A/SA106 seamless pipe is the industry standard for high-temperature and high-pressure carbon steel piping. Widely used in oil refineries, power plants, chemical processing, and shipbuilding, this pipe type ensures superior performance under extreme conditions.
In this guide, you’ll find technical charts, chemical and mechanical property comparisons, fabrication tips, and a complete checklist for safe and effective use.
📌 What Is A/SA106 Pipe?
ASTM A106 / ASME SA106 specifies seamless carbon steel pipes for high-temperature services. These pipes are ideal for transporting steam, oil, and gas in demanding environments.
🔍 Key Features:
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Seamless construction for high-pressure resistance
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Excellent machinability and weldability
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Suitable for bending, flanging, and forming
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Available in Grades A, B, and C
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NPS sizes: ¼” to 36″
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Thickness: Schedules 20 to XXH
🔬 Technical Specifications
📊 A/SA106 Chemical Composition
| Element | Grade A | Grade B | Grade C |
|---|---|---|---|
| Carbon (max) | 0.25% | 0.30%* | 0.35%* |
| Manganese | 0.27–0.93% | 0.29–1.06%* | 0.29–1.06%* |
| Phosphorus | ≤ 0.035% | ≤ 0.035% | ≤ 0.035% |
| Sulfur | ≤ 0.035% | ≤ 0.035% | ≤ 0.035% |
| Silicon (min) | ≥ 0.10% | ≥ 0.10% | ≥ 0.10% |
| Cr / Cu / Ni | ≤ 0.40% each | ≤ 0.40% each | ≤ 0.40% each |
| Mo / V | ≤ 0.15% / 0.08% | ≤ 0.15% / 0.08% | ≤ 0.15% / 0.08% |
📏 Dimensional Tolerances
| Specification | Tolerance |
|---|---|
| Wall Thickness (min) | -12.5% under nominal |
| Weight per foot | +10% / -3.5% from nominal |
| Outside Diameter (OD) tolerance | ±1% of specified OD |
🔩 Mechanical Properties
| Property | Grade A | Grade B | Grade C |
|---|---|---|---|
| Yield Strength (min) | 30,000 psi | 35,000 psi | 40,000 psi |
| Tensile Strength (min) | 48,000 psi | 60,000 psi | 70,000 psi |
🧪 A106 vs A53: What’s the Difference?
| Feature | A/SA106 Seamless Pipe | A53 Welded Pipe |
|---|---|---|
| Manufacturing Method | Seamless only | Seamless or ERW |
| Temperature Suitability | High-temperature (>400°F) | Moderate temperature |
| Pressure Handling | High | Moderate |
| Common Use | Refineries, boilers | Plumbing, low-pressure lines |
| Standards | ASTM A106, ASME SA106 | ASTM A53 |
✅ Final Installation Checklist
| Task | Completed |
|---|---|
| Confirmed operating temperature | ☐ |
| Verified correct grade & schedule | ☐ |
| Reviewed OD and wall tolerances | ☐ |
| Requested MTC and hydrostatic tests | ☐ |
| Checked for proper end finish | ☐ |
| Ensured heat treatment if required | ☐ |
| Compared with A53 if substituting | ☐ |