1、Designation: A 254 97 (Reapproved 2002)Standard Specification forCopper-Brazed Steel Tubing1This standard is issued under the fixed designation A 254; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification covers double-wall, copper-brazedstee
3、l tubing suitable for general engineering uses, particularlyin the automotive, refrigeration, and stove industries for fuellines, brake lines, oil lines, heating and cooling units, and thelike.1.2 The values stated in inch-pound units are to be regardedas the standard.2. Referenced Documents2.1 ASTM
4、 Standards:A 370 Test Methods and Definitions for Mechanical Testingof Steel Products2E 30 Test Methods for Chemical Analysis of Steel, CastIron, Open-Hearth Iron, and Wrought Iron3E 59 Practice for Sampling Steel and Iron for Determinationof Chemical Composition42.2 Society of Automotive Engineers
5、Standard:J 533 Flares for Tubing53. Ordering Information3.1 Orders for material under this specification shouldinclude the following, as required to describe the desiredmaterial adequately:3.1.1 Quantity (feet, metres),3.1.2 Name of material (copper-brazed steel tubing),3.1.3 Type, where necessary (
6、see Fig. 1) (normally the typeis not specified),3.1.4 Size (outside diameter and wall thickness; normallyinside diameter should not be specified),3.1.5 Length (specific or random),3.1.6 Inside surface cleanliness where required (see Section8),3.1.7 External coating, where required (see Section 7 and
7、Supplementary Requirement S2), and3.1.8 Special or supplementary requirements or exceptionsto specification.4. Manufacture4.1 The steel may be made by any process.4.2 If a specific type of melting is required by the purchaser,it shall be as stated on the purchase order.4.3 The primary melting may in
8、corporate separate degas-sing or refining and may be followed by secondary melting,such as electroslag remelting or vacuum-arc remelting. Ifsecondary melting is employed, the heat shall be defined as allof the ingots remelted from a single primary heat.4.4 Steel may be cast in ingots or may be stran
9、d cast. Whensteel of different grades is sequentially strand cast, identifica-tion of the resultant transition material is required. Theproducer shall remove the transition material by an establishedprocedure that positively separates the grades.4.5 The tubing shall be made by rolling steel strip in
10、to theform of tubing and subsequently copper brazing in a reducingatmosphere.4.6 Tubing shall be constructed as shown in Fig. 1.4.7 Tubing shall be suitably tested after brazing by themanufacturer to ensure freedom from leaks and detrimentalflaws.5. Chemical Composition5.1 The steel shall conform to
11、 the requirements as tochemical composition prescribed in Table 1.5.2 Heat AnalysisAn analysis of each heat of steel shallbe made by the steel manufacturer to determine the percentagesof the elements specified. If secondary melting processes areemployed, the heat analysis shall be obtained from oner
12、emelted ingot or the product of one remelted ingot of eachprimary melt. The chemical composition thus determined, or1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel, and Related Alloys and is the direct responsibility of SubcommitteeA01.09 on Carbon Steel
13、Tubular Products.Current edition approved Mar. 10, 1997. Published November 1997. Originallypublished as A 254 44. Last previous edition A 254 94.2Annual Book of ASTM Standards, Vol 01.03.3Discontinued 1995; see 1994 Annual Book of ASTM Standards, Vol 03.05.4Discontinued 1996; see 1995 Annual Book o
14、f ASTM Standards, Vol 03.05.Replaced by E 1806 (Vol 03.06).5Available from Society of Automotive Engineers, Inc. 400 Commonwealth Dr.,Warrendale, PA 15096-0001.Single-Strip Type Double-Strip TypeFIG. 1 Brazed Tubing, Double-Wall, 360-deg Brazed Construction1Copyright ASTM International, 100 Barr Har
15、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.that determined from a product analysis made by the tubularproduct manufacturer shall conform to the requirements speci-fied.5.3 Product AnalysisTubing of this quality is commonlyproduced in rimmed or capped steel which is chara
16、cterized bya lack of uniformity in its chemical composition. For thisreason, rejection for product analysis is not appropriate unlessmisapplication is clearly indicated.5.4 Methods of AnalysisMethods described in Test Meth-ods E 30 shall be used for referee purposes. Due allowanceshall be made for t
17、he presence of copper brazing metal.5.5 Samples for Product AnalysisExcept for spectro-graphic analysis, samples shall be taken in accordance withPractice E 59.6. Mechanical Requirements6.1 Tension TestTensile properties of tubing as manufac-tured (prior to cold working) shall conform to the require
18、mentsspecified in Table 2.6.1.1 The specimens and tension tests required shall bemade in accordance with Test Methods and Definitions A 370.6.1.2 Specimens shall be tested at room temperature.6.1.3 Test specimens shall be taken from the ends offinished tubes prior to upsetting, swaging, expanding, o
19、r otherforming operations, or being cut to length. They shall besmooth on the ends and free from burrs and flaws.6.1.4 If any test specimen shows flaws or defective machin-ing, it may be discarded and another specimen substituted.6.1.5 The yield strength shall be determined as that corre-sponding to
20、 a permanent offset of 0.2 % of the gage length ofthe specimen, or a total extension of 0.5 % of the gage lengthunder load.6.1.6 If the percentage of elongation of any test specimen isless than that specified and any part of the fracture is more than34 in. (19.0 mm) from the center of the gage lengt
21、h, asindicated by scribe marks on the specimen before testing, aretest shall be allowed.6.2 Flattening TestA section of tubing, not less than 212in. (64 mm) in length, shall stand being flattened betweenparallel plates until the inside walls are in contact withoutcracking or otherwise showing flaws.
