Bsi bs en 01515 2 2001 (2002)

BRITISH STANDARD BS EN 1515 2 2001 Flanges and their joints — Bolting — Part 2 Classification of bolt materials for steel flanges, PN designated The European Standard EN 1515 2 2001 has the status of[.]

Flanges and their

joints — Bolting —

Part 2: Classification of bolt materials

for steel flanges, PN designated

The European Standard EN 1515-2:2001 has the status of a

British Standard

ICS 21.060.01; 23.040.60

This British Standard, having

been prepared under the

direction of the Engineering

Sector Policy and Strategy

Committee, was published

under the authority of the

Standards Policy and Strategy

The British Standards which implement international or European

publications referred to in this document may be found in the BSI Catalogue

under the section entitled “International Standards Correspondence Index”, or

by using the “Search” facility of the BSI Electronic Catalogue or of British

— aid enquirers to understand the text;

— present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the

Amendments issued since publication

EUROPÄISCHE NORM December 2001

ICS 21.060.01; 23.040.60

English version

Flanges and their joints - Bolting - Part 2: Classification of bolt

materials for steel flanges, PN designated

Brides et leurs assemblages - Boulonnerie - Partie 2:

Classification de matériaux de boulonnerie pour brides en

acier, désignées PN

Flansche und ihre Verbindungen Schrauben und Muttern Teil 2: Klassifizierung von Schraubenwerkstoffen für Stahlflansche, nach PN bezeichnet

-This European Standard was approved by CEN on 20 October 2001.

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 Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä I S C H E S K O M I T E E F Ü R N O R M U N G

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2001 CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members.

Ref No EN 1515-2:2001 E

page

Foreword 2

1 Scope 2

2 Normative references 2

3 Combination of materials 3

4 Classification of bolt materials 3

Table 1 _ Classification of bolt materials 4

Annex A (informative) Basic information 17

Annex ZA (informative) Relationship with EU Directive(s) 19

Foreword

This European Standard 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 June 2002, and conflicting national standards shall be withdrawn at the latest by June 2002

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(s)

For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this document

EN 1515 consists of two Parts:

Part 1: Selection of bolting;

Part 2: Classification of bolt materials for steel flanges, PN designated

The annexes A and ZA are informative

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark,

Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom

1 Scope

This European Standard covers the classification of bolt materials combination with the flange material groups

of steel flanges prEN 1092-1 (PN-designated)

Bolt materials are listed in EN 1515-1, flange material groups are listed in prEN 1092-1

2 Normative references

This European Standard incorporates by dated or undated reference, provisions from other publications These normative references are cited at the appropriate places in the text’ and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard, only when incorporated in it by amendment or revision For undated references the latest edition of the publication referred to applies (including amendments)

prEN 1092-1, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories,

PN designated – Part 1: Steel flanges

EN 1515-1, Flanges and their joints - Bolting - Part 1: Selection of bolting.

EN 10269, Steels and nickel alloys for fasteners for use at elevated and/or low temperature properties

EN ISO 898-1, Mechanical properties of fasteners made of carbon steel and alloy steel - Part 1: Bolts, screwsand studs (ISO 898-1:1999)

EN ISO 3506-1, Mechanical properties of corrosion-resistant stainless steel fasteners – Part 1: Bolts, screwsand studs (ISO 3506-1:1997)

3 Combination of materials

Bolt materials can be combined with flange material groups as given in Table 1 This table is valid for all flangesfor which pressure temperature (p/T) ratings are given in prEN 1092-1 For flanges which have no p/T ratings(e.g DN 700 and above), the tables may be used as a guide

All bolt materials can be used in the range of the p/T ratings given for the flanges Restrictions due to the

classification shall be observed (see clause 4)

WARNING Bold materials 4.6 and 6.8 are not intended for the use in the scope of the Pressure Equipment Directive.

