ASTM A556/A556M-96(2005)
(Specification)Standard Specification for Seamless Cold-Drawn Carbon Steel Feedwater Heater Tubes
Standard Specification for Seamless Cold-Drawn Carbon Steel Feedwater Heater Tubes
ABSTRACT
This specification covers minimum-wall-thickness, seamless cold-drawn carbon steel tubes including bending into the form of U-tubes for use in tubular feedwater heaters. Mechanical tests shall be made on specimens including: tension test; flattening test; flaring test; hardness test; and hydrostatic test. Each tube shall be tested after the finish heat treatment following the final cold-drawn pass by passing through a nondestructive tester capable of detecting defects on the entire cross section of the tube.
SCOPE
1.1 This specification covers minimum-wall-thickness, seamless cold-drawn carbon steel tubes including bending into the form of U-tubes, if specified, for use in tubular feedwater heaters.
1.2 The tubing sizes covered shall be 5/8 to 1 ¼-in. [15.9 to 31.8-mm] outside diameter, inclusive, with minimum wall thicknesses equal to or greater than 0.045 in. [1.1 mm].
1.3 Optional supplementary requirements are provided, and when desired, shall be stated in the order.
1.4 The values stated in either inch-pound units or SI units are to be regarded separately as the standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. The inch-pound units shall apply unless the "M" designation of this specification is specified in the order.
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Designation:A556/A556M −96(Reapproved 2005)
Standard Specification for
Seamless Cold-Drawn Carbon Steel Feedwater Heater
Tubes
This standard is issued under the fixed designationA556/A556M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1 Quantity (feet, metres, or number of pieces),
2 3.1.2 Name of material (seamless steel tubing),
1.1 This specification covers minimum-wall-thickness,
3.1.3 Dimensions (outside diameter and minimum wall
seamless cold-drawn carbon steel tubes including bending into
thickness),
the form of U-tubes, if specified, for use in tubular feedwater
3.1.4 Length (specific or random),
heaters.
3.1.5 Manufacture (cold drawn),
5 1
1.2 The tubing sizes covered shall be ⁄8 to 1 ⁄4-in. [15.9 to
3.1.6 Grade (chemical composition),
31.8-mm] outside diameter, inclusive, with minimum wall
3.1.7 Optional requirements,
thicknesses equal to or greater than 0.045 in. [1.1 mm].
3.1.8 Bending Requirements—If order specifies tubes to be
1.3 Optional supplementary requirements are provided, and
bent, the design of the U-tubes shall accompany the order.
when desired, shall be stated in the order.
Purchaser must specify if stress-relief anneal of the U-bends is
required,
1.4 The values stated in either inch-pound units or SI units
3.1.9 Test report required (see Certification Section of
are to be regarded separately as the standard. Within the text,
Specification A450/A450M),
the SI units are shown in brackets. The values stated in each
3.1.10 Specification number, and
system are not exact equivalents; therefore, each system must
3.1.11 Specialrequirementsandanysupplementaryrequire-
beusedindependentlyoftheother.Combiningvaluesfromthe
ments selected.
two systems may result in nonconformance with the specifi-
cation. The inch-pound units shall apply unless the “M”
4. General Requirements
designation of this specification is specified in the order.
4.1 Material furnished to this specification shall conform to
2. Referenced Documents
the applicable requirements of the current edition of the
2.1 ASTM Standards:
Specification A450/A450M, unless otherwise provided herein.
A450/A450MSpecification for General Requirements for
5. Manufacture
Carbon and Low Alloy Steel Tubes
E30TestMethodsforChemicalAnalysisofSteel,CastIron,
5.1 Manufacture—Tubes shall be made by the seamless
Open-Hearth Iron, and Wrought Iron (Withdrawn 1995)
process and shall be cold drawn.
3. Ordering Information 5.2 Heat Treatment:
5.2.1 Cold-drawn tubes shall be heat treated after the final
3.1 Orders for material under this specification should
cold-drawpassatatemperatureof1200°F[640°C]orhigherto
include the following as required to describe the desired
ensure ductility satisfactory for rolling into tube sheets and to
material adequately:
meet mechanical properties as specified.
