ASTM A790 UNS S32750 is a standard specification for super duplex stainless steel welded pipes, specially designed for high-pressure and highly corrosive environments. GNEE maintains a large stock of S32750 pipes and supports bulk customization with fast delivery, providing a one-stop supply solution for high-strength, high-corrosion-resistant, and high-stability super duplex welded piping systems used in demanding industrial applications.
Our ASTM A790 UNS S32750 welded pipes are manufactured using precision roll forming combined with plasma welding and double-sided TIG welding technology. The pipes undergo solution annealing at 1050–1100°C to eliminate welding stress and intergranular precipitation. The weld seam is smooth and uniform, free from slag inclusion and porosity. The hardness is controlled at ≤310 HBW, while excellent low-temperature impact toughness is maintained at -46°C. Compared with 316L stainless steel and conventional 2205 duplex steel, S32750 welded pipes provide significantly higher pressure-bearing capacity, allowing thinner equipment design and reduced overall material costs.
S32750 welded pipes can withstand service temperatures up to 315°C and feature a Critical Pitting Temperature (CPT) of ≥50°C. Under seawater and high-chloride acidic or alkaline corrosion conditions, their service life is more than 8 times longer than that of 316L stainless steel. These pipes are widely used in offshore oil platforms, seawater desalination plants, flue gas desulfurization (FGD) systems, chemical pressure vessels, and heat exchangers.
GNEE can supply full-size ASTM A790 UNS S32750 welded pipes with outside diameters ranging from 12.7 mm to 325 mm and wall thicknesses from 1.2 mm to 20 mm. Customized fixed lengths from 6–12 meters, non-standard cutting, bevel machining, and surface pickling & passivation treatments are available. The outside diameter tolerance is strictly controlled within ±0.15 mm.
ASTM A790 UNS S32750 Specifications
| Specification of UNS S32750 Seamless Pipe | Astm A790 and Asme Sa790 |
| Standard | ASTM, AISI, EN, GB, DIN, JIS, ASME |
| UNS S32750 Seamless Pipe Outer Diameter | 6.00MM Outer Diameter upto 250MM Outer Diameter, Sizes upto 12Inch NB |
| UNS S32750 Welded Pipe size | 5.0 MM To 1219.2 MM |
| UNS S32750 EFW Pipe size | 5.0 To 1219.2 MM |
| Thickness | 0.3 To 50 MM |
| ASTM A790 UNS S32750 Welded Tube Sizes | 6.35MM Outer Diameter To 152MM Outer Diameter Pipe |
| Swg and Bwg | 10, 12, 14, 16, 18, 20 Swg. |
| uns S32750 tubing wall thickness | 0.020" –0.220 Inch (special wall thicknesses available) |
| ASTM A790 UNS S32750 Pipe Schedule | 5, 10, 40, 80, 80S, 160, XXS, XS ASTM A790 Uns S32750 Pipe Supplier |
| UNS S32750 Pipe Finish | NO.1, Polished, 2B, Annealed and Pickled, Bright and Annealed, MF, NO.4, BA, HL, 8K, Mirror finish etc |
Super Duplex 2507 Pipes Chemical Composition:
| Grade | C≤ | Mn≤ | P≤ | S≤ | Si≤ | Ni | Cr | Mo | N | Cu |
| S32750 | 0.03 | 1.20 | 0.035 | 0.02 | 0.80 | 6.0-8.0 | 24.0-26.0 | 3.0-5.0 | 0.24-0.32 | 0.5 |
Mechanical Properties of Super Duplex S32750 Pipes and Tubes:
| Mechanical properties | Tensile, min, ksi[MPa] | Yield, min, ksi[MPa] | Elongation, %(min) | Hardness, HB(max) |
| S32750 | 116 [800] | 80 [550] | 15 | 300 |
ASTM A790 Pipe Tolerances
| OD Tolerance | Wall Thickness Tolerance | ||
|---|---|---|---|
| Outer Diameter Tolerance | Outer Diameter | W.T.Tolerance | Outer Diameter |
| + .40/- .80 | 1 .3≤D≤48.3 | +20%/-12.5% | 1 .3≤D≤73 |
| + .80/- .80 | 48.3<D≤114.3 | +22.5%/-12.5% | 88.9≤D≤457 t/D ≤5% |
| +1.60/- .80 | 114.3<D≤219.1 | +15%/-12.5% | 88.9≤D≤457 t/D >5% |
| +2.40/- .80 | 219.1<D≤457 | ||
What is the difference between S32750 and S32760 welded pipes?
S32750 stainless steel is a general-purpose super duplex steel suitable for moderately harsh chloride-containing environments, such as offshore platforms, desalination plants, and chemical pressure vessels.
S32760 stainless steel, which contains copper and tungsten, offers enhanced protection and is suitable for more extreme environments-such as conditions involving sulfuric acid, Flue Gas Desulfurization (FGD) systems, and subsea pumps and valves.
What is the difference between ASTM A790 and A789?
ASTM A790 is mainly intended for nominal pipes, typically used for fluid transportation, with an emphasis on pressure ratings and standard pipe sizes (such as Sch 10S, Sch 40S). ASTM A789 is mainly intended for special-purpose tubes/heat exchanger tubes, commonly used in heat exchangers and instrumentation tubing, with an emphasis on the precision of outside diameter (OD) and wall thickness (WT).
Main Applications of S32750 Welded Pipes
Seawater Desalination (High-pressure piping in RO systems)
Offshore Oil and Gas Development (Subsea pipelines, risers)
Chemical Processing Industry (Environments containing organic acids and chlorides)
Pulp and Paper (Bleaching systems)
If you have requirements for any of the aforementioned items, we welcome your orders. GNEE maintains a substantial inventory of best-selling products for you to choose from. These materials are available in both seamless and welded forms; for detailed chemical compositions or free samples, please contact our factory immediately. We offer competitive pricing and exceptional service.
Prior to shipment, every single tube undergoes eddy current and ultrasonic flaw detection, as well as a 100% hydrostatic pressure test. With a finished product pass rate reaching 99.8%, we are able to provide EN 10204 3.2 material certificates, along with third-party salt spray and metallographic inspection reports.
