffe und Druck/
Temperatur-Zuordnungen fest.
Diese Norm gilt nicht für Flansche, die aus Stangenmaterial gedreht werden und nicht für Flanschtypen 11,
12, 13, 14 und 15 die aus Blech gefertigt werden.

Brides et leurs assemblages - Brides circulaires pour tubes, appareils de robinetterie, raccords et accessoires, désignées Class - Partie 1 : Brides en acier NPS 1/2 à 24

Prirobnice in prirobnični spoji - Okrogle prirobnice za cevi, ventile, fitinge in pribor z oznako Class - 1. del: Jeklene prirobnice NPS1/2 do 24

General Information

• Status: Published
• Publication Date: 23-Nov-2004
• Withdrawal Date: 30-May-2005
• ICS: 23.040.60 - Flanges, couplings and joints
• Technical Committee: CEN/TC 74 - Flanges and their joints
• Drafting Committee: CEN/TC 74/WG 2 - Steel flanges
• Current Stage: 9060 - Closure of 2 Year Review Enquiry - Review Enquiry
• Start Date: 04-Mar-2022
• Completion Date: 04-Mar-2022
• Ref Project: SIST EN 1759-1:2005 - Flanges and their joint - Circular flanges for pipes, valves, fittings and accessories, Class designated - Part 1: Steel flanges, NPS 1/2 to 24

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2005
Prirobnice in prirobnični spoji - Okrogle prirobnice za cevi, ventile, fitinge in pribor
z oznako Class - 1. del: Jeklene prirobnice NPS1/2 do 24
Flanges and their joint - Circular flanges for pipes, valves, fittings and accessories, Class
designated - Part 1: Steel flanges, NPS 1/2 to 24
Flansche und ihre Verbindungen - Runde Flansche für Rohre, Armaturen, Formstücke
und Zubehörteile, nach Class bezeichnet - Teil 1: Stahlflansche, NPS 1/2 bis 24
Brides et leurs assemblages - Brides circulaires pour tubes, appareils de robinetterie,
raccords et accessoires, désignées Class - Partie 1 : Brides en acier NPS 1/2 a 24
Ta slovenski standard je istoveten z: EN 1759-1:2004
ICS:
23.040.60 Prirobnice, oglavki in spojni Flanges, couplings and joints
elementi
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 1759-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2004
ICS 23.040.60
English version
Flanges and their joint - Circular flanges for pipes, valves,
fittings and accessories, Class designated - Part 1: Steel
flanges, NPS 1/2 to 24
Brides et leurs assemblages - Brides circulaires pour tubes, Flansche und ihre Verbindungen - Runde Flansche für
appareils de robinetterie, raccords et accessoires, Rohre, Armaturen, Formstücke und Zubehörteile, nach
désignées Class - Partie 1 : Brides en acier NPS 1/2 à 24 Class bezeichnet - Teil 1: Stahlflansche, NPS 1/2 bis 24
This European Standard was approved by CEN on 30 September 2004.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1759-1:2004: E
worldwide for CEN national Members.

Contents Page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .6
4 Designation .7
5 General requirements.8
Annex A (informative) Recommendations for weld ends of weld-neck flanges .65
Annex B (informative) Classification of bolting materials .66
Annex C (informative) Use of metric bolting in lieu of imperial bolting.67
Annex D (informative) Determination of p/T ratings for flanges using EN materials .69
Annex E (normative) Approximate masses of flanges and collars .70
Bibliography .74

Foreword
This document (EN 1759-1:2004) has been prepared by Technical Committee CEN/TC 74 "Flanges and their
joints" the secretariat of which is held by DIN.
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 May 2005, and conflicting national standards shall be withdrawn at the latest by
May 2005.
EN 1759 consists of the following parts:
 Part 1: Steel flanges;
 Part 3: Copper alloy flanges ;
 Part 4: Aluminium alloy flanges .
This document includes a Bibliography.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,
Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

