Based in Cape Town, South Africa, Khuliso Fittings has made a name for itself as a top-notch manufacturer and supplier of high-performance Duplex Steel S31803 pipe fittings. With a reputation for exceptional quality and precision engineering, Khuliso Fittings delivers durable and corrosion-resistant piping solutions tailored to meet the rigorous demands of various industries. Their Duplex Steel S31803 fittings adhere to international standards, guaranteeing reliable performance even in extreme conditions. Catering to sectors like oil and gas, chemical processing, marine, and power generation, Khuliso Fittings is dedicated to providing products that blend strength, efficiency, and long-lasting durability.
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
The Duplex Steel S31803 pipe fittings boast a well-balanced microstructure of austenite and ferrite, which results in an impressive mix of strength and corrosion resistance. This alloy typically features around 22% chromium, 5–6% nickel, 3% molybdenum, and trace amounts of nitrogen, all of which enhance its resistance to pitting, crevice corrosion, and stress corrosion cracking. These fittings showcase high tensile and yield strength—almost double that of standard austenitic stainless steels—along with remarkable fatigue and impact resistance. Plus, Duplex S31803 maintains good weldability and toughness, even in low-temperature environments.
| 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 % |
Khuliso Fittings is a leading supplier of Duplex Steel S31803 Pipe Fittings in Cape Town, South Africa. 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 Khuliso 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 Khuliso Fittings. We offer tailored solutions to meet your specific requirements, ensuring optimal performance for your projects. For more information, please contact us at sales@khulisofittings.co.za.
Duplex Steel S31803 pipe fittings are a go-to choice for applications that demand both strength and corrosion resistance. They find common use in the oil and gas industry, offshore platforms, desalination plants, chemical processing facilities, and the pulp and paper sector. These fittings excel in environments with chlorides and acidic media, making them ideal for seawater systems and chemical handling pipelines. Their durability, resistance to localized corrosion, and high mechanical strength ensure a long service life and cost-effective operation in critical industrial systems.
Get in touch with one of our Technical Sales Representatives to request a quote or get answers to any questions you may have.








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