ASTM A213 is a standard developed by the American Society for Testing and Materials (ASTM) for seamless alloy steel and stainless steel tubes used in boilers, superheaters, and heat exchangers. It is widely used in high-temperature and high-pressure applications. This standard covers a variety of ferritic and austenitic alloy steel grades and is considered a key material standard, especially in power plant boilers, petrochemical plants, oil refining units, and heat exchange systems.
Compared to ordinary carbon steel tubes, ASTM A213 alloy seamless steel tubes exhibit superior performance in high-temperature resistance, oxidation resistance, and creep resistance, maintaining stable mechanical properties under long-term high-temperature operation.
Specifications of alloy seamless steel pipes
ASTM A213 Alloy Seamless Steel Tube Specification Range1. Outer Diameter (OD) Range
ASTM A213 does not have a strict upper limit on tube dimensions, but commonly used industry specifications are:
Outer Diameter Range:
6.35 mm (1/4") – 127 mm (5")
Tubes for boilers and heat exchangers typically fall within the smaller diameter range.
2. Wall Thickness (WT) Range
Minimum Wall Thickness: Approximately 0.9 mm
Maximum Wall Thickness: Typically not exceeding 22% of the outer diameter
Common wall thickness ranges from 1.0 mm to 12 mm, depending on pressure and temperature design requirements.
3. Length Forms
Fixed Length
Random Length
U-bend Tubes (for heat exchangers)
| Item | Description |
| Product Type | Seamless Steel Pipe |
| Size Range | 1/8” – 48” / DN 6 – DN 1200 |
| Wall Thickness | SCH 20 – SCH 160, XXS |
| Length | 6 m, 12 m, or Random Length |
| Standard | ASME B36.10 |
| Surface Treatment | Blasting and Painting, Epoxy Powder (FBE), 2PE, 3PE Coating |
| Material Grades | ASTM A213 T11 / T12 / T22 / T5 / T9 / T91 / T92 |
Characteristics of ASTM A213 Alloy Seamless Steel Pipes
1. Excellent High-Temperature Performance:Creep Resistance: Under prolonged high-temperature stress, the material maintains stable dimensions and shape, resisting plastic deformation. This is a key characteristic of alloy seamless steel pipes, crucial for high-temperature equipment such as boilers and superheaters.
Oxidation Resistance: Effectively resists oxidation corrosion under high-temperature conditions, extending service life. High chromium content is the main factor enhancing oxidation resistance.
2. Superior Corrosion Resistance:
Intergranular Corrosion Resistance: For low-carbon grades (such as TP304L and TP316L) and stabilized grades, effective resistance to post-weld intergranular corrosion.
3. Seamless Structure:
High Structural Integrity: Compared to welded pipes, alloy seamless pipes have no weld joints during manufacturing, avoiding potential weld defects, stress concentrations, and microstructure inhomogeneities, thus providing higher structural integrity and reliability.
4. Excellent Mechanical Properties:
High Strength and Toughness: After alloying and heat treatment, the pipes possess high tensile strength, yield strength, and good toughness, enabling them to withstand complex stress conditions.
5. Strict Quality Control:
Rigorous Standards: ASTM A213 standard sets strict requirements for chemical composition, mechanical properties, heat treatment, non-destructive testing (such as eddy current, ultrasonic, and hydrostatic testing), and dimensional tolerances, ensuring reliable product quality.
Dimensions of alloy seamless steel pipes
| DN | NPS | OD | SCH10 | SCH20 | SCH30 | STD | SCH40 | SCH60 | XS | SCH80 |
| 6 | 1/8 | 10.3 | 1.24 | - | 1.45 | 1.73 | 1.73 | - | 2.41 | 2.41 |
| 8 | 1/4 | 13.7 | 1.65 | - | 1.85 | 2.24 | 2.24 | - | 3.02 | 3.02 |
| 10 | 3/8 | 17.1 | 1.65 | - | 1.85 | 2.31 | 2.31 | - | 3.2 | 3.2 |
| 15 | 1/2 | 21.3 | 2.11 | - | 2.41 | 2.77 | 2.77 | - | 3.73 | 3.73 |
| 20 | 3/4 | 26.7 | 2.11 | - | 2.41 | 2.87 | 2.87 | - | 3.91 | 3.91 |
| 25 | 1 | 33.4 | 2.77 | - | 2.9 | 3.38 | 3.38 | - | 4.55 | 4.55 |
| 32 | 1 1/4 | 42.2 | 2.77 | - | 2.97 | 3.56 | 3.56 | - | 4.85 | 4.85 |
| 40 | 1 1/2 | 48.3 | 2.77 | - | 3.18 | 3.68 | 3.68 | - | 5.08 | 5.08 |
| 50 | 2 | 60.3 | 2.77 | - | 3.18 | 3.91 | 3.91 | - | 5.54 | 5.54 |
| 65 | 2 1/2 | 73 | 3.05 | - | 4.78 | 5.16 | 5.16 | - | 7.01 | 7.01 |
| 80 | 3 | 88.9 | 3.05 | - | 4.78 | 5.49 | 5.49 | - | 7.62 | 7.62 |
| 90 | 31/2 | 101.6 | 3.05 | - | 4.78 | 5.74 | 5.74 | - | 8.08 | 8.08 |
| 100 | 4 | 114.37 | 3.05 | - | 4.78 | 6.02 | 6.02 | - | 8.56 | 8.56 |
In summary
ASTM A213 alloy seamless steel tubes, with their stable chemical composition and stringent manufacturing and inspection requirements, have become a core material standard in the global boiler and heat exchanger industry. Whether for conventional power plant boilers or high-parameter supercritical plants, ASTM A213 alloy steel tubes provide reliable heat resistance and pressure resistance.
During the selection process, the grade, specifications, operating temperature, pressure rating, and project standard requirements should be comprehensively considered to ensure the long-term safe operation of the system.