To be published
Introduction
When Technical Committee, CEN/TC 74, commenced its work of producing this European standard it took as its
basis, the International Standard, ISO 7005-1, Steel flanges.
In taking this decision, CEN/TC 74, agreed that this standard would differ significantly from the ISO standard in
respect of the following:
a) Whereas ISO 7005-1 included in its scope both the original DIN based flanges and also the original
ANSI/ASME based flanges, EN 1759-1 contains only the flanges with ANSI/ASME origin (ASME B16.5).
CEN/TC 74 has produced a separate series of standards, EN 1092 Parts 1, 2, 3 and 4, dealing with the DIN
based flanges in PN designations;
b) In this standard, the flanges are Class designated (not PN designated as in the ISO standard) and those
dimensions taken from ASME B16.5 are hard metricated.
Consequently, whilst the mating dimensions, the flange and facing types and designations are compatible with
those given in ISO 7005-1, it is important to take account of the following differences which exist in EN 1759-1:
1) The use of inch bolting requires the use of suitable gaskets, not necessarily compatible with the gaskets used
with ISO 7005-1 flanges (for metric bolts).
2) This standard specifies grades of ASTM steels similar to those specified in ISO 7005-1, but in addition permits
the use of grades of European steels according to EN 1092-1;

1 Scope
This European Standard for a single system of flanges specifies requirements for circular steel flanges in Class
designations Class 150 to Class 2 500 and nominal sizes from NPS ½ to NPS 24.
NOTE The relationship between nominal size (DN) and nominal size (NPS) is given for reference purposes in Tables 9
to 14.
This standard specifies the flange types and their facings, dimensions, tolerances, threading, bolt sizes, flange jointing
face surface finish, marking, materials and pressure/temperature ratings.
This standard does not apply to flanges made from bar stock by turning, or to flanges of types 11, 12, 13, 14 and
15 made from plate material.
2 Normative references
The following referenced documents are indispensable for the application 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
prEN 1515-3, Flanges and their joints — Bolting — Part 3: Classification of bolt materials for steel flanges, class
designated
EN 10025, Hot rolled products of non-alloy structural steels — Technical delivery conditions
EN 10028-2, Flat products made of steels for pressure purposes — Part 2: Non alloy and alloy steels with specified
elevated temperature properties
EN 10028-3, Flat products made of steels for pressure purposes — Part 3: Weldable fine grain steels, normalized
EN 10028-4, Flat products made of steels for pressure purposes — Part 4: Nickel alloy steels with specified low
temperature properties
EN 10028-7, Flat products made of steels for pressure purposes — Part 7: Stainless steels
EN 10213-2, Technical delivery conditions for steel castings for pressure purposes — Part 2: Steel grades for use
at room temperature and elevated temperatures
EN 10213-3, Technical delivery conditions for steel castings for pressure purposes — Part 3: Steel grades for use
at low temperatures
EN 10213-4, Technical delivery conditions for steel castings for pressure purposes — Part 4: Austenitic and
austenitic-ferritic steel grades
EN 10222-2, Steel forgings for pressure purposes — Part 2: Ferritic and martensitic steels with specified elevated
temperature properties
EN 10222-3, Steel forgings for pressure purposes — Part 3: Nickel steels with specified low temperature properties
EN 10222-4, Steel forgings for pressure purposes — Part 4: Weldable fine grain steels with high proof strength
EN 10222-5, Steel forgings for pressure purposes - Part 5: Martensitic, austenitic and austenitic-ferritic stainless
steels
EN ISO 887, Plain washers for metric bolts, screws and nuts for general purposes - General plan (ISO 887:2000)
EN ISO 6708, Pipe components — Definition and selection of DN (nominal size) (ISO 6708:1995)
ISO 4955, Heat-resisting steels and alloys
ISO 4991, Steel castings for pressure purposes
ISO 9327-1, Steel forgings and rolled or forged bars for pressure purposes — Technical delivery conditions —Part 1:
General requirements
ISO 9327-2, Steel forgings and rolled or forged bars for pressure purposes —Technical delivery conditions — Part 2:
Non-alloy and alloy (Mo, Cr and CrMo) steels with specified elevated temperature properties
ISO 9328-2, Steel flat products for pressure purposes — Technical delivery conditions —Part 2: Non-alloy and alloy
steels with specified elevated temperature properties
ISO 9328-3, Steel flat products for pressure purposes — Technical delivery conditions — Part 3: Weldable fine
grain steels, normalized
ISO 9328-5, Steel flat products for pressure purposes — Technical delivery conditions — Part 5: Weldable fine grain
steels, thermomechanically rolled
ASME B16.5: 1996 Pipe flanges and flanged fittings — NPS ½ through NPS 24
ASME/ANSI B1.20.1, Pipe threads, general purpose (inch)
ASTM A105/A105M, Forgings, Carbon Steel, for Piping Component
ASTM A182/A182M, Forged or Rolled Alloy-Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-
Temperature Service
ASTM A203/A203M, Pressure Vessel Plates, Alloy Steel, Nickel
ASTM A204/A204M, Specification for pressure vessel plates, alloy steel, molybdenum
ASTM A216/A216M, Steel Castings, Carbon Suitable for Fusion Welding for High-Temperature Service
ASTM A217/A217M, Steel Castings, Martensitic Stainless and Alloy, for Pressure-Containing Parts Suitable for High-
Temperature Service
ASTM A240/A240M, Heat-Resisting Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for
Pressure Vessels
ASTM A325, High-Strength Bolts for Structural Steel Joints
ASTM A350/A350M, Forgings, Carbon and Low-Alloy Steel, Requiring Notch Toughness Testing for Piping
Components
ASTM A351/A351M, Castings, Austenitic, Austenitic-Ferritic (Duplex) for Pressure-Containing Parts
ASTM A352/A352M, Steel Castings, Ferritic and Martensitic, for Pressure-Containing Parts Suitable for Low-
Temperature Service
ASTM A387/A387M, Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum
ASTM A515/A515M, Pressure Vessel Plates, Carbon Steel, for Intermediate and Higher-Temperature Service
ASTM A516/A516M, Pressure Vessel Plates, Carbon Steel, for Moderate and Lower-Temperature Service
ASTM A537/A537M, Pressure Vessel Plates, Heat-Treated, Carbon-Manganese-Silicon Steel
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
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 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 The designation Class is not meaningful unless it is related to the relevant component standard number.
NOTE 3 It is intended that all components with the same Class and NPS (see below) designations should have the same
mating dimensions for compatible flange types.
3.2
DN
see EN ISO 6708
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 standard, 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 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.
3.4
maximum allowable pressure, PS
means the maximum pressure for which the equipment is de
...