22、6.3 Expansion TestA section of tubing approximately 4in. (100 mm) in length shall stand being expanded over atapered mandrel having a slope of 1 in 10 until the outsidediameter at the expanded end is increased 20 % withoutcracking or otherwise showing flaws. (Prior to the expansiontest, tubing shall
23、 be cut off square, edge crowned, anddeburred. It shall be held firmly and squarely in the die, andpunch must be guided on the axis of the tubing.)6.4 Bend TestThe finished tubing shall stand bending on acenterline radius equal to three times the tubing outsidediameter without kinking, cracking, or
24、developing other flawswhere proper bending fixtures are used.6.5 Pressure Proof TestsEach tube shall be capable ofwithstanding, without bursting or leaking, either of the follow-ing proof tests:6.5.1 An internal hydrostatic pressure sufficient to subjectthe material to a minimum fiber stress of 16 0
25、00 psi (110MPa). Hydrostatic pressure shall be determined by the follow-ing formula:P 5 2St/Dwhere:P = hydrostatic pressure, psi (or MPa),S = allowable fiber stress, 16 000 psi (110 MPa),t = actual wall thickness of tubing, in. (or mm), andD = actual outside diameter of tubing, in. (or mm).6.5.2 An
26、underwater air pressure between 225 and 250 psi(1.55 and 1.73 MPa).7. Coating7.1 Tubing may be furnished with a copper coating on theinside and outside surfaces, at the option of the manufacturer.8. Inside Surface Cleanliness8.1 When inside surface cleanliness is specified by thepurchaser, tubing fo
27、r certain uses, such as refrigeration con-densers, shall conform to the following requirement for inter-nal cleanliness:8.1.1 When a length of tubing is washed internally withredistilled chloroform or redistilled 1,1,1-trichloroethane, theresidue remaining upon evaporation of the solvent shall notex
28、ceed 1.25 3 104g/in.2(0.194 g/m2) of internal surface. Toperform the test, pour 100 mL of solvent through the tubingand collect. The total length of tubing tested should not be lessthan 40 ft (12 m), although this total length may be obtained bywashing several separate lengths and pouring the same s
29、olventthrough each in succession. Evaporate the solvent in a steam orhot water bath, and dry at 110C (230F) until the vapors arecompletely removed.8.2 To maintain this level of cleanliness in shipping, han-dling, and storage, the purchaser may request that the manu-facturer seal the tube ends with c
30、aps or closures.9. Dimensional Tolerances9.1 The tubing shall conform to the permissible variations inTable 3, Table 4, and Table 5.10. Workmanship, Finish, and Appearance10.1 Finished tubing shall be clean, smooth and round, bothinside and outside, and shall be free of rust, scale, and defectsthat
31、impair processing and serviceability. Finished tubes shallbe reasonably straight.TABLE 1 Chemical RequirementsElement Composition, %Carbon 0.05 to 0.15Manganese 0.27 to 0.63Phosphorus, max 0.035Sulfur, max 0.035TABLE 2 Tensile RequirementsProperty RequirementTensile strength, min, psi (MPa) 42 000 (
32、290)Yield strength, min, psi (MPa) 25 000 (172)Elongation in 2 in. (50.8 mm) min, % 25A 254 97 (2002)211. Retests11.1 If the results of the mechanical tests of any group or lotdo not conform to the requirements specified in the individualspecification, retests may be made on additional tubes ofdoubl
33、e the original number from the same group or lot, each ofwhich shall conform to the requirements specified.12. Retreatment12.1 If the individual tubes or the tubes selected to representany group or lot fail to conform to the test requirements, theindividual tubes or the group or lot represented may
34、beretreated and resubmitted for test. Not more than two reheattreatments shall be permitted.13. Inspection13.1 The inspector representing the purchaser shall haveentry at all times while work on the contract of the purchaseris being performed, to all parts of the manufacturers worksthat concern the
35、manufacture of the material ordered. Themanufacturer shall afford the inspector all reasonable facilitiesto satisfy him that the material is being furnished in accordancewith this specification. All required tests and inspection shallbe made at the place of manufacture prior to shipment, unlessother
