Duplex Steel Pipes

Duplex steel pipe is a ferritic-austenitic alloy pipe built on a 50/50 microstructure of austenite and ferrite. Produced mainly in grades UNS S31803 and UNS S32205 (2205), it delivers a yield strength of ~450 MPa, roughly 2x that of standard 304 or 316 austenitic grades. The dual-phase structure provides strong resistance to chloride-induced pitting, crevice corrosion, and stress corrosion cracking. We supply duplex stainless steel pipes for oil and gas, chemical processing, marine, desalination, and power generation industries. Pricing, grades, specifications, and a full schedule chart are all covered below.

Duplex Steel Pipe Price

The price of duplex steel pipes mainly depends on the grade, outside diameter, wall schedule, and current raw material rates.

Approximate Price Range

The duplex stainless steel pipe price in India ranges from Rs. 400 to Rs. 600 per kg for standard grades such as 2205 (UNS S31803/S32205), depending on OD, wall thickness, and order quantity.

Factors Affecting Price

Grade and alloy content: Higher chromium, molybdenum, and nitrogen concentrations increase base material cost. Grade 2507 costs more than 2205 due to its higher alloy content.

Wall thickness and schedule: Heavier schedules, such as 80S and 160, use more material and carry a higher price per unit length compared to 5S or 10S.

Manufacturing method: Seamless pipes cost more than welded pipes due to the intensive hot-extrusion process and lower production yields.

Market fluctuations: Global nickel and molybdenum prices directly affect duplex stainless steel pipe pricing, and do check the LME rates before bulk procurement.

Duplex Stainless Steel Pipe Grades

Duplex stainless steel pipe grades are differentiated by alloy composition and pitting resistance equivalent number (PREN). The 3 most widely specified duplex grades are listed below.

Duplex steel S32205 pipes
Duplex steel 2205 pipes
Duplex steel S31803 pipes

Types Of Duplex Steel Pipe

Duplex stainless steel pipes are manufactured in 2 primary forms, each suited to specific pressure ratings and service environments.

Seamless duplex steel pipe
Welded duplex steel pipe

Duplex Steel Pipe Specifications

Review the core specification parameters below before ordering. These values define compatibility with your system design and governing project standards.

Parameter	Typical specification/range
Main standard	ASTM A790 / ASME SA790 (seamless & welded ferritic‑austenitic pipe); ASTM A789 for duplex tubing; EN 10216‑5 often referenced for European duplex pipe.
Common grades / UNS	2205 / UNS S31803; 2507 / UNS S32750 (often grouped under duplex/super duplex); other ASTM A790 grades such as S32520, S32550, etc.
Microstructure	≈50% austenite + 50% ferrite; high strength and good chloride SCC resistance.
Typical application	Offshore, chemical, petrochemical, sour (H₂S/CO₂), seawater cooling, desalination, and high‑pressure process lines.
NPS size range	≈1/2" to 24" NPS for standard duplex pipe; some suppliers cover up to 48" (≈1219 mm) for welded line pipe.
OD range (mm)	≈6–630 mm (small‑OD tubing) up to ≈1219 mm for large‑diameter welded line pipe.
Wall thickness range	0.5–30 mm depending on form: thinner for small‑OD tubing, thicker for line pipe and high‑pressure risers.
Schedules/wall series	5S, 10S, 40S, 80S, 100, 120, 140, 160, and XXS (per ASME B36.19M for stainless‑steel pipe).
Forms	Seamless, welded (ERW, EFW, LSAW), U‑bent, coiled (small OD).
Typical finishes	Mill finish, pickled, and abrasive‑blast‑cleaned; some suppliers offer polished or dressed finishes for high‑integrity services.
Corrosion target	High resistance to pitting, crevice, and chloride stress‑corrosion cracking vs 304/316 austenitic grades.
Typical strength level	Min ~450 MPa yield (2205 / S31803) to ~550 MPa+ (2507 / S32750); roughly 2–3× annealed 304/316 austenitic yield strength.

Duplex Steel Pipe Size Chart

The size chart below covers NPS 1/2" to 12" with OD, typical small-OD range, and wall thickness range by pipe size. Use it to confirm dimensional compatibility with your system before ordering.