1 5.2.2 If stress-relief anneal of the U-bends is specified, the
This specification is under the jurisdiction ofASTM Committee A01 on Steel,
Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee anneal shall consist of heating the bent portion within a range
A01.09 on Carbon Steel Tubular Products.
of 1100 to 1200°F [585 to 640°C].
Current edition approved Oct. 1, 2005. Published November 2005. Originally
approved in 1965. Last previous edition approved in 2001 as A556/A556M–96
6. Chemical Composition
(2001). DOI: 10.1520/A0556_A0556M-96R05.
For ASME Boiler and Pressure Vessel Code applications see related Specifi-
6.1 The steel shall conform to one of the requirements as to
cation SA-556 in Section II of that Code.
chemical composition as prescribed in Table 1.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.2 When a grade is ordered under this specification, sup-
Standards volume information, refer to the standard’s Document Summary page on
plying an alloy grade that specifically requires the addition of
the ASTM website.
any element other than those listed for the ordered grade in
The last approved version of this historical standard is referenced on
www.astm.org. Table 1 is not permitted.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A556/A556M−96 (2005)
TABLE 1 Chemical Requirements TABLE 3 Hardness Requirements
Element Composition, % Grade A2 HR B 72
Grade B2 HR B 79
Grade A2 Grade B2 Grade C2
Grade C2 HR B 89
Carbon, max 0.18 0.27 0.30
Manganese 0.27–0.63 0.29–0.93 0.29–1.06
Phosphorus, max 0.035 0.035 0.035
Sulfur, max 0.035 0.035 0.035
Silicon, min . 0.10 0.10
9.2 Permissible variations from the specified minimum wall
thickness shall not exceed +20% or −0. The wall thickness of
the tube in U-bent section shall be not less than value
determined by:
7. Product Analysis
t 5T ~2R!/~2R1D! (1)
f
7.1 When requested in the purchase order, a product analy-
where:
sisshallbemadebythemanufacturerorsupplierfromonetube
t = wall thickness after bending, in. [mm],
or billet per heat. f
T = specified minimum tube wall thickness, in. [mm],
7.2 If the original test for product analysis fails, retests of
R = centerline bend radius, in. [mm], and
two additional tubes or billets shall be made. Both retests for
D = nominal outside tube diameter, in. [mm].
the elements in question shall meet the requirements of this
9.3 In the case of U-tubes, the length of the tube legs as
specification; otherwise, all remaining material in the heat or
measured from the point of tangency of the bend and the tube
lot (Note 1) shall be rejected or, at the option of the producer,
legtotheendofthetubelegshallnotbelessthanspecified,but
eachtubemaybeindividuallytestedforacceptance.Tubesthat
may exceed the specified values by the amount given in Table
do not meet the requirements of this specification shall be
4.Thedifferenceinlengthsofthetubelegsshallnotbegreater
rejected.
than ⁄8 in. [3 mm] unless otherwise specified.
NOTE 1—For tension and hardness test requirements, the term lot
9.4 The end of any tube may depart from square by not
appliestoalltubespriortocutting,ofthesamenominaldiameterandwall
more than the amount given in Table 5.
thicknesswhichareproducedfromthesameheatofsteel.Whenfinalheat
treatmentisinabatch-typefurnace,alotshallincludeonlythosetubesof
9.5 The leg spacing measured between the points of tan-
thesamesizeandthesameheatwhichareheattreatedinthesamefurnace
gency of the bend to the legs shall not vary from the value (2R
charge.Whenthefinalheattreatmentisinacontinuousfurnace,alotshall
includealltubesofthesamesizeandheat,heattreatedinthesamefurnace − specified tube OD) by more than ⁄16 in. [1.5 mm] whereR is
at the same temperature, time at heat and furnace speed.
the centerline bend radius.
7.3 For referee purposes, Test Methods E30 shall be used.
9.6 The bent portion of the U-tube shall be substantially
uniformincurvatureandnotexceed 6 ⁄16in.[61.5mm]ofthe
8. Mechanical Properties
normal centerline radius.
8.1 Tensile Properties—The material shall conform to the
10. Workmanship, Finish, and Appearance
requirements as to tensile properties prescribed in Table 2,
when pulled in full section.
