Duplex Steel Seamless Pipes Manufacturer in India
Duplex Steel Seamless Pipes Manufacturer in India
Sachiya Steel International is a leading Duplex Steel Seamless Pipes Manufacturer in India, supplying high-quality seamless pipes for demanding industrial applications. We have been manufacturing and supplying pipes and tubes in India since 2005, with a facility near Mumbai and an export office in Mumbai. Our duplex steel seamless pipes offer a useful combination of high strength, good toughness, and strong resistance to corrosion and chloride-containing environments. They are suitable for industries where standard stainless steel may not provide the required performance. We supply pipes in different grades, sizes, wall thicknesses, and specifications to meet project requirements.
Our duplex steel seamless pipes are used in oil and gas, petrochemical, chemical processing, marine, power, desalination, and process industries. We can supply popular sizes from ready stock, subject to availability, and arrange third-party inspection when required. Every order includes an EN 10204 3.1 certificate, while 3.2 certification is available on request. With ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, PED 2014/68/EU, and TUV approvals, we support customers in India and export markets across 85+ countries.
What Are Duplex Steel Seamless Pipes?
Duplex Steel Seamless Pipes are pipes made from duplex stainless steel, which contains two main phases: austenite and ferrite. These pipes are manufactured without a welded joint, giving them uniform strength and good resistance to pressure and corrosion. Duplex steel seamless pipes are known for their high strength, excellent corrosion resistance, and resistance to stress corrosion cracking. Common grades include Duplex 2205 and Super Duplex 2507. They are widely used in oil and gas, chemical processing, marine, petrochemical, desalination, and power industries where both strength and corrosion resistance are important.
Duplex Steel Seamless Pipes
High-quality Duplex Steel Seamless Pipes manufactured for demanding applications across chemical, petrochemical, oil & gas, power generation, marine, construction and engineering industries. Available in UNS S31803 and S32205 grades, multiple sizes, wall thicknesses and ASTM A790 / ASME specifications.
Types of Duplex Steel Seamless Pipes
As a Duplex Steel Seamless Pipes Manufacturer, we supply different types of duplex seamless pipes based on grade, manufacturing process, finish, and end connection. Common types include:
- Duplex 2205 Seamless Pipes – UNS S31803/S32205 grade for general corrosion-resistant applications.
- Super Duplex 2507 Seamless Pipes – UNS S32750 grade for severe chloride and marine environments.
- Duplex UNS S32205 Seamless Pipes – Used in chemical, oil and gas, and process industries.
- Duplex UNS S31803 Seamless Pipes – Suitable for pressure piping and corrosion-resistant services.
- Hot Finished Duplex Seamless Pipes – Manufactured for demanding industrial and high-pressure applications.
- Cold Finished Duplex Seamless Pipes – Used where closer dimensional control and a smoother surface are required.
- Plain End Duplex Seamless Pipes – Suitable for welding and standard pipe connections.
- Beveled End Duplex Seamless Pipes – Prepared for butt-welding during pipeline installation.
S31803, S32205, S32750, S32760 and S32304 Duplex Steel Seamless Pipes Manufacturers and Suppliers in India
Duplex Steel Seamless Pipes are available in different grades for applications that require high strength and corrosion resistance. As a manufacturer and supplier in India, we supply UNS S31803, S32205, S32750, S32760 and S32304 grades for various industrial requirements.
- UNS S31803 Duplex Steel Seamless Pipes: Duplex 2205 grade offering good strength and corrosion resistance. Suitable for chemical processing, oil and gas, and process piping.
- UNS S32205 Duplex Steel Seamless Pipes: Duplex 2205 grade with controlled chemistry and good resistance to corrosion. Used in petrochemical, marine, oil and gas, and process industries.
- UNS S32750 Duplex Steel Seamless Pipes: Super Duplex 2507 grade with high strength and excellent resistance to chloride-related corrosion. Commonly used in desalination, offshore, marine, and chemical applications.
- UNS S32760 Duplex Steel Seamless Pipes: Super Duplex grade providing high strength and strong resistance to pitting and crevice corrosion. Used in oil and gas, seawater, marine, and chemical processing systems.
