1、Designation: A 234/A 234M 07Used in USDOE-NE StandardsStandard Specification forPiping Fittings of Wrought Carbon Steel and Alloy Steel forModerate and High Temperature Service1This standard is issued under the fixed designationA 234/A 234M; the number immediately following the designation indicates
2、 the yearof original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the
3、 Department of Defense.1. Scope*1.1 This specification2covers wrought carbon steel andalloy steel fittings of seamless and welded construction coveredby the latest revision of ASME B16.9, B16.11, MSS-SP-79,MSS-SP-83, and MSS-SP-95. These fittings are for use inpressure piping and in pressure vessel
4、fabrication for service atmoderate and elevated temperatures. Fittings differing fromthese ASME and MSS standards shall be furnished in accor-dance with Supplementary Requirement S58 of SpecificationA 960/A 960M.1.2 Optional supplementary requirements are provided forfittings where a greater degree
5、of examination is desired. Whendesired, one or more of these supplementary requirements maybe specified in the order.1.3 This specification does not cover cast welding fittings orfittings machined from castings. Cast steel welding fittings aregoverned by Specifications A 216/A 216M and A 217/A 217M.
6、1.4 This specification is expressed in both inch-pound unitsand in SI units. However, unless the order specifies theapplicable “M” specification designation (SI units), the mate-rial shall be furnished to inch-pound units.1.5 The values stated in either inch-pound units or SI unitsare to be regarded
7、 separately as standard. Within the text, theSI units are shown in brackets. The values stated in eachsystem are not exact equivalents; therefore, each system mustbe used independently of the other. Combining values from thetwo systems may result in nonconformance with the specifi-cation.2. Referenc
8、ed Documents2.1 In addition to those reference documents listed inSpecification A 960/A 960M, the following list of standardsapply to this specification.2.2 ASTM Standards:3A 216/A 216M Specification for Steel Castings, Carbon,Suitable for Fusion Welding, for High-Temperature Ser-viceA 217/A 217M Sp
9、ecification for Steel Castings, MartensiticStainless and Alloy, for Pressure-Containing Parts, Suit-able for High-Temperature ServiceA 960/A 960M Specification for Common Requirementsfor Wrought Steel Piping Fittings2.3 ASME Standards:4B16.9 Steel Butt-Welding FittingsB16.11 Forged Steel Fittings, S
10、ocket Welding and Threaded2.4 ASME Boiler and Pressure Vessel Code:4Section V Nondestructive ExaminationSection VIII, Division 1, Pressure VesselsSection IX Welding Qualifications2.5 MSS Standards:5MSS-SP-25 Standard Marking System for Valves, Fittings,Flanges, and UnionsMSS-SP-79 Socket Welding Red
11、ucer InsertsMSS-SP-83 Steel Pipe Unions, Socket-Welding andThreadedMSS-SP-95 Swage(d) Nipples and Bull Plugs2.6 ASNT Standard:SNT-TC-1A Recommended Practice for NondestructiveTesting Personnel Qualification and Certification63. Ordering Information3.1 See Specification A 960/A 960M.4. General Requir
12、ements4.1 Product furnished to this specification shall conform tothe requirements of Specification A 960/A 960M, including1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.22 on Steel F
13、orgings and Wrought Fittings for Piping Applications and BoltingMaterials for Piping and Special Purpose Applications.Current edition approved March 1, 2007. Published April 2007. Originallyapproved in 1940. Last previous edition approved in 2006 as A 234/A 234M 06a.2For ASME Boiler and Pressure Ves
14、sel Code applications see related Specifi-cation SA-234 in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary pa
15、ge onthe ASTM website.4Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990.5Available from Manufacturers Standardization Society of the Valve and FittingsIndustry (MSS), 127 Park St., NE, Vienna, VA 22180-4602.6Avai
16、lable fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United State
17、s.any supplementary requirements that are indicated in thepurchase order. Failure to comply with the requirements ofSpecification A 960/A 960M constitutes non-conformancewith this specification. In case of a conflict between therequirements of this specification and Specification A 960/A 960M, this
18、specification shall prevail.5. Materials5.1 The material for fittings shall consist of killed steel,forgings, bars, plates, seamless or fusion-welded tubular prod-ucts with filler metal added and shall conform to the chemicalrequirements of Table 1. Unless otherwise specified for carbonsteel plates,
19、 the steel may be made to either coarse grain or finegrain practice. Grade WP9 shall be made to fine grain practice.5.2 A starting material specification that specifically re-quires the addition of any element beyond those listed for thematerials in Table 1 for the applicable grade of material is no
20、tpermitted. This does not preclude the use of deoxidizers or thejudicious use of elements for grain size control.6. Manufacture6.1 Forging or shaping operations may be performed byhammering, pressing, piercing, extruding, upsetting, rolling,bending, fusion welding, machining, or by a combination oft
