Duplex Steel UNS S31803 Pipes & Tubes are used where chloride containing fluids are carried at pressures that would need a much heavier wall in 316L. Under ASTM A790, the pipe grade has a minimum yield strength of 450 MPa, compared to 170 MPa for 316L. This often allows the use of a thinner section. Metinox Overseas supplies ASTM A790 UNS S31803 seamless and welded pipe, and A789 duplex steel UNS S31803 tube, as part of its duplex steel pipes range. Buyers often ask whether the material is S31803 only or dual certified with S32205, so check your project specification before issuing a PO. Most enquiries come from offshore, gas plants and desalination units in the GCC and other export markets.
Table of Contents
- Specifications of Duplex Steel UNS S31803 Pipes & Tubes
- Choosing Between Duplex S31803 Seamless Pipe and 31803 ERW Pipes
- UNS S31803 Pipe Chemical Composition (ASTM A790)
- UNS S31803 Pipe Mechanical Properties
- Duplex Steel S31803 Pipes Size and Weight Chart
- UNS S31803 Seamless Pipe Pressure Rating
- Physical Properties of UNS S31803 (Duplex 2205) Pipe
- Equivalent Grades for Duplex Steel S31803 Pipes
- Applications of ASTM A790 UNS S31803 Pipes
- Duplex Steel UNS S31803 Pipe Price: What Moves It
- Delivery and Packing for Duplex Steel S31803 Pipes Exporters
- Get a Quote for A790 S31803 Pipe and A789 Tube
- Complete the Line: Fittings and Flanges in UNS S31803
- Duplex Steel UNS S31803 Pipes & Tubes FAQ
Specifications of Duplex Steel UNS S31803 Pipes & Tubes
| Specification | Details |
|---|---|
| Standard | ASTM A790 / ASME SA790 (pipe), ASTM A789 / ASME SA789 (tube) |
| Material Grade | UNS S31803 (EN 1.4462, Duplex 2205), dual certified S31803 / S32205 on request |
| Size | 1/2" NB to 24" NB |
| Seamless Pipes & Tubes Sizes | 1/2" NB to 8" NB |
| Welded Pipes & Tubes Sizes | 6" NB to 24" NB |
| Wall Thickness | 0.5 mm to 45 mm |
| Outer Diameter | 6.0 mm to 630 mm |
| Dimensions | OD (6.0 to 630) mm × WT (0.5 to 45) mm |
| Schedule | Sch 5S, 10S, 40S, 80S, 160, XXS (ASME B36.19M / B36.10M) |
| Type | Seamless / Welded / ERW / EFW |
| End Finish | Plain End, Bevelled End (ASME B16.25), Threaded |
| Length | Single Random, Double Random, Cut Length; 5.8 m and 11.8 m for 20 ft and 40 ft containers |
| Heat Treatment | Solution annealed at 1020 to 1100 °C (1870 to 2010 °F) |
| Delivery Condition | Solution Annealed and Pickled |
Choosing Between Duplex S31803 Seamless Pipe and 31803 ERW Pipes
Seamless pipe is made by hot extrusion or piercing, then cold finished to size. Because there is no weld, the whole wall has the same structure. Buyers usually choose seamless for high pressure lines, cyclic loading and sour service, and in small bore sizes, where welded pipe has little price advantage.
Welded pipe is formed from strip or plate, welded along a straight seam and then solution annealed so the weld and the parent metal have matching properties. It becomes the more practical choice as diameter goes up and wall thickness comes down, where seamless gets expensive or hard to source. ASTM A790 covers welded pipe made without filler metal.