10.1 Finished tubes shall be free from scale but may have a
superficialoxidefilmonthesurfaces.Alightoxidescaleonthe
8.2 HardnessRequirements—Thetubesshallnotexceedthe
outside and inside surfaces of U-bend shall be allowed for
Rockwell Hardness shown in Table 3.
tubes which have been heat treated.
9. Permissible Variations in Dimensions (Fig. 1)
10.2 Finished tubes shall be reasonably straight and have
smooth ends free from burrs. Tubes shall have a workmanlike
9.1 Permissible variations from the specified outside diam-
finish and shall be free of surface imperfections that cannot be
eter shall not exceed 60.004 in. [0.10 mm] for tubing under
1.0-in. [25.4-mm] outside diameter nor 60.006 in. [0.15 mm] removed within the allowable wall tolerances. Removal of
surface imperfections such as handling marks, straightening
for tubing 1.0 in. [25.4 mm] to 1.25 in. [31.7 mm] inclusive.
These tolerances do not apply to the bent portion of the marks, light mandrel and die marks, shallow pits, and scale
pattern will not be required provided they are within the
U-tubes. At the bent portion of a U-tube for R=2× D or
greater neither the major nor minor diameter of tube shall allowable wall tolerances.
deviatefromnominalbymorethan10%.If1 ⁄2Disspecified,
10.3 Finished tubes shall be coated both on the outside and
tolerances could be greater.
the inside diameter to prevent corrosion in transit. The type of
coating applied should be mutually agreed upon and specified
in the order.
TABLE 2 Tensile Requirements
11. Mechanical Tests Required
Grade A2 Grade B2 Grade C2
Tensile strength, min, ksi [MPa] 47 [320] 60 [410] 70 [480] 11.1 Tension Test—One tension test shall be made on a
Yield strength, min, ksi [MPa] 26 [180] 37 [260] 40 [280]
specimenforlotsofnotmorethan50tubes.Tensiontestsshall
Elongation in 2 in. or 50 mm, 35 30 30
be made on specimens from two tubes for lots of more than 50
min, % (longitudinal)
tubes (Note 1).
A556/A556M−96 (2005)
FIG. 1 Bent Portion of U-Tube
TABLE 4 Tube Leg Length Tolerance
upon between the purchaser and manufacturer, they may be
Leg Length, ft [m] Plus Tolerance tested at 1 ⁄2 times the specified design working pressure.
in. [mm]
12. Nondestructive Test (Electric Test)
Up to 20 [6], incl ⁄8 [3.2]
12.1 Each tube shall be tested after the finish heat treatment
Over 20 to 30 [6 to 9], incl ⁄32 [4.0]
Over 30 to 40 [9 to 12.2], incl ⁄16 [4.8] following the final cold-drawn pass by passing through a
nondestructive tester capable of detecting defects on the entire
cross section of the tube, in accordance with Specification
TABLE 5 Squareness of Ends Tolerance
A450/A450M.
Tube OD, in. [mm] Tolerance,
in. [mm] 13. Packaging and Package Marking
⁄8 [15.9] 0.010 [0.25]
13.1 The tubing shall be packaged or bundled in such a
5 1
Over ⁄8 to 1 ⁄4 [15.9 to 31.7], incl 0.016 [0.4]
manner as to prevent damage in ordinary handling and trans-
portation and identified by a tag with the name of the
manufacturer, purchase order number, specification number
11.2 Flattening Test—One flattening test shall be made on
and grade, and size.
specimens taken from each end of one finished tube, not the
13.2 InthecaseofU-tubes,eachboxshallbepalletizedand
oneusedfortheflaringtest,fromeachlotofnotmorethan125
legibly marked showing the manufacturer’s name, purchase
tubes or fraction thereof.
order number, specification number and grade, size, and
11.3 Flaring Test—One flaring test shall be made on speci-
identification of items contained.
mens taken from each end of one finished tube, not the one
13.3 Bar Coding—In addition to the requirements in 13.1
used for flattening test, from each lot of not more than 125
and 13.2, bar coding is acceptable as a supplemental identifi-
tubes or fraction thereof.
cation method. The purchaser may specify in the order a
11.4 Hardness Test—Brinell or Rockwell hardness tests
specific bar coding system to be used.
shall be made on specimens from two tubes from each lot
(Note 1). 14. Keywords
11.5 Hydrostatic Test—Each U-tube shall be subjected to a 14.1 carbon; feedwater heater tubes; seamless steel tube;
hydrostatic test, using a noncorrosive fluid, or when agreed
steel tube
A556/A556M−96 (2005)
SUPPLEMENTARY REQUIREMENTS
The following supplementary requirement or requirements may become a part of the specification
when specified in the inquiry or invitation to bid, and purchase order or contract. These requirements
shall not be considered, unless specified in the order, in which even the necessary tests shall be made
by the manufacturer prior to the bending or shipment of the tubing.
