Super Duplex Seamless Pipe Manufacturer in India
Super Duplex Seamless Pipe Manufacturer in India
Sachiya Steel International is a trusted Super Duplex Seamless Pipe Manufacturer in India, manufacturing and supplying high-quality pipes and tubes since 2005. With a facility near Mumbai and an export office in Mumbai, we serve industrial buyers, project contractors, stockists and distributors across India and international markets. Our super duplex seamless pipes are suitable for demanding applications that require high strength and excellent resistance to pitting, crevice corrosion and chloride-related corrosion.
We supply super duplex pipe grades such as UNS S32750 (2507) and UNS S32760, subject to specification and availability. Our certifications and approvals include ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, PED 2014/68/EU and TUV approvals. Every order includes an EN 10204 Type 3.1 certificate, with Type 3.2 certification and third-party inspection available on request. We export to 85+ countries, supporting varied industrial requirements with dependable documentation and supply services.
What Are Super Duplex Seamless Pipe?
Super Duplex Seamless Pipe is stainless steel pipe with no weld seam, made from a duplex steel whose pitting resistance equivalent number (PREN) is 40 or higher. PREN is a simple index: Cr + 3.3 × Mo + 16 × N. The higher the number, the better the steel resists pitting in chloride fluids.
The steel holds roughly equal parts austenite and ferrite. High chromium, molybdenum and nitrogen give it excellent resistance to pitting, crevice corrosion and chloride stress cracking, and its yield strength is more than three times that of 316L. After the pipe is pierced and rolled, it is solution annealed and quenched fast. That step matters as much as the chemistry, because slow cooling lets brittle phases form and robs the pipe of toughness and corrosion resistance.
Super Duplex Seamless Pipe
High-quality Super Duplex Seamless Pipes manufactured for demanding applications across oil & gas, petrochemical, chemical, marine, power generation and engineering industries. Available in various sizes, grades, wall thicknesses and manufacturing specifications.
Types of Super Duplex Seamless Pipes
As a Super Duplex Seamless Pipe Manufacturer, we offer different types of super duplex pipes based on material grade, manufacturing process, dimensions and industrial application, subject to project specifications and availability.
- UNS S32750 (2507) Super Duplex Seamless Pipes: Provide high strength and excellent resistance to pitting, crevice corrosion and chloride-related corrosion. Commonly used in offshore, marine and chemical processing applications.
- UNS S32760 Super Duplex Seamless Pipes: Contain additional alloying elements, including copper and tungsten, to support corrosion resistance in demanding environments.
- Hot-Finished Super Duplex Seamless Pipes: Produced through hot-working processes to achieve the required pipe dimensions and material properties.
- Cold-Finished Super Duplex Seamless Pipes: Processed further where required to achieve specified dimensional accuracy and surface quality.
- Heavy-Wall Super Duplex Seamless Pipes: Used in applications requiring greater wall thickness, subject to design requirements and dimensional availability.
- Custom-Size Super Duplex Seamless Pipes: Specified according to the required outside diameter, wall thickness, length and applicable material standard.
S32750, S32760, S32550 and S32520 Super Duplex Seamless Pipe Manufacturers and Suppliers in India
We manufacture and supply pipes in UNS S32750, S32760, S32550 and S32520 grades for demanding industrial applications. Other duplex stainless steel grades and nickel alloys can also be quoted on request. Popular sizes are available in ready stock, subject to availability, while other dimensions can be arranged to order.
UNS S32750 is commonly selected for seawater, brine and chloride-rich environments, while UNS S32760 is used for projects that specifically require this grade. UNS S32550 and S32520 offer copper-alloyed compositions for selected acid-handling and chloride-containing process applications. Grade selection should always match the operating conditions and project specification. Buyers can also request details of solution annealing and phase-balance verification to help assess material quality and suitability for the intended service.
Types of Pipes & Tubes
Explore our range of industrial pipes and tubes, manufactured for different applications, materials, specifications and engineering requirements.
