Super Duplex Welded Pipes Manufacturer in India
Super Duplex Welded Pipes Manufacturer in India
Sachiya Steel International, established in 2005, is a Super Duplex Welded Pipes Manufacturer in India with long-standing experience in manufacturing and supplying pipes and tubes for industrial applications. Our facility near Mumbai and export office in Mumbai support requirements across different grades, sizes, wall thicknesses and specifications. Our super duplex welded pipe range includes grades such as UNS S32750 and S32760, produced for applications where high strength and strong corrosion resistance are required.
We serve industries including oil and gas, offshore, marine, chemical processing, desalination and petrochemical. Our quality systems are supported by ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certifications, along with PED 2014/68/EU and TUV approvals. We provide EN 10204 3.1 certification with every order, while 3.2 certification and third-party inspection are available on request. With experience in international supply and shipments to 85+ countries, we support both domestic and export requirements with suitable documentation and shipping arrangements.
What Are Super Duplex Welded Pipes?
Super Duplex Welded Pipes are stainless steel pipes made by rolling super duplex plate or strip into a round and joining the edges with a longitudinal weld, usually with filler metal. Super duplex means a 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.
The steel has about equal parts austenite and ferrite. High chromium, molybdenum and nitrogen give it excellent resistance to pitting, crevice corrosion and chloride cracking. The weld is made with an over-alloyed filler, so the seam keeps the same two-phase balance as the plate. After welding, the pipe is heat treated as the standard and your specification require.
Super Duplex Welded Pipes
High-quality super duplex welded pipes 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 Welded Pipes
We manufacture and supply Super Duplex Welded Pipes in different grades, weld constructions, schedules, surface conditions and end finishes. Our range includes:
S32750 Super Duplex Welded Pipes: UNS S32750 grade, commonly known as 2507, for seawater, offshore, desalination, chemical and oil and gas applications.
S32760 Super Duplex Welded Pipes: Grade with tungsten and copper additions for aggressive chloride environments, marine systems and demanding process service.
S32550 Super Duplex Welded Pipes: Copper-bearing super duplex grade for selected chemical, marine and acidic service applications.
Single-Welded Pipes: Suitable for applications where the required diameter and wall thickness can be produced with a single longitudinal weld.
Double-Welded Pipes: Manufactured with welding from both sides for selected larger-diameter and heavier-wall requirements.
Solution-Annealed Welded Pipes: Heat treated after fabrication to achieve the required metallurgical condition and mechanical properties.
Pickled and Passivated Welded Pipes: Surface treated to remove scale and contamination and provide a clean passive surface.
Heavy-Wall Welded Pipes: Available in higher wall thicknesses and schedules for demanding pressure and industrial piping systems.
Plain-End and Bevelled-End Welded Pipes: Supplied with end preparation suited to installation and butt-welding requirements.
Our experience as a Super Duplex Welded Pipes Manufacturer allows us to supply these pipe types according to the required grade, dimensions, schedule, finish and application.
S32750, S32760 and S32550 Super Duplex Welded Pipes Manufacturers and Suppliers in India
Our Super Duplex Welded Pipes range covers UNS S32750, S32760 and S32550, giving different options for applications exposed to seawater, chlorides, chemicals and other corrosive conditions. We manufacture these grades in welded construction with dimensions and finishes selected according to the piping requirement.
- UNS S32750 / 1.4410: Super Duplex 2507 is widely specified for offshore piping, desalination equipment, seawater systems and oil and gas service. Its high chromium and molybdenum content provides strong resistance to pitting and crevice corrosion.
- UNS S32760 / 1.4501: This grade includes tungsten and copper along with chromium and molybdenum. It is suited to aggressive chloride environments and demanding marine, offshore and process applications.
- UNS S32550 / 1.4507: A copper-alloyed super duplex grade used where strength and resistance to acidic and chloride-containing media are important. It can be supplied for selected chemical, marine and process applications.
We supply these grades in different pipe sizes, wall thicknesses, schedules, lengths and end configurations. The required grade and dimensions can be matched to the service conditions, fabrication requirements and applicable product specification.
