1、BRITISH STANDARDBS EN ISO 13704:2007Petroleum,petrochemical and natural gas industries Calculation of heater-tube thickness in petroleum refineriesICS 75.180.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44
2、g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Incorporatingcorrigendum June 2008National forewordThis British Standard is the UK implementation of EN ISO 13704:2007. It is identical with ISO 13704:2007, incorporating corrigendum June 2008. It supersedes BS ISO 13704:2001 which is withd
3、rawn.The start and finish of text introduced or altered by corrigendum is indicated in the text by tags. Text altered by ISO corrigendum June 2008 is indicated in the text by .The UK participation in its preparation was entrusted by Technical Committee PSE/17, Materials and equipment for petroleum,
4、petrochemical and natural gas industries, to Panel PSE/17/-/6, Processing equipment and systems for petroleum and natural gas industries. A list of organizations represented on this subcommittee can be obtained on request to its secretary. This publication does not purport to include all the necessa
5、ry provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. BS EN ISO 13704:2007Amendments/corrigenda issued since publicationDate Comments 31 October 2009 Implementation of ISO corrigendum June 200
6、8This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2008 BSI 2009ISBN 978 0 580 63971 5EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 13704November 2007ICS 75.180.20English VersionPetroleum, petrochemical and natural gas indust
7、ries -Calculation of heater-tube thickness in petroleum refineries (ISO13704:2007)Industries du ptrole, de la ptrochimie et du gaz naturel -Calcul de lpaisseur des tubes de fours de raffineries deptrole (ISO 13704:2007)Erdl- und Erdgasindustrie - Berechnung der Wanddickevon Heizrohren in Erdlraffine
8、rien (ISO 13704:2007)This European Standard was approved by CEN on 3 November 2007.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
9、bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 responsibilit
10、y of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Irel
11、and, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36
12、B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 13704:2007: EForeword This document (EN ISO 13704:2007) has been prepared by Technical Committee ISO/TC 67 “Materials, equipment and offshore structures for pet
13、roleum and natural gas industries“ in collaboration with Technical Committee CEN/TC 12 “Materials, equipment and offshore structures for petroleum, petrochemical and natural gas industries” the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national stan
14、dard, either by publication of an identical text or by endorsement, at the latest by May 2008, and conflicting national standards shall be withdrawn at the latest by May 2008. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound
15、 to implement this European Standard: Austria, Belgium, Bulgaria, 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, Swi
16、tzerland and the United Kingdom. Endorsement notice The text of ISO 13704:2007 has been approved by CEN as a EN ISO 13704:2007 without any modification. BS EN ISO 13704:2007EN ISO 13704:2007iiiContents Page1 Scope12 Terms and definitions .13 General design information33.1 Information required .33.2
17、Limitations for design procedures 44 Design.44.1 General .44.2 Equation for stress74.3 Elastic design (lower temperatures)74.4 Rupture design (higher temperatures) 84.5 Intermediate temperature range 84.6 Minimum allowable thickness84.7 Minimum and average thicknesses.84.8 Equivalent tube metal temp
18、erature .94.9 Component fittings135 Allowable stresses 155.1 General .155.2 Elastic allowable stress 165.3 Rupture allowable stress165.4 Rupture exponent165.5 Yield and tensile strengths.165.6 Larson-Miller parameter curves.165.7 Limiting design metal temperature175.8 Allowable stress curves176 Samp
19、le calculations186.1 Elastic design 186.2 Thermal-stress check (for elastic range only).196.3 Rupture design with constant temperature236.4 Rupture design with linearly changing temperature .25Annex A (informative) Estimation of remaining tube life28Annex B (informative) Calculation of maximum radia
20、nt section tube skin temperature 33Annex C (normative) Thermal-stress limitations (elastic range) .44Annex D (informative) Calculation sheets48Annex E (normative) Stress curves (SI units)50Annex F (normative) Stress curves (USC units)70Annex G (normative) Derivation of corrosion fraction and tempera
