Super Duplex Seamless Tubes Manufacturer in India
Super Duplex Seamless Tubes Manufacturer in India
Sachiya Steel International, established in 2005, is a Super Duplex Seamless Tubes Manufacturer in India with experience in manufacturing and supplying pipes and tubes for industrial requirements. Our facility near Mumbai and export office in Mumbai support orders for different grades, sizes, wall thicknesses and specifications. Over the years, we have developed experience in handling both domestic requirements and international orders, with our products supplied to customers across 85+ countries.
Our focus is on supplying Super Duplex Seamless Tubes for demanding sectors including oil and gas, offshore, marine, chemical processing, desalination and petrochemical industries. We operate with ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certifications, along with PED 2014/68/EU and TUV approvals. Every order comes with an EN 10204 3.1 certificate, while 3.2 certification and third-party inspection are available on request. Our team manages the manufacturing, documentation and export requirements needed to supply super duplex tubes from India to different international markets
What Are Super Duplex Seamless Tubes?
Super Duplex Seamless Tubes are seamless stainless steel tubes made from duplex steel with a PREN of 40 or higher. PREN, the pitting resistance equivalent number, is a rough index of pitting resistance: Cr + 3.3 × Mo + 16 × N. A higher number means better resistance to chloride pitting.
The steel holds about equal parts austenite and ferrite. High chromium, molybdenum and nitrogen give it excellent resistance to pitting, crevice corrosion and chloride cracking. Its yield strength is more than three times that of 316L, so thin walls carry high pressure. The tube is pierced from a billet, drawn or rolled to size, then solution annealed and quenched to lock in the balanced structure. Tubes are sized by outside diameter and wall thickness, with tighter tolerances than pipe.
Super Duplex Seamless Tubes
High-quality super duplex seamless tubes manufactured for demanding applications across chemical, petrochemical, power generation, marine, construction and engineering industries. Available in multiple sizes, wall thicknesses, grades and manufacturing specifications, with required testing, inspection and material certificates.
Types of Super Duplex Seamless Tubes
We manufacture and supply Super Duplex Seamless Tubes in different grades, manufacturing conditions, dimensions and finishes to suit heat exchangers, condensers, process equipment and other demanding applications.
- S32750 Seamless Tubes: Super Duplex 2507 tubes for seawater, desalination, offshore, chemical and oil and gas applications.
- S32760 Seamless Tubes: Tungsten- and copper-alloyed super duplex tubes for aggressive chloride and marine environments.
- S32550 Seamless Tubes: Copper-bearing super duplex tubes for selected acidic, chloride and process applications.
- Hot-Finished Seamless Tubes: Suitable for larger tube dimensions and heavier wall requirements.
- Cold-Drawn Seamless Tubes: Produced with additional cold working for closer dimensional control and a smoother surface.
- Solution-Annealed Seamless Tubes: Heat treated to obtain the required metallurgical structure and mechanical properties.
- Pickled Seamless Tubes: Surface treated to remove scale and leave a clean surface suitable for corrosion-resistant service.
- Polished Seamless Tubes: Finished to achieve a smoother surface where appearance or surface condition is important.
Our experience as a Super Duplex Seamless Tubes Manufacturer allows us to supply different tube grades, dimensions and finishes according to the required application and specification.
S32750, S32760 and S32550 Super Duplex Seamless Tubes Manufacturers and Suppliers in India
Our Super Duplex Seamless Tubes range includes UNS S32750, UNS S32760 and UNS S32550, giving customers material options for applications involving seawater, chlorides, acids and other demanding service conditions. We manufacture and supply these grades in different tube dimensions and specifications.
- UNS S32750 (1.4410): Super Duplex 2507 grade offering high strength and strong resistance to pitting and crevice corrosion. It is suitable for heat exchangers, desalination equipment, offshore systems, seawater service and oil and gas applications.
- UNS S32760 (1.4501): Super duplex grade containing tungsten and copper, selected for aggressive chloride environments and demanding marine, offshore and chemical applications.
- UNS S32550 (1.4507): Copper-bearing super duplex grade with good mechanical strength and resistance to acidic and chloride-containing media. It can be used for selected process, chemical and marine applications.
As Super Duplex Seamless Tubes Suppliers, we can supply these grades in different outside diameters, wall thicknesses, lengths and finishes according to the required specification and service conditions.
