Import Astm A790 S31803 Seamless Pipe — Buy in wholesale FOB from Supplier in China

ASTM A790 S31803 seamless pipe is a duplex stainless steel tube manufactured to the ASTM A790 standard, combining ferritic and austenitic microstructures in approximately equal proportions. The UNS S31803 grade contains 22% chromium, 3% molybdenum, 0.14% nitrogen and balance iron, delivering yield strength roughly double that of austenitic grades like 316L. Zhengzhou Huitong Pipe Fittings supplies this pipe in sizes from 1/8 inch to 56 inches, with wall thicknesses ranging from Sch5s to XXS, suitable for corrosive service where chloride stress corrosion cracking resistance is paramount.

The dual-phase microstructure of S31803 provides superior resistance to pitting and crevice corrosion compared to standard 300-series stainless steels, with a typical PREN (pitting resistance equivalent number) of approximately 34. Seamless manufacture eliminates weld seam vulnerability, ensuring uniform mechanical properties circumferentially and axially. The alloy's high nitrogen content stabilises the austenite phase, improving weldability and toughness at sub-zero temperatures relative to earlier duplex grades like 2205 without nitrogen additions. Standard delivery conditions include solution annealed and pickled, with pipe ends prepared as plain end (PE) or bevelled end (BE) for welding.

This pipe serves oil and gas transmission lines, seawater cooling systems, chemical process vessels, and offshore platform structural applications where weight reduction and fatigue resistance are valued. Buyers typically include EPC contractors, refinery operators, desalination plant engineers, and marine equipment fabricators. Trade terms, MOQ and lead time should be confirmed directly with Zhengzhou Huitong Pipe Fittings, as the listing does not specify these terms. Packaging is typically bundle, steel strip, wooden case or woven bags, as stated in the supplier's standard offering.

Zhengzhou Huitong Pipe Fittings operates from Room 2004, Expo Center, Dongfeng Road, Zhengzhou 450000, Henan Province, China. The supplier is classified as an imported-tier vendor with a harbor trust tier. The response rate is listed at 0.00% with an average response time of 0 hours, which indicates no response data is currently available through the platform. The company's product range covers seamless and welded pipes across carbon steel, alloy steel, stainless steel, duplex, nickel alloy and titanium grades, including specialised products for pharmaceutical and sanitary applications.

The listing presents Zhengzhou Huitong as a stockist and distributor with broad material coverage rather than a single-product manufacturer. No specific factory certification, production capacity, year of establishment, or workforce size is stated in the available profile. Buyers should conduct independent due diligence on quality management system certification, mill test certificate provision, and third-party inspection capability before placing orders. The address places the supplier in Zhengzhou, a major logistics and industrial hub in central China with established steel distribution infrastructure.