S1. Nondestructive Ultrasonic Test—Round Tubing (Com- S1.1.6.4 The recording equipment, if agreed upon, shall be
adjusted to clearly indicate the reference notch or notches and
mercial Grade)
also whether or not any reflected signals actuate the alarm
S1.1 The manufactuer shall test the tubing by an ultrasonic
system.
nondestructive test for detection of harmful faults and sound-
S1.1.7 A reference standard of an appropriate length (suffi-
ness.
cient to allow in-line feeding) shall be prepared from a
S1.1.1 Ultrasonic testing shall be performed using pulse-
randomly selected tube of the same size, grade, and physical
echo shear wave techniques to locate longitudinal or circum- condition as the material to be tested.
ferential defects, or both. S1.1.8 The reference standard shall contain machined
notchesasfollows:Notchtobe10%ofwallthicknessindepth
S1.1.2 Tubes being tested shall be reasonably straight for
but not less than 0.004 in. [0.10 mm]. Tolerance on depth
properrotation.Theoutsideandinsidediametersurfacesofthe
+0.0000 in. or −0.001 in. [0.03 mm].
tubes shall be free of dirt, grit, grease, oil, loose scale, or other
S1.1.8.1 Notch Locations and Orientation—Notches shall
materials which tend to attenuate, scatter, or reflect ultrasonic
be located on outside or inside diameter, or both, and shall be
signals.
oriented to lie in a longitudinal direction for radial inspection
S1.1.3 Tubing shall be inspected by feeding spirally past a
or circumferentially, or both, for transverse inspection. The
suitable transducer with rotation of material to be toward the
notch or notches shall be located in the reference tube in such
transducer.
a manner that no physical or acoustical interference exists
S1.1.4 Suitable ultrasonic instrumentation shall be used to
between notches or end of reference tube. These various
clearly distinguish the artificial defects (hereafter called refer- locations and orientations will be classified as follows:
ence notches) described later.Automatic electronic monitoring TypeA—Longitudinaloutsidediameterforradialinspection,
Type B—Longitudinal inside diameter for radial inspection,
of the reflected ultrasonic signals shall be provided in such
Type C—Circumferential outside diameter for transverse
manner that any naturally occurring defects which present an
inspection, and
ultrasonic reflection equal to or greater than the reference
Type D—Circumferential inside diameter for transverse in-
standard(s) shall trigger audible and visible alarms.
spection.
S1.1.5 Instrument calibration as described herein shall be
S1.1.8.2 Standard Nomenclature— The size, location, and
accomplishedwiththereferencestandardbeingrotatedandfed
orientation of th
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:A 556/A 556M–96 (Reapproved 2001) Designation: A556/A556M – 96
(Reapproved 2005)
Standard Specification for
Seamless Cold-Drawn Carbon Steel Feedwater Heater
Tubes
This standard is issued under the fixed designationA556/A556M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 Thisspecification coversminimum-wall-thickness,seamlesscold-drawncarbonsteeltubesincludingbendingintotheform
of U-tubes, if specified, for use in tubular feedwater heaters.
5 1
1.2 The tubing sizes covered shall be ⁄8 to 1 ⁄4-in. [15.9 to 31.8-mm] outside diameter, inclusive, with minimum wall
thicknesses equal to or greater than 0.045 in. [1.1 mm].
1.3 Optional supplementary requirements are provided, and when desired, shall be stated in the order.
1.4 The values stated in either inch-pound units or SI units are to be regarded separately as the standard. Within the text, the
SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used
independently of the other. Combining values from the two systems may result in nonconformance with the specification. The
inch-pound units shall apply unless the “M” designation of this specification is specified in the order.
