EN 12952-3:2011

Water-tube boilers and auxiliary installations - Part 3: Design and calculation for pressure parts of the boiler

This European Standard specifies the requirements for the design and calculation of water-tube boilers as defined in EN 12952-1.
The purpose of this European Standard is to ensure that the hazards associated with water-tube boilers are reduced to a minimum by the proper application of the design according to this part of EN 12952.

Wasserrohrkessel und Anlagenkomponenten - Teil 3: Konstruktion und Berechnung für drucktragende Kesselteile

Diese Europäische Norm legt Anforderungen an die Konstruktion und Berechnung von Wasserrohrkesseln
nach der Definition in EN 12952-1 fest.
Durch die sachgemäße Konstruktion nach diesem Teil der Europäischen Norm EN 12952 wird sichergestellt,
dass die Gefahren, die mit Wasserrohrkesseln einhergehen auf ein Minimum reduziert werden.

Chaudières à tubes d'eau et installations auxiliaires - Partie 3: Conception et calcul des parties sous pression de la chaudière

La présente Norme européenne spécifie les règles de conception et de calcul des chaudières à tubes d'eau
telles que définies dans l'EN 12952-1.
L’objet de la présente Norme européenne est d’assurer que les phénomènes dangereux associés aux
chaudières à tubes d’eau sont réduits au minimum par l’application appropriée des exigences de conception
de la présente partie de l’EN 12952.

Vodocevni kotli in pomožne napeljave - 3. del: Konstruiranje in izračun tlačno obremenjenih delov

Ta evropski standard določa zahteve za konstruiranje in izračun vodocevnih kotlov iz standarda EN 12952-1. Namen tega evropskega standarda je zagotoviti, da se nevarnosti, povezane z vodocevnimi kotli, čim bolj zmanjšajo s pravilnim konstruiranjem v skladu s tem delom standarda EN 12952.

General Information

• Status: Withdrawn
• Publication Date: 20-Dec-2011
• Withdrawal Date: 13-Apr-2025
• ICS: 27.040 - Gas and steam turbines. Steam engines
• Technical Committee: CEN/TC 269 - Shell and water tube boilers
• Drafting Committee: CEN/TC 269/WG 1 - Water-tube boilers
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 02-Nov-2022
• Completion Date: 14-Apr-2025
• Directive: 2014/68/EU - Directive 2014/68/EU of the European Parliament and of the Council of 15 May 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of pressure equipment
• Directive: 97/23/EC - 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
• Mandate: M/071 - Mandate to CEN for standardization in the field of Pressure equipment
• Ref Project: SIST EN 12952-3:2012 - Water-tube boilers and auxiliary installations - Part 3: Design and calculation for pressure parts

Relations

• Replaces: EN 12952-3:2001 - Water-tube boilers and auxilliary installations - Part 3: Design and calculation for pressure parts
• Effective Date: 28-Dec-2011
• Replaced By: EN 12952-3:2022 - Water-tube boilers and auxiliary installations - Part 3: Design and calculation for pressure parts of the boiler
• Effective Date: 11-May-2020

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Wasserrohrkessel und Anlagenkomponenten - Teil 3: Konstruktion und Berechnung für drucktragende TeileChaudières à tubes d'eau et installations auxiliaires - Partie 3: Conception et calcul des parties sous pressionWater-tube boilers and auxiliary installations - Part 3: Design and calculation for pressure parts27.060.30Grelniki vode in prenosniki toploteBoilers and heat exchangersICS:Ta slovenski standard je istoveten z:EN 12952-3:2011SIST EN 12952-3:2012en,fr,de01-maj-2012SIST EN 12952-3:2012SLOVENSKI
STANDARDSIST EN 12952-3:20021DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 12952-3
December 2011 ICS 27.040 Supersedes EN 12952-3:2001English Version
Water-tube boilers and auxiliary installations - Part 3: Design and calculation for pressure parts of the boiler
Chaudières à tubes d'eau et installations auxiliaires - Partie 3: Conception et calcul des parties sous pression de la chaudière
Wasserrohrkessel und Anlagenkomponenten - Teil 3: Konstruktion und Berechnung für drucktragende KesselteileThis European Standard was approved by CEN on 26 November 2011.
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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12952-3:2011: ESIST EN 12952-3:2012

