ASME SA556 Seamless cold drawn carbon steel feedwater heater tubes
Standard: ASTM A556 / ASME SA556
Steel grade: Carbon steel
Material shall conform to the applicable requirements of
specification A450/A450M
The tubes are mainly delivered in the form of U-tubes.
Steel grade | 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 |
Phosphorous, max, % | 0.035 | 0.035 | 0.035 |
Sulfur, max, % | 0.035 | 0.035 | 0.035 |
Silicon, min, % | - | 0.10 | 0.10 |
Process: cold drawn
The tubes cover minimum wall thickness.
Application: Tubular feedwater heaters
Dimensional range:
OD: 15.9-31.8mm
Any specific size is to be discussed before offer
The tube be 100% eddy current tested
Ultrasonic test is as option
Straightness ≤1mm/1000mm
Roughness: Ra ≤0.8
Surface quality
- 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.
- 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.
- 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.
Test
- One tension test shall be made on a specimen for lots of not more
than 50 tubes. Tension tests shall be made on specimens from two
tubes for lots of more than 50 tubes.
- One flattening test shall be made on specimens taken from each end
of one finished tube, not the one used for the flaring test, from
each lot of not more than 125 tubes or fraction thereof.
- 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.
- Brinell or Rockwell hardness tests shall be made on specimens from
two tubes from each lot
- 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 11⁄2 times the specified design
working pressure.
- 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 Specification A 450/A 450M.
Mechanical properties
| 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 50mm, min, % | 35 | 30 | 30 |
Packing and marking
- Tubes shall delivered with square cut ends. The ends are free of
excessive burrs.
- 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.
- 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.
- Bar coding – In addition to the requirements in above two items,
bar coding is acceptable as a supplemental identification method.
The purchaser may specify in the order a specific bar coding system
to be used.
- The case is most suitable for hanging by forklift.
EN10204-3.1 MTC shall be issued
EN10204-3.2 MTC is as option