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Copper Nickel Alloy Pipe
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Super Duplex Seamless Pipe Specification
The table sums up how we describe a Super Duplex Seamless Pipe order.
| Item | Detail |
|---|---|
| Product | Super Duplex Seamless Pipe |
| Method | Seamless, hot finished or cold drawn |
| Grades | S32750, S32760, S32550, S32520 |
| Pipe standards | ASTM A790 / ASME SA790, EN 10216-5 |
| General requirements | ASTM A999 |
| Size basis | NPS and schedule, or OD and wall in mm |
| Size range shown | NPS 1/2 to 12, other sizes on request |
| Schedules | Sch 10S, 40S, 80S, XXS; other walls on request |
| Lengths | Single random, double random or cut length |
| Ends | Plain or bevelled (ASME B16.25) |
| Heat treatment | Solution annealed and quenched, as the grade requires |
| Surface | Pickled and passivated |
| Tests | Chemical analysis, tensile, hardness, flattening, hydrostatic or non-destructive test, ASTM A923 and G48 on request |
| Certificate | EN 10204 3.1 with every order, 3.2 on request |
| Inspection | Third-party inspection on request |
Super Duplex Seamless Pipe Standards and Specifications
Super duplex pipe is bought to a pipe standard, with test methods and sour-service rules around it. The table shows how each is used.
| Standard | What it covers | Where it applies |
|---|---|---|
| ASTM A790 / ASME SA790 | Seamless and welded ferritic/austenitic stainless pipe | Core pipe standard |
| ASTM A999 | General requirements for alloy and stainless pipe | Tolerances and test rules |
| EN 10216-5 | Seamless stainless steel tubes for pressure purposes | EN-code projects |
| ASTM A923 | Test methods for detrimental intermetallic phases | Structure check, Method A, B or C |
| ASTM G48 | Pitting and crevice corrosion test in ferric chloride | Corrosion check, Method A or C |
| NACE MR0175 / ISO 15156 | Materials for sour service | Oil and gas projects |
| ASTM A182 | Forged fittings and flanges, F53, F55, F61 | Matching forgings |
| ASME B36.19M and B36.10M | Pipe dimensions and weights | OD and wall by schedule |
| ASME B16.25 | Butt-welding ends | Bevel angle and root face |
| EN 10204 | Types of inspection documents | 3.1 and 3.2 certificates |
Super Duplex Seamless Pipe Material and Grades
Choose the grade by the fluid, the chloride level and the project specification. The table lists the grades and their matching forgings.
| Grade | UNS | EN number (closest) | Matching forging | PREN (about) | Typical use |
|---|---|---|---|---|---|
| S32750 | S32750 | 1.4410 | A182 F53 | 42 | Hot seawater, subsea, sour service |
| S32760 | S32760 | 1.4501 | A182 F55 | 41 | Offshore and aggressive chloride duty |
| S32550 | S32550 | 1.4507 | A182 F61 | 39 | Acid and chloride process lines |
| S32520 | S32520 | 1.4507 | — | 41 | Acid and chloride process lines |
What Is the Difference Between Super Duplex Seamless Pipe and 6Mo Stainless Steel Seamless Pipe?
The short answer: super duplex has about twice the strength of 6Mo (UNS S31254) super-austenitic pipe and resists chloride stress cracking better. 6Mo has a higher nickel content, which gives it good resistance to crevice corrosion and some acids, and it forms more easily. Both have a PREN above 40.
| Factor | Super Duplex Seamless Pipe | 6Mo Seamless Pipe (S31254) |
|---|---|---|
| Structure | Austenite and ferrite | Fully austenitic |
| Nickel | 4 to 8% | About 18% |
| Molybdenum | 3 to 5% | About 6% |
| Yield strength, minimum | 550 MPa | About 300 MPa |
| Chloride stress cracking | Very good | Good |
| Crevice corrosion | Very good | Very good |
| Magnetic | Slightly | No |
| Temperature limit | Keep below about 250°C | Higher |
| Wall for the same pressure | Thinner | Thicker |
| Typical use | Subsea, hot seawater, sour service | Acid, bleach plants, seawater |
Super Duplex Seamless Pipe Chemical Composition
Chemistry gives super duplex its pitting resistance. The first table shows the corrosion-resistance elements under ASTM A790, with the PREN calculated from mid-range values. Values are percentage by weight.