- UNS S32304 Duplex Steel Seamless Pipes: Lean Duplex 2304 grade offering a balance of strength and corrosion resistance. Used in process equipment, structural applications, and general corrosion-resistant services.
S31803 and S32205 are associated with Duplex 2205, while S32750 and S32760 are Super Duplex grades. S32304 is a Lean Duplex grade used where good corrosion resistance and strength are required with a lower alloy content.
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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→Get Certified Duplex Steel Seamless Pipes at Competitive Factory Prices
Duplex Steel Seamless Pipes Specification
The table lists the working specification.
| Item | Detail |
|---|---|
| Product | Duplex Steel Seamless Pipes |
| Process | Seamless, hot finished or cold drawn |
| Grades | S31803, S32205, S32750, S32760, S32304, S32101 |
| Pipe standards | ASTM A790 / ASME SA790, EN 10216-5 |
| General requirements | ASTM A999 |
| Dimensions | ASME B36.19M (Sch 10S, 40S, 80S), ASME B36.10M for other walls |
| Size reference | NPS 1/2 to 12 in the weight chart, other sizes on request |
| Length | Single random, double random or cut length |
| Ends | Plain or bevelled (ASME B16.25) |
| Heat treatment | Solution annealed and quenched |
| Surface | Pickled and passivated |
| Tests | Chemical analysis, tensile, hardness, flattening, hydrostatic or non-destructive test, ASTM A923 phase test on request |
| Certificate | EN 10204 3.1 with every order, 3.2 on request |
| Inspection | Third-party inspection on request |
Duplex Steel Seamless Pipes Standards and Specifications
Duplex pipe is bought to a pipe standard, a general standard and, for harsh service, a corrosion or sour-service standard. The table sets them out.
| Standard | What it covers | Used for |
|---|---|---|
| ASTM A790 / ASME SA790 | Seamless and welded ferritic/austenitic stainless pipe | Core duplex pipe standard |
| ASTM A789 | Seamless and welded ferritic/austenitic tubes | Duplex tubing |
| 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 in duplex steel | Quality check of structure |
| ASTM G48 | Pitting and crevice corrosion test in ferric chloride | Corrosion check |
| NACE MR0175 / ISO 15156 | Materials for sour service | Oil and gas projects |
| ASME B36.19M | Stainless pipe dimensions | Sch 10S, 40S, 80S walls |
| ASME B16.25 | Butt-welding ends | Bevel angle and root face |
| EN 10204 | Types of inspection documents | 3.1 and 3.2 certificates |
Duplex Steel Seamless Pipes Material and Grades
The grade decides corrosion resistance, strength and cost. PREN, the pitting resistance equivalent number, is a rough index of pitting resistance: Cr + 3.3 × Mo + 16 × N. A higher PREN means better resistance to chloride pitting.
| Grade | UNS | EN number | Common name | PREN (about) | Typical use |
|---|---|---|---|---|---|
| S32101 | S32101 | 1.4162 | Lean duplex 2101 | 26 | Tanks, structures, mild chloride duty |
| S32304 | S32304 | 1.4362 | Lean duplex 2304 | 25 | Water and process lines |
| S31803 | S31803 | 1.4462 | Duplex 2205 | 34+ | General process, seawater cooling |
| S32205 | S32205 | 1.4462 | Duplex 2205 | 35 | General process, higher spec than S31803 |
| S32750 | S32750 | 1.4410 | Super duplex 2507 | 40+ | Subsea, brine, sour service |
| S32760 | S32760 | 1.4501 | Super duplex | 40+ | Seawater and aggressive chloride duty |
What Is the Difference Between Duplex Steel Seamless Pipes and Stainless Steel Seamless Pipes?