21、ture fraction90Annex H (informative) Data sources .98Bibliography103BS EN ISO 13704:2007EN ISO 13704:2007blank1Petroleum, petrochemical and natural gas industries Calculation of heater-tube thickness in petroleum refineries 1 Scope This International Standard specifies the requirements and gives rec
22、ommendations for the procedures and design criteria used for calculating the required wall thickness of new tubes and associated component fittings for petroleum-refinery heaters. These procedures are appropriate for designing tubes for service in both corrosive and non-corrosive applications. These
23、 procedures have been developed specifically for the design of refinery and related process-fired heater tubes (direct-fired, heat-absorbing tubes within enclosures). These procedures are not intended to be used for the design of external piping. This International Standard does not give recommendat
24、ions for tube retirement thickness; Annex A describes a technique for estimating the life remaining for a heater tube. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1actual inside diameter Diinside diameter of a new tube NOTE The actual insid
25、e diameter is used to calculate the tube skin temperature in Annex B and the thermal stress in Annex C. 2.2component fitting fitting connected to the fired heater tubes EXAMPLES Return bends, elbows, reducers. NOTE 1 There is a distinction between standard component fittings and specially designed c
26、omponent fittings; see 4.9. NOTE 2 Typical material specifications for standard component fittings are ASTM A 234, ASTM A 403 and ASTM B 366. 2.3corrosion allowance GCAadditional material thickness added to allow for material loss during the design life of the component 2.4design life tDLoperating t
27、ime used as a basis for tube design NOTE The design life is not necessarily the same as the retirement or replacement life. BS EN ISO 13704:2007EN ISO 13704:200722.5design metal temperatureTdtube-metal or skin temperature used for designNOTE This is determined by calculating the maximum tube metal t
28、emperature (Tmaxin Annex B) or the equivalenttube metal temperature (Teqin 2.8) and adding an appropriate temperature allowance (see 2.16). A procedure for calculating the maximum tube metal temperature from the heat-flux density is included in Annex B. When the equivalenttube metal temperature is u
29、sed, the maximum operating temperature can be greater than the design metal temperature.When the equivalent tube metal temperature is used to determine the design metal temperature, this design metaltemperature is only applicable to the rupture design. It is necessary to develop a separate design me
30、tal temperatureapplicable to the elastic design. The design metal temperature applicable to the elastic design is the maximum calculatedtube metal temperature among all operating cases plus the appropriate temperature allowance.2.6elastic allowable stressVelallowable stress for the elastic rangeSee
31、5.2. 2.7elastic design pressurepelmaximum pressure that the heater coil can sustain for short periods of time NOTE This pressure is usually related to relief-valve settings, pump shut-in pressures, etc. 2.8equivalent tube metal temperatureTeqcalculated constant metal temperature that in a specified
32、period of time produces the same creep damage as does a changing metal temperatureNOTE In 4.8 the equivalent tube metal temperature concept is described in more detail. It provides a procedure tocalculate the equivalent tube metal temperature based on a linear change of tube metal temperature from s
33、tart-of-run to end-of-run.2.9inside diameter iinside diameter of a tube with the corrosion allowance removed; used in the design calculationsDNOTE The inside diameter of an as-cast tube is the inside diameter of the tube with the porosity and corrosionallowances removed.2.10minimum thicknessGminmini
34、mum required thickness of a new tube, taking into account all appropriate allowancesNOTE See Equation (5).2.11outside diameterDooutside diameter of a new tube BS EN ISO 13704:2007EN ISO 13704:200732.12rupture allowable stress Vrallowable stress for the creep-rupture range See 4.4. 2.13rupture design
35、 pressure prmaximum operating pressure that the coil section can sustain during normal operation 2.14rupture exponent nparameter used for design in the creep-rupture range NOTE See figures in Annexes E and F. 2.15stress thickness GVthickness, excluding all thickness allowances, calculated from an eq