| Grade | Cr | Ni | Mo | N | Cu | W | PREN (about) |
|---|---|---|---|---|---|---|---|
| S32750 | 24.0–26.0 | 6.0–8.0 | 3.0–5.0 | 0.24–0.32 | 0.50 max | — | 42 |
| S32760 | 24.0–26.0 | 6.0–8.0 | 3.0–4.0 | 0.20–0.30 | 0.50–1.00 | 0.50–1.00 | 41 |
| S32550 | 24.0–27.0 | 4.5–6.5 | 2.9–3.9 | 0.10–0.25 | 1.50–2.50 | — | 39 |
| S32520 | 24.0–26.0 | 5.5–8.0 | 3.0–5.0 | 0.20–0.35 | 0.50–3.00 | — | 41 |
The second table shows the limits on the control elements, as maximum values.
| Grade | C | Mn | Si | P | S |
|---|---|---|---|---|---|
| S32750 | 0.030 | 1.20 | 0.80 | 0.035 | 0.020 |
| S32760 | 0.030 | 1.00 | 1.00 | 0.030 | 0.010 |
| S32550 | 0.040 | 1.50 | 1.00 | 0.040 | 0.030 |
| S32520 | 0.030 | 1.50 | 0.80 | 0.035 | 0.020 |
Super Duplex Seamless Pipe Mechanical Properties
Mechanical properties show why super duplex allows thin walls. The table gives minimum values, with ksi in brackets, and the minimum solution annealing temperature that ASTM A790 sets for each grade.
| Grade | Yield min, MPa (ksi) | Tensile min, MPa (ksi) | Elongation min (%) | Hardness max | Anneal at least |
|---|---|---|---|---|---|
| S32750 | 550 (80) | 800 (116) | 15 | 310 HBW | 1025°C |
| S32760 | 550 (80) | 750 (109) | 25 | — | 1100°C |
| S32550 | 550 (80) | 760 (110) | 15 | — | 1040°C |
| S32520 | 550 (80) | 770 (112) | 25 | — | 1080°C |
Super Duplex Seamless Pipe Size and Weight Chart
Weight depends on OD and wall, and the wall depends on the schedule. Super duplex has a density of about 7.80 g/cm³, so we use this formula:
OD and wall are in mm. Example: NPS 6 Sch 40S is (168.3 − 7.11) × 7.11 × 0.02450 = 28.08 kg/m. Walls for each schedule are listed in the next section.
| NPS | OD (mm) | Sch 10S (kg/m) | Sch 40S (kg/m) | Sch 80S (kg/m) | XXS (kg/m) |
|---|---|---|---|---|---|
| 1/2" | 21.3 | 0.99 | 1.26 | 1.61 | 2.53 |
| 3/4" | 26.7 | 1.27 | 1.68 | 2.18 | 3.62 |
| 1" | 33.4 | 2.08 | 2.49 | 3.22 | 5.41 |
| 1-1/2" | 48.3 | 3.09 | 4.02 | 5.38 | 9.49 |
| 2" | 60.3 | 3.90 | 5.40 | 7.43 | 13.35 |
| 3" | 88.9 | 6.42 | 11.22 | 15.17 | 27.50 |
| 4" | 114.3 | 8.31 | 15.97 | 22.18 | 40.76 |
| 6" | 168.3 | 13.74 | 28.08 | 42.28 | 78.70 |
| 8" | 219.1 | 19.84 | 42.27 | 64.22 | 107.22 |
| 10" | 273.1 | 27.60 | 59.92 | 81.02 | 154.14 |
| 12" | 323.9 | 35.75 | 73.40 | 96.83 | 185.76 |
Pipe is bought by the length, so the next table gives the weight of one 6 m length, calculated from the unrounded kg/m figures. All figures are in kg per length.