The short answer: duplex has two phases and about twice the strength of austenitic grades like 304 and 316L, with much better resistance to chloride stress corrosion cracking. Austenitic stainless steel is easier to weld and form, and handles higher temperatures, so it remains the pick for general duty.
| Point | Duplex Steel Seamless Pipes | Stainless Steel Seamless Pipes (304, 316L) |
|---|---|---|
| Structure | Austenite and ferrite | Austenite |
| Yield strength | Around 450 to 550 MPa and above | Around 170 to 205 MPa |
| Chloride stress corrosion | High resistance | Low resistance |
| Wall for the same pressure | Thinner | Thicker |
| Temperature limit | Keep below about 300°C | Higher |
| Magnetic | Yes, slightly | No |
| Welding | Needs controlled heat input | Easier |
| Price per tonne | Higher, but less steel is needed | Lower |
| Typical use | Subsea, desalination, offshore, chemical | General process, food, water |
Duplex Steel Seamless Pipes Chemical Composition
Chemistry controls the phase balance and corrosion resistance. Nitrogen is added to boost strength and pitting resistance. The table shows ASTM A790 limits. Values are percentage by weight, maximum unless shown as a range.
| Grade | C | Mn | Si | P | S | Cr | Ni | Mo | N | Other |
|---|---|---|---|---|---|---|---|---|---|---|
| S31803 | 0.030 | 2.00 | 1.00 | 0.030 | 0.020 | 21.0–23.0 | 4.5–6.5 | 2.5–3.5 | 0.08–0.20 | — |
| S32205 | 0.030 | 2.00 | 1.00 | 0.030 | 0.020 | 22.0–23.0 | 4.5–6.5 | 3.0–3.5 | 0.14–0.20 | — |
| S32750 | 0.030 | 1.20 | 0.80 | 0.035 | 0.020 | 24.0–26.0 | 6.0–8.0 | 3.0–5.0 | 0.24–0.32 | Cu 0.50 max |
| S32760 | 0.030 | 1.00 | 1.00 | 0.030 | 0.010 | 24.0–26.0 | 6.0–8.0 | 3.0–4.0 | 0.20–0.30 | Cu 0.50–1.00, W 0.50–1.00 |
| S32304 | 0.030 | 2.50 | 1.00 | 0.040 | 0.040 | 21.5–24.5 | 3.0–5.5 | 0.05–0.60 | 0.05–0.20 | Cu 0.05–0.60 |
| S32101 | 0.040 | 4.00–6.00 | 1.00 | 0.040 | 0.030 | 21.0–22.0 | 1.35–1.70 | 0.10–0.80 | 0.20–0.25 | Cu 0.10–0.80 |
Duplex Steel Seamless Pipes Mechanical Properties
Mechanical properties show why duplex allows thinner walls. The table gives minimum values under ASTM A790.
| Grade | Yield strength min (MPa) | Tensile strength min (MPa) | Elongation min (%) | Hardness max |
|---|---|---|---|---|
| S31803 | 450 | 620 | 25 | 290 HBW |
| S32205 | 450 | 655 | 25 | 290 HBW |
| S32750 | 550 | 795 | 15 | 310 HBW |
| S32760 | 550 | 750 | 25 | — |
| S32304 | 400 | 600 | 25 | 290 HBW |
| S32101 | 450 | 650 | 30 | 290 HBW |
Duplex Steel Seamless Pipes Size and Weight Chart
Weight depends on OD and wall thickness. Duplex steel has a density of about 7.80 g/cm³, so we use this formula:
OD and wall are in mm. Example: NPS 4 Sch 40S is (114.3 − 6.02) × 6.02 × 0.02450 = 15.97 kg/m. Multiply by length for total weight.
