A333 Seamless & Welded Steel Pipe Product Overview
ASTM A333 Steel Pipes are notch-tough, alloy-enhanced tubing engineered for cryogenic systems, LNG terminals, and arctic oil pipelines operating down to -196°C (-321°F). Available in 9 grades (1, 3, 4, 6–11) with Charpy V-notch impact values up to 40 J @ -100°C, these pipes prevent brittle fracture in subzero environments. Grade 6 (3.5% Ni) and Grade 11 (36% Ni) dominate LNG storage, while Grade 8 (9% Ni) handles ethylene processing at -150°C. Compliant with ASME B31.3 Process Piping Code, they replace costly stainless steels in -50°C to -200°C critical systems.
Key Technical Specifications
1. Dimensional & Manufacturing Properties
- Size Range:
- Seamless: 6.35 mm (¼”) – 914 mm (36″) OD | Wall Thickness: 1.25–50 mm
- Welded: 21.3–3,620 mm OD | Wall Thickness: 1.65–65 mm
- Tolerances:
- OD: ±0.75% (seamless), ±1.2% (welded)
- Concentricity: ≤90% wall thickness variation
- Surface Treatments:
- Black Annealed: For ASME B16.25 end prep
- 3LPE Coated: 2–3 mm triple-layer anti-corrosion for buried pipelines
2. Mechanical & Chemical Performance
Chemical Composition (Key Grades):
| Grade | C | Mn | Ni | Cr | Impact Test Temp |
|---|---|---|---|---|---|
| 6 | ≤0.30% | 0.29–1.06% | 2.03–2.57% | – | -45°C |
| 8 | ≤0.13% | 0.90% | 8.4–9.6% | – | -196°C |
| 11 | ≤0.10% | 0.60% | 35–37% | ≤0.50% | -269°C (liquid helium) |
Mechanical Properties:
| Grade | Tensile (MPa) | Yield (MPa) | Elongation (%) | Charpy V-Notch (J) |
|---|---|---|---|---|
| 3 | ≥450 | ≥240 | ≥30 | 18 @ -100°C |
| 6 | ≥415 | ≥240 | ≥30 | 20 @ -45°C |
| 8 | ≥690 | ≥515 | ≥22 | 27 @ -196°C |
| 11 | ≥450 | ≥240 | ≥18 | 40 @ -269°C |
Applications by Industry
| Industry | Use Case | Grade | Key Benefit |
|---|---|---|---|
| Oil & Gas | LNG storage tanks (-162°C) | Grade 6 | 25% cost savings vs. 304L stainless |
| Chemicals | Ethylene cracking units (-150°C) | Grade 8 | 9% Ni prevents hydrogen embrittlement |
| Cryogenics | Liquid nitrogen pipelines (-196°C) | Grade 8 | 690 MPa tensile strength |
| Aerospace | Liquid helium transfer lines (-269°C) | Grade 11 | 36% Ni stabilizes FCC crystal structure |
| Power | Ammonia refrigeration systems (-33°C) | Grade 3 | Eliminates brittle fracture at -100°C |
Global Standard Equivalents
| USA (ASTM) | Europe (EN) | Japan (JIS) | China (GB) |
|---|---|---|---|
| A333 Gr.6 | EN 10216-4 11MnNi5-3 | STPL 380 | GB/T 18984 L245 |
| A333 Gr.8 | EN 10216-5 X8Ni9 | STPA 26 | GB/T 14976 |
Certifications & Compliance
- Impact Testing: ASTM A370 (Longitudinal), ASTM A673 (Frequency H/V)
- Welding: ASME Section IX with PWHT (Post-Weld Heat Treatment)
- Certifications: NACE MR0103 (Sour Service), AD2000-W0, PED 2014/68/EU
Packing And Delivery
