ASTM A556, ASME SA 556 is a common standard specification for seamless cold-drawn carbon steel feedwater heater tubes. It covers minimum-wall-thickness, seamless cold-drawn carbon steel tubes including bending into the form of U-tubes. In order to increase the heating area and prevent heat from being taken away by cooling water in the condenser, the U-bending design is essential. The steel pipe is used for making a water cooling wall of the power plant boiler, it can effectively eliminate the steam film on the inner wall of the steel tube and improve the thermal efficiency of the furnace wall.
ASTM A556 is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
This standard2 is issued under the fixed designation A 556/A 556M; 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 ( ュ) indicates an editorial change since the last revision or reapproval.
Scope
1.1 This specification covers minimum-wall-thickness, seamless cold-drawn carbon steel tubes including bending into the from of u-tubes, if specified, for use in tubular feedwater heaters.
1.2 The tubing sizes covered shall be 5/8 to 1 2/4-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 hen desired, shall be stated in the order.
1.4 The values stared 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 sated 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.
Chemistry composition of ASTM A556
| Grade | C % | Si % | Mn % | P % | S % |
|---|---|---|---|---|---|
| A2 | 0.18 | ... | 0.27–0.63 | 0.035 | 0.035 |
| B2 | 0.27 max | 0.10 min | 0.29-0.93 | 0.030 max | 0.030 max |
| C2 | 0.30 max | 0.10 min | 0.29-1.06 | 0.030 max | 0.030 max |
Mechanical properties of ASTM A556
| Grade | Tensile strength, min, ksi [MPa] | Yield strength, min, ksi [MPa] | Elongation in 2 in. or 50 mm, min, % (longitudinal) | Hardness Requirements |
|---|---|---|---|---|
| A2 | 47 [320] | 26 [180] | 35 | HR B 72 |
| B2 | 60 [410] | 37 [260] | 30 | HR B 79 |
| C2 | 70 [480] | 40 [280] | 30 | HR B 89 |
Comparison table of international standards
| ASTM | BS | DIN | NFA | JIS |
|---|---|---|---|---|
| A210 A1 | 3602 Pt1 | 17175 | A 49215/9 | G 3461 |
| A566 B2 | ST 430 Cat2 | St 45.8/1 | T 442 b/F | ST B 410 |
| 210 Gr. C | 3606 | 17175 | - | - |
| A 566 Gr. C2 | St 440 Cat. 2 | 17 Mn 4 | - | - |