Types of Pipes & Tubes
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→Get Certified Super Duplex Seamless Tubes at Competitive Factory Prices
Super Duplex Seamless Tubes Specification
The table sets out the working specification.
| Item | Detail |
|---|---|
| Product | Super Duplex Seamless Tubes |
| Process | Seamless, hot finished or cold drawn |
| Grades | S32750, S32760, S32550 |
| Tube standards | ASTM A789 / ASME SA789, EN 10216-5 |
| General requirements | ASTM A1016 |
| Size basis | OD and wall thickness in mm or inches, wall by minimum or average |
| Size reference | OD 6.35 to 50.8 mm in the weight chart, other sizes on request |
| Length | Random, fixed or cut length |
| Shapes | Straight tubes, or U-bend against a drawing |
| Heat treatment | Solution annealed and quenched |
| Surface | Pickled and passivated, or bright annealed |
| Tests | Chemical analysis, tensile, hardness, flattening, flaring, hydrostatic or eddy current 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 Tubes Standards and Specifications
Super duplex tubes are bought to a tube standard, a general requirements standard and test methods for structure and corrosion. The table lists each.
| Standard | Scope | Where it applies |
|---|---|---|
| ASTM A789 / ASME SA789 | Seamless and welded ferritic/austenitic stainless tubing for general service | Core tube standard |
| ASTM A1016 | General requirements for ferritic alloy, austenitic and duplex tubes | Tolerances, tests, marking |
| EN 10216-5 | Seamless stainless steel tubes for pressure purposes | EN-code projects |
| ASTM A923 | Test methods for detrimental intermetallic phases | Method A, B or C structure check |
| ASTM G48 | Pitting and crevice corrosion test | Corrosion check |
| NACE MR0175 / ISO 15156 | Materials for sour service | Oil and gas projects |
| TEMA | Standards for shell and tube heat exchangers | Tube sizes and fits |
| ASME Section VIII, Div. 1 | Pressure vessel design rules | Wall and allowable stress by your designer |
| EN 10204 | Types of inspection documents | 3.1 and 3.2 certificates |
Super Duplex Seamless Tubes Material and Grades
Pick the grade by the fluid, the chloride level and the temperature. The table lists the grades and their use.
| Grade | UNS | EN number | Name | PREN (about) | Typical tube use |
|---|---|---|---|---|---|
| S32750 | S32750 | 1.4410 | Super duplex 2507 | 42 | Hot-seawater exchangers, injection lines, sour service |
| S32760 | S32760 | 1.4501 | Super duplex | 41 | Offshore coolers and aggressive chloride duty |
| S32550 | S32550 | 1.4507 | Super duplex | 39 | Acid and chloride process exchangers |
What Is the Difference Between Super Duplex Seamless Tubes and Duplex Steel Seamless Tubes?
The short answer: super duplex tubes have more chromium, molybdenum and nitrogen than 2205 tubes, so PREN rises from about 35 to above 40. They resist pitting at much higher temperatures and are stronger, but cost more. Use 2205 for cool or mild chloride duty and super duplex for hot seawater, sour fluids and thin-wall, high-pressure work.
| Property | Super Duplex Seamless Tubes | Duplex Steel Seamless Tubes (2205) | What it means for a tube |
|---|---|---|---|
| PREN | 40 and above | About 35 | Better pitting resistance in hot seawater |
| Yield strength | 550 MPa minimum | 450 MPa minimum | Thinner wall at the same pressure |
| Critical pitting temperature (typical) | About 80°C | About 35°C | Wider safe temperature window |
| Temperature limit | Keep below about 250°C | Keep below about 300°C | Check against service temperature |
| Hardness limit | 310 HBW (S32750) | 290 HBW | Check against tubesheet hardness |
| Cost | Higher | Lower | Match the grade to the duty |
| Typical use | Hot seawater, subsea lines, sour service | Condensers, cool seawater, general process | Pick by duty |
Super Duplex Seamless Tubes Chemical Composition
Chemistry gives super duplex its pitting resistance. The first table shows the corrosion-resistance elements under ASTM A789, with the PREN of each grade 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 |
Control Elements
| 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 |
Super Duplex Seamless Tubes Mechanical Properties
Mechanical properties show why super duplex allows thin walls. The table gives minimum values and compares yield strength with 2205, which has a minimum yield of 450 MPa.
