Stainless Steel Duplex Pipe 2205 2507 Cold Drawn Seamless Tubing
Seamless duplex stainless steel tube is manufactured without any weld seam, produced by extruding a solid billet of duplex stainless steel into a hollow tube through a piercing and rolling process. The absence of a weld seam provides superior strength, uniform wall thickness, and excellent performance under high pressure, high temperature, and corrosive conditions.
Our seamless duplex tubes offer the unique combination of high strength (approximately twice that of austenitic grades) and outstanding corrosion resistance, making them ideal for critical applications where welded tubes may present a risk of failure.
| Parameter | Details |
|---|---|
| Standard | ASTM A789, A790, A269, EN 10216-5, ISO 13628 |
| Grades | 2205 (UNS S31803, S32205), 2507 (UNS S32750, S32760), 2304 (UNS S32304) |
| Size (OD) | 1.6 mm – 254 mm (1/16" – 10") |
| Wall Thickness | 0.5 mm – 12.5 mm |
| Length | Random lengths 3m – 12m (custom cut available, coil lengths for small diameters) |
| Production Process | Cold drawn seamless (CDS) or Cold rolled seamless (CRS) |
| Surface Finish | Annealed and pickled, Bright annealed (BA), Polished, Mechanically descaled |
| End Finish | Plain ends, Beveled ends, Threaded |
| 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 |
| Copper (Cu) ≤ | — | — | 0.50 | — |
| Tungsten (W) | — | — | — | — |
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) | Hardness (HRC) |
|---|---|---|---|---|---|
| 2205 (S31803) | ≥ 620 | ≥ 450 | ≥ 25 | ≤ 290 | ≤ 30 |
| 2205 (S32205) | ≥ 620 | ≥ 450 | ≥ 25 | ≤ 290 | ≤ 30 |
| 2507 (S32750) | ≥ 730 | ≥ 550 | ≥ 20 | ≤ 310 | ≤ 32 |
| 2304 (S32304) | ≥ 600 | ≥ 400 | ≥ 25 | ≤ 290 | ≤ 30 |
Note: The values above are minimum requirements per ASTM A789/A790. Please refer to the mill test certificate for actual data.
| Property | 2205 | 2507 | 2304 |
|---|---|---|---|
| Density (g/cm³) | 7.8 | 7.8 | 7.8 |
| Modulus of Elasticity (GPa) | 200 | 200 | 200 |
| Thermal Conductivity (W/m·K at 20°C) | 19 | 15 | 21 |
| Specific Heat (J/kg·K at 20°C) | 500 | 480 | 500 |
| Electrical Resistivity (μΩ·m) | 850 | 800 | 850 |
| Magnetic Permeability | Magnetic | Magnetic | Magnetic |
| PREN | 33 – 35 | ≥ 41 | 24 – 26 |
No Weld Seam – Eliminates the potential weak point found in welded tubes
Uniform Wall Thickness – Consistent dimensions throughout the tube length
High Strength – Yield strength of 400-550 MPa minimum (2x austenitic grades)
Superior Corrosion Resistance – Excellent pitting, crevice, and SCC resistance
High Pressure Capability – Suitable for critical high pressure service
High Temperature Performance – Operates reliably up to 300°C
Full Traceability – Complete mill documentation from billet to final tube
| Feature | Seamless Tube | Welded Tube |
|---|---|---|
| Weld Seam | None | Present |
| Wall Thickness Consistency | Very consistent | Consistent |
| Pressure Rating | Higher | Lower |
| Corrosion Resistance | Uniform throughout | Potential weld seam corrosion |
| Sour Service (H₂S) | Preferred | Acceptable with NACE qualification |
| Small Diameters (< 25mm) | Yes | Difficult / expensive |
| Length Availability | Shorter typical | Longer lengths available |
| Cost | Higher | Lower |
| Lead Time | Longer | Shorter |
| Best For | High pressure, sour gas, heat exchangers, umbilical tubing | General corrosive service, structural, lower pressure |
Seamless duplex stainless steel tube is specified for critical applications where reliability cannot be compromised:
Oil & Gas
- Downhole production tubing
- Subsea control umbilicals
- Instrumentation tubing
- Hydraulic lines
- Sour service (H₂S) flow lines
- Christmas tree components
- Wellhead control lines
Chemical & Petrochemical
- High pressure chemical injection lines
- Heat exchanger tubes
- Reactor tubes
- Corrosive fluid transfer
- Process instrumentation lines
Marine & Offshore
- Seawater hydraulic lines
- Subsea control systems
- ROV umbilicals
- Offshore platform instrumentation
- Desalination plant tubing
Power Generation
- Nuclear power instrumentation lines
- Geothermal production tubing
- Condenser tubes (small diameter)
- Steam sampling lines
Pharmaceutical & Food
- High purity fluid transfer
- Sanitary process lines
- Brine handling systems
Aerospace & Defense
- Hydraulic systems
- Fuel lines
- Instrumentation tubing
| OD (mm) | Wall Thickness (mm) | Typical Application |
|---|---|---|
| 6.35 (1/4") | 0.89, 1.24, 1.65 | Hydraulic lines, instrumentation |
| 9.53 (3/8") | 1.24, 1.65, 2.11 | Control lines, umbilicals |
| 12.70 (1/2") | 1.65, 2.11, 2.77 | Chemical injection, hydraulics |
| 15.88 (5/8") | 1.65, 2.11, 2.77 | Umbilical tubes |
| 19.05 (3/4") | 1.65, 2.11, 2.77 | Service lines |
| 25.40 (1") | 2.11, 2.77, 3.40 | Flow lines |
| Process | Recommendation |
|---|---|
| Bending | Cold bending with minimum radius of 3x OD. Use mandrel for tight radii. |
| Flaring / Swaging | Acceptable with proper tooling. Annealed condition preferred. |
| Cutting | Use abrasive saw, cold saw, or precision tube cutter. No thermal cutting. |
| Threading | Possible on thicker walls. Use sharp tools and proper lubrication. |
| Welding (to fittings) | Use matching filler metal (2209 for 2205, 2509 for 2507). Strict heat input control. |
| Heat Treatment | Solution anneal after cold working. 1040-1120°C followed by water quench. |
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