Nguyen Fittings and Plates provides high-performance Duplex Steel S31803 Pipe Fittings, known for their strength and corrosion resistance. These buttweld fittings meet ASTM A815 and ASME B16.9 standards, making them suitable for aggressive chloride-rich environments like marine, offshore, and chemical processing. S31803, also called UNS S31803, is a duplex stainless steel that combines austenitic and ferritic structures, offering excellent resistance to pitting, crevice corrosion, and stress corrosion cracking. Our collection includes elbows, reducers, tees, and caps that meet strict mechanical and dimensional standards.
Specifications ASTM A815 / ASME SA815
Dimensions ASME/ANSI B16.9, ASME B16.28, MSS-SP-43
Size 1/2″ NB to 24″NB in
Type Seamless / Welded / Fabricated
Bending Radius R=1D, 2D, 3D, 5D, 6D, 8D, 10D or Custom
Thickness Sch 5s, Sch 10s, Sch 40s, Sch 80s, Sch 160s, Sch XXS
Duplex S31803 consists of about 22% chromium, 5–6.5% nickel, 3% molybdenum, and the remainder iron, with nitrogen added for strength. It has a tensile strength of 620–880 MPa and a yield strength ≥450 MPa, which is nearly double that of 304/316 stainless steel. The alloy resists chloride stress corrosion cracking, pitting, and crevice corrosion, especially in seawater and acidic conditions. S31803 has excellent mechanical strength and good weldability, making it perfect for high-load settings where both corrosion and pressure resistance are needed.
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | Fe |
| S31803 | 0.030 max | 2.00 max | 1.00 max | 0.030 max | 0.020 max | 22.0 – 23.0 | 3.0 – 3.5 | 4.50 – 6.50 | 0.14 – 0.20 | 63.72 min |
| Grade | Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| S31803 | 7.8 g/cm3 | 1350 °C (2460 °F) | Psi – 116000 , MPa – 800 | Psi – 80000 , MPa – 550 | 15 % |
Nguyen Fittings is a leading supplier of Duplex Steel S31803 Pipe Fittings in Da Nang, Vietnam. We offer an extensive range of Monel K500 fittings, renowned for their excellent corrosion resistance and high strength, which makes them perfect for demanding industrial applications like chemical processing, marine environments, and high-temperature systems. With a commitment to quality and reliable delivery, we ensure our clients receive top-tier products tailored to meet the specific needs of various industries.
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
| STANDARD | UNS | WERKSTOFF NR. |
| Duplex 2205 | S31803 | 1.4462 |
Duplex Steel S31803 Pipe Fittings from Nguyen Fittings offer exceptional corrosion resistance, especially in seawater and harsh environments. They are known for their high strength, durability, and resistance to pitting and crevice corrosion, ensuring long-lasting performance. We provide precise manufacturing, quality control, and reliable service for diverse industrial applications.
Duplex Steel S31803 pipe fittings offer exceptional corrosion resistance, particularly against pitting, crevice corrosion, and stress corrosion cracking, making them ideal for harsh environments. They provide high strength and excellent resistance to fatigue, making them durable under pressure. The alloy’s good weldability and formability enhance the ease of fabrication. Duplex Steel S31803 pipe fittings also offer superior toughness and stress resistance, ensuring reliability in demanding applications such as chemical processing, marine, and oil & gas industries. Their cost-effectiveness and long-lasting performance make them a preferred choice for critical piping systems.
| Outer Diameter And Inside Diameter | Equivalent | Diameter Of Pipe Nominal | Typical Threads In Inches |
| 5/16 | 0.313 | 1/16 | 27 |
| 13/32 | 0.405 | 1/8 | 27 |
| 35/64 | 0.540 | 1/4 | 18 |
| 43/64 | 0.675 | 3/8 | 18 |
| 27/32 | 0.840 | 1/2 | 14 |
| 1-3/64 | 1.050 | 3/4 | 14 |
| 1-5/16 | 1.315 | 1 | 11-1/2 |
| 1-21/32 | 1.660 | 1-1/4 | 11-1/2 |
| 1-29/32 | 1.900 | 1-1/2 | 11-1/2 |
| 2-3/8 | 2.375 | 2 | 11-1/2 |
| 2-7/8 | 2.875 | 2-1/2 | 8 |
| 3-1/2 | 3.500 | 3 | 8 |
| 4 | 4.000 | 3-1/2 | 8 |
Yes, custom sizes for Duplex Steel S31803 Pipe Fittings are available at Nguyen Fittings. We offer tailored solutions to meet your specific requirements, ensuring optimal performance for your projects. For more information, please contact us at sales@nguyenfittings.com.
Duplex Steel S31803 pipe fittings are commonly found in marine structures, offshore oil platforms, chemical processing plants, and desalination units. They are perfect for heat exchangers, pressure vessels, cooling systems, and firefighting systems in offshore and industrial applications. These fittings also work well in paper mills, petrochemical refineries, and biomass plants, where chloride-heavy fluids are handled.
Get in touch with one of our Technical Sales Representatives to request a quote or get answers to any questions you may have.
©2024 Nguyen Fittings. All Rights Reserved.