| NPS | OD (mm) | Sch 10S wall (mm) | Sch 10S (kg/m) | Sch 40S wall (mm) | Sch 40S (kg/m) | Sch 80S wall (mm) | Sch 80S (kg/m) |
|---|---|---|---|---|---|---|---|
| 1/2" | 21.3 | 2.11 | 0.99 | 2.77 | 1.26 | 3.73 | 1.61 |
| 3/4" | 26.7 | 2.11 | 1.27 | 2.87 | 1.68 | 3.91 | 2.18 |
| 1" | 33.4 | 2.77 | 2.08 | 3.38 | 2.49 | 4.55 | 3.22 |
| 1-1/2" | 48.3 | 2.77 | 3.09 | 3.68 | 4.02 | 5.08 | 5.38 |
| 2" | 60.3 | 2.77 | 3.90 | 3.91 | 5.40 | 5.54 | 7.43 |
| 3" | 88.9 | 3.05 | 6.42 | 5.49 | 11.22 | 7.62 | 15.17 |
| 4" | 114.3 | 3.05 | 8.31 | 6.02 | 15.97 | 8.56 | 22.18 |
| 6" | 168.3 | 3.40 | 13.74 | 7.11 | 28.08 | 10.97 | 42.28 |
| 8" | 219.1 | 3.76 | 19.84 | 8.18 | 42.27 | 12.70 | 64.22 |
| 10" | 273.1 | 4.19 | 27.60 | 9.27 | 59.92 | 12.70 | 81.02 |
| 12" | 323.9 | 4.57 | 35.75 | 9.53 | 73.40 | 12.70 | 96.83 |
Available Sizes, Dimensions and Schedules
Duplex Steel Seamless Pipes follow ASME B36.19M for Sch 10S, 40S and 80S, and B36.10M for other walls. The chart above covers NPS 1/2 to 12, and other sizes and walls can be quoted on request. Because duplex is strong, many designs use a lighter schedule than they would in 316L. Your engineer should confirm the wall with the design code.
Tolerances follow ASTM A999. The wall may run up to 12.5% under nominal, and the OD limits depend on the pipe size.
| NPS range | OD tolerance (mm) |
|---|---|
| 1/8 to 1-1/2 | +0.4 / −0.8 |
| Over 1-1/2 to 4 | ±0.8 |
| Over 4 to 8 | +1.6 / −0.8 |
| Over 8 to 18 | +2.4 / −0.8 |
Common Materials in Duplex Steel Seamless Pipes
These are some of the commonly requested materials from Duplex Steel Seamless Pipes Suppliers for different industrial applications.
UNS S31803 and S32205 (1.4462): Duplex 2205 grades containing about 22% chromium and 3% molybdenum. Commonly selected for oil and gas, chemical processing, marine, and general duplex applications.
UNS S32750 (1.4410): Super Duplex 2507 with about 25% chromium and 4% molybdenum. Suitable for severe chloride environments, seawater systems, offshore applications, and demanding process service.
UNS S32760 (1.4501): Super Duplex grade containing chromium, molybdenum, tungsten, and copper. Used for seawater, marine, oil and gas, and highly corrosive environments.
UNS S32304 (1.4362): Lean Duplex 2304 with good strength and corrosion resistance. Suitable for moderate-duty applications where a lower-alloy duplex material is appropriate.
UNS S32101 (1.4162): Lean Duplex 2101 with lower nickel content and additions of manganese and nitrogen. Used in applications requiring good strength and corrosion resistance with controlled alloying.
Duplex Steel Seamless Pipes We Manufacture and Supply
We make Duplex Steel Seamless Pipes for the services below. The grade follows the environment.
| Service | Grades | Why duplex |
|---|---|---|
| Subsea and offshore flowlines | S32750, S32760 | Strength and pitting resistance in seawater |
| Seawater cooling and desalination | S31803, S32205, S32750 | Chloride resistance |
| Process and chemical piping | S31803, S32205, S32304 | Strength and corrosion resistance |
| Sour gas service | S31803, S32205, S32750 | Resistance to cracking, within NACE limits |
| Structural and storage use | S32101, S32304 | Strength with lower alloy cost |
Applications of Duplex Steel Seamless Pipes
- Oil and gas: Flowlines, manifolds, risers and topside process piping.
- Offshore and marine: Seawater systems, firewater lines and subsea equipment.
- Desalination plants: Brine heaters, seawater intake and high-pressure lines.
- Chemical and petrochemical plants: Lines carrying chlorides, acids and caustic liquids.
- Pulp and paper mills: Digesters, bleach plants and liquor lines.
- Power generation: Flue gas desulphurisation and cooling water lines.
- Pharmaceutical plants: Utility and process lines where chloride resistance is needed.
- Construction and infrastructure: Bridges, tanks and structural pipework.
Why Choose Us as Your Duplex Steel Seamless Pipes Manufacturer in India?