| Grade | Yield min, MPa (ksi) | Tensile min, MPa (ksi) | Elongation min (%) | Hardness max | Yield vs 2205 |
|---|---|---|---|---|---|
| S32750 | 550 (80) | 800 (116) | 15 | 310 HBW | About 1.2 times |
| S32760 | 550 (80) | 750 (109) | 25 | — | About 1.2 times |
| S32550 | 550 (80) | 760 (110) | 15 | — | About 1.2 times |
Super Duplex Seamless Tubes Size and Weight Chart
Weight depends on OD and wall thickness. Super duplex has a density of about 7.80 g/cm³, so we use this formula:
OD and wall are in mm. Example: a 19.05 mm (3/4") OD tube with a 1.65 mm wall weighs (19.05 − 1.65) × 1.65 × 0.02450 = 0.70 kg/m. A dash means the wall is too thick for that OD.
| OD (mm) | 0.89 mm wall (0.035") | 1.24 mm wall (0.049") | 1.65 mm wall (0.065") | 2.11 mm wall (0.083") | 2.77 mm wall (0.109") |
|---|---|---|---|---|---|
| 6.35 | 0.12 | 0.16 | 0.19 | 0.22 | — |
| 9.53 | 0.19 | 0.25 | 0.32 | 0.38 | 0.46 |
| 12.7 | 0.26 | 0.35 | 0.45 | 0.55 | 0.67 |
| 15.88 | 0.33 | 0.44 | 0.58 | 0.71 | 0.89 |
| 19.05 | 0.40 | 0.54 | 0.70 | 0.88 | 1.10 |
| 25.4 | 0.53 | 0.73 | 0.96 | 1.20 | 1.54 |
| 31.75 | 0.67 | 0.93 | 1.22 | 1.53 | 1.97 |
| 38.1 | 0.81 | 1.12 | 1.47 | 1.86 | 2.40 |
| 50.8 | 1.09 | 1.51 | 1.99 | 2.52 | 3.26 |
All weights are in kg/m.
Available Sizes, Dimensions and Tolerances
Super Duplex Seamless Tubes are ordered by OD, wall and length. The chart above covers OD 6.35 to 50.8 mm, and other sizes can be quoted on request. Tolerances follow ASTM A1016 and depend on the OD. The table shows typical limits for cold-finished tubes.
| OD (mm) | OD tolerance (±mm) | OD tolerance (±inch) |
|---|---|---|
| 6.35 | 0.10 | 0.004 |
| 12.7 | 0.10 | 0.004 |
| 19.05 | 0.10 | 0.004 |
| 25.4 | 0.15 | 0.006 |
| 38.1 | 0.15 | 0.006 |
| 50.8 | 0.25 | 0.010 |
For tubes ordered by minimum wall, wall may run up to 20% over nominal for OD up to 38.1 mm, and up to 22% over above that. Tell us the OD and wall tolerance your tubesheet, fitting or umbilical design needs, and we will quote against it.
Super Duplex Seamless Tubes Common Materials
These are the materials most often asked for in Super Duplex Seamless Tubes.
UNS S32750 (1.4410): Super duplex 2507, with 25% chromium and 4% molybdenum, for hot-seawater and sour service.
UNS S32760 (1.4501): Super duplex with tungsten and copper, often named in offshore specifications.
UNS S32550 (1.4507): Copper-bearing super duplex for acid and chloride process tubes.
Super Duplex Seamless Tubes We Manufacture and Supply
We make Super Duplex Seamless Tubes for the jobs below. The grade and finish follow the duty.
| Service | Grades | Tube form |
|---|---|---|
| Hot-seawater heat exchangers and coolers | S32750, S32760 | Straight or U-bend, cold drawn |
| Subsea control and chemical injection lines | S32750, S32760 | Cold drawn, bright annealed |
| Instrumentation tubing | S32750 | Bright annealed |
| Desalination exchangers | S32750, S32760 | Straight, cold drawn |
| Acid and chloride process exchangers | S32550, S32750 | Straight, cold drawn |
Applications of Super Duplex Seamless Tubes
- Heat exchangers and coolers: Shell and tube bundles running on hot seawater.
- Subsea oil and gas: Control, hydraulic and chemical injection lines.
- Sour gas processing: Instrument and sampling tubes, within NACE limits.
