EN 12952-3:2001
(Main)Water-tube boilers and auxilliary installations - Part 3: Design and calculation for pressure parts
Water-tube boilers and auxilliary installations - Part 3: Design and calculation for pressure parts
This Part of this European Standard specifies the requirements for the design and calculation of water-tube boilers
as defined in EN 12952-1.
Wasserrohrkessel und Anlagenkomponenten - Teil 3: Konstruktion und Berechnung für drucktragende Teile
Dieser Teil der Europäischen Norm legt Anforderungen für die Konstruktion und Berechnung von Wasserrohrkesseln nach der Definition in EN 12952-1 fest.
Chaudières à tubes d'eau et installations auxiliaires - Partie 3: Conception et calcul des parties sous pression
Cette partie de la Norme européenne spécifie les règles de conception et de calcul des chaudières à tubes d'eau telles que définies dans l'EN 12952-1.
Vodocevni kotli in pomožne napeljave - 3. del: Konstrukcija in izračun delov, ki so pod tlakom
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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 TeileChaudieres a tubes d'eau et installations auxiliaires - Partie 3: Conception et calcul des parties sous pressionWater-tube boilers and auxilliary 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 12952-3:2001SIST EN 12952-3:2002en01-maj-2002SIST EN 12952-3:2002SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12952-3December 2001ICS 27.040English versionWater-tube boilers and auxilliary installations - Part 3: Designand calculation for pressure partsChaudières à tubes d'eau et installations auxiliaires - Partie3: Conception et calcul des parties sous pressionWasserrohrkessel und Anlagenkomponenten - Teil 3:Konstruktion und Berechnung für drucktragende TeileThis European Standard was approved by CEN on 25 July 2001.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 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 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2001 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12952-3:2001 ESIST EN 12952-3:2002
5.4Design by analysis.
5.5Cyclic loading .5.6General design requirements .5.7Design and calculation pressures .5.8Metal wastage .5.9Attachments on pressure parts .6Calculation temperature and nominal design stress .6.1Calculation temperature . 6.2Maximum through-the-wall temperaturedifference and maximum flue gastemperature for heated drums and headers .6.3Design stress .7Cylindrical shells of drums and headersunder internal pressure.7.1Shell thickness .7.2Basic calculation .7.3Combined stresses in drum and header shells .7.4Boiler drum supports.7.5Other stresses in cylindrical shells .8Openings and branches in cylindrical shells of drums and headers and integral tubes .8.1General .8.2Efficiency factor, calculation by way ofapproximation, and maximum diameter of unreinforced openings .8.3Design of openings and branches in cylindrical shells (efficiency and reinforcement) .8.4Bolted connections .8.5Screwed connections .9Headers and plain tubes of rectangular section .9.1General .9.2Symbols and abbreviations.9.3Required wall thickness.10Ends and spherical shells .10.1Symbols and abbreviations.10.2Spherical shells and dished ends .10.3Unstayed flat ends .10.4Flat unstayed closures .11Tubes .11.1Symbols and abbreviations .11.2Thickness of straight boiler tubes .11.3Thickness of tube bends and elbows .11.4Flexibility of integral tubing tube systems 11.5Structural attachments to tubes .11.6Fitting and joining of heated tubes .11.7Joining of unheated tubes .12Pressure parts of irregular shape .12.1Hydrostatic test for determining the allowable internal pressure .12.2Numerical methods .13Fatigue .13.1General .13.2Symbols and abbreviations .13.3Exemption rule for fatigue analysis .13.4Stress analysis for fatigue calculation .13.5Example calculations .Annex A (normative) Calculation of tube bends and elbows .A.1General .A.2Symbols and abbreviations .A.3Required wall thickness .A.4Calculation .Annex B
(normative) Fatique cracking – Design to allow for fluctuating stress .B.1General .B.2Conditions .B.3Symbols and abbreviations .B.4Cyclic stress range and meancyclic stress in the case of uniaxial and multiaxial fluctuating stress .B.5Correction factors for taking into account the influences of surface finish and weldments .B.6Controlling stress range .B.7Permissible stress range with a known number of load cycles .Annex C
(informative) Examples of calculating the effects of fatigue .C.1General .C.2Calculation of the admissible numberof load cycles .C.3Calculation of the admissible temperature gradient .Annex D (informative) Physical properties ofsteel .D.1General .D.2Symbols and abbreviations .D.3Physical properties .D.4Physical properties of steels .Annex ZA (informative) Clauses of this European Standard addressing essentialrequirements or other provisions of the Pressure Equipment Directive .Bibliography .2SIST EN 12952-3:2002
Part 4 is not applicable during the design, construction and installation stages.The annexes A and B of this European Standard are normative.The annexes C, D, and ZA of this European Standard are informative.3SIST EN 12952-3:2002