| NPS | Sch 40S, 6 m length (kg) | Sch 80S, 6 m length (kg) |
|---|---|---|
| 1/2" | 7.55 | 9.63 |
| 3/4" | 10.05 | 13.10 |
| 1" | 14.92 | 19.30 |
| 1-1/2" | 24.14 | 32.27 |
| 2" | 32.41 | 44.60 |
| 3" | 67.31 | 91.04 |
| 4" | 95.82 | 133.05 |
| 6" | 168.47 | 253.71 |
| 8" | 253.62 | 385.33 |
| 10" | 359.52 | 486.14 |
| 12" | 440.40 | 580.98 |
Available Sizes, Dimensions and Schedules
Super Duplex Seamless Pipe follows ASME B36.19M for Sch 10S, 40S and 80S, and ASME B36.10M for XXS. The charts above cover NPS 1/2 to 12, and other sizes and walls can be quoted on request. Because super duplex is strong, your engineer may pick a lighter schedule than 316L would need. Confirm the wall against the design code. The table gives the wall for each schedule.
| NPS | OD (mm) | Sch 10S wall (mm) | Sch 40S wall (mm) | Sch 80S wall (mm) | XXS wall (mm) |
|---|---|---|---|---|---|
| 1/2" | 21.3 | 2.11 | 2.77 | 3.73 | 7.47 |
| 3/4" | 26.7 | 2.11 | 2.87 | 3.91 | 7.82 |
| 1" | 33.4 | 2.77 | 3.38 | 4.55 | 9.09 |
| 1-1/2" | 48.3 | 2.77 | 3.68 | 5.08 | 10.15 |
| 2" | 60.3 | 2.77 | 3.91 | 5.54 | 11.07 |
| 3" | 88.9 | 3.05 | 5.49 | 7.62 | 15.24 |
| 4" | 114.3 | 3.05 | 6.02 | 8.56 | 17.12 |
| 6" | 168.3 | 3.40 | 7.11 | 10.97 | 21.95 |
| 8" | 219.1 | 3.76 | 8.18 | 12.70 | 22.23 |
| 10" | 273.1 | 4.19 | 9.27 | 12.70 | 25.40 |
| 12" | 323.9 | 4.57 | 9.53 | 12.70 | 25.40 |
Tolerances follow ASTM A999. The wall may run up to 12.5% under nominal, and the OD limit grows with pipe size, from +0.4 / −0.8 mm in small sizes to +1.6 / −0.8 mm between NPS 4 and 8.
Super Duplex Seamless Pipe Common Materials
Super duplex seamless pipes are available in different grades to meet demanding strength and corrosion-resistance requirements. Super Duplex Seamless Pipe Suppliers commonly offer the following materials for marine, offshore, chemical processing and industrial applications.
UNS S32750 (1.4410): Super Duplex 2507, containing approximately 25% chromium and 4% molybdenum, with excellent resistance to pitting and crevice corrosion.
UNS S32760 (1.4501): Contains chromium, molybdenum, tungsten and copper for specified aggressive service environments.
UNS S32550 (1.4507): A copper-alloyed super duplex grade used in selected chloride-containing and chemical processing applications.
UNS S32520: A super duplex grade used where high strength and corrosion resistance are required.
The appropriate grade depends on operating temperature, pressure, process fluid and project standards. When sourcing from Super Duplex Seamless Pipe Suppliers, verify the specified UNS grade, applicable ASTM standard and material test certificate.
Super Duplex Seamless Pipe We Manufacture and Supply
We make Super Duplex Seamless Pipe for the services below. The grade and wall follow the fluid and the pressure.
| Service | Grades | Typical wall |
|---|---|---|
| Subsea flowlines and jumpers | S32750, S32760 | Sch 80S to XXS |
| Wellhead and manifold piping | S32750, S32760 | Sch 80S to XXS |
| Hot seawater and firewater systems | S32750, S32760 | Sch 10S to 40S |
| Desalination high-pressure lines | S32750, S32760 | Sch 40S to 80S |
| Acid and chloride process piping | S32550, S32520, S32750 | Sch 10S to 80S |
Applications of Super Duplex Seamless Pipe
- Subsea oil and gas: Flowlines, jumpers, manifolds and risers.
- Sour gas processing: Wellhead and gathering lines, within NACE limits.
- Offshore platforms: Seawater, firewater and produced-water systems.
- Desalination plants: High-pressure reverse-osmosis and brine lines.
- Chemical and petrochemical plants: Acid and chloride process lines.
- Marine: Scrubber and seawater cooling systems on ships.