| Seamless | Welded (ERW / EFW) | |
|---|---|---|
| Standard | ASTM A790 | ASTM A790, or A928 with filler metal |
| Typical sizes | Small and medium bore | Medium and large bore, thinner walls |
| Common service | High pressure, cyclic, sour | Utility, water, low to medium pressure process |
| Weld seam checks | - | Flattening, hydrostatic or NDE, radiography if specified |
UNS S31803 Pipe Chemical Composition (ASTM A790)
| Element | C | N | Mn | Si | Cr | Mo | Ni | P | S | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| S31803 | 0.030 max | 0.08 to 0.20 | 2.00 max | 1.00 max | 21.0 to 23.0 | 2.5 to 3.5 | 4.5 to 6.5 | 0.030 max | 0.020 max | Balance |
UNS S31803 Pipe Mechanical Properties
| Property | A790 pipe, S31803 | A789 tube, S31803 | A790 pipe, S32205 |
|---|---|---|---|
| Tensile strength, min | 620 MPa (90 ksi) | 620 MPa (90 ksi) | 655 MPa (95 ksi) |
| Yield strength (0.2%), min | 450 MPa (65 ksi) | 450 MPa (65 ksi) | 450 MPa (65 ksi) |
| Elongation in 50 mm, min | 25% | 25% | 25% |
| Hardness, max | 290 HBW / 30 HRC | 290 HBW / 30 HRC | 290 HBW / 30 HRC |
Duplex Steel S31803 Pipes Size and Weight Chart
| NPS | DN | OD (mm) | Sch 10S Wall (mm) | Sch 10S Weight (kg/m) | Sch 40S Wall (mm) | Sch 40S Weight (kg/m) | Sch 80S Wall (mm) | Sch 80S Weight (kg/m) |
|---|---|---|---|---|---|---|---|---|
| 1/2 | 15 | 21.3 | 2.11 | 0.99 | 2.77 | 1.26 | 3.73 | 1.61 |
| 3/4 | 20 | 26.7 | 2.11 | 1.27 | 2.87 | 1.68 | 3.91 | 2.18 |
| 1 | 25 | 33.4 | 2.77 | 2.08 | 3.38 | 2.49 | 4.55 | 3.22 |
| 1 1/2 | 40 | 48.3 | 2.77 | 3.09 | 3.68 | 4.02 | 5.08 | 5.38 |
| 2 | 50 | 60.3 | 2.77 | 3.90 | 3.91 | 5.40 | 5.54 | 7.43 |
| 3 | 80 | 88.9 | 3.05 | 6.42 | 5.49 | 11.22 | 7.62 | 15.18 |
| 4 | 100 | 114.3 | 3.05 | 8.31 | 6.02 | 15.97 | 8.56 | 22.18 |
| 6 | 150 | 168.3 | 3.40 | 13.74 | 7.11 | 28.08 | 10.97 | 42.29 |
| 8 | 200 | 219.1 | 3.76 | 19.84 | 8.18 | 42.28 | 12.70 | 64.23 |
| 10 | 250 | 273.1 | 4.19 | 27.61 | 9.27 | 59.93 | 12.70 | 81.04 |
| 12 | 300 | 323.9 | 4.57 | 35.76 | 9.53 | 73.41 | 12.70 | 96.85 |
Heavier walls (Sch 160, XXS) and sizes above NPS 12 follow ASME B36.10M. Quote them on request.