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Flansche und ihre Verbindungen - Runde Flansche für Rohre, Armaturen, Formstücke und Zubehörteile, nach Class bezeichnet - Teil 1: Stahlflansche, NPS 1/2 bis 24Brides et leurs assemblages - Brides circulaires pour tubes, appareils de robinetterie, raccords et accessoires, désignées Class - Partie 1 : Brides en acier NPS 1/2 a 24Flanges and their joint - Circular flanges for pipes, valves, fittings and accessories, Class designated - Part 1: Steel flanges, NPS 1/2 to 2423.040.60Prirobnice, oglavki in spojni elementiFlanges, couplings and jointsICS:Ta slovenski standard je istoveten z:EN 1759-1:2004SIST EN 1759-1:2005en01-marec-2005SIST EN 1759-1:2005SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 1759-1November 2004ICS 23.040.60English versionFlanges and their joint - Circular flanges for pipes, valves,fittings and accessories, Class designated - Part 1: Steelflanges, NPS 1/2 to 24Brides et leurs assemblages - Brides circulaires pour tubes,appareils de robinetterie, raccords et accessoires,désignées Class - Partie 1 : Brides en acier NPS 1/2 à 24Flansche und ihre Verbindungen - Runde Flansche fürRohre, Armaturen, Formstücke und Zubehörteile, nachClass bezeichnet - Teil 1: Stahlflansche, NPS 1/2 bis 24This European Standard was approved by CEN on 30 September 2004.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2004 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1759-1:2004: ESIST EN 1759-1:2005