- Pulp and paper mills: Bleach plant and liquor lines.
- Power generation: Flue gas desulphurisation and seawater cooling.
Why Choose Us as Your Super Duplex Seamless Pipe Manufacturer in India?
With experience in manufacturing and supplying pipes and tubes in India since 2005, we cater to industrial buyers, project contractors and international customers requiring super duplex seamless pipes for demanding applications. Our product range includes grades such as UNS S32750 (1.4410), UNS S32760 (1.4501), UNS S32550 (1.4507) and UNS S32520, subject to order requirements and availability. Pipes can be specified in different outside diameters, wall thicknesses, schedules and lengths according to the applicable ASTM or ASME standards and project specifications. Our monthly manufacturing capacity is 100 tons, supporting planned procurement and export orders.
Quality and documentation are important parts of our supply process. We hold ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certifications, along with PED 2014/68/EU and TUV approvals. Every order includes an EN 10204 Type 3.1 certificate, while Type 3.2 documentation and third-party inspection can be arranged on request. With our facility near Mumbai and export office in Mumbai, we ship to 85+ countries. Popular sizes may be available from ready stock, subject to availability, and we coordinate grade, dimensions, inspection requirements and export documentation according to each order.
Countries We Export Super Duplex Seamless Pipe To
We supply super duplex seamless pipes to customers in 85+ countries, supporting offshore engineering, subsea projects, marine applications and industrial process plants. Our export operations from Mumbai help coordinate international supply, shipment arrangements and product documentation according to buyer requirements.
Gulf and Middle East: UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain.
Europe: Norway, United Kingdom, Netherlands, Germany, Italy, France and Spain.
Southeast Asia and Oceania: Singapore, Malaysia, Indonesia, Thailand, Vietnam and Australia.
Africa: Nigeria, South Africa, Egypt and Kenya.
Americas: USA, Canada, Mexico and Brazil.
As a Super Duplex Seamless Pipe Supplier in India, we support export enquiries for specified grades, sizes, wall thicknesses and quantities, subject to availability and order requirements. Shipping arrangements, inspection documents, material certificates and export documentation are coordinated according to the destination and project specifications.
Super Duplex Seamless Pipe FAQs
Common questions about super duplex grades, PREN, temperature limits, testing, welding, and supply.
Which super duplex grade should I choose?
S32750 is the usual choice and the most widely stocked. Pick S32760 when your project specification names it, and S32550 or S32520 where copper helps in acid service.
How is PREN calculated, and what number do I need?
PREN = Cr + 3.3 × Mo + 16 × N. Super duplex has a PREN of 40 or higher, against about 35 for 2205 and 24 for 316L. A higher number means better pitting resistance.
What is the maximum service temperature?
Keep super duplex below about 250°C. Long exposure at higher temperatures can make it brittle. Your engineer should check the limit for the grade and code.
What do ASTM A923 and G48 tests show?
A923 checks for brittle intermetallic phases that hurt toughness and corrosion resistance. G48 tests resistance to pitting and crevice corrosion in ferric chloride. Both can be specified on request.
Can super duplex be used with cathodic protection?
Yes, but with care. High stress combined with hydrogen from cathodic protection can cause cracking, so your designer should check strain and potential limits.
How should I weld super duplex pipe?
Use a matching super duplex filler, controlled heat input and a low interpass temperature, under a qualified procedure. Post-weld heat treatment is not normally applied, and the weld phase balance should be checked.
What tolerances apply to OD and wall?
ASTM A999 sets them. Wall may run up to 12.5% under nominal, and OD limits depend on the pipe size.
What sizes can I order?
The tables above cover NPS 1/2 to 12 in Sch 10S, 40S, 80S and XXS. Other sizes and walls can be quoted on request.
How do I calculate the weight of an order?
Use Weight (kg/m) = (OD − Wall) × Wall × 0.02450, with OD and wall in mm. Multiply by length and quantity. Real weight varies slightly with wall tolerance.
Which certificates and tests come with the pipe?
Each order carries an EN 10204 3.1 certificate showing chemistry and mechanical results. A 3.2 certificate, third-party inspection and ASTM A923 or G48 tests are available on request.