36、uation that uses an allowable stress 2.16temperature allowance TApart of the design metal temperature that is included for process- or flue-gas mal-distribution, operating unknowns, and design inaccuracies NOTE The temperature allowance is added to the calculated maximum tube metal temperature or to
37、 the equivalent tube metal temperature to obtain the design metal temperature (see 2.5). 3 General design information 3.1 Information required The design parameters (design pressures, design fluid temperature, corrosion allowance and tube material) shall be defined. In addition, the following inform
38、ation shall be furnished: a) design life of the heater tube; b) whether the equivalent-temperature concept is to be applied and, if so, the operating conditions at the start and at the end of the run; c) temperature allowance (see ISO 13705), if any; d) corrosion fraction (if different from that sho
39、wn in Figure 1); e) whether elastic-range thermal-stress limits are to be applied. If any of items a) to e) are not furnished, use the following applicable parameters: design life equal to 100 000 h; design metal temperature based on the maximum metal temperature (the equivalent-temperature concept
40、shall not apply); BS EN ISO 13704:2007EN ISO 13704:20074 temperature allowance equal to 15 C (25 F); corrosion fraction given in Figure 1; elastic-range thermal-stress limits. 3.2 Limitations for design procedures 3.2.1 The allowable stresses are based on a consideration of yield strength and ruptur
41、e strength only; plastic or creep strain has not been considered. Using these allowable stresses can result in small permanent strains in some applications; however, these small strains do not affect the safety or operability of heater tubes.3.2.2 No considerations are included for adverse environme
42、ntal effects, such as graphitization, carburization or hydrogen attack. Limitations imposed by hydrogen attack can be developed from the Nelson curves in API 941 1.3.2.3 These design procedures have been developed for seamless tubes. They are not applicable to tubes that have a longitudinal weld. IS
43、O 13705 allows only seamless tubes. 3.2.4 These design procedures have been developed for thin tubes (tubes with a thickness-to-outside-diameter ratio, Gmin/Do, of less than 0,15). Additional considerations can apply to the design of thicker tubes. 3.2.5 No considerations are included for the effect
44、s of cyclic pressure or cyclic thermal loading. 3.2.6 Limits for thermal stresses are provided in Annex C. Limits for stresses developed by mass, supports, end connections and so forth are not discussed in this International Standard. 3.2.7 Most of the Larson-Miller parameter referenced curves in 5.
45、6 are not Larson-Miller curves in the traditional sense but are derived from the 100 000 h rupture strength as explained in Clause H.3. Consequently, the curves might not provide a reliable estimate of the rupture strength for a design life that is less than 20 000 h or more than 200 000 h. 3.2.8 Th
46、e procedures in this International Standard have been developed for systems in which the heater tubes are subject to an internal pressure that exceeds the external pressure. There are some cases in which a heater tube can be subject to a greater external pressure than the internal pressure. This can
47、 occur, for example, in vacuum heaters or on other types of heaters during shutdown or trip conditions, especially when a unit is cooling or draining, forming a vacuum inside the heater tubes. Conditions where external pressures exceed the internal pressures can govern heater-tube wall thickness. De
48、termination of this (i.e. vacuum design) is not covered in this International Standard. In the absence of any local or national codes that can apply, it is recommended that a pressure vessel code, such as ASME VIII (Division 1, UG-28) or EN 13445, be used, as such codes also address external pressur
49、e designs. 4 Design 4.1 General There is a fundamental difference between the behaviour of carbon steel in a hot-oil heater tube operating at 300 C (575 F) and that of chromium-molybdenum steel in a catalytic-reformer heater tube operating at 600 C (1 110 F). The steel operating at the higher temperature creeps, or deforms permanently, even at stress levels well below the yield strength. If the tube metal temperature is high enough for the effects of creep to be significant, the tube eventually fails due to creep rupture, although no corrosio
