Duplex Stainless Steel Seamless Pipes (UNS S31803 / S32205) – High-Strength, Corrosion-Resistant Solutions

Duplex Stainless Steel Seamless Pipes (UNS S31803 / S32205) are high-performance alloy pipes engineered with a balanced austenitic-ferritic (50/50) microstructure, delivering an optimal combination of high mechanical strength, excellent corrosion resistance, and long-term durability.

Compared to conventional austenitic stainless steels such as 304L and 316L, duplex pipes offer:

• Up to 2× higher yield strength
• Improved resistance to chloride environments
• Reduced wall thickness and overall system weight

These advantages make duplex seamless pipes an ideal solution for high-pressure, corrosive, and safety-critical applications.

1. Superior Corrosion Resistance (High PREN Value)

With elevated levels of Chromium (Cr), Molybdenum (Mo), and Nitrogen (N), duplex stainless steel pipes achieve a high Pitting Resistance Equivalent Number (PREN), ensuring outstanding performance in aggressive environments.

Performance Highlights:

• Excellent resistance to pitting and crevice corrosion
• Superior protection in chloride-rich and marine environments
• High resistance to Chloride Stress Corrosion Cracking (SCC)

2. High Mechanical Strength & Structural Integrity

Duplex S31803 / S32205 seamless pipes provide:

• Nearly double the yield strength of 300-series stainless steel
• High toughness at sub-zero temperatures
• Stable performance up to 300°C (572°F)

Engineering Benefits:

• Reduced material consumption
• Lower installation and transportation costs
• Enhanced safety in high-pressure systems

3. Compliance with International Standards

Our duplex stainless steel seamless pipes are manufactured in full compliance with global standards:

• ASTM A790 / ASTM A789
• ASME SA790 / SA789
• EN standards available upon request

Quality Control:

• 100% Non-Destructive Testing (NDT)
  • Ultrasonic Testing (UT)
  • Eddy Current Testing (ECT)
  • Hydrostatic Testing
• Full traceability with Mill Test Certificates (EN 10204 3.1)

Oil & Gas Industry

• Offshore platforms and subsea pipelines
• Sour gas environments (H₂S service)
• Flowlines and risers

Chemical & Petrochemical Processing

• Heat exchangers and pressure vessels
• Transport systems for acids, alkalis, and chlorides

Marine & Desalination

• Seawater cooling systems
• Reverse osmosis (RO) plants
• Desalination pipelines

Power Generation

• Flue Gas Desulfurization (FGD) systems
• Nuclear and thermal power cooling circuits

• Export-grade packaging for global shipping
• Complete documentation package
• Fast delivery for urgent project timelines
• Compliance with international logistics standards

• Specialized in Duplex & Super Duplex stainless steel pipes
• Extensive export experience across global markets
• Competitive pricing with stable supply chain
• Technical support for material selection and engineering optimization
• Reliable quality with strict inspection protocols