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We supply a comprehensive range of Duplex and Super Duplex stainless steel pipe grades to ASME SA789 & SA790.
Duplex Stainless Steel Grades
UNS S31803 / F51
UNS S32205 / F60 (2205 Duplex)
Super Duplex Stainless Steel Grades
UNS S32750 / F53 (2507 Super Duplex)
UNS S32760 / F55
Super Duplex 2507
These grades are selected based on operating temperature, chloride concentration, pressure conditions, and corrosion severity.
Type | Seamless/Welded/SAW/ERW/EFW Pipe | |
End | BE (Beveled End) | |
Size | OD: 1/2"-48" | |
Manufacturing Technique | Hot rolling / Hot work / Cold rolling / Cold-drawn | |
Producing Standard | ASME B36.10 and ASME B36.19 | |
Duplex Steel Grades | ASTM A789 | S31803, S32205, S32750, S32760 |
ASTM A790 | S31803, S32205, S32750, S32760 | |
Our Duplex and Super Duplex stainless steel pipes are manufactured in accordance with internationally recognized production standards to ensure quality, dimensional accuracy, and mechanical performance.
ASTM / ASME Standards
ASTM A790 / ASME SA790 — Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
ASTM A789 / ASME SA789 — Seamless and Welded Stainless Steel Tubing
Dimensional Standards
ASME B36.19M
ASME B36.10M
ANSI / ASME piping dimensions
Material and Testing Standards
NACE MR0175 / ISO 15156
EN 10216-5
EN 10217-7
PED 2014/68/EU requirements
PMI, Hydrostatic Testing, UT, RT, and Third-Party Inspection available upon request
Duplex and Super Duplex steel pipes are classified based on their pitting corrosion resistance (PREN), alloy content, and specific service conditions.
Standard Duplex Grades (PREN 30-35)
Grade | UNS | EN No. | Cr (%) | Ni (%) | Mo (%) | N (%) | PREN | Key Applications |
2205 | S31803 | 1.4462 | 21-23 | 4.5-6.5 | 2.5-3.5 | 0.08-0.20 | 32-35 | Chemical tanks, piping, heat exchangers |
2205 (High N) | S32205 | 1.4462 | 22-23 | 4.5-6.5 | 3.0-3.5 | 0.14-0.20 | 34-36 | Offshore platforms, seawater systems |
Standard Duplex Stainless Steel Grades — Source: ASTM A789/A790, EN 10216-5
Super Duplex Grades (PREN 40-45+)
Grade | UNS | EN No. | Cr (%) | Ni (%) | Mo (%) | N (%) | PREN | Key Applications |
2507 | S32750 | 1.4410 | 24-26 | 6.0-8.0 | 3.0-5.0 | 0.24-0.32 | 40-43 | Seawater, offshore, desalination |
2507 (High N) | S32760 | 1.4501 | 24-26 | 6.0-8.0 | 3.0-4.0 | 0.20-0.30 | 41-44 | Subsea, heat exchangers, aggressive media |
Zeron 100 | S32760 | 1.4501 | 24-26 | 6.0-8.0 | 3.0-4.0 | 0.20-0.30 | 41-44 | Oil & gas, seawater cooling |
Super Duplex Stainless Steel Grades — Source: ASTM A789/A790, EN 10216-5, Manufacturer Data Sheets
Grade Selection Guidance:
· For general seawater and moderate chloride service: UNS S32205 (2205) provides excellent performance at competitive cost.
· For offshore oil & gas and high-temperature seawater: UNS S32750 (2507) or S32760 (Zeron 100) are the industry standards.