36、wise specified, and shall be conducted so as not tointerfere unnecessarily with the operation of the works.14. Rejection14.1 Each length of tubing received from the manufacturermay be inspected by the purchaser and, if it does not meet therequirements of the specification based on the inspection and
37、test method as outlined in the specification, the tubing may berejected and the manufacturer shall be notified. Disposition ofrejected tubing shall be a matter of agreement between themanufacturer and the purchaser.14.2 Material that fails in any of the forming operations orin the process of install
38、ation and is found to be defective shallbe set aside, and the manufacturer shall be notified for mutualevaluation of the materials suitability. Disposition of suchmaterial shall be a matter for agreement.15. Certification15.1 When requested on the purchasers order, a test report,signed by an authori
39、zed employee or representative of themanufacturer, shall be furnished to the purchaser to indicate thespecification and year date and grade, the results of thechemical analysis, hardness, and tension tests, when specified,and other tests as may be specified in writing by the purchaser.16. Product Ma
40、rking16.1 The specification number (the marking need not in-clude the year date of the specification), the name or brand ofthe manufacturer and the size of tubing or the part number shallbe marked on a tag or label securely attached to the bundles orboxes in which the tubes are shipped.16.2 Bar Codi
41、ngIn addition to the requirements in 16.1bar coding is acceptable as a supplemental identificationmethod. The purchaser may specify in the order a specific barcoding system to be used.17. Keywords17.1 steel tubeSUPPLEMENTARY REQUIREMENTSOne or more of the following supplementary requirements shall a
42、pply only when specified by thepurchaser in the inquiry, contract, or order. Details of these supplementary requirements shall beagreed upon by the manufacturer and the purchaser.S1. Flare TestS1.1 Brazed tubing shall stand being double flared todimensions shown in SAE Standard J 533, without splitt
43、ingthrough the wall at the major diameter of the flare. A separationof the outer lap joint is permissible on the flared end of the tubeonly in Area A (see Fig. S1.1). This separation shall not exceedTABLE 3 Outside Diameter RequirementsSpecified Outside Diameter, in. (mm) Variations, in. (mm)Plus or
44、 MinusUnder316 (4.76) 0.002 (0.051)316 (4.76) through38 (9.53) 0.003 (0.076)716 (11.1) through58 (15.9) 0.004 (0.102)TABLE 4 Wall Thickness RequirementsSpecified Wall Thickness, in. (mm) Variations, in. (mm)Plus or Minus0.020 (0.51) through 0.030 (0.76) 0.003 (0.08)0.031 (0.79) through 0.049 (1.24)
45、0.0035 (0.09)TABLE 5 Length RequirementsSpecified Cut Length, in. (m) Variations, in. (mm)18 (0.46) and under 60.03 (60.76)Over 18 (0.46) through 40 (1.02) 60.06 (61.52)Over 40 (1.02) through 80 (2.03) 60.12 (63.05)Over 80 (2.03) through 120 (3.05) 60.25 (66.35)Over 120 (3.05) +1.00 (+25.4), 0.0A 25
46、4 97 (2002)30.12 in. (3.0 mm) in length and shall be confined to the outerthickness only. Seam separation is not permitted in the follow-ing areas:S1.1.1 Area B (the flare seat, defined as the surface withinthe 90 included angle); conical surface shall be smooth andfree from cracks or other irregula
47、rities that could cause leaksafter assembly.S1.1.2 Area C (the surface beyond the length of the doublethickness created by the flare).S1.2 The flare seat may contain superficial random radialmarks or indentations which are not detrimental to the seal-ability of the flare. No indentations of a repeti
48、tive natureresulting from flaring tooling deterioration or adhesion of chipsor dirt to the flaring tooling are permissible. In the event thatthe physical appearance of the flare seat is questioned, thecriterion for final judgment is whether or not the flare seat willseal when subjected to a pressure
49、 test at the prescribed torquelevel.S2. External CoatingS2.1 The outside surface of the tubing shall be coated witha hot-dipped, lead-tin alloy coating. Weight and composition ofcoating shall be agreed upon between the manufacturer andpurchaser.S3. End FinishS3.1 Finished tubing shall have smooth ends free of burrs.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent r
