Designation: A 254 97 An American National Standard

Standard Specication for

Copper-Brazed Steel Tubing
1
This standard is issued under the xed designation A 254; the number immediately following the designation indicates the year of
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 Department of Defense. Consult the DoD Index of Specications and
Standards for the specic year of issue which has been adopted by the Department of Defense.
1. Scope
1.1 This specication covers double-wall, copper-brazed
steel tubing suitable
for general engineering uses, particularly in the automotive,
refrigeration, and stove industries for fuel lines, brake lines, oil
lines, heating and cooling units, and the like.
1.2 The values stated in inch-pound units are to be regarded
as the standard.
2. Referenced Documents
2.1 ASTM Standards:
A 370 Test Methods and Denitions for Mechanical Testing
of Steel Products
2
E 30 Test Methods for Chemical Analysis of Steel, Cast
Iron, Open-Hearth Iron, and Wrought Iron
3
E 59 Practice for Sampling Steel and Iron for Determination
of Chemical Composition
4
2.2 Society of Automotive Engineers Standard:
J 533 Flares for Tubing
5
3. Ordering Information
3.1 Orders for material under this specication should
include the following, as required to describe the desired
material adequately:
3.1.1 Quantity (feet, meters),
3.1.2 Name of material (copper-brazed steel tubing),
3.1.3 Type, where necessary (see Fig. 1) (normally the type
is not specied),
3.1.4 Size (outside diameter and wall thickness; normally
inside diameter should not be specied),
3.1.5 Length (specic or random),
3.1.6 Inside surface cleanliness where required (see Section
8),
3.1.7 External coating, where required (see Section 7 and
Supplementary Requirement S2), and
3.1.8 Special or supplementary requirements or exceptions
to specication.
4. Manufacture
4.1 The steel may be made by any process.
4.2 If a specic type of melting is required by the purchaser,
it shall be as stated on the purchase order.
4.3 The primary melting may incorporate separate degas-
sing or rening and may be followed by secondary melting,
such as electroslag remelting or vacuum-arc remelting. If
secondary melting is employed, the heat shall be dened as all
of the ingots remelted from a single primary heat.
4.4 Steel may be cast in ingots or may be strand cast. When
steel of different grades is sequentially strand cast, identica-
tion of the resultant transition material is required. The
producer shall remove the transition material by an established
procedure that positively separates the grades.
4.5 The tubing shall be made by rolling steel strip into the
form of tubing and subsequently copper brazing in a reducing
atmosphere.
4.6 Tubing shall be constructed as shown in Fig. 1.
4.7 Tubing shall be suitably tested after brazing by the
manufacturer to ensure freedom from leaks and detrimental
aws.
5. Chemical Composition
5.1 The steel shall conform to the requirements as to
chemical composition prescribed in Table 1.
5.2 Heat AnalysisAn analysis of each heat of steel shall
be made by the steel manufacturer to determine the percentages
of the elements specied. If secondary melting processes are
employed, the heat analysis shall be obtained from one
remelted ingot or the product of one remelted ingot of each
primary melt. The chemical composition thus determined, or
1
This specication is under the jurisdiction of ASTM Committee A-1 on Steel,
Stainless Steel, and Related Alloys, and is the direct responsibility of Subcommittee
A01.09 on Carbon Steel Tubular Products.
Current edition approved Oct. 10, 1996 and March 10, 1997. Published
November 1997. Originally published as A 254 44. Last previous edition
A 254 94.
2
Annual Book of ASTM Standards, Vol 01.03.
3
Discontinued 1995; see 1994 Annual Book of ASTM Standards, Vol 03.05.
4
Discontinued 1996; see 1995 Annual Book of ASTM Standards, Vol 03.05.
5
Available from Society of Automotive Engineers, Inc. 400 Commonwealth
Drive, Warrendale, PA 15096.
Single-Strip Type Double-Strip Type
FIG. 1 Brazed Tubing, Double-Wall, 360-deg Brazed Construction
1
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
that determined from a product analysis made by the tubular
product manufacturer shall conform to the requirements speci-
ed.
5.3 Product AnalysisTubing of this quality is commonly
produced in rimmed or capped steel which is characterized by
a lack of uniformity in its chemical composition. For this
reason, rejection for product analysis is not appropriate unless
misapplication is clearly indicated.
5.4 Methods of AnalysisMethods described in Test Meth-
ods E 30 shall be used for referee purposes. Due allowance
shall be made for the presence of copper brazing metal.
5.5 Samples for Product AnalysisExcept for spectro-
graphic analysis, samples shall be taken in accordance with
Practice E 59.