Mechanical Properties Comparison
Property | 2205 (S32205) | 2507 (S32750) | 316L (Reference) | Advantage vs 316L |
Yield Strength (min) | 450 MPa | 550 MPa | 170 MPa | 2.6-3.2x higher |
Tensile Strength (min) | 620 MPa | 795 MPa | 485 MPa | 28-64% higher |
Elongation (%) | 25% | 15% | 40% | Lower but adequate |
Hardness (HRB) | ≤ 290 HB | ≤ 310 HB | ≤ 217 HB | Higher hardness |
Charpy Impact at -40°C | ≥ 40 J | ≥ 45 J | ≥ 100 J | Adequate for cryogenic |
Young's Modulus | 200 GPa | 200 GPa | 195 GPa | Similar |
Density | 7.80 g/cm³ | 7.80 g/cm³ | 8.00 g/cm³ | 2.5% lighter |
Mechanical Properties Comparison — Source: ASTM A789/A790, EN 10216-5
Corrosion Resistance Indicators
Grade | UNS | PREN | CPT (°C) | CCT (°C) | Critical Pitting Temp | Crevice Corrosion Temp |
2205 | S31803 | 32-35 | 25-35 | 15-22 | Excellent in seawater up to 20°C | Good up to 15°C |
2205 (High N) | S32205 | 34-36 | 30-40 | 18-25 | Excellent in seawater up to 25°C | Good up to 20°C |
2507 | S32750 | 40-43 | 50-60 | 35-45 | Excellent in seawater up to 35°C | Good up to 30°C |
S32760 | Zeron 100 | 41-44 | 55-65 | 38-48 | Excellent in seawater up to 40°C | Good up to 35°C |
316L (Ref) | S31603 | 22-26 | 10-20 | 5-10 | Not recommended for seawater | Poor in chlorides |
Corrosion Resistance Indicators — CPT = Critical Pitting Temperature, CCT = Critical Crevice Temperature. Source: ASTM G48, manufacturer test data, NACE Corrosion Data Survey
Duplex and Super Duplex steel pipes are manufactured and tested in accordance with rigorous international standards.
ASTM Standards (American)
ASTM Standard | Title / Scope | Product Form | Key Requirements |
ASTM A789 | Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service | Tube (Seamless/Welded) | Chemical composition, mechanical properties, hydrostatic test |
ASTM A790 | Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe | Pipe (Seamless/Welded) | Chemical, mechanical, NDE options, hydrostatic test |
ASTM A928 | Ferritic/Austenitic Stainless Steel Pipe Electric Fusion Welded with Filler Metal | EFW Pipe | Welding procedure qualification, impact testing |
ASTM A270 | Seamless and Welded Austenitic and Ferritic/Austenitic Stainless Steel Sanitary Tubing | Sanitary Tube | Surface finish, tolerances, cleaning |
ASTM B622 | Seamless Nickel and Nickel-Cobalt Alloy Pipe and Tube | Seamless Pipe/Tube | For high-nickel duplex variants |
ASTM A999 | General Requirements for Alloy and Stainless Steel Pipe | All Pipe Forms | Marking, certification, testing frequency |
ASTM Standards for Duplex/Super Duplex Pipes — Source: ASTM International, 2024 Annual Book of Standards
ASME Standards (Pressure Applications)
ASME Standard | ASTM Equivalent | Code Section | Application |
ASME SA-789 | ASTM A789 | Section II-B | Heat exchanger tubes, general tubing |
ASME SA-790 | ASTM A790 | Section II-B | Pressure piping, process piping |
ASME SA-928 | ASTM A928 | Section II-B | Large diameter welded pipe |
ASME B31.3 | — | Process Piping Code | Design, materials, fabrication, examination |
ASME B31.4 | — | Pipeline for Liquids | Onshore/offshore hydrocarbon pipelines |
ASME B31.8 | — | Gas Transmission | Natural gas pipelines |
ASME BPVC VIII | — | Pressure Vessels | Pressure vessel design & fabrication |
ASME Standards for Duplex/Super Duplex Pipe Applications — Source: ASME Boiler and Pressure Vessel Code, ASME B31 Piping Codes (2024 Editions)
EN Standards (European)
EN Standard | Title / Scope | Product Form | Key Requirements |
EN 10216-5 | Seamless Steel Tubes for Pressure — Part 5: Stainless Steel | Seamless Tube/Pipe | Chemical, mechanical, NDE, hydrostatic test |
EN 10217-7 | Welded Steel Tubes for Pressure — Part 7: Stainless Steel | Welded Tube/Pipe | Weld quality, NDE, mechanical properties |
EN 10222-5 | Steel Forgings for Pressure — Part 5: Martensitic, Austenitic & Austenitic-Ferritic SS | Forgings (flanges, fittings) | Mechanical, impact testing, UT examination |
