What are ASTM A252 Grade 3 Pipes
A252 GR3 steel pipe conforms to Grade 3 (GR3) of the American ASTM A252 standard. It is designed for high-load pile foundations and is mainly made of welded steel pipe (straight seam weld/spiral weld). Seamless technology is less common (seamless pipe is not mainstream in the standard and needs to be specially customized). It is used for deep foundation support structures that bear extreme loads (such as super high-rise buildings, cross-sea bridges, etc.).
ASTM A252 Grade 3 Pipes Specification
| Product Name | ASTM A252 Piling Pipe |
| Wall Thickness | SCH 20, SCH30, SCH40, Standard (STD), Extra Heavy (XH), 80, 100, 120, 140, 160, XXH |
| Wall Thickness Tolerance | ± 12.5% of specified wall thickness per A252 |
| Steel Piles Length | SRL, DRL or as required length |
| Grade 3 Piling Pipe Straightness | 0,20 % of total length and 3 mm over any 1 m length |
| Pipe Standard | ASTM A252 |
| Steel Piles Grade | Grade 1, Grade 2, Grade 3 or other equivalent steel grade |
| Piling Pipe Test | UT test, Tensile test, Yield test, Flatten test or other required tests |
| Pipe Coating | Black painting, varnish paint, anti rust oil, bare or other coating required |
| Steel Piles Package | Plastic caps on both ends, Steel bundle, or acc. to customers' request |
| Steel Piles Capacity | 10000 metric tons per month |
| A252 Piling Pipe Delivery time | 30 days against deposit or LC at sight |
A252 GR3 V.S. A252 GR2
| Performance Category | GR3 Requirement | Advantage over GR2 |
|---|---|---|
| Mechanical Properties | ||
| - Yield Strength | ≥310 MPa (45 ksi) | 28% higher than GR2 (≥242 MPa) |
| - Tensile Strength | 455–565 MPa (66–82 ksi) | ~10% increase in upper limit |
| - Elongation | ≥23% | Superior toughness |
| Chemical Composition | ||
| - Carbon (C) | ≤0.22% | Lower carbon content, improved weldability |
| - Phosphorus (P) | ≤0.025% | Stricter control of harmful elements |
| - Sulfur (S) | ≤0.035% | Reduced hot-shortness risk |
Summary of core application scenarios for A252 GR3 steel pipe:
I. Deep foundations for super high-rise buildings: Used in projects such as the Shanghai Tower (82m pile depth) and the Shenzhen Ping An Finance Center. Its high yield strength (≥310MPa) effectively resists deep soil lateral pressure and uneven settlement. Low sulfur and phosphorus content (P≤0.025%, S≤0.035%) reduces the risk of welding cracks, making it suitable for concrete composite pile foundations with loads >15,000kN.
II. Cross-sea bridge and tunnel engineering: Typical examples include the artificial island foundation piles of the Hong Kong-Zhuhai-Macau Bridge and the immersed tunnel support of the Shenzhen-Zhongshan Bridge:
In highly corrosive seawater environments (Cl⁻>20,000mg/L), a 50-year design life is achieved through 3PE coating + sacrificial anodes.
High elongation (≥23%) adapts to wave impact and geological shear stress, avoiding brittle fracture.
III. Key Supporting Elements for Energy Infrastructure
Offshore Wind Turbine Jacket Foundations (e.g., Rudong Project, Jiangsu): Thick-walled GR3 pipes (wall thickness ≥ 50mm) resist alternating ocean wind and wave loads; Matched cathodic protection to combat salt spray corrosion.
LNG Storage Tank Foundations (e.g., Tianjin Nangang Project):
Low phosphorus and sulfur content prevents brittle failure at -162℃.
IV. Heavy Port Machinery Foundations
Supporting scenarios such as the Qingdao Port automated terminal:
Providing container crane track beams with 455–565MPa tensile strength, capable of withstanding >5,000kN dynamic impact loads; Mooring piers employ 3PE coating (2.8mm) + monitoring anodes to resist ship impacts and seawater erosion.
V. Special Geological Challenges
High-intensity earthquake zones (e.g., Tokyo Bay Tunnel): Utilizing an elongation rate of ≥23% to absorb earthquake energy;
Deep soft soil zones (e.g., Singapore reclamation projects): Relying on high yield strength to achieve vertical stability of piles >60m deep.