UNS S31803 Seamless Pipe Pressure Rating
| NPS | Sch 10S (bar) | Sch 40S (bar) | Sch 80S (bar) |
|---|---|---|---|
| 1/2 | 385 | 518 | 722 |
| 3/4 | 303 | 421 | 591 |
| 1 | 319 | 394 | 545 |
| 1 1/2 | 216 | 291 | 411 |
| 2 | 172 | 246 | 355 |
| 3 | 127 | 234 | 330 |
| 4 | 98 | 198 | 286 |
| 6 | 74 | 158 | 247 |
| 8 | 63 | 139 | 219 |
| 10 | 56 | 126 | 174 |
| 12 | 52 | 109 | 146 |
Need a size or schedule not listed? Send OD, wall and quantity and we will confirm stock and price within one working day. Request a Quote
Physical Properties of UNS S31803 (Duplex 2205) Pipe
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.8 g/cm³ | 0.282 lb/in³ |
| Elastic modulus | 200 GPa | 29 × 10⁶ psi |
| Thermal expansion, 20 to 100 °C | 13.0 µm/m·°C | 7.2 µin/in·°F |
| Thermal conductivity, 20 °C | 19 W/m·K | 11 Btu/h·ft·°F |
| Melting range | 1385 to 1440 °C | 2525 to 2625 °F |
Equivalent Grades for Duplex Steel S31803 Pipes
| Common Name | Werkstoff Nr. | UNS | EN | JIS |
|---|---|---|---|---|
| Duplex 2205 | 1.4462 | S31803 / S32205 | X2CrNiMoN22-5-3 | SUS329J3L |
Applications of ASTM A790 UNS S31803 Pipes
- Oil and gas piping: produced water, seawater injection and flowlines within ISO 15156-3 limits
- Marine and offshore: firewater, ballast and seawater cooling lines on platforms and FPSOs
- Refinery pipes and tubes: crude overhead condensers and chloride-bearing process streams
- Petrochemical: process lines where 316L suffers chloride stress corrosion cracking
- Chemical processing: organic acid, caustic and brine service
- Desalination: high-pressure brine and RO feed lines in GCC plants
Duplex Steel UNS S31803 Pipe Price: What Moves It
No price is published here, because duplex pricing tracks nickel and molybdenum markets and changes often. The quote depends on:
- Grade: S31803 only, or S31803/S32205 dual certified
- Seamless or welded, size and wall
- Quantity, and whether the material is from stock or a mill order
- Certification level: EN 10204 3.1 or 3.2
- Third-party inspection and any extra testing (G48, A923, ferrite, PMI)
- Incoterm and destination port
For a fast quotation, send: grade, standard, OD, wall, length, quantity, end finish, certification level, inspection requirement, destination port and required date.
Delivery and Packing for Duplex Steel S31803 Pipes Exporters
- Plastic end caps on plain ends, bevel protectors on bevelled ends
- Bundling with non-metallic or stainless strapping, never carbon steel straps in direct contact, to avoid iron contamination
- Wooden cases or crates for small bore and tube
- Laydown in hot coastal climates: keep pipe off sand and the ground, covered against UV and salt spray, and separated from carbon steel to avoid rust staining and chloride deposits
Get a Quote for A790 S31803 Pipe and A789 Tube
Send your enquiry with your size list and project specification. We will check it against ASTM A790 or A789 and come back with a quotation and lead time.
Request a QuotationComplete the Line: Fittings and Flanges in UNS S31803
- Duplex 2205 pipe fittings, UNS S31803 (ASTM A815 WPS31803, ASME B16.9)
- ASTM A815 S31803 pipe fittings
- Duplex 2205 flanges (ASTM A182 F51, ASME B16.5)
- Related: Duplex vs super duplex pipes, Duplex stainless steel grades
Duplex Steel UNS S31803 Pipes & Tubes FAQ
Both are 22Cr duplex in ASTM A790. S32205 has higher minimum chromium, molybdenum and nitrogen, which raises minimum PREN and, for pipe, minimum tensile strength to 655 MPa. Material certified to both grades meets either requirement.
Only within the limits of ISO 15156-3, which restricts H₂S partial pressure, chloride content and temperature, and sets ferrite and hardness requirements. For more severe sour conditions, super duplex or nickel alloys are normally specified.
Single random, double random and cut lengths are possible. Lengths of 5.8 m and 11.8 m are commonly specified because they fit 20 ft and 40 ft containers.
Yes. ASTM A790 covers both seamless and welded pipe. Welded is common in larger diameters and thinner walls. State whether filler metal and full radiography of the seam are required.
Grade, standard, OD, wall, length, quantity, end finish, certification level, inspection requirement, destination port and required date.
ASME B31.3 lists allowable stresses for S31803 up to 316 °C (600 °F). Above about 300 °C, long exposure causes 475 °C embrittlement, so duplex is not used for continuous high-temperature service.
S31803 has more than twice the minimum yield strength of 316L (450 vs 170 MPa) and a minimum PREN of about 31 vs about 24, giving better resistance to chloride pitting and stress corrosion cracking, often at a thinner wall.
Enquire Now
Get pricing within 24 hours!
