ASTM A790 UNS S31803 Pickled Duplex Stainless Steel Seamless Pipe For Water Treatment
ASTM A790 UNS S31803 Pickled Duplex Stainless Steel Seamless Pipe For Water Treatment
ASTM A790 is the standard specification for seamless and welded ferritic/austenitic duplex stainless steel pipe, intended for general corrosive service, with particular emphasis on environments containing chlorides, acids, or high pressures. UNS S31803 (often referred to as the original “2205” duplex grade) contains approximately 22% chromium, 5–6% nickel, 3% molybdenum, and 0.08–0.20% nitrogen. The seamless manufacturing process involves piercing a solid billet and then hot rolling or extruding it into a hollow tube without any longitudinal weld seam. This results in a pipe with uniform grain structure, predictable mechanical properties, and complete structural integrity—making it ideal for high-pressure, high-temperature. Typical applications for ASTM A790 UNS S31803 seamless pipe include offshore oil & gas platforms (subsea and topside piping), chemical processing plants (heat exchangers, reactors), marine desalination systems, pulp & paper digesters, and flue gas desulfurization units in power plants. The pipe is normally delivered in the solution annealed and pickled condition, free from scale and with maximum corrosion resistance.
YUHONG GROUP is one of the leading manufacturer and supplier of stainless steel pipes in China, specilizing in ASTM A790 UNS S31803/S32205/S32750/S32760 duplex stainless steel pipes. Our duplex steel pipes are widely used in chemical industry, oil&gas plant, power generation, water treatment, and so on. If you're interested in our stainless steel pipes, just welcome to send your inquiry to us.
Key Advantages and Features:
- High Yield Strength
- Superior Stress Corrosion Cracking Resistance
- Good Pitting & Crevice Corrosion Resistance
- Excellent Fatigue Resistance
- Low Thermal Expansion
- Good Weldability
- Cost-Effective
Different Surface Finishes:
| Finish Type | Description | Typical Application |
| Mill Finish | Dark, oxidized surface from hot forming; may contain scale. | Temporary protection during transport; requires pickling before use. |
| Pickled Finish | Oxide scale removed by acid bath; clean, matte gray appearance. | Standard for most industrial applications (chemical, oil & gas). |
| Annealed & Pickled | Heat-treated to restore corrosion resistance, then pickled. | Highest corrosion resistance; required by ASTM A790 as standard delivery condition. |
| Mechanically Polished | Surface ground to a smooth finish (e.g., 120–400 grit). | Food processing, pharmaceutical, architectural. |
| Bare / Bright Annealed | Bright, reflective surface from annealing in a controlled atmosphere (no scale). | Instrumentation, clean rooms, aesthetic applications. |
Different Applications:
| Industry | Specific Applications |
| Oil & Gas | Offshore platforms (topside & subsea), flowlines, wellhead equipment, downhole tubing, Christmas trees. |
| Chemical & Petrochemical | Heat exchangers, pressure vessels, reactors, columns, piping for acetic acid, formic acid, and chloride-containing media. |
| Marine Engineering | Desalination plants (high-pressure brine lines), seawater cooling systems, firewater systems, shipbuilding. |
| Pulp & Paper | Digester vessels, bleaching plants (chlorine dioxide service). |
| Power Generation | Condenser tubes, feedwater heaters, flue gas desulfurization systems. |
| Mining & Mineral Processing | Slurry lines, autoclaves, leaching circuits where abrasion and corrosion coexist. |
| Food & Pharmaceutical | High-purity processing equipment where both strength and cleanability are required. |
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.