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
→Get Certified Super Duplex Welded Pipes at Competitive Factory Prices
Super Duplex Welded Pipes Specification
The table sets out the working specification.
| Item | Detail |
|---|---|
| Product | Super Duplex Welded Pipes |
| Process | Formed from plate or strip, longitudinal arc weld with over-alloyed filler metal |
| Grades | S32750, S32760, S32550 |
| Pipe standards | ASTM A790 / ASME SA790, ASTM A928 / ASME SA928 |
| General requirements | ASTM A999 |
| Dimensions | ASME B36.19M (Sch 10S, 40S, 80S), ASME B36.10M for other walls |
| Size reference | NPS 4 to 36 in the weight chart, other sizes on request |
| Weld classes | Single or double welded, with or without radiography, per ASTM A928 |
| Length | Single random, double random or cut length |
| Ends | Plain or bevelled (ASME B16.25) |
| Heat treatment | Solution annealed and quenched, as the standard and specification require |
| Surface | Pickled and passivated |
| Tests | Chemical analysis, tensile, hardness, flattening or bend, hydrostatic or non-destructive test, radiography per class, 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 Welded Pipes Standards and Specifications
Welded super duplex pipe is bought to a pipe standard, a weld class standard and test methods for structure and corrosion. The table lists each.
| Standard | Scope | Where it applies |
|---|---|---|
| ASTM A790 / ASME SA790 | Seamless and welded ferritic/austenitic stainless pipe | Core pipe standard |
| ASTM A928 / ASME SA928 | Electric fusion welded duplex pipe, made with filler metal | Weld classes and radiography |
| ASTM A999 | General requirements for alloy and stainless pipe | Tolerances and test rules |
| ASTM A240 | Plate, sheet and strip for pressure vessels | Plate behind welded pipe |
| 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 |
| AWS A5.9 | Bare stainless steel welding electrodes and rods | Filler metal classes ER2594, ER2553 |
| ASME B31.3 | Process piping design code | Weld joint factors applied by your engineer |
| EN 10204 | Types of inspection documents | 3.1 and 3.2 certificates |
Super Duplex Welded Pipes Material and Grades
Pick the grade by the fluid, the chloride level and the temperature. The table also shows the matching filler for each grade.
| Grade | UNS | EN number | Name | PREN (about) | Matching filler | Typical use |
|---|---|---|---|---|---|---|
| S32750 | S32750 | 1.4410 | Super duplex 2507 | 42 | ER2594 | Seawater, brine, sour service |
| S32760 | S32760 | 1.4501 | Super duplex | 41 | ER2594 | Offshore and aggressive chloride duty |
| S32550 | S32550 | 1.4507 | Super duplex | 39 | ER2553 | Acid and chloride process lines |
What Is the Difference Between Super Duplex Welded Pipes and Super Duplex Seamless Pipes?
The short answer: welded pipe is rolled from plate and has a weld seam, while seamless pipe is pierced from a billet and has none. Welded super duplex reaches larger diameters at lower cost. Seamless is preferred for small bores and for the severest pressure duty.
| Factor | Welded | Seamless | Note |
|---|---|---|---|
| Size range | Very large bore | Limited by mill size | Seamless rarely goes beyond mid sizes |
| Wall for large OD | Easy | Hard | Welded gives flexible walls |
| Cost per metre | Lower in large sizes | Higher | Alloy is costly, so material saved matters |
| Seam | One weld, filler added | None | Seam needs weld class and testing |
| Design weld factor | Set by weld class | Not applied | ASME B31.3 uses the class |
| Delivery time | Often shorter | Often longer | Depends on size and stock |
| Best fit | Large seawater and brine headers | Small-bore, high-pressure lines | Pick by size and duty |
Super Duplex Welded Pipes Chemical Composition
Chemistry gives super duplex its pitting resistance. The first table shows the parent grades under ASTM A790. Values are percentage by weight, maximum unless shown as a range.
| Grade | C | Mn | Si | Cr | Ni | Mo | N | Cu | W | P / S max |
|---|---|---|---|---|---|---|---|---|---|---|
| S32750 | 0.030 | 1.20 | 0.80 | 24.0–26.0 | 6.0–8.0 | 3.0–5.0 | 0.24–0.32 | 0.50 max | — | 0.035 / 0.020 |
| S32760 | 0.030 | 1.00 | 1.00 | 24.0–26.0 | 6.0–8.0 | 3.0–4.0 | 0.20–0.30 | 0.50–1.00 | 0.50–1.00 | 0.030 / 0.010 |
| S32550 | 0.040 | 1.50 | 1.00 | 24.0–27.0 | 4.5–6.5 | 2.9–3.9 | 0.10–0.25 | 1.50–2.50 | — | 0.040 / 0.030 |
Matching Weld Fillers
The second table shows the matching fillers. Their nickel is higher than the plate, which keeps the weld metal in the right phase balance after it cools.