Contents Page Foreword.3 Introduction.4 1 Scope.5 2 Normative references.5 3 Terms and definitions.6 4 Designation.7 5 General requirements.8 Annex A (informative)
Recommendations for weld ends of weld-neck flanges.65 Annex B (informative)
Classification of bolting materials.66 Annex C (informative)
Use of metric bolting in lieu of imperial bolting.67 Annex D (informative)
Determination of p/T ratings for flanges using EN materials.69 Annex E (normative)
Approximate masses of flanges and collars.70 Bibliography.74
3 Foreword This document (EN 1759-1:2004) has been prepared by Technical Committee CEN/TC 74 "Flanges and their joints" the secretariat of which is held by DIN. 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 May 2005, and conflicting national standards shall be withdrawn at the latest by May 2005. EN 1759 consists of the following parts:  Part 1: Steel flanges;  Part 3: Copper alloy flanges1;  Part 4: Aluminium alloy flanges1. This document includes a Bibliography. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
1 To be published SIST EN 1759-1:2005

Introduction When Technical Committee, CEN/TC 74, commenced its work of producing this European standard it took as its basis, the International Standard, ISO 7005-1, Steel flanges. In taking this decision, CEN/TC 74, agreed that this standard would differ significantly from the ISO standard in respect of the following: a) Whereas ISO 7005-1 included in its scope both the original DIN based flanges and also the original ANSI/ASME based flanges, EN 1759-1 contains only the flanges with ANSI/ASME origin (ASME B16.5). CEN/TC 74 has produced a separate series of standards, EN 1092 Parts 1, 2, 3 and 4, dealing with the DIN based flanges in PN designations; b) In this standard, the flanges are Class designated (not PN designated as in the ISO standard) and those dimensions taken from ASME B16.5 are hard metricated. Consequently, whilst the mating dimensions, the flange and facing types and designations are compatible with those given in ISO 7005-1, it is important to take account of the following differences which exist in EN 1759-1: 1) The use of inch bolting requires the use of suitable gaskets, not necessarily compatible with the gaskets used with ISO 7005-1 flanges (for metric bolts). 2) This standard specifies grades of ASTM steels similar to those specified in ISO 7005-1, but in addition permits the use of grades of European steels according to EN 1092-1;
5 1 Scope This European Standard for a single system of flanges specifies requirements for circular steel flanges in Class designations Class 150 to Class 2 500 and nominal sizes from NPS ½ to NPS 24. NOTE The relationship between nominal size (DN) and nominal size (NPS) is given for reference purposes in Tables 9
to 14. This standard specifies the flange types and their facings, dimensions, tolerances, threading, bolt sizes, flange jointing face surface finish, marking, materials and pressure/temperature ratings. This standard does not apply to flanges made from bar stock by turning, or to flanges of types 11, 12, 13, 14 and 15 made from plate material. 2 Normative references The following referenced documents are indispensable for the application 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 prEN 1515-3, Flanges and their joints — Bolting — Part 3: Classification of bolt materials for steel flanges, class designated EN 10025, Hot rolled products of non-alloy structural steels — Technical delivery conditions EN 10028-2, Flat products made of steels for pressure purposes — Part 2: Non alloy and alloy steels with specified elevated temperature properties EN 10028-3, Flat products made of steels for pressure purposes — Part 3: Weldable fine grain steels, normalized EN 10028-4, Flat products made of steels for pressure purposes — Part 4: Nickel alloy steels with specified low temperature properties EN 10028-7, Flat products made of steels for pressure purposes — Part 7: Stainless steels EN 10213-2, Technical delivery conditions for steel castings for pressure purposes — Part 2: Steel grades for use at room temperature and elevated temperatures EN 10213-3, Technical delivery conditions for steel castings for pressure purposes — Part 3: Steel grades for use at low temperatures EN 10213-4, Technical delivery conditions for steel castings for pressure purposes — Part 4: Austenitic and austenitic-ferritic steel grades EN 10222-2, Steel forgings for pressure purposes — Part 2: Ferritic and martensitic steels with specified elevated temperature properties EN 10222-3, Steel forgings for pressure purposes — Part 3: Nickel steels with specified low temperature properties EN 10222-4, Steel forgings for pressure purposes — Part 4: Weldable fine grain steels with high proof strength EN 10222-5, Steel forgings for pressure purposes - Part 5: Martensitic, austenitic and austenitic-ferritic stainless steels EN ISO 887, Plain washers for metric bolts, screws and nuts for general purposes - General plan (ISO 887:2000) EN ISO 6708, Pipe components — Definition and selection of DN (nominal size) (ISO 6708:1995) ISO 4955, Heat-resisting steels and alloys SIST EN 1759-1:2005

