Welded Austenitic Stainless Steel Pipe ASTM A312 TP304 TP316
ASTM A312 stainless steel pipe is a high-performance austenitic stainless steel pipe manufactured in accordance with ASTM A312 / ASME SA312, available in both seamless and welded types. This series of pipes offers excellent corrosion resistance, high-temperature strength, and good workability. It is widely used in industries such as oil and gas, chemical processing, power generation, marine engineering, water treatment, and pressure vessels. Full-size ranges, multiple grades, and custom lengths are available to meet global project requirements.
| Parameter | Specification / Range |
|---|---|
| Standard | ASTM A312 / ASME SA312 |
| Material Grades | TP304, TP304L, TP316, TP316L, TP321, TP347 |
| Manufacturing Type | Seamless / Welded |
| Outer Diameter (OD) | 10.3mm – 609.6mm (1/8″ – 24″) |
| Wall Thickness (WT) | 0.2mm – 60mm (SCH 5S – SCH 80S and custom) |
| Length | 5-12m or as required |
| End Finish | Plain / Beveled / Threaded / With plastic caps |
| Surface Condition | Annealed & pickled / Bright annealed / Blasted / Passivated / Polished |
| Inspection Methods | Hydrostatic test, Eddy current test, Infrared test, PMI, UT, Third-party inspection (SGS/BV) |
| Certifications | ISO 9001, MTC (EN 10204 3.1), RoHS |
| Delivery Condition | Hot rolled, Cold drawn, Solution annealed |
| Grade | C ≤ | Mn ≤ | P ≤ | S ≤ | Si ≤ | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|---|
| TP304 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-11.0 | — |
| TP304L | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-13.0 | — |
| TP316 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0-18.0 | 11.0-14.0 | 2.00-3.00 |
| TP316L | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0-18.0 | 10.0-14.0 | 2.00-3.00 |
| TP321 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-12.0 | — |
| TP347 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-13.0 | — |
Note: TP316/316L contains molybdenum (Mo), offering superior resistance to chloride-induced pitting and crevice corrosion, making them ideal for marine environments and desalination applications.
| Grade | Tensile Strength (MPa) min | Yield Strength (MPa) min | Elongation % min |
|---|---|---|---|
| TP304 / TP304H | 515 | 205 | 35 |
| TP304L | 485 | 170 | 35 |
| TP316 / TP316H | 515 | 205 | 35 |
| TP316L | 485 | 170 | 35 |
| TP321 / TP347 | 515 | 205 | 35 |
Heat Treatment Temperature: 1900°F (1040°C) as per standard
Service Temperature Range: Cryogenic to 870°C (depending on grade; TP310S suitable for higher temperatures)
| NPS | Positive Tolerance (in/mm) | Negative Tolerance (in/mm) |
|---|---|---|
| 1/8 – 1½ | +0.015" / 0.4mm | -0.031" / 0.8mm |
| >1½ – 4 | +0.031" / 0.8mm | -0.031" / 0.8mm |
| >4 – 8 | +0.062" / 1.6mm | -0.031" / 0.8mm |
| >8 – 18 | +0.093" / 2.4mm | -0.031" / 0.8mm |
| >18 – 26 | +0.125" / 3.2mm | -0.031" / 0.8mm |
| NPS | Positive Tolerance | Negative Tolerance |
|---|---|---|
| 1/8 – 2½ | +20.0% | -12.5% |
| 3 – 18 (t/D ≤5%) | +22.5% | -12.5% |
| 3 – 18 (t/D >5%) | +15.0% | -12.5% |
| ≥20 welded | +17.5% | -12.5% |
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Oil & Gas Industry: Onshore/offshore pipelines, platform piping, refining units. TP316/316L preferred in chloride-containing environments.
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Chemical & Petrochemical: Acid/alkali media handling, reactors, heat exchangers, process piping.
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Power Generation: Boiler systems, steam lines, heat transfer equipment.
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Water Treatment & Desalination: Resistant to pitting and crevice corrosion; used in seawater lines, wastewater treatment, and potable water systems.
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Food & Beverage Industry: Sanitary piping to ensure no contamination; TP304/316 commonly used.
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HVAC & Heat Exchangers: Good thermal stability and corrosion resistance.
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Marine & Offshore Engineering: Salt-spray resistant; suitable for shipbuilding and offshore structures.
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General Industrial: Structural piping, instrumentation lines, mechanical systems.
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Hot rolled or cold rolled mill finish,
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2B finish (cold rolled, polished)
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Bright Annealed (BA)
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#4 Polished (120-320 grit)
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Mirror polish (#8)
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Blasted / Pickled / Passivated
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Electropolished / Colored / Painted / Metal sprayed
| Feature | ASTM A312 | ASTM A358 | ASTM A269 |
|---|---|---|---|
| Scope | Seamless & welded austenitic pipes | Electric fusion-welded (EFW) large-diameter pipes | Seamless precision tubing |
| Manufacturing | Seamless / Welded | Welded | Seamless |
| Size Range | 1/8″ – 30″ | ≥8″ (large diameter) | Small diameter |
| Typical Application | General industrial, oil & gas, chemical | High-temperature large-diameter piping | Instrumentation, heat exchangers |
| Pressure Rating | High (seamless) | Medium to high | Medium |
| Key Advantage | Most widely used standard | Ideal for large-diameter high-temp pipelines | High precision, clean surface |
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PMI (Positive Material Identification)
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Hydrostatic test / NDT (UT/ET)
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Chemical composition & mechanical property re-testing
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Flattening/flaring test
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Third-party inspection available (SGS / BV)
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Mill Test Certificate (EN 10204 3.1) supplied with shipment
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ISO 9001 / RoHS compliant
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Export-standard wooden cases or seaworthy packaging
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End protection: plastic caps/thread protectors
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Delivery terms: CFR, CIF, etc.
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Mixed sizes and custom length packing are supported
1. What are the main grades of ASTM A312 stainless steel pipe?
The standard covers TP304, TP304L, TP316, TP316L, TP321, TP347, and others. TP316L contains molybdenum, providing enhanced resistance to chloride corrosion.
2. How to choose between seamless and welded pipe?
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Seamless pipe: Suitable for high-pressure, high-temperature, and critical applications.
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Welded pipe: More cost-effective for general pressure systems and large diameters.
3. What is the temperature range for this standard pipe?
Austenitic stainless steel pipes can operate from cryogenic temperatures (e.g., -196°C for liquid nitrogen) up to 870°C, depending on the grade and service conditions.
4. Can a third-party inspection be arranged?
Yes. Inspection by SGS, BV, TUV, or other agencies can be arranged before or during shipment. Terms and costs are available upon request.
5. Do you support small quantities or custom cut lengths?
Yes. Minimum order quantity is negotiable, and lengths can be customized (e.g., 5.8m, 6m, 12m, or as specified).
6. What documents are provided with the shipment?
Standard shipping documents include: Mill Test Certificate (EN 10204 3.1), packing list, commercial invoice, and certificate of origin (if applicable).
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