2. Referenced Documents
2.1 ASTM Standards:
A450/A450M Specification for General Requirements for Carbon, FerriticAlloy, Carbon andAusteniticLowAlloy SteelTubes
E30 Test Methods for Chemical Analysis of Steel, Cast Iron, Open-Hearth Iron, and Wrought Iron
3. Ordering Information
3.1 Orders for material under this specification should include the following as required to describe the desired material
adequately:
3.1.1 Quantity (feet, metres, or number of pieces),
3.1.2 Name of material (seamless steel tubing),
3.1.3 Dimensions (outside diameter and minimum wall thickness),
3.1.4 Length (specific or random),
3.1.5 Manufacture (cold drawn),
3.1.6 Grade (chemical composition),
3.1.7 Optional requirements,
3.1.8 BendingRequirements—Iforderspecifiestubestobebent,thedesignoftheU-tubesshallaccompanytheorder.Purchaser
must specify if stress-relief anneal of the U-bends is required,
3.1.9 Test report required (see Certification Section of Specification A 450/A 450MA450/A450M),
3.1.10 Specification number, and
3.1.11 Special requirements and any supplementary requirements selected.
4. General Requirements
4.1 Material furnished to this specification shall conform to the applicable requirements of the current edition of the
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel,Steel and Related Alloys,Alloys and is the direct responsibility of
Subcommittee A01.09 on Carbon Steel Tubular Products.
´1
Current edition approved October 10, 1996. Published October 1997. Originally published as A 556–65. Last previous edition A 556–90 (l995) .
CurrenteditionapprovedOct.1,2005.PublishedNovember2005.Originallyapprovedin1965.Lastpreviouseditionapprovedin2001asA556/A556M–96(2001).DOI:
10.1520/A0556_A0556M-96R05.
For ASME Boiler and Pressure Vessel Code applications see related Specification SA-556 in Section II of that Code.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.ForAnnualBookofASTMStandards
, Vol 01.01.volume information, refer to the standard’s Document Summary page on the ASTM website.
Annual Book of ASTM Standards, Vol 03.05.
Withdrawn. The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A556/A556M – 96 (2005)
Specification A 450/A 450MA450/A450M, unless otherwise provided herein.
5. Manufacture
5.1 Manufacture—Tubes shall be made by the seamless process and shall be cold drawn.
5.2 Heat Treatment:
5.2.1 Cold-drawn tubes shall be heat treated after the final cold-draw pass at a temperature of 1200°F [640°C] or higher to
ensure ductility satisfactory for rolling into tube sheets and to meet mechanical properties as specified.
5.2.2 Ifstress-reliefannealoftheU-bendsisspecified,theannealshallconsistofheatingthebentportionwithinarangeof1100
to 1200°F [585 to 640°C].
6. Chemical Composition
6.1 The steel shall conform to one of the requirements as to chemical composition as prescribed in Table 1.
6.2 When a grade is ordered under this specification, supplying an alloy grade that specifically requires the addition of any
element other than those listed for the ordered grade in Table 1 is not permitted.
7. ProductAnalysis
7.1 When requested in the purchase order, a product analysis shall be made by the manufacturer or supplier from one tube or
billet per heat.
7.2 If the original test for product analysis fails, retests of two additional tubes or billets shall be made. Both retests for the
elements in question shall meet the requirements of this specification; otherwise, all remaining material in the heat or lot (Note
1) shall be rejected or, at the option of the producer, each tube may be individually tested for acceptance. Tubes that do not meet
the requirements of this specification shall be rejected.
NOTE 1—For tension and hardness test requirements, the termlot applies to all tubes prior to cutting, of the same nominal diameter and wall thickness
which are produced from the same heat of steel. When final heat treatment is in a batch-type furnace, a lot shall include only those tubes of the same
size and the same heat which are heat treated in the same furnace charge. When the final heat treatment is in a continuous furnace, a lot shall include
all tubes of the same size and heat, heat treated in the same furnace at the same temperature, time at heat and furnace speed.
7.3 For referee purposes, Test Methods E 30E30 shall be used.
8. Mechanical Properties
8.1 Tensile Properties—The material shall conform to the requirements as to tensile properties prescribed in Table 2, when
pulled in full section.