With experience in manufacturing and supplying pipes and tubes since 2005, we understand the requirements of buyers who need reliable duplex steel seamless pipes for demanding industrial applications. We can manufacture and supply commonly requested duplex grades such as UNS S31803, S32205, S32750, S32760 and S32304 in different sizes, wall thicknesses and specifications. Our regular supply capability is up to 100 tons per month, depending on grade, size and order requirements. Popular sizes can also be available from ready stock, subject to availability. As a Duplex Steel Seamless Pipes Supplier in India, we support domestic and international orders with proper material identification, dimensional requirements and project-specific documentation.
Our quality documentation includes an EN 10204 3.1 certificate with every order, while 3.2 certification and third-party inspection are available on request. Our management systems include ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018, along with PED 2014/68/EU and TUV approvals. We have experience handling export requirements and ship duplex steel seamless pipes to 85+ countries. This helps customers source duplex seamless pipes from India with the required grades, sizes, documentation, packing and export support.
Countries We Export Duplex Steel Seamless Pipes To
We supply Duplex Steel Seamless Pipes to customers across 85+ countries, with export support covering material selection, sizes, inspection documents, packing and shipment requirements. Our export experience helps us handle orders for different duplex grades and specifications based on the destination country's project and documentation needs.
Middle East: UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain
Europe: Germany, Italy, United Kingdom, Netherlands, France, Norway and Spain
Asia-Pacific: Singapore, Malaysia, Indonesia, Thailand, Vietnam and Australia
North and South America: USA, Canada, Mexico and Brazil
Africa: South Africa, Nigeria, Egypt and Kenya
For export orders, we provide EN 10204 3.1 certification with every order, while 3.2 certification and third-party inspection can be arranged on request. Packing and shipping documentation can be prepared according to the order and destination requirements, helping buyers source duplex seamless pipes from India for international projects.
Duplex Steel Seamless Pipes FAQs
Common questions about duplex seamless pipe grades, seawater service, welding, dimensions, and supply.
Which duplex grade should I pick for seawater service?
S32205 works for many seawater lines. For warm, stagnant or high-chloride seawater, move up to super duplex S32750 or S32760, which have higher pitting resistance.
How do I choose between 2205 and 2507?
Compare the chloride level and temperature. 2205 suits most process and moderate chloride duty. 2507 is for severe chloride, higher temperatures and sour service, and costs more.
What is the maximum temperature for duplex pipes?
Keep service below about 300°C. At higher temperatures, long exposure can make duplex steel brittle. Your engineer should check the limit against the grade and code.
Can duplex pipes be used in sour service?
Yes, within the limits of NACE MR0175 / ISO 15156, which set hardness, temperature and H2S limits. State the sour-service requirement when you enquire.
How should I weld duplex steel pipes?
Use a matching duplex filler metal, controlled heat input and a controlled interpass temperature, under a qualified procedure. Post-weld heat treatment is usually not applied, and welds should be tested for phase balance.
Is duplex steel magnetic?
Yes, slightly, because of the ferrite in its structure. Austenitic grades like 316L are not magnetic.
What tolerances apply to OD and wall?
ASTM A999 sets them. The table above shows the OD limits, and wall may run up to 12.5% under nominal.
What sizes can I order?
The chart above covers NPS 1/2 to 12 in Sch 10S, 40S and 80S. 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.
What affects the price of Duplex Steel Seamless Pipes?
The grade is the main factor, because nickel, molybdenum and nitrogen content move the cost. Size, wall, finish, testing, quantity, inspection and freight also count.
Which certificates come with the pipes?
Each order carries an EN 10204 3.1 certificate showing chemistry and mechanical results. A 3.2 certificate and third-party inspection are available on request.
Are you a manufacturer or a supplier of Duplex Steel Seamless Pipes?
We are both. We manufacture near Mumbai and supply ready stock of popular sizes from the same location, subject to availability.
Can duplex pipes replace 316L pipes?
Often, yes, where chloride cracking or strength is the issue. The wall can usually be thinner, but you must check welding, temperature and cost against your design.
Do you export Duplex Steel Seamless Pipes, and how are they packed?
Yes. We ship to 85+ countries from our Mumbai export office, and we pack the pipes to suit sea or air freight and your project needs.