Standard: ASME B16.9/MSS SP-43, NACE MR0103

Grade: WPS31803 (UNS S31803), WPS32750 (UNS S32750), WPS32760 (UNS S32760), WPS32205 (UNS S32205)

OD: NPS 1/2" - 48"

WT: SCH 5S, 10S, 40S, 80S, XS, XXS

ASTM A815 UNS S31803 (2205 Duplex / F51) pipe fittings are wrought duplex stainless steel pipe connectors fully compliant with ASTM A815/A815M standard for forged seamless & welded pipe fittings.

UNS S31803 is a balanced ferritic-austenitic dual-phase alloy (50% ferrite + 50% austenite), also called 2205 duplex steel, widely used in chloride-rich harsh industrial piping systems.

Common types: 90°/45° elbow, tee, reducer, cap, stub end, flange, cross, concentric/eccentric reducer.

• Product standard: ASTM A815 (WP-S seamless / WP-W welded fittings)
• Material base standard: ASTM A240, ASTM A790
• Anti-sour gas: NACE MR0175 / ISO 15156
• Offshore certification: NORSOK M-650
• Domestic equivalent: GB 022Cr22Ni5Mo3N, EN 1.4462

PREN value: 32–35, superior chloride corrosion resistance vs 316L

• Tensile strength: ≥620 MPa
• 0.2% Yield strength: ≥450 MPa (twice higher than 316L austenitic steel)
• Elongation: ≥25%
• Max Hardness: ≤290 HB
• Low-temperature impact toughness: ≥45J at -46℃
• Metallurgy requirement: Ferrite volume fraction 40%–60%, no σ brittle phase

• Dual-phase structure combines merits of austenite & ferrite: high strength + good toughness + weldability
• Outstanding resistance to pitting, crevice corrosion, chloride stress corrosion cracking (SCC), suitable for seawater & sour oil-gas media
• High yield strength reduces pipe wall thickness, cuts overall engineering weight & cost
• Lower thermal expansion coefficient, higher thermal conductivity than 304/316L
• Good resistance to erosion corrosion & corrosion fatigue, long service life in cycling corrosive environment
• Compatible with matching S31803 duplex pipes for full duplex piping system

Raw duplex steel pipe/forging blank inspection → hot forming (press/forging/bending) → trimming & machining → solution annealing (1020–1100℃, rapid water quenching to avoid brittle phase) → pickling & passivation → dimensional tolerance inspection → NDT test (eddy current, hydrostatic, UT) → ferrite content metallurgy test → marking, MTC certification, export moisture-proof packaging

• Offshore & Oil & Gas: FPSO, offshore platform firewater, ballast, sour gas pipeline, subsea fittings
• Seawater Desalination: multi-stage flash distillation, seawater cooling pipeline system
• Chemical & Petrochemical: chloride reactor, acid/alkali heat exchanger, fertilizer plant piping
• Pulp & Paper: bleach process piping resistant to chlorine bleaching agent
• Marine Engineering, Power Plant Cooling Circulation, Wastewater Treatment

Custom OD, wall thickness, length; polished surface, customized special non-standard fittings per drawing

Supply EN10204 3.1 / 3.2 MTC test reports, PMI composition test, NDT certificates, NACE/NORSOK supporting documents

Full batch traceable by heat number; free replacement for unqualified dimension, metallurgy or corrosion performance within 7 days after receipt

15–25 days for customized forged duplex pipe fittings

Premium ASTM A815 UNS S31803 (2205 Duplex Stainless Steel) Pipe Fittings in stock! High yield strength, excellent anti-chloride & anti-sour gas corrosion, perfect for offshore, desalination, chemical & oil-gas piping. Full sizes elbows, tees, reducers & caps available, complete MTC & NACE certification. Send inquiry for factory wholesale price now!

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S31803 is the original UNS grade, S32205 is upgraded 2205 duplex; most factory materials meet both standards for dual certification, with identical performance in engineering application.

316L fails quickly in high-chloride seawater/sour gas; S31803 has 2x yield strength and far better resistance to pitting & stress corrosion cracking.

Must conduct full solution annealing + rapid water cooling after forming; slow cooling will precipitate σ brittle phase and sharply reduce corrosion resistance & toughness.

Use matching duplex welding wire, full argon shielding for weld root; control interpass temperature below 150℃ to maintain balanced dual-phase microstructure.