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1、BRITISH STANDARD BS EN 12953-3:2002 Shell boilers Part 3: Design and calculation for pressure parts The European Standard EN 12953-3:2002 has the status of a British Standard ICS 27.060.30; 27.100 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Licensed Copy: sheffieldun sheff
2、ieldun, na, Sat Oct 28 06:36:18 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 12953-3:2002 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 Committee on 1
3、4 June 2002 BSI 14 June 2002 ISBN 0 580 39851 X National foreword This British Standard is the official English language version of EN 12953-3:2002. It partially supersedes BS 2790:1992 which will be withdrawn on publication of BS EN 12953 Parts 1, 2, 3, 4, 5, 6, 8 and 9. When the reference to this
4、European Standard has been published in the Official Journal of the European Communities (OJ), compliance with it will confer a presumption of conformity with the essential requirements covered by the standard in respect of the Pressure Equipment Directive. The UK participation in its preparation wa
5、s entrusted to Technical Committee PVE/16, Shell boilers, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in t
6、his 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 Standards Online. This publication does not purport to include all the necessary provisions of a c
7、ontract. Users of this publication are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the inter
8、pretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 90, an inside back cover and a b
9、ack cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 06:36:18 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROP
10、ENNE EUROPISCHE NORM EN 12953-3 May 2002 ICS 27.060.30; 27.100 English version Shell boilers - Part 3: Design and calculation for pressure parts Chaudires tubes de fume - Partie 3: Conception et calcul des parties sous pression Growasserraumkessel - Teil 3: Konstruktion und Berechnung fr drucktragen
11、de Teile This European Standard was approved by CEN on 15 May 2002. 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 bibliographica
12、l 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 memb
13、er 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, Malta, Netherlands, Norway,
14、Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2002 CENAll rights of exploitation in any form and by any means reserved worldwide for
15、CEN national Members. Ref. No. EN 12953-3:2002 E Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 06:36:18 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12953-3:2002 (E) 2 Contents Page Foreword4 1Scope 5 2Normative references 5 3Terms and definitions5 4Symbols and abbreviations5 5General5 5.1
16、Boilers.5 5.2Hot-water generators.5 5.3Design of principal welds6 5.4Thermal design of furnaces tubes .6 5.5Dimensions of pressure parts7 5.6Establishment of pressures7 5.7Allowances .8 6Calculation temperature and nominal design stress.9 6.1Calculation temperature9 6.2Nominal design stress.10 7Cyli
17、ndrical shells under internal pressure10 7.1Shell thickness.10 7.2Basic calculation11 7.3Boiler support.11 7.4Reinforcing pads11 8Openings and branches in cylindrical shells11 8.1General11 8.2Efficiency factor, calculation by way of approximation and maximum diameter of an unrein- forced opening.17
18、8.3Design of openings and branches in cylindrical shells (efficiency and reinforcement)19 9Ends 26 9.1Unstayed dished heads without openings26 9.2Flat unstayed removable closures.28 9.3Flange connections .30 10Supported flat plates, stays and stiffeners .30 10.1Breathing spaces for flat plates .30 1
19、0.2Stayed flat surfaces.32 11Design of isolated openings in shell boiler flat end plates .52 11.1Unreinforced isolated openings.52 11.2Branch openings52 11.3Manholes, headholes and handholes53 12Unpierced tubes and tube plates .54 12.1Thickness of straight tubes subject to external pressure.54 12.2T
20、hickness of straight tubes subject to internal pressure55 12.3Wall thickness and ovality of elbows and tube bends.55 12.4Stay tubes.56 12.5Smoke tubes.58 12.6Pitch of tubes .58 12.7Thickness of the tube plates within tube nests58 13Furnaces tubes, furnace tube components and reversal chambers of cyl
21、indrical form subject to external pressure.58 13.1Furnaces tubes.58 13.2Calculation length of composite furnaces tubes60 13.3Tolerances of furnaces tubes.61 13.4Stiffeners.61 Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 06:36:18 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12953-3:2002 (E
22、) 3 14Access and inspection openings.64 14.1General requirements64 14.2Types and minimum dimensions of access and inspection openings64 14.3Minimum gasket bearing width and clearance for access and inspection doors 67 14.4Access and inspection openings in flat plates.68 14.5Inspection requirements.6
23、8 14.6Requirements for entry into boilers with a shell outside diameter greater than 1 400 mm.69 14.7Accessibility and arrangement of entry and inspection openings.69 Annex A (normative) Calculation of tube plate temperatures70 Annex B (informative) Calculation form for “Walker“-type reverse curve s
24、ections or corrugations.87 Annex ZA (informative) Clauses of this European Standard addressing essential requirements or other provisions of the Pressure Equipment Directive .89 Bibliography90 Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 06:36:18 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
25、EN 12953-3:2002 (E) 4 Foreword This document (EN 12953-3:2002) has been prepared by Technical Committee CEN/TC 269 “Shell and water-tube boilers“, the secretariat of which is held by DIN. This European Standard has been prepared under a mandate given to CEN by the European Commission and the Europea
26、n 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 standard. This European Standard shall be given the status of a national standard, either by publication of an identica
27、l text or by endorsement, at the latest by November 2002, and conflicting national standards shall be withdrawn at the latest by November 2002. This European Standard EN 12953 concerning shell boilers consists of the following Parts: ?Part 1:General. ?Part 2:Materials for pressure parts of boilers a