Calculation of tube bends and elbows . 119Annex B (normative)
Fatigue cracking – Design to allow for fluctuating stress . 129Annex C (informative)
Examples of calculating the effects of fatigue . 145Annex D (informative)
Physical properties of steels . 152Annex E (informative)
Significant technical changes between this European Standard and the previous edition . 162Annex ZA (informative)
Clauses of this European Standard addressing essential safety requirements of the Pressure Equipment Directive 97/23/EC . 163Bibliography . 165 SIST EN 12952-3:2012

269 “Shell and water-tube boilers”, 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 2012, and conflicting national standards shall be withdrawn at the latest by June 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 12952-3:2001. 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 97/23/EC, see informative Annex ZA, which is an integral part of this document. Annex E provides details of significant technical changes between this European Standard and the previous edition. The European Standard series EN 12952 concerning water-tube boilers and auxiliary installations consists of the following parts:  Part 1: General;  Part 2: Materials for pressure parts of boilers and accessories;  Part 3: Design and calculation for pressure parts of the boiler;  Part 4: In-service boiler life expectancy calculations;  Part 5: Workmanship and construction of pressure parts of the boiler;  Part 6: Inspection during construction, documentation and marking of pressure parts of the boiler;  Part 7: Requirements for equipment for the boiler;  Part 8: Requirements for firing systems for liquid and gaseous fuels for the boiler;  Part 9: Requirements for firing systems for pulverized solid fuels for the boiler;  Part 10: Requirements for safeguards against excessive pressure;  Part 11: Requirements for limiting devices of the boiler and accessories;  Part 12: Requirements for boiler feedwater and boiler water quality;  Part 13: Requirements for flue gas cleaning systems; SIST EN 12952-3:2012

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 12952-3:2012

EN 12952-1:2001, Clause 7. SIST EN 12952-3:2012

EN 12952-6:2011: a) the design shall be such that manufacturing and welding in accordance with EN 12952-5:2011 and inspection in accordance with EN 12952-6:2011 shall be possible; b) where partial penetration welds are to be used, the depth of the required weld preparation groove shall be specified on the drawing; c) the welds attaching branches, nozzles, stubs and supports to drums and headers shall not involve any combination of austenitic and ferritic steel; d) the requirements covering the attachment of nozzles and branches to drums and headers without strength welding shall be in accordance with EN 12952-5:2011, 9.3; e) the requirements covering tube connections to drums and headers without strength welding shall be in accordance with EN 12952-5:2011, 9.4; f) limits of operation for nodular graphite cast iron valves and fittings; g) where random NDE of welds is permitted by EN 12952-6:2011, it shall be demonstrated that the welding is adequate for the imposed loading when a weld joint factor of 0,85 is applied; h) the special requirements applicable to coil boilers are given in EN 12952-5:2011, Annex D; i) the special requirements applicable to chemical recovery boilers are given in EN 12952-5:2011, Annex E. For major components operating in the creep range, facilities shall be provided for monitoring the creep in relation to operation. 5.6.2 Access The boiler shall be designed to ensure adequate access is provided to facilitate the internal examination of the drums and headers. The examination may be either manual or remote in accordance with the physical size of the components. The requirements and limitations of access and inspection openings shall be in accordance with EN 12952-5:2011, 9.2. SIST EN 12952-3:2012

to be used shall be the lowest of those permitted for the components under consideration, based on the material properties and the specific calculation temperature and should not be less than 1, see also 6.3. If the minimum yield strength data at higher temperatures are not available, linear extrapolation may be allowed. SIST EN 12952-3:2012

1) For the purpose of design in accordance with this European Standard, metal wastage includes oxidation, corrosion, erosion and abrasion. SIST EN 12952-3:2012

radiation b Heating mainly by convection Protected against radiation Water or water/steam mixture Saturation temperature at allowable (working gauge) pressure ps1 or at allowable (total gauge) pressure ps2
0 °C 50 °C For headers c (30 + 3 es) °C but not less than 50 °C (15 + 2 es) °C but not more than 50 °C 20 °C Superheated steam Superheated steam, see also 6.1.3 15 °C,
see also 6.1.5 50 °C 35 °C 20 °C a For definitions of types of heating see 6.1.7 to 6.1.10. b Platen type superheaters are treated like convection type superheaters. c For definition of header see 6.1.6.
6.1.2 Circulation boilers For circulation boilers, the reference temperature and the temperature allowance shall be in accordance with Table 6.1-1. 6.1.3 Once-through boilers, superheaters and reheaters For once-through boilers, the reference temperature tor is the temperature of the fluid. The temperature of the fluid shall be calculated by taken into account of variations in heat transfer and fluid flow in the boiler. For superheaters and reheaters the reference temperature shall be the mean temperature expected during service, of the fluid flowing through the various boiler parts. The temperature allowance shall be in accordance with Table 6.1-1. 6.1.4 Hot water generators For the special case of hot water generators, where the temperature of the contained fluid is limited by thermostats2), the reference temperature of the components shall be the fluid temperature.
2) Temperature limiters manufactured and tested in accordance with EN 12952-11:2007 are considered to be reliable. SIST EN 12952-3:2012

