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ASTM A790 / A928 – UNS S31803, S32205, S32750
Inox Steel India is one of the leading manufacturers, suppliers, and exporters of Duplex & Super Duplex Stainless Steel Pipes in India, supplying to global industries across the GCC, Middle East, African nations, European countries, and both North & South America.
We specialize in Duplex & Super Duplex pipes made from premium grades — Duplex 2205 (UNS S31803 / S32205) and Super Duplex 2507 (UNS S32750) — conforming to ASTM A790 and ASTM A928 standards for seamless, welded, and EFW pipes.
With ISO, PED, and NACE certifications, every pipe from Inox Steel India is manufactured using controlled solution annealing, pickling, and precision sizing processes, ensuring excellent pitting resistance, chloride corrosion resistance, and high mechanical strength even in seawater and offshore environments.
Our Duplex & Super Duplex pipes are widely used in desalination plants, offshore platforms, marine engineering, oil & gas, petrochemicals, subsea pipelines, and high-pressure chemical service — where strength + corrosion resistance + reliability are non-negotiable.
A Duplex / Super Duplex Stainless Steel Pipe is a hollow tube made with a dual-phase microstructure (50% ferrite + 50% austenite), combining the advantages of both ferritic and austenitic stainless steels:
Duplex 2205 is ideal for high-strength + moderate-chloride service, while Super Duplex 2507 provides PREN > 40, making it suitable for seawater, RO desalination, offshore, and subsea environments.
Below is the consolidated Duplex & Super Duplex Stainless Steel Pipe Technical Datasheet, covering:
DUPLEX & SUPER DUPLEX STAINLESS STEEL PIPE
ASTM A790 / ASME SA790 — UNS S31803 / S32205, S32750
| Parameter / Property | Duplex 2205 (UNS S31803 / S32205) | Super Duplex 2507 (UNS S32750) |
|---|---|---|
| Material Type | Duplex Stainless Steel | Super Duplex Stainless Steel |
| UNS Number | S31803 / S32205 | S32750 |
| Standard / Specification | ASTM A790 / ASME SA790 | ASTM A790 / A928 / ASME SA928 |
| Material Class | 22% Cr Duplex | 25% Cr Super Duplex |
| Temperature Service | Up to 250–300 °C | Up to 250–300 °C (avoid 300–350 °C exposure) |
| Tensile Strength (MPa) | 620 Min | 800 Min |
| Yield Strength (MPa) | 450 Min | 550 Min |
| Elongation (%) | 25% | 25% |
| Hardness (HBW) | 290 Max | 310 Max |
| Creep Resistance | High | Very High |
| Thermal Stability | High | Excellent |
| Impact Toughness | High | Very High |
| Chemical Composition (%) | Cr 21–23, Ni 4.5–6.5, Mo 2.5–3.5, N 0.14–0.20, C ≤0.03 | Cr 24–26, Ni 6–8, Mo 3–5, N 0.24–0.32, C ≤0.03 |
| Heat Treatment | Solution Annealed | Solution Annealed |
| Manufacturing Method | Seamless / Welded | Seamless / Welded / EFW |
| Equivalent EN / DIN Grades | 1.4462 | 1.4410 |
| Available Sizes (OD) | 12.7 – 660 mm | 12.7 – 660 mm |
| Schedules (Thickness) | SCH 10 – SCH XXS | SCH 10 – SCH XXS |
| Application Areas | Oil & Gas, Chemical, Marine, Heat Exchangers | Offshore, Subsea, Desalination, High-Chloride Plants |
| End Finishes | Plain / Bevelled / Threaded | Plain / Bevelled / Threaded |
| Testing Requirements | Hydro, UT, Eddy Current, PMI, Ferrite Test | Hydro, UT, Eddy Current, PMI, ASTM G48 (pitting) |
| HS Code / HSN Code | 7304.19.20 | 7304.19.20 |
| Certifications | EN 10204 3.1/3.2, PED | EN 10204 3.1/3.2, PED, NACE MR0175/MR0103 |
This table provides engineers and procurement teams a complete overview of chemical composition, mechanical properties, and corrosion performance for selecting the right material.
Choosing the correct Duplex/Super Duplex grade depends on:
Operating Environment:
Temperature & Pressure Ratings:
Select appropriate Schedules (SCH 10 to XXS) per ASME B36.19 / B36.10.
Corrosion Resistance & PREN Value:
Stress Corrosion Cracking (SCC)
Both grades outperform 316L and 317L significantly in chloride-rich environments.
Certification & Compliance Requirements
Ensure material comes with:
India:
Widespread use in Mumbai, Hazira, Dahej, Vizag for desalination, chemical units, offshore projects.
GCC & Middle East:
Saudi Arabia, UAE, Qatar, Oman use Super Duplex 2507 for:
Africa:
Nigeria, Angola, Egypt import Super Duplex for marine and subsea operations.
Europe & Americas:
Germany, Italy, UK, USA demand Duplex/Super Duplex due to stringent PED and corrosion test requirements.
Inox Steel India maintains ready stock and dispatch capability from JNPT, Mundra, and Hazira ports.
Duplex & Super Duplex Stainless Steel Pipes from Inox Steel India deliver outstanding performance in harsh, chloride-rich, high-pressure, and corrosive environments. Their dual-phase (austenite + ferrite) microstructure provides superior mechanical strength and excellent pitting resistance, making them ideal for offshore oil & gas, desalination, and chemical processing industries.
Below are grade-wise application profiles, technical characteristics, and dimensional capabilities — aligned exactly with how the Stainless Steel sample is written.
Service Use:
High-strength applications with moderate to high chloride exposure.