ISO 4991, Steel castings for pressure purposes ISO 9327-1, Steel forgings and rolled or forged bars for pressure purposes — Technical delivery conditions —Part 1: General requirements
ISO 9327-2, Steel forgings and rolled or forged bars for pressure purposes —Technical delivery conditions — Part 2: Non-alloy and alloy (Mo, Cr and CrMo) steels with specified elevated temperature properties ISO 9328-2, Steel flat products for pressure purposes — Technical delivery conditions —Part 2: Non-alloy and alloy steels with specified elevated temperature properties ISO 9328-3, Steel flat products for pressure purposes — Technical delivery conditions — Part 3: Weldable fine grain steels, normalized ISO 9328-5, Steel flat products for pressure purposes —
Technical delivery conditions — Part 5: Weldable fine grain steels, thermomechanically rolled ASME B16.5: 1996 Pipe flanges and flanged fittings — NPS ½ through NPS 24 ASME/ANSI B1.20.1, Pipe threads, general purpose (inch) ASTM A105/A105M, Forgings, Carbon Steel, for Piping Component ASTM A182/A182M, Forged or Rolled Alloy-Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service ASTM A203/A203M, Pressure Vessel Plates, Alloy Steel, Nickel ASTM A204/A204M, Specification for pressure vessel plates, alloy steel, molybdenum ASTM A216/A216M, Steel Castings, Carbon Suitable for Fusion Welding for High-Temperature Service ASTM A217/A217M, Steel Castings, Martensitic Stainless and Alloy, for Pressure-Containing Parts Suitable for High-Temperature Service ASTM A240/A240M, Heat-Resisting Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels ASTM A325, High-Strength Bolts for Structural Steel Joints ASTM A350/A350M, Forgings, Carbon and Low-Alloy Steel, Requiring Notch Toughness Testing for Piping Components ASTM A351/A351M, Castings, Austenitic, Austenitic-Ferritic (Duplex) for Pressure-Containing Parts ASTM A352/A352M, Steel Castings, Ferritic and Martensitic, for Pressure-Containing Parts Suitable for Low-Temperature Service ASTM A387/A387M, Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum ASTM A515/A515M, Pressure Vessel Plates, Carbon Steel, for Intermediate and Higher-Temperature Service ASTM A516/A516M, Pressure Vessel Plates, Carbon Steel, for Moderate and Lower-Temperature Service ASTM A537/A537M, Pressure Vessel Plates, Heat-Treated, Carbon-Manganese-Silicon Steel 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 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 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. SIST EN 1759-1:2005

7 NOTE 2 The designation Class is not meaningful unless it is related to the relevant component standard number. NOTE 3 It is intended that all components with the same Class and NPS (see below) designations should have the same mating dimensions for compatible flange types. 3.2 DN see EN ISO 6708 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 standard, 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 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. 3.4 maximum allowable pressure, PS means the maximum pressure for which the equipment is designed, as specified by the equipment manufacturer 3.5 maximum allowable temperature, TS means the maximum temperature for which the equipment is designed, as specified by the equipment manufacturer 4 Designation 4.1 General Table 1 and Figure 1 show the flange types and their relevant type numbers. Flanges shall be denoted with "flange type" and "flange number". Figure 2 shows flange facing types, which may be used with the flanges shown in Figure 1. Flange facings shall be denoted with "type" and the relevant symbol. The range of NPS, applicable to each flange type and each Class designation shall be as given in Table 2. 4.2 Information to be supplied by the equipment manufacturer
The following information should be supplied by the equipment manufacturer in the enquiry and/or order. Flanges and ancillary components in accordance with this standard shall be designated with the followin
...