ASTM A790 Welded Duplex Stainless Steel Pipe Grade 2205 2507 2304
Welded duplex stainless steel pipe is manufactured by forming a flat strip of duplex stainless steel into a cylindrical shape and welding the longitudinal seam. This process produces a pipe with excellent dimensional accuracy, consistent wall thickness, and a cost-effective solution for corrosive service applications.
Our welded duplex pipes are produced using advanced welding techniques including ERW (Electric Resistance Welding), EFW (Electric Fusion Welding), and DSAW (Double Submerged Arc Welding). They offer the same high strength and corrosion resistance as seamless pipes at a more economical price point for many applications.
| Parameter | Details |
|---|---|
| Standard | ASTM A790, A928, ASME SA790, EN 10217-7, ISO 13628 |
| Grades | 2205 (UNS S31803, S32205), 2507 (UNS S32750, S32760), 2304 (UNS S32304) |
| Size (OD) | 6.0 mm – 1829 mm (1/8" – 72") |
| Wall Thickness | 1.0 mm – 50.0 mm (Schedule 5S through XXS) |
| Length | 3000 mm, 6000 mm, random lengths 6m – 12m (custom cut available) |
| Welding Process | ERW (up to 24"), EFW (16" – 72"), DSAW (24" – 72") |
| Surface Finish | Mill finish, Annealed and pickled, Mechanically polished |
| End Finish | Plain ends, Beveled ends, Threaded, Grooved |
| Process | Size Range | Description | Best For |
|---|---|---|---|
| ERW (Electric Resistance Welding) | 6 mm – 610 mm (1/8" – 24") | High frequency current welds the seam without filler metal | Small to medium diameters, high volume |
| EFW (Electric Fusion Welding) | 406 mm – 1829 mm (16" – 72") | TIG or plasma arc welding with filler metal | Large diameters, critical service |
| DSAW (Double Submerged Arc Welding) | 610 mm – 1829 mm (24" – 72") | Welded from both inside and outside | Heavy wall, large diameter pipelines |
| Element | 2205 (S31803) | 2205 (S32205) | 2507 (S32750) | 2304 (S32304) |
|---|---|---|---|---|
| Carbon (C) ≤ | 0.030 | 0.030 | 0.030 | 0.030 |
| Silicon (Si) ≤ | 1.00 | 1.00 | 0.80 | 1.00 |
| Manganese (Mn) ≤ | 2.00 | 2.00 | 1.20 | 2.50 |
| Phosphorus (P) ≤ | 0.030 | 0.030 | 0.035 | 0.035 |
| Sulfur (S) ≤ | 0.020 | 0.020 | 0.020 | 0.020 |
| Chromium (Cr) | 21.0 – 23.0 | 22.0 – 23.0 | 24.0 – 26.0 | 21.5 – 24.5 |
| Nickel (Ni) | 4.5 – 6.5 | 4.5 – 6.5 | 6.0 – 8.0 | 3.0 – 5.5 |
| Molybdenum (Mo) | 2.5 – 3.5 | 3.0 – 3.5 | 3.0 – 5.0 | 0.05 – 0.60 |
| Nitrogen (N) | 0.08 – 0.20 | 0.14 – 0.20 | 0.24 – 0.32 | 0.05 – 0.20 |
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) |
|---|---|---|---|---|
| 2205 (S31803) | ≥ 620 | ≥ 450 | ≥ 25 | ≤ 290 |
| 2205 (S32205) | ≥ 620 | ≥ 450 | ≥ 25 | ≤ 290 |
| 2507 (S32750) | ≥ 730 | ≥ 550 | ≥ 20 | ≤ 310 |
| 2304 (S32304) | ≥ 600 | ≥ 400 | ≥ 25 | ≤ 290 |
*Note: The values above are minimum requirements per ASTM A790/A928. Please refer to the mill test certificate for actual data.*
- Cost Effective – Lower cost than seamless duplex pipe for equivalent performance
- Long Lengths – Can be produced in very long continuous lengths
- Consistent Dimensions – Uniform OD, ID, and wall thickness
- High Strength – Yield strength twice that of austenitic grades
- Excellent Corrosion Resistance – Superior pitting and SCC resistance
- Large Diameter Capability – Available up to 72" (1829 mm) OD
- Full Heat Treatment – Solution annealed and pickled after welding
| Feature | Welded Pipe | Seamless Pipe |
|---|---|---|
| Weld Seam | Present | None |
| Size Range | 6 mm – 1829 mm | 6 mm – 610 mm |
| Maximum Wall Thickness | Up to 50 mm | Up to 25 mm |
| Length Availability | Very long coils / lengths | Shorter typical lengths |
| Cost | Lower | Higher (30-50% more) |
| Lead Time | Shorter | Longer |
| Dimensional Consistency | Excellent | Very good |
| Pressure Rating | Good (with proper weld) | Higher |
| Sour Service (H₂S) | Yes (with NACE qualification) | Preferred |
| Best For | General corrosive service, pipelines, large diameters | Critical high pressure, small diameters |
Welded duplex stainless steel pipe is widely used across demanding industries:
- Onshore and offshore flow lines
- Pipeline systems
- Platform topside piping
- Gathering lines
- Water injection lines
- Process piping
- Chemical transfer lines
- Heat exchanger shell and tube
- Storage tank piping
- Seawater intake and discharge lines
- Desalination plant piping
- Ballast water systems
- Firewater systems
- Bleach plant piping
- Process liquor lines
- Effluent treatment systems
- Cooling water systems
- Flue gas desulfurization (FGD) piping
- Condenser water lines
- Slurry pipelines
- Process water lines
- Tailings lines
- Reverse osmosis piping
- High pressure brine lines
- Wastewater treatment
For applications containing hydrogen sulfide (H₂S), welded duplex pipe can be supplied in accordance with NACE MR0175 / ISO 15156.
| Requirement | Detail |
|---|---|
| Applicable Grades | 2205, 2507 |
| Hardness Limit | ≤ 28 HRC (for sour service) |
| Weld Seam Hardness | ≤ 28 HRC |
| Certification | NACE MR0175 compliance certificate |
| Testing | HIC and SSC testing available |
| OD (inches) | OD (mm) | Typical Wall Thickness (mm) | Typical Application |
|---|---|---|---|
| 16" – 24" | 406 – 610 | 6.0 – 12.7 | Process piping |
| 26" – 36" | 660 – 914 | 8.0 – 15.9 | Seawater intake |
| 38" – 48" | 965 – 1219 | 9.5 – 19.1 | Large diameter pipelines |
| 50" – 72" | 1270 – 1829 | 12.7 – 25.4 | Penstocks, large headers |
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