8.2 Hardness Requirements—The tubes shall not exceed the Rockwell Hardness shown in Table 3.
9. Permissible Variations in Dimensions (Fig. 1)
9.1 Permissible variations from the specified outside diameter shall not exceed 60.004 in. [0.10 mm] for tubing under 1.0-in.
[25.4-mm] outside diameter nor 60.006 in. [0.15 mm] for tubing 1.0 in. [25.4 mm] to 1.25 in. [31.7 mm] inclusive. These
tolerances do not apply to the bent portion of the U-tubes. At the bent portion of a U-tube for R=2 3 D or greater neither the
majornorminordiameteroftubeshalldeviatefromnominalbymorethan10%.If1 ⁄2Disspecified,tolerancescouldbegreater.
9.2 Permissible variations from the specified minimum wall thickness shall not exceed +20% or −0. The wall thickness of the
tube in U-bent section shall be not less than value determined by:
t 5T ~2R!/ ~2R1D! (1)
f
A0556_A0556M-96R05_1
where:
t = wall thickness after bending, in. [mm],
f
T = specified minimum tube wall thickness, in. [mm],
R = centerline bend radius, in. [mm], and
D = nominal outside tube diameter, in. [mm].
9.3 In the case of U-tubes, the length of the tube legs as measured from the point of tangency of the bend and the tube leg to
the end of the tube leg shall not be less than specified, but may exceed the specified values by the amount given in Table 4. The
TABLE 1 Chemical Requirements
Element Composition, %
Grade A2 Grade B2 Grade C2
Carbon, max 0.18 0.27 0.30
Manganese 0.27–0.63 0.29–0.93 0.29–1.06
Phosphorus, max 0.035 0.035 0.035
Sulfur, max 0.035 0.035 0.035
Silicon, min . 0.10 0.10
A556/A556M – 96 (2005)
TABLE 2 Tensile Requirements
Grade A2 Grade B2 Grade C2
Tensile strength, min, ksi [MPa] 47 [320] 60 [410] 70 [480]
Yield strength, min, ksi [MPa] 26 [180] 37 [260] 40 [280]
Elongation in 2 in. or 50 mm, 35 30 30
min, % (longitudinal)
TABLE 3 Hardness Requirements
Grade A2 HR B 72
Grade A2 HRB72
Grade B2 HR B 79
Grade B2 HRB79
Grade C2 HR B 89
Grade C2 HRB89
FIG. 1 Bent Portion of U-Tube
TABLE 4 Tube Leg Length Tolerance
Leg Length, ft [m] Plus Tolerance in. [mm]
Up to 20 [6], incl ⁄8 [3.2]
Over 20 to 30 [6 to 9], incl ⁄32 [4.0]
Over 30 to 40 [9 to 12.2], incl ⁄16 [4.8]
difference in lengths of the tube legs shall not be greater than ⁄8 in. [3 mm] unless otherwise specified.
9.4 The end of any tube may depart from square by not more than the amount given in Table 5.
9.5 The leg spacing measured between the points of tangency of the bend to the legs shall not vary from the value (2R −
specified tube OD) by more than ⁄16 in. [1.5 mm] where R is the centerline bend radius.
9.6 ThebentportionoftheU-tubeshallbesubstantiallyuniformincurvatureandnotexceed 6 ⁄16in.[61.5mm]ofthenormal
centerline radius.
10. Workmanship, Finish, andAppearance
10.1 Finished tubes shall be free from scale but may have a superficial oxide film on the surfaces. A light oxide scale on the
outside and inside surfaces of U-bend shall be allowed for tubes which have been heat treated.
10.2 Finished tubes shall be reasonably straight and have smooth ends free from burrs. Tubes shall have a workmanlike finish
and shall be free of surface imperfections that cannot be removed within the allowable wall tolerances. Removal of surface
imperfections such as handling marks, straightening marks, light mandrel and die marks, shallow pits, and scale pattern will not
be required provided they are within the allowable wall tolerances.
TABLE 5 Squareness of Ends Tolerance
Tube OD, in. [mm] Tolerance,
in. [mm]
⁄8 [15.9] 0.010 [0.25]
5 1
Over ⁄8 to 1 ⁄4 [15.9 to 31.7], incl 0.016 [0.4]
A556/A556M – 96 (2005)
10.3 Finished tubes shall be coated both on the outside and the inside diameter to prevent corrosion in transit. The type of
coating applied should be mutually agreed upon and specified in the order.