| Filler | C max | Cr | Ni | Mo | N |
|---|---|---|---|---|---|
| ER2594 | 0.03 | 24.0–27.0 | 8.0–10.5 | 3.5–4.5 | 0.20–0.30 |
| ER2553 | 0.04 | 24.0–27.0 | 4.5–6.5 | 2.9–3.9 | 0.10–0.25 |
Super Duplex Welded Pipes Mechanical Properties
Mechanical properties show the strength of the pipe after heat treatment. The table gives minimum parent-metal values.
| Grade | Yield min, MPa (ksi) | Tensile min, MPa (ksi) | Elongation min (%) | Hardness max |
|---|---|---|---|---|
| S32750 | 550 (80) | 800 (116) | 15 | 310 HBW |
| S32760 | 550 (80) | 750 (109) | 25 | — |
| S32550 | 550 (80) | 760 (110) | 15 | — |
Welded pipe also takes weld tests, such as a transverse tension test across the seam and a bend test. The weld must meet the minimum tensile strength of the grade.
Super Duplex Welded Pipes 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: NPS 20 with a 10 mm wall weighs (508.0 − 10) × 10 × 0.02450 = 122.01 kg/m. All figures below are in kg/m.
| NPS | OD (mm) | 6 mm wall | 8 mm wall | 10 mm wall | 12 mm wall |
|---|---|---|---|---|---|
| 4" | 114.3 | 15.92 | 20.83 | 25.55 | 30.08 |
| 6" | 168.3 | 23.86 | 31.42 | 38.78 | 45.95 |
| 8" | 219.1 | 31.33 | 41.38 | 51.23 | 60.89 |
| 10" | 273.1 | 39.26 | 51.96 | 64.46 | 76.76 |
| 12" | 323.9 | 46.73 | 61.92 | 76.91 | 91.70 |
| 14" | 355.6 | 51.39 | 68.13 | 84.67 | 101.02 |
| 16" | 406.4 | 58.86 | 78.09 | 97.12 | 115.95 |
| 18" | 457.2 | 66.33 | 88.04 | 109.56 | 130.89 |
| 20" | 508.0 | 73.79 | 98.00 | 122.01 | 145.82 |
| 24" | 609.6 | 88.73 | 117.91 | 146.90 | 175.69 |
| 30" | 762.0 | 111.13 | 147.78 | 184.24 | 220.50 |
| 36" | 914.4 | 133.53 | 177.65 | 221.58 | 265.31 |
Available Sizes, Dimensions and Schedules
Super Duplex Welded Pipes are ordered by OD and wall thickness in millimetres, and the walls in the chart above are examples. Other sizes and walls can be quoted on request. For schedule-based orders, ASME B36.10M gives these walls for large sizes. Because super duplex is strong, your engineer may choose a lighter wall than 316L would need.
| NPS | OD (mm) | Sch 10 wall (mm) | Standard wall (mm) | Extra strong wall (mm) |
|---|---|---|---|---|
| 14" | 355.6 | 6.35 | 9.53 | 12.70 |
| 16" | 406.4 | 6.35 | 9.53 | 12.70 |
| 18" | 457.2 | 6.35 | 9.53 | 12.70 |
| 20" | 508.0 | 6.35 | 9.53 | 12.70 |
| 24" | 609.6 | 6.35 | 9.53 | 12.70 |
| 30" | 762.0 | 7.92 | 9.53 | 12.70 |
Tolerances follow ASTM A999. Wall may run up to 12.5% under nominal. For pipe over NPS 8 up to NPS 18, OD varies by +2.4 / −0.8 mm, and above NPS 18 up to NPS 26 by +3.2 / −0.8 mm.
Super Duplex Welded Pipes Common Materials
We supply Super Duplex Welded Pipes in commonly requested grades for seawater, brine, chloride, offshore, chemical and sour-service applications. The materials available through our range include:
UNS S32750 (1.4410) Super Duplex Welded Pipes: Super Duplex 2507 grade used for seawater, brine, offshore and sour-service systems. ER2594 filler metal is commonly used with suitable welding procedures.