ScopeThis Part of this European Standard specifies the requirements for the design and calculation of water-tube boilersas defined in EN 12952-1.2
Normative referencesThis Part of the 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 EuropeanStandard only when incorporated in it by amendment or revision. For undated references, the latest editions of thepublication referred to applies (including amendments).prEN 1092-1,
Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN de-signated — Part 1: Steel flanges.EN 1591,
Flanges and their joints — Design rules for gasketed circular flange connections — Calculation method.prEN 1759-1,
Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, classdesignated — Part 1: Steel flanges NPS ½ to 24.EN 10025,
Hot rolled products of non-alloy structural steels — Technical delivery conditions (includes amendmentA1 : 1993).prEN 10266,
Steel tubes, fittings and structural hollow sections — Definitions and symbols for use in productstandards.prEN 12953-3,
Shell boilers — Part 3: Design and calculation.EN 12952 series,
Water-tube boilers and auxilliary installations.prEN 13445 series,
Unfired pressure vessels.prEN 13480 series,
Metallic industrial piping.ISO 7-1,
Pipe threads where pressure-tight joints are made on the threads — Part 1: Dimensions, tolerances anddesignations.ISO 4287,
Geometrical Product Specification (GPS) — Surface texture: Profile method — Terms, definitions andsurface texture parameters.3
Terms and definitionsFor the purpose of this standard the terms and definitions given in EN 12952-1 apply.4SIST EN 12952-3:2002
Symbols and abbreviationsFor the purposes of this standard, the symbols given in Table 4-1 of EN 12952-1 shall apply. Throughout thisEuropean Standard, additional terminology and symbols have been included where necessary to meet therequirements of the specific text concerned.5
General5.1
PurposeWater-tube boiler pressure parts shall be designed in accordance with the requirements of EN 12952-3. Theresulting designs shall be reproduced in the form of approved drawings and specifications to ensure the properapplication of the design requirements during the manufacturing and inspection stages.5.2
Dimensions of pressure partsThe wall thickness and other dimensions of pressure parts sufficient to withstand the calculation pressure atcalculation temperature for the design lifetime shall be determined in accordance with EN 12952-3 using materialsin accordance with EN 12952-2.The design for loadings arising from the following situations shall also be determined in accordance with this part ofEN 12952:a)the bending of a drum or header as a beam under self weight and imposed loads;b)local support loads on drums;c)thermally induced forces and moments within or arising from systems of integral tubing;d)local loading of tubes by structural attachments;e)rapid and frequent changes of pressure and temperature.Methods for calculating stresses caused by external loads applied to nozzles and to attachments shall be inaccordance with prEN 13445.NOTE
The purpose of this part is to give specific design rules for common forms of loadings to which boiler parts are normallysubjected to and general rules on how other loadings are to be considered. It does not give specific design rules for loadings otherthan those described in a) to e).These design rules are adequate for boilers of established construction, installed and operated in accordance withthe manufacturer's instructions.Determination of the dimensions of pressure parts shall be given special consideration not included in this standard,when abnormal conditions are present, such as:f)abnormally high corrosive products of combustion;g)highly pressurized products of combustion;h)poor feedwater.Deviations from the requirements of this standard by the use of alternative design methods shall be permitted,provided it can be shown that the adoption of such methods does not impair the safety of the component. A recordof all deviations shall be recorded in the manufacturer`s dossier. See also clause 7 of EN 12952-1.5.3
Strength of pressure partsThe strengths of the pressure parts shall be such as to withstand the following loads:a)internal pressure5SIST EN 12952-3:2002
Design by analysisIt shall be permissible to design by analysis provided the safety and functional requirements of the components arenot impaired.The results of any stress calculations carried out for loadings not explicitly covered by equations in this clause shallbe determined by using the criteria given in prEN 13445.5.5
Cyclic loadingBoiler components are deemed to be exposed to cyclic loading if the boiler is designed for more than 500 cold startups. Where cylindrical or spherical pressure parts with openings are subject to cyclic loading, the followingcalculation shall be carried out:(5.5.-1)vt
550N/mm2 p0
am×dmns×ems 0,5
Ze2mswherep0 is the maximum operating pressure,dmis t
...
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