4 Classification of bolt materials

The classification of bolt materials as given in Table 1 is based on the comparison of the strengths of the flangematerial and the bolt material The strength ratio r of the flange/bolt combination chosen is compared with thestrength ratio of the flange bolt combination used for the standard flange calculation (see annex A)

For each flange material group the classification is done in three strength levels:

Low strength: The strength ratio of the chosen flange/bolt combination is less than that used in the

standard flange calculation

These bolts may be used for less severe service, e.g for water service or in case of oversized flangedjoints For definition of these service conditions, special experience is necessary otherwise a recalculation ofthe flanged joint shall be done

Normal strength: The strength ratio of the chosen flange/bolt combination is similar (within defined limits)

to that used in the standard flange calculation

These bolts may be used for all service in the range of the P/T-ratings unless there are other restrictions tothe contrary

High strength: The strength ratio of the chosen flange/bolt combination is much more higher than that used

in the standard flange calculation

These bolts may be used in the same range like normal strength level bolting During assembly however,care should be taken not to overstress the flanges (e g by means of torque control)

Table 1 _

Classification of bolt materials

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (continued)

Flange materials prEN

1092-1

Table 1 (concluded)

Flange materials prEN

1092-1

Flange calculation model: PN designated steel flanges, for which p/t ratings are given (see prEN 1092-1)

have been calculated at ambient temperature with a flange material yield stress of 225 N/mm² and a boltmaterial yield stress of 300 N/mm² This is the calculation model for the flanges

Classification: Bolt materials are set in relation to flange material groups and classified on the basis of their

strength Starting from the flange calculation model classification of the bolt material is done as given in thisannex A (See also prEN 1092-1 annex F: Determination of p/T ratings for flanges using EN materials.)

r: stress ratio for classification of the bolt material (see also clause 4)

r min: minimum value of all stress ratios of one flange material to one bolt material calculated over all

temperatures

r 20: stress ratio at 20 °C of one flange material to one bolt material.

A.2 Combination of flange and bolt materials

From each flange material group (e.g group 3E0) the material with the lowest stress at 20 °C has been selectedfor the calculations of this group (Cast stainless steel has not been used, as the stress values are too low) Thep/T ratings of the flanges itself has been calculated with the lowest value of a material group

This material is combined with each bolt material given in EN 1515-1 and the stress ratio r is calculated for alltemperatures

The results are evaluated for the classification of the bolt material

g = Stress ratio for a flange/bolt combination at temperature

gm = Stress ratio for calculation model

Smf = Flange material stress for flange calculation model at 20 °C (= 225 N/mm²)

Smb = Bolt material stress for calculation model at 20 °C (= 300 N/mm²)

STf = Flange material stress at temperature (N/mm²)

STb = Bolt material stress at temperature (N/mm²)

r = Stress ratio model/combination

A.4 Classification

The bolt materials combined with a flange material group are classified in low – normal – high strength (see alsoclause 4)

The minimum value of r (r min) and the value at 20 °C (r 20) of one flange material to one bolt material

calculated over all temperatures is used for the classification (e.g flange material group 3E0 compared with boltmaterial 5.6 and temperatures from 20 °C to 300 °C)

Stress ratio r below 1 means: Bolts are weaker than calculation model

Stress ratio r above 1 means: Bolts are stronger than calculation model

Classification has been done according to the following criteria:

Low strength: for bolt materials with r min  0,9;

Normal strength: for bolt materials with r min  0,9 & r 20 < 2;

High strength: for bolt materials with r 20  2

Annex ZA

(informative)

Relationship with EU Directive(s)

Clauses of this European Standard addressing essential requirements or

other provisions of EU Directives

This European Standard has been prepared under a mandate given to CEN by the European Commission andthe European Free Trade Association (EFTA) and supports essential requirements of EU Directive 97/23/EC(Pressure Equipment Directive, PED)

WARNING: Other requirements and other EU Directives may be applicable to the products falling within the

scope of this standard

The following clauses of this standard are likely to support requirements of Directive 97/23/EC

Compliance with the clauses of this standard provides one means of conforming with the specific essentialrequirements of the Directive concerned and associated EFTA regulations

Table ZA.1 - Correspondence between this European Standard and Directive 97/23/EC

3 and 4 Annex 1,

Clause 4

Materials:

Materials for pressure equipment to be suitable during lifetime

- unless replacement is foreseen

- to be sufficiently ductile and tough;

- characteristics of material to comply with ESR's at 7.5

- to be selected in order to prevent brittle-type fracture, orappropriate measures to be taken

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We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover

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