11. Mechanical Tests Required
11.1 TensionTest—Onetensiontestshallbemadeonaspecimenforlotsofnotmorethan50tubes.Tensiontestsshallbemade
on specimens from two tubes for lots of more than 50 tubes (Note 1).
11.2 FlatteningTest—Oneflatteningtestshallbemadeonspecimenstakenfromeachendofonefinishedtube,nottheoneused
for the flaring test, from each lot of not more than 125 tubes or fraction thereof.
11.3 Flaring Test—One flaring test shall be made on specimens taken from each end of one finished tube, not the one used for
flattening test, from each lot of not more than 125 tubes or fraction thereof.
11.4 Hardness Test—Brinell or Rockwell hardness tests shall be made on specimens from two tubes from each lot (Note 1).
11.5 Hydrostatic Test—Each U-tube shall be subjected to a hydrostatic test, using a noncorrosive fluid, or when agreed upon
between the purchaser and manufacturer, they may be tested at 1 ⁄2 times the specified design working pressure.
12. Nondestructive Test (Electric Test)
12.1 Each tube shall be tested after the finish heat treatment following the final cold-drawn pass by passing through a
nondestructive tester capable of detecting defects on the entire cross section of the tube, in accordance with SpecificationA450/A
450MA450/A450M.
13. Packaging and Package Marking
13.1 The tubing shall be packaged or bundled in such a manner as to prevent damage in ordinary handling and transportation
and identified by a tag with the name of the manufacturer, purchase order number, specification number and grade, and size.
13.2 In the case of U-tubes, each box shall be palletized and legibly marked showing the manufacturer’s name, purchase order
number, specification number and grade, size, and identification of items contained.
13.3 Bar Coding—In addition to the requirements in 13.1 and 13.2, bar coding is acceptable as a supplemental identification
method. The purchaser may specify in the order a specific bar coding system to be used.
14. Keywords
14.1feedwater heater tubes; seamless steel tube; steel tube; carbon
14.1 carbon; feedwater heater tubes; seamless steel tube; steel tube
SUPPLEMENTARY REQUIREMENTS
The following supplementary requirement or requirements may become a part of the specification
when specified in the inquiry or invitation to bid, and purchase order or contract. These requirements
shall not be considered, unless specified in the order, in which even the necessary tests shall be made
by the manufacturer prior to the bending or shipment of the tubing.
S1. Nondestructive Ultrasonic Test—Round Tubing (Commercial Grade)
S1.1 The manufactuer shall test the tubing by an ultrasonic nondestructive test for detection of harmful faults and soundness.
S1.1.1 Ultrasonic testing shall be performed using pulse-echo shear wave techniques to locate longitudinal or circumferential
defects, or both.
S1.1.2 Tubes being tested shall be reasonably straight for proper rotation.The outside and inside diameter surfaces of the tubes
shall be free of dirt, grit, grease, oil, loose scale, or other materials which tend to attenuate, scatter, or reflect ultrasonic signals.
S1.1.3 Tubing shall be inspected by feeding spirally past a suitable transducer with rotation of material to be toward the
transducer.
S1.1.4 Suitable ultrasonic instrumentation shall be used to clearly distinguish the artificial defects (hereafter called reference
notches) described later.Automatic electronic monitoring of the reflected ultrasonic signals shall be provided in such manner that
anynaturallyoccurringdefectswhichpresentanultrasonicreflectionequaltoorgreaterthanthereferencestandard(s)shalltrigger
audible and visible alarms.
S1.1.5 Instrument calibration as described herein shall be accomplished with the reference standard being rotated and fed past
the transducer at the same approximate rate at which the tubing under test will be tested.
S1.1.6 The following factors will be adjusted so as to achieve optimum instrument distinction between the reference notch(es)
and plain portion of tubing when calibrating equipment to the reference standard. standard:
S1.1.6.1 Search unit position shall be such that shear waves are propagated within the tube being tested. If both outside and
insidediameterreferencenotchesareused,theoptimumangleshallbeusedwhichwillindicatebothnotchesasclosetoequalsize
as possible.
S1.1.6.2 The test frequency to be used shall be chosen to yield the best distinction be
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