Duplex Steel S31803/S32205 Flanges Supplier in the US – Nakoda Steel Industry
Nakoda Steel Industry is a globally recognized Duplex Steel S31803/S32205 Flanges Manufacturer and Supplier, now delivering precision-engineered solutions to the United States. Renowned for our expertise in corrosion-resistant alloys, we produce flanges that excel in extreme environments, from subzero temperatures to chloride-rich settings. Compliant with ASTM A182, ASME SA182, and ANSI B16.5 standards, our products are trusted in oil & gas, chemical processing, marine, and pharmaceutical industries.

Product Range & Key Features
Nakoda Steel Industry offers a versatile range of Duplex Steel S31803/S32205 Flanges, designed for durability and performance:
1. Duplex Steel S31803 Slip-On Flanges
- Corrosion Resistance: Superior to stainless steel 317, ideal for acidic and chloride environments.
- Welding Suitability: Low carbon content prevents carbide precipitation during welding.
2. Duplex S31803 Threaded Flanges
- Applications: Chemical plants, food processing, and offshore platforms.
- Design: Precision threads for secure, leak-proof connections.
3. Duplex S31803 Weld Neck Flanges
- Strength: Enhanced stress resistance in high-pressure pipelines.
- Material: Molybdenum and nickel-enriched for austenitic stability at low temperatures.
4. Duplex S31803 Blind Flanges
- Versatility: Suitable for marine environments and subzero industrial applications.
Additional Variants:
- Socket Weld Flanges
- Lap Joint Flanges
- Ring Joint Type Flanges
- Spectacle Blind Flanges
- Nippolet Flanges
Technical Specifications
Our flanges meet rigorous international standards, ensuring reliability across industries:
- Grades: Duplex S31803 (UNS S31803), Duplex S32205 (UNS S32205)
- Standards: ANSI B16.5, ASME B16.47, DIN, EN 1092, BS 4504
- Size Range: ½″ (15 NB) to 24″ (1200 NB)
- Pressure Ratings: 150# to 2500#, PN6 to PN64
- Temperature Range: -50°C to 300°C
Industry Applications
Nakoda’s Duplex Steel Flanges are pivotal in demanding sectors:
- 1. Oil & Gas: Offshore rigs, pipelines, and subsea equipment exposed to H₂S and CO₂.
- 2. Chemical & Pharmaceutical: Reactors, storage tanks, and acid-handling systems.
- 3. Marine Engineering: Desalination plants and shipbuilding in chloride-rich waters.
- 4. Power Generation: High-temperature steam systems and cooling circuits.
Engineering Excellence
Material Advantages:
- Austenitic Stability: Nickel content maintains microstructure integrity at lower temperatures.
- Stress Corrosion Resistance: Molybdenum enhances performance in polluted or saline environments.
- High-Temperature Strength: Retains tensile and fatigue resistance up to 300°C.
Challenges Addressed:
- Welding Precision: Low carbon minimizes carbide formation, ensuring weld integrity.
- Chloride Resistance: Withstands pitting in chlorinated water up to 60°C.
Quality Assurance & Certifications
Nakoda Steel Industry adheres to stringent quality protocols:
- Certifications: EN 10204/3.1B, NACE MR 01075 (sour service compliance).
- Testing Protocols:
- Mechanical: Tensile strength, hardness, flaring, and flattening tests.
- Chemical: Spectrographic analysis and PMI (Positive Material Identification).
- Corrosion Resistance: Pitting, intergranular corrosion (IGC), and radiography testing.
- Third-Party Inspections: SGS, TÜV, and API audits.
Why Partner with Nakoda Steel Industry?
- 1. US-Centric Supply Chain: Rapid delivery and local inventory for reduced lead times.
- 2. Custom Solutions: Tailored dimensions, pressure ratings, and finishes (RTJ, RF, FF).
- 3. Competitive Pricing: Premium quality at industry-leading rates.
- 4. Technical Expertise: Decades of experience in duplex steel fabrication and testing.
Commitment to Sustainability
Our flanges reduce lifecycle costs through:
- Longevity: Resists degradation in harsh conditions, minimizing replacements.
- Recyclability: Eco-friendly material supporting circular manufacturing.
Contact Us
As a trusted Duplex Steel S31803/S32205 Flanges Supplier in the US, Nakoda Steel Industry combines innovation with unwavering quality. Whether you need Slip-On Flanges for chemical plants or Weld Neck Flanges for offshore drilling, we deliver precision, compliance, and unmatched service.