21、wo or more of these operations. The forming procedure shallbe so applied that it will not produce injurious imperfections inthe fittings.NOTE 1Fittings NPS-4 and under may be machined from hot-forgedor rolled, cold-sized, and straightened bar stock having the chemicalcomposition of the Grade in Tabl
22、e 1 and the mechanical properties of theGrade in Table 2. Heat treatment shall be in accordance with Section 7.Allcaps machined from bar stock shall be examined by liquid penetrant ormagnetic particle in accordance with S52 or S53 in SpecificationA 960/A 960M.6.2 All welds including welds in tubular
23、 products fromwhich fittings are made shall be (1) made by welders, weldingoperators, and welding procedures qualified under the provi-sions of ASME Section IX,(2) heat treated in accordance withSection 7 of this specification, and (3) radiographically exam-ined throughout the entire length of each
24、weld in accordancewith Article 2, ASME Section V with acceptance limits inaccordance with Paragraph UW-51 of ASME Section VIII,Division 1 of the ASME Boiler min % in 2 in. 50 mm30 20A28 . . .Rectangular specimen for wall thickness less than516 in. 7.94 mm;min % in 2 in. 50 mm (12-in. 12.7-mm wide sp
25、ecimen)BBB. . .AWPB and WPC fittings manufactured from plate shall have a minimum elongation of 17 %.BFor each132 in. 0.79 mm decrease in wall thickness below516 in. 7.94 mm, a deduction of 1.5 % for longitudinal and 1.0 % for transverse from the values shownabove is permitted. The following table g
26、ives the minimum value for various wall thicknesses.Wall ThicknessGradesAll Grades except WPR, WP91 and WP911 WPR WP91 and WP911in. mm Longitudinal Transverse Longitudinal Longitudinal516 (0.312) 7.94 30.0 20.0 28.0 20932 (0.281) 7.14 28.5 19.0 26.5 1914 (0.250) 6.35 27.0 18.0 25.0 18732 (0.219) 5.5
27、6 25.5 . . . 23.5 17316 (0.188) 4.76 24.0 . . . 22.0 16532 (0.156) 3.97 22.5 . . . 20.5 1518 (0.125) 3.17 21.0 . . . 19.0 14332 (0.094) 2.38 19.5 . . . 17.5 13116 (0.062) 1.59 18.0 . . . 16.0 12NoteThis table gives the computed minimum % elongation value for each132 in. 0.79 mm decrease in wall thic
28、kness. Where the wall thickness lies between twovalues above, the minimum elongation value is determined by the following equations:Direction of Test EquationLongitudinal E=48t + 15.00Transverse E=32t + 10.00where:E = elongation in 2 in. or 50 mm, %, andt = actual thickness of specimen, in. mm.A 234
29、/A 234M 073pipe, provided the weld is double welded, is a full penetrationjoint, satisfies the requirements of 6.2 for qualifications and7.3.3 for post weld heat treatment.7. Heat Treatment7.1 Heat Treatment ProceduresFittings, after forming atan elevated temperature, shall be cooled to a temperatur
30、ebelow the critical range under suitable conditions to preventinjurious defects caused by too rapid cooling, but in no casemore rapidly than the cooling rate in still air. Heat treatmenttemperatures specified are metal (part) temperatures. Heat-treated fittings shall be treated according to paragrap
31、h 7 inSpecification A 960/A 960M.7.2 WPB, WPC, and WPR Fittings:7.2.1 Hot-formed WPB, WPC, and WPR fittings uponwhich the final forming operation is completed at a temperatureabove 1150 F 620 C and below 1800 F 980 C need notbe heat treated provided they are cooled in still air.7.2.2 Hot-formed or f
32、orged WPB, WPC, and WPR fittingsfinished at temperature in excess of 1800 F 980 C shallsubsequently be annealed, normalized, or normalized andtempered. Hot-forged fittings NPS 4 or smaller need not beheat treated.7.2.3 WPB, WPC, and WPR fittings over NPS 12, producedby locally heating a portion of t
33、he fitting stock to anytemperature for forming, shall be subsequently annealed,normalized, or normalized and tempered. Fittings such aselbows, tees, header tees, reducers and lap joint stub ends witha carbon content less than 0.26 %, NPS 12 and under, shall notrequire heat treatment after forming a
34、locally heated portion ofthe fitting.7.2.4 Cold-formed WPB, WPC, and WPR fittings, uponwhich the final forming operation is completed at a temperaturebelow 1150 F 620 C, shall be normalized, or shall be stressrelieved at 1100 to 1275 F 595 to 690 C.7.2.5 WPB, WPC, and WPR fittings produced by fusion
35、welding and having a nominal wall thickness at the weldedjoint of34 in. 19 mm or greater shall be post-weld heat treatedat 1100 to 1250 F 595 to 675 C, or in accordance with 7.2.6.7.2.6 At the option of the manufacturer, WPB and WPCfittings produced by any of the methods in Section 6 may beannealed,
36、 normalized, or normalized and tempered.7.3 Fittings Other than WPB, WPC, and WPR:7.3.1 Fittings of Grades WP1, WP11 Class 1, WP11 Class 2,WP11 Class 3, WP12 Class 1, WP12 Class 2, WP22 Class 1,WP22 Class 3, WP5, and WP9 shall be furnished in thefull-annealed, isothermal-annealed, or normalized and
37、tem-pered condition. If normalized and tempered, the temperingtemperature for WP11 Class 1, WP11 Class 2, WP11 Class 3,WP12 Class 1, and WP12 Class 2 shall not be less than 1150F 620 C; for Grades WP5, WP9, WP22 Class 1, and WP22Class 3 the tempering temperature shall not be less than 1250F 675 C.7.