6. Mechanical Requirements
6.1 Tension TestTensile properties of tubing as manufac-
tured (prior to cold working) shall conform to the requirements
specied in Table 2.
6.1.1 The specimens and tension tests required shall be
made in accordance with Test Methods and Denitions A 370.
6.1.2 Specimens shall be tested at room temperature.
6.1.3 Test specimens shall be taken from the ends of
nished tubes prior to upsetting, swaging, expanding, or other
forming operations, or being cut to length. They shall be
smooth on the ends and free from burrs and aws.
6.1.4 If any test specimen shows aws 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 a permanent offset of 0.2 % of the gage length of
the specimen, or a total extension of 0.5 % of the gage length
under load.
6.1.6 If the percentage of elongation of any test specimen is
less than that specied and any part of the fracture is more than
3
4 in. (19.0 mm) from the center of the gage length, as
indicated by scribe marks on the specimen before testing, a
retest shall be allowed.
6.2 Flattening TestA section of tubing, not less than 2
1
2
in. (64 mm) in length, shall stand being attened between
parallel plates until the inside walls are in contact without
cracking or otherwise showing aws.
6.3 Expansion TestA section of tubing approximately 4
in. (100 mm) in length shall stand being expanded over a
tapered mandrel having a slope of 1 in 10 until the outside
diameter at the expanded end is increased 20 % without
cracking or otherwise showing aws. (Prior to the expansion
test, tubing shall be cut off square, edge crowned, and
deburred. It shall be held rmly and squarely in the die, and
punch must be guided on the axis of the tubing.)
6.4 Bend TestThe nished tubing shall stand bending on a
centerline radius equal to three times the tubing outside
diameter without kinking, cracking, or developing other aws
where proper bending xtures are used.
6.5 Pressure Proof TestsEach tube shall be capable of
withstanding, without bursting or leaking, either of the
following proof tests:
6.5.1 An internal hydrostatic pressure sufficient to subject
the material to a minimum ber stress of 16 000 psi (110
MPa). Hydrostatic pressure shall be determined by the
following formula:
P 5 2St/D
where:
P 5 hydrostatic pressure, psi (or MPa),
S 5 allowable ber stress, 16 000 psi (110 MPa),
t 5 actual wall thickness of tubing, in. (or mm), and
D 5 actual outside diameter of tubing, in. (or mm).
6.5.2 An underwater air pressure between 225 and 250 psi
(1.55 and 1.73 MPa).
7. Coating
7.1 Tubing may be furnished with a copper coating on the
inside and outside surfaces, at the option of the manufacturer.
8. Inside Surface Cleanliness
8.1 When inside surface cleanliness is specied by the
purchaser, tubing for certain uses, such as refrigeration
condensers, shall conform to the following requirement for
internal cleanliness:
8.1.1 When a length of tubing is washed internally with
redistilled chloroform or redistilled 1,1,1-trichloroethane, the
residue remaining upon evaporation of the solvent shall not
exceed 1.25 3 10
4
g/in.
2
(0.194 g/m
2
) of internal surface. To
perform the test, pour 100 mL of solvent through the tubing
and collect. The total length of tubing tested should not be less
than 40 ft (12 m), although this total length may be obtained by
washing several separate lengths and pouring the same solvent
through each in succession. Evaporate the solvent in a steam or
hot water bath, and dry at 110C (230F) until the vapors are
completely removed.
8.2 To maintain this level of cleanliness in shipping,
handling, and storage, the purchaser may request that the
manufacturer seal the tube ends with caps or closures.
9. Dimensional Tolerances
9.1 The tubing shall conform to the permissible variations in
Table 3, Table 4, and Table 5.
10. Workmanship, Finish, and Appearance
10.1 Finished tubing shall be clean, smooth and round, both
TABLE 1 Chemical Requirements
Element Composition, %
Carbon 0.05 to 0.15
Manganese 0.27 to 0.63
Phosphorus, max 0.035
Sulfur, max 0.035
TABLE 2 Tensile Requirements
Property Requirement
Tensile strength, min, psi (MPa) 42 000 (290)
Yield strength, min, psi (MPa) 25 000 (172)
Elongation in 2 in. (50.8 mm) min, % 25
TABLE 3 Outside Diameter Requirements
Specied Outside Diameter, in. (mm) Variations, in. (mm)
Plus or Minus
Under
3
16 (4.76) 0.002 (0.051)
3
16 (4.76) through
3
8 (9.53) 0.003 (0.076)
7
16 (11.1) through
5
8 (15.9) 0.004 (0.102)
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inside and outside, and shall be free of rust, scale, and defects
that impair processing and serviceability. Finished tubes shall
be reasonably straight.