28、nd accessories. ?Part 3:Design and calculation for pressure parts. ?Part 4:Workmanship and construction of pressure parts of the boiler. ?Part 5:Inspection during construction, documentation and marking of pressure parts of the boiler. ?Part 6:Requirements for equipment for the boiler. ?Part 7:Requi
29、rements for firing systems for liquid and gaseous fuels for the boiler. ?Part 8:Requirements for safeguards against excessive pressure. ?Part 9:Requirements for limiting devices, and of the boiler and accessories. ?Part 10: Requirements for boiler feedwater and boiler water quality. ?Part 11: Accept
30、ance tests. ?Part 12: Requirements for firing systems for solid fuels for the boiler. ?Part 13: Operational Instructions. CR 12953-14:Guidelines for the involvement of an inspection body independent of the manufacturer. Although these Parts can be obtained separately, it should be recognized that th
31、e Parts are inter-dependent. As such, the design and manufacture of shell boilers requires the application of more than one Part in order for the require- ments of the standard to be satisfactorily fulfilled. The Annex A of this European Standard is informative. The Annex B of this European Standard
32、 is normative. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following coun- tries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta,
33、Netherlands, Norway, Portugal, Spain, Swe- den, Switzerland and the United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 06:36:18 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12953-3:2002 (E) 5 1 Scope This Part of this European Standard specifies requirements for the design and c
34、alculation of pressure parts of shell boilers as defined in EN 12953-1. 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 li
35、sted 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). EN
36、12953-1:2001, Shell boilers Part 1: General. EN 12953-2, Shell boilers Part 2: Materials for pressure parts of boilers and accessories. EN 12953-4, Shell boilers Part 4: Workmanship and construction of pressure parts of the boiler. EN 12953-5:2002, Shell boilers Part 5: Inspection during constructio
37、n, documentation and marking of pressure parts of the boiler. EN 12953-8, Shell boilers Part 8: Requirements for safeguards against excessive pressure. prEN 12953-10, Shell boilers Part 10: Requirements for boiler feedwater and boiler water quality. EN 13445-3, Unfired pressure vessels - Part 3: Des
38、ign. 3 Terms and definitions For the purposes of this European Standard the terms and definitions given in EN 12953-1 apply. 4 Symbols and abbreviations For the purposes of this Part of this European Standard, the symbols given in EN 12953-1:2002, Table 4-1 shall apply. Throughout this standard, add
39、itional terminology and symbols have been included where necessary to meet the requirements of the specific text concerned. It should also be noted that in some clauses the same additional symbol is used in different formulae to represent different terms. However, in all such cases, the special mean
40、ing of each symbol is indicated for each formula. 5 General 5.1 Boilers The requirements in this standard shall apply to boilers constructed throughout under the conditions specified herein and which are to be operated under normal operating conditions, with feedwater and boiler water in accordance
41、with prEN 12953-10, and under adequate supervision. Where the risk of abnormal working conditions is foreseen, such as severe cyclic service, the design shall be given special consideration. 5.2 Hot-water generators For directly fired hot-water generators the difference between the outlet temperatur
42、e and the inlet temperature should not exceed 50 K. If the difference between these two temperatures is greater than 50 K, either internal or external mixing devices shall be used to limit the differential temperature within the boiler to 50 K. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28
43、06:36:18 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12953-3:2002 (E) 6 The difference between the saturation temperature corresponding to the maximum working pressure, and the outlet temperature, should not exceed 80 K. If the difference is greater than 80 K, the distances in accordance with 10.1
44、 shall be increased by 50 %. Furthermore the maximum heat input in accordance with Figure 5.4-1 shall be reduced by 20 %. The inlet water entering the boiler shall not impinge directly on the furnace tube. 5.3 Design of principal welds The types of weld employed in the design of the boiler shall be
45、in accordance with EN 12953-4. Welds which are subjected to non-destructive examination (NDE) in accordance with the requirements of EN 12953-5 shall be designed so that the required NDE can be carried out. The value of the weld factor v used in the calculation for the shell thickness shall be eithe
46、r 0,85 or 1 depending on the extent of NDE to be carried out (see 7.2 and EN 12953-5). 5.4 Thermal design of furnaces tubes In order to ensure safe burner/boiler combinations, the heat input for a given furnace tube inside diameter shall not exceed the value given in Figure 5.4-1. Burners with a fix
47、ed firing rate (also called on/off or single stage burners) shall not be used for heat inputs exceeding 1 MW per furnace tube. Combustion shall be completed in the furnace tube. NOTEExamples 1 and 2 show how Figure 5.4-1 is used. EXAMPLE 1Furnace tube inside diameter required for a given heat input
48、Oil flow: 0,1 kg/s Net calorific value: 42,9 MJ/kg Air flow (with air excess 15 %): 1,76 kg/s Air temperature (with air preheater): 120 C Heat input: 4 290 ? 214 = 4 504 kW Furnace tube steel: P295 GH a) Minimum plain furnace tube inside diameter: 810 mm b) Minimum Fox 150 ? 50 (Table 13.1-1) corrug
49、ated furnace tube inside diameter: 760 mm. EXAMPLE 2: Allowable heat input for a given furnace tube inside diameter a) Plain furnace tube inside diameter: 1 500 mm ? P295 GH, oil firing:12,90 MW ? P295 GH, gas firing:16,77 MW ? P265 GH, oil firing: 8,00 MW ? P265 GH, gas firing:10,40 MW b) Fox 150 ? 50 (Table 13.1-1) corrugated furnace tube inside diameter 1 000 mm ? P265 GH, gas firing:7,02 MW. The length of the refractory should not be larger than one third of the inside furnace tube diameter measured from the end of the burner. NOTEAttention is dra