- Offshore platforms: Firewater, cooling and produced-water tubing.
- Desalination plants: Brine heaters and high-pressure seawater tubes.
- Chemical and petrochemical plants: Exchangers carrying chloride or acid fluids.
- Marine: Scrubber and cooling water systems on ships.
- Pulp and paper mills: Liquor heaters and bleach plant tubing.
Why Choose Us as Your Super Duplex Seamless Tubes Manufacturer in India?
Since 2005, we have been involved in manufacturing and supplying pipes and tubes, with experience across different grades, dimensions and industrial specifications. Our facility near Mumbai supports the production and supply of Super Duplex Seamless Tubes in grades such as UNS S32750, S32760 and S32550. We handle different tube sizes and wall thicknesses, while commonly requested sizes may be available from ready stock, subject to availability. Our supply capability can reach 100 tons per month, depending on the product, size and order requirements. This practical experience makes us a dependable Super Duplex Seamless Tubes Supplier in India.
We also focus on the documentation and inspection requirements that accompany industrial tube orders. An EN 10204 3.1 certificate is provided with every order, while 3.2 certification and third-party inspection are available on request. Our certifications include ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018, together with PED 2014/68/EU and TUV approvals. With an export office in Mumbai and shipments reaching 85+ countries, we support international requirements through suitable export packing, documentation and shipment coordination.
Countries We Export Super Duplex Seamless Tubes To
Our Super Duplex Seamless Tubes are supplied internationally to 85+ countries, with orders moving from India to major industrial markets across several regions. Our export work covers product coordination, material documentation, packing and shipment arrangements based on the requirements of each destination.
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 international orders, we provide an EN 10204 3.1 certificate with every order, with 3.2 certification and third-party inspection available on request. Our Mumbai export office coordinates the documentation, export packing and shipment process, helping customers in different countries source Super Duplex Seamless Tubes from India according to their specified requirements.
Super Duplex Seamless Tubes FAQs
Common questions about super duplex seamless tube grades, seawater service, U-bends, testing, and supply.
Which super duplex grade should I choose for tubes?
S32750 is the usual choice and the most widely stocked. Pick S32760 when your project specification names it, and S32550 where copper helps in acid service.
When should I choose super duplex tubes over 2205 tubes?
Choose super duplex when seawater is hot, chloride is high, the fluid is sour or a thin, strong wall is needed. For cool, mild chloride duty, 2205 is often enough.
What PREN should I look for?
Super duplex grades have a PREN of 40 or higher by common definition. Our grades sit at or around that mark by typical chemistry.
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.
Should I order tubes by minimum wall or average wall?
Minimum wall guarantees the thinnest point meets your design calculation. Average wall allows a plus-minus variation around nominal. Your designer should state the basis on the order.
Can the tubes be expanded into a tubesheet or welded to it?
Yes. Super duplex tubes are rolled or welded into tubesheets in practice. Use a qualified procedure and a compatible tubesheet material, and control heat input when welding.
Can super duplex tubes 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.
What tolerances apply to OD and wall?
ASTM A1016 sets them. The table above gives typical OD limits for cold-finished tubes, and hot-finished tubes carry wider limits.
What sizes can I order?
The chart above covers OD 6.35 to 50.8 mm in walls from 0.89 to 2.77 mm. Other sizes and walls can be quoted on request.
How do I calculate the weight of a tube 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 Super Duplex Seamless Tubes?
Grade is the main factor, because nickel, molybdenum, chromium and nitrogen content move the cost. OD, wall, finish, length, testing, inspection, quantity and freight also count.
Which certificates and tests come with the tubes?
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.
Is every tube tested before it ships?
ASTM A789 requires a hydrostatic test or a non-destructive electric test on each tube. Tell us your preferred test when you enquire.
Are you a manufacturer or a supplier of Super Duplex Seamless Tubes?
We are both. We manufacture near Mumbai and supply ready stock of popular sizes from the same location, subject to availability.
Can you supply U-bend super duplex tubes?
Send your drawing with the bend radius and leg length, and we will confirm what can be made and what heat treatment applies. Straight tubes in standard sizes are the quickest to supply.
Do you export Super Duplex Seamless Tubes, and how are they packed?
Yes. We ship to 85+ countries from our Mumbai export office, and we pack the tubes to suit sea or air freight and your project needs.