11. Retests
11.1 If the results of the mechanical tests of any group or lot
do not conform to the requirements specied in the individual
specication, retests may be made on additional tubes of
double the original number from the same group or lot, each of
which shall conform to the requirements specied.
12. Retreatment
12.1 If the individual tubes or the tubes selected to represent
any group or lot fail to conform to the test requirements, the
individual tubes or the group or lot represented may be
retreated and resubmitted for test. Not more than two reheat
treatments shall be permitted.
13. Inspection
13.1 The inspector representing the purchaser shall have
entry at all times while work on the contract of the purchaser
is being performed, to all parts of the manufacturers works
that concern the manufacture of the material ordered. The
manufacturer shall afford the inspector all reasonable facilities
to satisfy him that the material is being furnished in accordance
with this specication. All required tests and inspection shall
be made at the place of manufacture prior to shipment, unless
otherwise specied, and shall be conducted so as not to
interfere unnecessarily with the operation of the works.
14. Rejection
14.1 Each length of tubing received from the manufacturer
may be inspected by the purchaser and, if it does not meet the
requirements of the specication based on the inspection and
test method as outlined in the specication, the tubing may be
rejected and the manufacturer shall be notied. Disposition of
rejected tubing shall be a matter of agreement between the
manufacturer and the purchaser.
14.2 Material that fails in any of the forming operations or
in the process of installation and is found to be defective shall
be set aside, and the manufacturer shall be notied for mutual
evaluation of the materials suitability. Disposition of such
material shall be a matter for agreement.
15. Certication
15.1 When requested on the purchasers order, a test report,
signed by an authorized employee or representative of the
manufacturer, shall be furnished to the purchaser to indicate the
specication and year date and grade, the results of the
chemical analysis, hardness, and tension tests, when specied,
and other tests as may be specied in writing by the purchaser.
16. Product Marking
16.1 The specication number (the marking need not
include the year date of the specication), the name or brand of
the manufacturer and the size of tubing or the part number shall
be marked on a tag or label securely attached to the bundles or
boxes in which the tubes are shipped.
16.2 Bar CodingIn addition to the requirements in 16.1
bar coding is acceptable as a supplemental identication
method. The purchaser may specify in the order a specic bar
coding system to be used.
17. Keywords
17.1 steel tube
SUPPLEMENTARY REQUIREMENTS
One or more of the following supplementary requirements shall apply only when specied by the
purchaser in the inquiry, contract, or order. Details of these supplementary requirements shall be
agreed upon by the manufacturer and the purchaser.
S1. Flare Test
S1.1 Brazed tubing shall stand being double ared to
dimensions shown in SAE Standard J 533, without splitting
through the wall at the major diameter of the are. Aseparation
of the outer lap joint is permissible on the ared end of the tube
only in Area A (see Fig. 2). This separation shall not exceed
0.12 in. (3.0 mm) in length and shall be conned to the outer
thickness only. Seam separation is not permitted in the
following areas:
S1.1.1 Area B (the are seat, dened as the surface within
TABLE 4 Wall Thickness Requirements
Specied Wall Thickness, in. (mm) Variations, in. (mm)
Plus or Minus
0.020 (0.51) through 0.030 (0.76) 0.003 (0.08)
0.031 (0.79) through 0.049 (1.24) 0.0035 (0.09)
TABLE 5 Length Requirements
Specied 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), 0.0
FIG. 2 Double-Flare Test
A 254
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the 90 included angle); conical surface shall be smooth and
free from cracks or other irregularities that could cause leaks
after assembly.
S1.1.2 Area C (the surface beyond the length of the double
thickness created by the are).
S1.2 The are seat may contain supercial random radial
marks or indentations which are not detrimental to the
sealability of the are. No indentations of a repetitive nature
resulting from aring tooling deterioration or adhesion of chips
or dirt to the aring tooling are permissible. In the event that
the physical appearance of the are seat is questioned, the
criterion for nal judgment is whether or not the are seat will
seal when subjected to a pressure test at the prescribed torque
level.
S2. External Coating
S2.1 The outside surface of the tubing shall be coated with
a hot-dipped, lead-tin alloy coating. Weight and composition of
coating shall be agreed upon between the manufacturer and
purchaser.
S3. End Finish
S3.1 Finished tubing shall have smooth ends free of burrs.
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with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ve years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
A 254
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