Duplex Steel Pipes Manufacturer & Exporter

Leoscor Alloy Pipes is a trusted supplier, stockist, and exporter of high-quality Duplex Steel 2205 Pipes in Mumbai, India, supplying customers across the Middle East, Southeast Asia, Africa, and other global markets. We maintain a wide inventory of ASTM A789 Welded and ASTM A790 Seamless Duplex 2205 Pipes in grades UNS S31803 and UNS S32205.

Our Duplex 2205 Pipes are available in sizes ranging from NPS 1/2” to 24” and are supplied with an EN 10204 3.1 Mill Test Certificate along with a traceable heat number to ensure complete material identification, quality assurance, and reliability.

Duplex Steel 2205 Pipes are duplex stainless steel pipes with a unique microstructure consisting of nearly equal amounts of austenite and ferrite phases. This balanced structure provides a combination of high mechanical strength, excellent toughness, and superior resistance to corrosion compared to conventional austenitic stainless steel grades.

The duplex structure allows 2205 Stainless Steel Pipes to offer significantly higher yield strength than 316L stainless steel along with excellent resistance against chloride stress corrosion cracking. These properties make Duplex 2205 Pipes a preferred choice for applications where standard stainless steel grades may experience premature failure.

OUR RANGE OF DUPLEX STEEL PIPES

Duplex Steel Pipes

Why Buy Duplex Steel Pipes from Leoscor Alloy Pipes

Leoscor Alloy Pipes is a trusted stockist, exporter, and supplier of Duplex Steel Pipes from India, with decades of experience serving global industries. Our focus on quality, reliable supply, and customer satisfaction ensures dependable piping solutions.

Key advantages of choosing us:

Extensive inventory of standard sizes and grades
Reliable sourcing from reputed manufacturers
Strict quality control and experienced professionals
Strong logistics and timely delivery support
Modern infrastructure with large storage capacity
ISO 9001:2015 certified company
Contact us – info@leoscoralloypipes.com

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What we hold in stock

Both grades below refer to the same duplex 2205 chemistry — S31803 is the original, wider-tolerance specification, and S32205 tightened the nitrogen range for more consistent pitting resistance. Most mills today certify to both simultaneously.

Specifications	Details
Standards	ASTM A789 (welded), A790 (seamless), and matching ASME SA specifications
Grades	UNS S31803, UNS S32205 (EN 1.4462)
Size Range	NPS 1/2″ to 24″ (15 mm to 600 mm NB)
Schedules	SCH 10S, 40S, 80S, and standard/heavy wall per ASME B36.10M
Forms	Seamless, Welded, ERW, EFW
Shapes	Round (standard stock); square, rectangular and oval on request
Lengths	Single Random (5 to 7 m), Double Random (8 to 13 m), Cut to Length
End Finish	Plain End, Bevelled
Certification	EN 10204 3.1 as Standard, 3.2 on Request

Choosing between duplex, stainless and super duplex

2205 sits in the middle of the corrosion-resistance ladder. This is where our team places it against the grades on either side.

Grade	PREN (approx.)	Pick it when
316L Stainless	24 to 26	Chlorides are mild — coastal air, chlorinated water. Duplex is not needed and costs more.
Duplex 2205	34 to 36	316L is cracking under chloride stress, or you need roughly double the yield strength for a thinner, lighter wall.
Super Duplex 2507	42 to 44	2205 is pitting — hot seawater, brine, or stagnant chloride zones above what 2205 can hold.

If your service condition sits above 300°C continuous, none of these three are the right answer — move to a nickel alloy. See our
nickel alloy pipe range.

Sizes and wall thicknesses

Duplex 2205 pipe follows the same ASME B36.10M dimensions as carbon and stainless pipe. Density is close to austenitic stainless at 7.80 g/cm³, so the standard weight formula applies: kg per metre = (OD minus WT) × WT × 0.0246, both dimensions in mm.

NPS	OD (mm)	SCH 10S	SCH 40	SCH 80
1/2″	21.3	2.11	2.77	3.73
2″	60.3	2.77	3.91	5.54
4″	114.3	3.05	6.02	8.56
6″	168.3	3.40	7.11	10.97
8″	219.1	3.76	8.18	12.70

FAQ

What is the difference between S31803 and S32205?

Both are duplex 2205. S31803 is the original 1990s specification with a wider nitrogen range (0.08 to 0.20%). S32205 tightened that range (0.14 to 0.20%) for more predictable pitting resistance batch to batch. Mills producing to modern practice generally certify pipe as dual-marked S31803/S32205, which is what we stock.

Can duplex 2205 replace 316L in every application?

Not always. Duplex is stronger and more chloride-resistant, but it is harder to weld correctly — heat input has to be controlled to keep the ferrite-austenite balance close to 50/50, and it should not be used above 300°C. For low-pressure, low-chloride, non-critical lines, 316L is simpler to fabricate and often the more sensible choice.

What temperature range is duplex 2205 rated for?

Minus 50°C to plus 300°C for continuous service. Below minus 50°C, and above 300°C, ask about super duplex or a nickel alloy instead.

Do you supply mill test certificates?

Yes, EN 10204 3.1 as standard on every consignment, 3.2 with third-party witness on request.

Get a quote for duplex steel pipes

Send your grade, size, schedule and quantity. Request a quote | Call +91 22 2386 7540