NPS (in)	OD (mm)	Typical size range (small OD)	Wall thickness range (mm)	Notes
1/2	21.3	6–50 mm	0.5–6.0	Common for small‑bore lines.
3/4	26.7	8–60 mm	0.5–6.0	Instrument/service lines.
1	33.4	10–75 mm	0.5–7.0	General process piping.
1‑1/4	42.2	12–100 mm	0.5–8.0	Process/control lines.
1‑1/2	48.3	15–125 mm	0.5–8.5	Branch lines, headers.
2	60.3	20–150 mm	0.5–10.0	Main small‑bore process lines.
3	88.9	30–200 mm	0.5–12.0	Larger process/seawater lines.
4	114.3	40–250 mm	0.5–15.0	Offshore/onshore lines.
6	168.3	65–300 mm	0.5–20.0	Trunk line, riser‑type service.
8	219.1	75–350 mm	0.5–25.0	Larger offshore / process lines.
10	273.0	100–500 mm	0.5–30.0	Main trunk lines, high‑integrity.
12	323.9	120–600 mm	0.5–30.0	Large‑diameter duplex lines.

Schedule Chart Of Duplex Steel Pipe

The duplex stainless steel pipe schedule chart below shows wall thickness across 5 schedule series (5S, 10S, 40S, 80S, 160/XXS) for NPS 1/2" to 12". A higher schedule number means a thicker wall and a higher pressure rating.

NPS (in)	OD (mm)	5S wall (mm)	10S wall (mm)	40S wall (mm)	80S wall (mm)	160 / XXS wall (mm)
1/2	21.3	1.7	2.1	2.8	3.9	≈5.5
3/4	26.7	1.7	2.1	2.9	3.9	≈5.5
1	33.4	1.7	2.8	3.4	4.5	≈6.0
1‑1/4	42.2	1.7	2.8	3.6	4.9	≈6.5
1‑1/2	48.3	1.7	2.9	3.7	5.1	≈6.8
2	60.3	1.7	2.8	3.9	5.5	≈7.5
3	88.9	2.1	3.0	5.5	7.6	≈9.5
4	114.3	2.1	3.0	6.0	8.6	≈11.0
6	168.3	2.8	3.4	7.1	11.0	≈15.0
8	219.1	2.8	3.8	8.2	12.7	≈17.5
10	273.0	3.4	4.2	9.3	12.7	≈18.3
12	323.9	4.0	4.6	9.5	12.7	≈18.3

Key Features Of Duplex Steel Pipe

Duplex steel pipe is selected for demanding service conditions where standard austenitic grades fall short. The 7 standout features are listed below.

High Strength
Corrosion Resistance
Enhanced Toughness
High Fatigue Resistance
Good Weldability
Magnetic Properties
High Thermal Conductivity

Applications Of Duplex Steel Pipe

Duplex stainless steel pipes handle demanding process environments across 8 major industries. Below are the primary application areas where duplex pipe is specified.

Oil and Gas Industry
Chemical Processing
Marine Industry
Pulp and Paper Industry
Water Treatment
Power Generation
Pharmaceutical Industry
Food and Beverage Industry

How To Choose The Right Duplex Steel Pipe Manufacturer And Supplier?

Selecting the right duplex stainless steel pipe manufacturers and suppliers directly affects pipe integrity, project timelines, and total procurement cost. Evaluate the 4 areas below before finalising a vendor.

Selecting The Right Supplier

Begin by checking that the manufacturer produces duplex stainless steel pipes in the exact grade and NPS that your project requires. Not every facility handles duplex alloys; verify production capabilities for grades S31803 and S32205 before issuing an RFQ.

Technical Considerations

Grade suitability: Match the UNS grade to the service environment, such as chloride-rich, sour, or high-pressure. Request the material test certificate (MTC) confirming chemical composition, PREN, and mechanical properties.

Standard compliance: Confirm pipes are produced to ASTM A790 / ASME SA790 for seamless and welded ferritic-austenitic pipe. Non-compliant pipes fail pressure and corrosion tests.

Size and schedule availability: Check that the required NPS and wall schedule are in stock. Custom schedules can carry 8-12 week lead times.

Evaluating Supplier Credibility

Certifications: A credible duplex stainless steel supplier holds ISO 9001, PED, and NACE MR0175 certifications at a minimum for high-integrity piping supply.

Mill traceability: Every pipe batch must carry a heat number traceable to the originating mill. This is mandatory for project documentation and quality audits.

References and track record: Request a client list. References from oil and gas, subsea, and chemical projects carry the most weight for duplex alloy procurement decisions.

Procurement Strategy

Request for quotation (RFQ): Send a clear RFQ specifying grade (UNS number), NPS, schedule, finish, governing standard, and quantity. Vague RFQs produce inaccurate quotes.

Compare at least 3 quotes: Evaluate on price, lead time, MTC availability, and minimum order quantity (MOQ) before committing.

Inspect before dispatch: For bulk orders, conduct a pre-dispatch inspection (PDI) or third-party inspection (TPI) at the manufacturer's facility. This is standard practice for high-integrity piping.

Duplex Steel Pipes Suppliers

Premium

goodluck metal corporation

mumbai - maharashtra - india

4 Year