= 0°; do is the outside diameter. This requires a value of P0/do ≤ 1,3 for one row of tubes in accordance with Figure 6.1-1; P0/do ≤ 2,0 for two rows of tubes in accordance with Figure 6.1-2; P0/do ≤ 2,6 for three rows of tubes in accordance with Figure 6.1-3. d) the components are provided with closely spaced tubes in accordance with Figure 6.1-4 with a ratio of 1,02900≤lPPπ (6.1-2) where P0 is the longitudinal pitch with
= 0°; P90 is the circumferential tube pitch on the external surface with
= 90°; l is the distance between component and furnace envelope. 6.1.10 Components heated by radiation Unscreened components shall be considered to be primarily heated by radiation, if they are subject to radiation by flue gases with a temperature > 950 °C. SIST EN 12952-3:2012

Figure 6.1-1 — Components protected by one row of tubes
Figure 6.1-2 — Components protected by two rows of tubes
Figure 6.1-3 — Components protected by three rows of tubes
Key 1 flue gas flow 2 boundary of flue gas flow Figure 6.1-4 — Components protected by closely spaced tubes 6.2 Maximum through-the-wall temperature difference and maximum flue gas temperature for heated drums and headers 6.2.1 Maximum through-the-wall temperature difference The through-the-wall temperature difference (defined as outside wall temperature minus inside wall surface temperature) of heated drums and headers, shall not exceed 30 K. NOTE Components made from ferritic steel not exceeding 32 mm wall thickness and exposed to a heat flux less or equal to 40 kW/m2 will meet this requirement. 6.2.2 Headers exposed to flue gas Surfaces of superheater and reheater headers shall not be exposed to flue gas temperatures in excess of 500 °C. 6.2.3 Allowable deviations In cases where it is necessary to deviate from 6.2.1 and 6.2.2 it shall be verified that unsteady and steady thermal stresses do not lead to unacceptable stresses in the component wall. 6.3 Design stress 6.3.1 General The design stress f to be used for the design of components primarily subjected to static loading shall be
KfS= (6.3-1) where
K
is the material strength value for the design conditions in accordance with the material standards and specifications given e.g. in EN 12952-2:2011 and where S is the safety factor SIST EN 12952-3:2012

Kt’
is the material strength value and St’ is the safety factor, both for the test condition. 6.3.2 Rolled and forged steels The design stress f shall be the lowest value obtained from the equation =1,25;1,5and/or1,5;2,4mintcmTtcp0,2tceH20mRRRRf (6.3-3) where Rm 20
is the tensile strength at room temperature (20 °C); ReH tc
is the upper yield strength at calculation temperature tc; Rp0,2 tc
is the 0,2%-proof strength at calculation temperature tc and RmT tc3, 4
is the creep rupture strength for the specified lifetime T at calculation temperature tc. 6.3.3 Austenitic steels The design stress f shall be in accordance with the following:  for steels with a specified minimum transverse elongation A < 30%, the lowest value obtained from the equation RRfmin,,=;15125p0,2tcmTtc (6.3-4) where Rp0,2 tc
is the 0,2%-proof strength Rp0,2 at calculation temperature tc and RmT tc3, 4 is the creep rupture strength for the specified lifetime T at calculation temperature tc.  for steels with a specified minimum transverse elongation A ≥ 30 %, the lowest value obtained from equation
3 T is the minimum specified design lifetime with a minimum of 100 000 h. If no lifetime is specified 200 000 h shall be taken. Should creep rupture strength values for times in excess of 100 000 h not be available, 100 000 h data may be used with S = 1,5 for internal pressure. In exceptional cases, where pressure parts are operated in the creep range for short duration (less than 10 000 h) e.g. discharge, relief lines, T may be reduced to 10 000 h with the safety factor S = 1,25. 4 Creep rupture strength values for intermediate lifetimes shall be obtained by linear interpolation in a double logarithmic system. SIST EN 12952-3:2012

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