38、3.2 Fittings of Grades WP1, WP12 Class 1, or WP12Class 2 either hot formed or cold formed may be given a finalheat treatment at 1200 F 650 C instead of the heat treatmentspecified in 7.3.1.7.3.3 Fittings in all thicknesses produced by fusion weldingafter the heat treatment specified in 7.3.1 shall b
39、e post-weldheat treated at a temperature not less than prescribed above fortempering except that Grade WP1 is required to be post-weldheat treated only when the nominal wall thickness at thewelded joint is12 in. 13 mm or greater.7.3.4 Except when Supplementary Requirement S1 is speci-fied by the pur
40、chaser, Grade WP91 shall be normalized at 1900F 1040 C minimum, and 1975 F 1080 C maximum, andtempered in the temperature range of 1350 F 730 C to 1470F 800 C as a final heat treatment.7.3.5 Grade WP911 shall be normalized in the temperaturerange of 1900 to 1975 F 1040 to 1080 C, and tempered inthe
41、temperature range of 1365 to 1435 F 740 to 780 C as afinal heat treatment.7.4 WPB and WPC Fittings Made from Bar Cold-finishedbars reduced in cross-sectional area more than 10 % by colddrawing or cold rolling are not acceptable for use in themanufacture of these fittings unless the bars have been ei
42、therstress relieved in the temperature range of 1100 to 1250 F595 to 675 C, normalized, normalized and tempered, or fullyannealed. Mechanical testing must be performed subsequent tothe final heat-treating operation.7.5 Liquid quenching followed by tempering shall be per-mitted for all grades when ap
43、proved by the purchaser. Mini-mum tempering temperature shall be 1100 F 595 C forWPB, WPC, and WPR, 1150 F 620 C for Grades WP1,WP11 Class 1, WP11 Class 2, WP11 Class 3, WP 12 Class 1,and WP12 Class 2 and 1250 F 675 C for Grades WP5,WP9, WP22 Class 1, and WP22 Class 3, and 1350 F 730 Cfor Grade WP91
44、 and WP911.8. Chemical Composition8.1 The chemical composition of each cast or heat usedshall be determined and shall conform to the requirements ofthe chemical composition for the respective materials listed inTable 1. The ranges as shown have been expanded to includevariations of the chemical anal
45、ysis requirements that are listedin the various specifications for the starting materials (pipe,tube, plate, bar, and forgings) normally used in the manufac-turing of fittings to this specification.8.2 The steel shall not contain any unspecified elements forthe ordered grade to the extent that it co
46、nforms to therequirements of another grade for which that element is aspecified element having a required minimum content.8.3 Weld metal used in the construction of carbon-steelfittings shall be mild steel analysis No. A1 of Table QW-442,Section IX of the ASME Boiler and Pressure Vessel Code, No.A2
47、may be used for Grade WPCW.8.4 The molybdenum and chromium content of the depos-ited weld metal of alloy steel fittings shall be within the samepercentage range as permitted for the base metal.9. Tensile Requirements9.1 The tensile properties of the fitting material shall con-form to the requirement
48、s listed in Table 2.9.1.1 Specimens cut either longitudinally or transverselyshall be acceptable for the tension test.9.1.2 While Table 2 specifies elongation requirements forboth longitudinal and transverse specimens, it is not the intentthat both requirements apply simultaneously. Instead, it isA
49、234/A 234M 074intended that only the elongation requirement that is appropri-ate for the specimen used be applicable.9.2 One tension test shall be made on each heat of materialand in the same condition of heat treatment as the finishedfittings it represents. The sample thickness shall not vary morethan14 in. 6 mm from the fitting wall thickness it represents.9.3 When cold-formed fittings are furnished, samples of theraw material shall be normalized or stres