EN 10088-2 | Stainless Steels — Part 2: Technical Delivery Conditions for Sheet/Plate/Strip | Plate/Sheet (for pipe manufacturing) | Chemical, mechanical, surface finish |
EN 10088-3 | Stainless Steels — Part 3: Technical Delivery Conditions for Semi-Finished Products, Bars | Bars (for seamless pipe billets) | Chemical, mechanical properties |
EN Standards for Duplex/Super Duplex Steel Products — Source: CEN European Committee for Standardization
Other International Standards
Standard | Country/Region | Scope | Notes |
NORSOK M-630 | Norway (Offshore) | Material data sheets for offshore piping | Widely adopted for North Sea projects |
NACE MR0175/ISO 15156 | International | Sour Service (H2S) Requirements | Essential for oil & gas applications |
API 5LC | USA (Oil & Gas) | Cr-Mo and Stainless Steel Line Pipe | Includes duplex grades for pipelines |
ISO 15156 | International | Materials for H2S-Containing Environments | Sour service qualification |
JIS G3463 | Japan | Stainless Steel Boiler and Heat Exchanger Tubes | Japanese market specification |
GB/T 14976 | China | Stainless Steel Seamless Tubes for Fluid Transport | Chinese national standard |
Other International Standards for Duplex/Super Duplex Pipes — Source: NORSOK, NACE, API, ISO, JIS, GB Standards
Seamless vs Welded Pipe
Product Form | Manufacturing Method | Size Range | Pressure Rating | Typical Applications |
Seamless Pipe | Extrusion / Pilgering | 1/8" to 24" NB | Highest | High-pressure systems, offshore, subsea |
Welded Pipe (SAW) | Submerged Arc Welded | 6" to 48" NB | High | Process piping, structural, water transport |
Welded Pipe (TIG) | Tungsten Inert Gas Welded | 1/2" to 24" NB | Medium-High | Chemical, pharmaceutical, food grade |
Welded Pipe (EFW) | Electric Fusion Welded | 16" to 60" NB | Medium | Large diameter, low-pressure applications |
ERW Pipe | Electric Resistance Welded | 1/2" to 24" NB | Medium | Water, gas distribution, structural |
Seamless vs Welded Pipe Comparison — Source: ASTM A789, A790, A928
Standard Dimensions and Schedules
Nominal Size | Schedule Range | Wall Thickness (mm) | Working Pressure (bar) | Typical Use |
1/2" - 2" | SCH 10S - SCH 80S | 1.73 - 5.54 | Up to 200 | Instrumentation, small bore |
3" - 8" | SCH 10S - SCH 80S | 2.11 - 7.62 | Up to 180 | Process piping, utilities |
10" - 24" | SCH 10S - SCH 60 | 3.40 - 12.70 | Up to 150 | Main process lines, seawater |
26" - 48" | SCH 10 - SCH 40 | 6.35 - 15.09 | Up to 80 | Large diameter transport |
Standard Dimensions and Schedules — Source: ASME B36.19 (Stainless Steel Pipe Dimensions)
Industry | Typical Service | Recommended Grade | Why Duplex/Super Duplex |
Oil & Gas Offshore | Seawater injection, firewater, risers | S32750 / S32760 | Seawater resistance, high strength, SCC resistance |
Oil & Gas Onshore | Flowlines, gathering lines | S32205 / S32750 | Cost-effective, sour service capability |
Petrochemical | Process piping, heat exchangers | S32205 / S31803 | Chloride resistance, lower cost than nickel alloys |
Chemical Processing | Reactors, pressure vessels, piping | S32205 / S32750 | Organic acids, chloride service, long life |
Desalination | Brine piping, heat recovery | S32205 / S32750 | Hot brine resistance, high strength |
Pulp & Paper | Digesters, bleach washers, effluent | S32205 | Chemical resistance, cost-effective |
Marine & Shipbuilding | Seawater cooling, ballast systems | S32750 / S32760 | Seawater corrosion, long service life |
Power Generation | Cooling water, condensers, FGD | S32205 / S32750 | Cooling water, chloride resistance |
Water Treatment | Seawater intake, desalination, RO plants | S32205 / S32750 | Seawater, high pressure, reliability |
Mining & Minerals | Slurry transport, process water | S32205 | Abrasion + corrosion resistance |
