EN 12953-3:2016

SLOVENSKI STANDARD
01-junij-2016
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SIST EN 12953-3:2002
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Shell boilers - Part 3: Design and calculation for pressure parts
Großwasserraumkessel - Teil 3: Konstruktion und Berechnung für drucktragende Teile
Chaudières à tube de fumée - Partie 3: Conception et calcul des parties sous pression
Ta slovenski standard je istoveten z: EN 12953-3:2016
ICS:
27.060.30 Grelniki vode in prenosniki Boilers and heat exchangers
toplote
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12953-3
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2016
EUROPÄISCHE NORM
ICS 27.060.30; 27.100 Supersedes EN 12953-3:2002
English Version
Shell boilers - Part 3: Design and calculation for pressure
parts
Chaudières à tubes de fumée - Partie 3: Conception et Großwasserraumkessel - Teil 3: Konstruktion und
calcul des parties sous pression Berechnung für drucktragende Teile
This European Standard was approved by CEN on 23 January 2016.

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 CEN-CENELEC 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 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12953-3:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Symbols and abbreviations . 8
5 General . 8
5.1 Boilers . 8
5.2 Hot-water boilers . 8
5.3 Main welds . 8
5.4 Weld factor . 9
5.5 Thermal design of furnaces tubes . 9
5.5.1 Design conditions . 9
5.5.2 Furnace dimensions . 11
5.5.3 Heat input . 11
5.5.4 Additional operating conditions . 12
5.6 Dimensions of pressure parts . 12
5.7 Determination of pressures . 12
5.7.1 Maximum allowable pressure . 12
5.7.2 Calculation pressure . 12
5.7.3 Safety valves set pressure . 12
5.7.4 Hydrostatic test pressure . 13
5.8 Allowances . 13
5.8.1 Allowance for material supply tolerances and forming processes . 13
5.8.2 Allowance for metal wastage . 13
5.9 Additional material requirements for plates . 13
5.10 Standardized fittings . 14
5.11 Flanges . 14
5.12 Design by analysis . 14
5.13 Economizer and superheater. 14
6 Calculation temperature and nominal design stress . 14
6.1 Calculation temperature . 14
6.2 Nominal design stress. 15
7 Cylindrical shells . 15
7.1 Shell thickness . 15
7.1.1 Requirements . 15
7.1.2 Required wall thickness including allowances . 16
7.2 Basic calculation subjected to internal pressure . 16
7.3 Boiler supports and lifting lugs . 16
8 Openings and branches in cylindrical shells . 16
8.1 General . 16
8.1.1 Introduction . 16
8.1.2 Requirements for the reinforcement of openings in shells . 16
8.1.3 Effective lengths l for calculation of efficiencies and of compensations. 18
rs
8.1.4 Condition of isolated openings . 22
8.1.5 Requirements for design of branches . 22
8.1.6 Requirements for design of reinforcing pads . 22
8.1.7 General requirements for calculation of cross-sectional and pressure-loaded areas . 23
8.2 Efficiency factor, alternative calculation method, maximum diameter of an un-reinforced
opening . 23
8.2.1 General . 23
8.2.2 Allowable efficiency and maximum diameter of an unreinforced opening . 24
8.2.3 Isolated openings . 24
8.2.4 Adjacent openings . 25
8.3 Design of openings and branches in shells (efficiency and reinforcement) . 25
8.3.1 Symbols and abbreviations . 25
8.3.2 Requirements for application . 26
8.3.3 Design of isolated openings and branch connections . 30
8.3.4 Design of adjacent openings and branch connections . 32
9 Ends . 33
9.1 Unstayed dished heads without openings . 33
9.1.1 Unstayed dished heads under internal pressure . 33
9.1.2 Limiting conditions . 33
9.1.3 Unstayed dished heads under external pressure . 35
9.2 Flat unstayed removable closures . 36
9.3 Unstayed flat plates. 37
10 Supported flat plates, stays and stiffeners . 38
10.1 Breathing space for flat plates . 38
10.2 Stayed flat surfaces . 40
10.2.1 General . 40
10.2.2 Radius of flange . 40
10.2.3 Point of support . 40
10.2.4 Thickness . 41
10.2.5 Values of constant C . 44
10.2.6 Stays for wet back reversal chambers . 54
10.2.7 Stay tubes and bars .
...