Typical Applications:
Size Range:
½″ – 36″ NB (SCH 10 to XXS)
Temperature Range:
Up to ~300 °C (short exposure allowed beyond, as per design)
Industry Sectors:
Oil & Gas | Petrochemicals | Chemical | Marine | Fertilizer | Water Treatment
Super Duplex 2507 (UNS S32750) – ASTM A790 / A928
Service Use:
Seawater, high chloride, high pressure, offshore, subsea & RO desalination service.
Typical Applications:
Size Range:
½″ – 24″ NB seamless, up to 48″ NB EFW (ASTM A928)
Temperature Range:
Up to ~300 °C (avoid continuous 300–350°C exposure)
Industry Sectors:
Desalination | Offshore Oil & Gas | Marine | Chemical | Power Generation
| NPS (Inch) | OD (mm) | Wall Thickness (SCH 40) | Approx. Weight (kg/m) |
|---|---|---|---|
| ½″ | 21.3 | 2.77 | 1.40 |
| 1″ | 33.4 | 3.38 | 2.70 |
| 2″ | 60.3 | 3.91 | 5.90 |
| 3″ | 88.9 | 5.49 | 12.50 |
| 4″ | 114.3 | 6.02 | 17.20 |
| 6″ | 168.3 | 7.11 | 29.80 |
| 8″ | 219.1 | 8.18 | 46.00 |
| 10″ | 273.1 | 9.27 | 68.50 |
| 12″ | 323.9 | 9.53 | 89.80 |
Prices vary based on grade, OD, wall thickness, heat treatment, and project requirement.
| Grade / Standard | Size Range (OD) | Avg. Price INR/kg (FOB Mumbai) | Approx. USD/kg (FOB India) | Typical Use |
|---|---|---|---|---|
| Duplex 2205 (A790) | 6 – 610 mm | ₹ 480 – ₹ 650 | $ 5.90 – $ 8.00 | Chemical & industrial service |
| Super Duplex 2507 (A790/A928) | 6 – 610 mm | ₹ 650 – ₹ 900 | $ 8.00 – $ 11.00 | Seawater, offshore, RO desalination |
🧾 Prices vary by schedule, polish, and origin (Aperam, Outokumpu, POSCO, Indian Mills).
HSN 7304.19.20 – Duplex & Super Duplex Stainless Steel Seamless / Welded Pipes & Tubes
(Used for both ASTM A790 & A928 products)
Every Duplex and Super Duplex pipe supplied by Inox Steel India undergoes rigorous testing to ensure complete compliance with ASTM, ASME, and NACE standards.
Quality Tests Conducted:
Documentation Supplied:
This strict quality control ensures safe and reliable service in offshore, marine, chemical, and desalination environments.
Engineers searching for a Duplex & Super Duplex Stainless Steel Pipe supplier near Alankar Cinema, Mumbai choose Inox Steel India for:
Our proximity to key industrial hubs and ports ensures uninterrupted supply for Indian and global clients.
At Inox Steel India, we combine technical expertise with global supply capability to deliver Duplex 2205 and Super Duplex 2507 pipes that meet international quality standards and project-critical requirements.
Key Advantages Our Clients Rely On:
Inox Steel India focuses on long-term reliability, not just supply.
| Industry | Application | Preferred Grade / Standard |
|---|---|---|
| Offshore Oil & Gas | Subsea lines, offshore risers, platforms | Super Duplex 2507 |
| Desalination Plants | RO feed lines, intake & outfall systems | Super Duplex 2507 |
| Petrochemicals | Reactors, heat exchangers, chemical transfer | Duplex 2205 / Super Duplex 2507 |
| Chemical & Fertilizers | Corrosive process pipelines | Duplex 2205 |
| Marine Engineering | Cooling lines, ballast systems | Super Duplex 2507 |
| Refineries | High-chloride process streams | Duplex 2205 |
| Power Plants | FGD systems, condenser water lines | Duplex 2205 |
| Mining & Mineral Processing | Slurry lines, abrasive environments | Super Duplex 2507 |
Each project is reviewed to ensure grade correctness by pressure, temperature, and corrosion parameters.
All Duplex & Super Duplex pipes are export-packed as per international shipping norms:
Regular Export Destinations:
UAE • Saudi Arabia • Oman • Qatar • Kuwait • Nigeria • South Africa • Germany • Italy • UK • USA • Brazil • Mexico
Our sales & technical teams respond within 24 hours with:
✔ Grade recommendation
✔ Price list (INR + USD)
✔ Stock availability
✔ Test certificates
✔ Delivery timeline
📥 Download: Product Catalog • Price List 2025 • Schedule Chart (Coming Soon)
52-A, Mulji Thackersi Bldg, Islampura Street, Shop No. 10, Near Alankar Cinema, Mumbai – 400 004
steel@inoxsteelindia.in
+91 9930796690
Super Duplex 2507 has higher chromium, molybdenum, and nitrogen, giving PREN > 40 and exceptional seawater resistance.
ASTM A790 for seamless/welded and ASTM A928 for EFW large-diameter Super Duplex pipes.
Yes — especially Super Duplex 2507, which delivers outstanding corrosion resistance in seawater and high-chloride conditions.
HSN Code: 7304.19.20
Yes — Super Duplex 2507 & Duplex 2205 with NACE-compliant MTCs are available on request.
Yes, regular export to UAE, Saudi Arabia, Oman, Qatar, Nigeria, Egypt, and South Africa.
Yes — 3m to 12m customized lengths with polished or pickled finish are available.
At Inox Steel India, every Duplex & Super Duplex pipe represents quality, traceability, and long service life.
Whether sourcing for a desalination project, offshore platform, or chemical processing plant, we deliver ASTM A790 / A928 pipes that exceed global performance expectations.