UNS S32760 (1.4501) Super Duplex Welded Pipes: Super duplex grade with tungsten and copper additions, selected for aggressive chloride and marine service. ER2594 filler metal is commonly associated with suitable welding procedures.
UNS S32550 (1.4507) Super Duplex Welded Pipes: Copper-bearing super duplex grade used for selected acid and chloride process lines. ER2553 filler metal is commonly used for suitable welding procedures.
As Super Duplex Welded Pipes Suppliers, we supply these grades in different sizes, wall thicknesses, schedules, lengths and end preparations according to the required specification.
Super Duplex Welded Pipes We Manufacture and Supply
We make Super Duplex Welded Pipes for the jobs below. The grade and weld class follow the duty.
| Service | Grades | Weld class guide |
|---|---|---|
| Seawater intake and cooling headers | S32750, S32760 | Double welded, radiographed where required |
| Firewater mains | S32750, S32760 | Double welded |
| Desalination brine and high-pressure lines | S32750, S32760 | Double welded, radiographed |
| Offshore topside process piping | S32750, S32760 | As the project code requires |
| Acid and chloride process piping | S32550, S32750 | As the process code requires |
Applications of Super Duplex Welded Pipes
- Offshore oil and gas: Topside seawater, firewater and produced-water lines.
- Desalination plants: Intake headers, brine lines and high-pressure reverse-osmosis piping.
- Marine: Ballast, scrubber and seawater cooling systems on ships.
- Chemical and petrochemical plants: Large process lines carrying chlorides and acids.
- Power generation: Seawater cooling and flue gas desulphurisation headers.
- Pulp and paper mills: Bleach plant and liquor lines.
- Pharmaceutical plants: Large utility and water lines where chloride resistance is needed.
- Infrastructure: Large-diameter water transfer and structural pipework in corrosive sites.
Why Choose Us as Your Super Duplex Welded Pipes Manufacturer in India?
Since 2005, we have been manufacturing and supplying pipes and tubes, building practical experience with demanding steel grades and industrial specifications. Our facility near Mumbai handles requirements for UNS S32750, S32760 and S32550 Super Duplex Welded Pipes in different sizes, wall thicknesses and schedules. Popular sizes may be available from ready stock, subject to availability, and our supply capability can reach 100 tons per month, depending on the grade, dimensions and order requirements. This long-standing experience makes us a reliable Super Duplex Welded Pipes Supplier in India.
Our approach combines product supply with proper quality documentation. EN 10204 3.1 certification is provided with every order, while 3.2 certification and third-party inspection can be arranged on request. We hold ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certifications, together with PED 2014/68/EU and TUV approvals. Our export office in Mumbai supports international shipments to 85+ countries, with export packing and documentation handled according to the order and destination requirements.
Countries We Export Super Duplex Welded Pipes To
Our export network covers 85+ countries, allowing us to supply Super Duplex Welded Pipes for industrial projects and regular procurement requirements across different regions. We handle international orders from India with attention to product specifications, documentation, packing and shipment requirements.
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 overseas shipments, we coordinate the material paperwork and export requirements along with the pipe order. Every order includes an EN 10204 3.1 certificate, while 3.2 certification and third-party inspection are available on request. Our Mumbai export office supports shipment coordination for customers sourcing Super Duplex Welded Pipes from India.
Super Duplex Welded Pipes FAQs
Common questions about super duplex welded pipe grades, weld classes, seawater service, dimensions, and supply.
Which super duplex grade should I choose for a seawater header?
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.
How do I choose between single-welded and double-welded pipe?
Double welding gives a fuller weld section and suits harsher or higher-pressure duty. Single welding costs less and suits lighter service. Your design code and weld class decide.
Which ASTM A928 weld class should I order?
The class sets how the pipe is welded and how much of the seam is radiographed. Choose it from your piping code and the weld joint factor your design needs, and state it on the order.
Is the weld as corrosion resistant as the pipe?
Yes, when the pipe is welded with a correct super duplex filler and heat treated as the standard requires. The filler is over-alloyed in nickel so the seam keeps the right balance of phases.
Which filler metal is used for welded super duplex pipe?
ER2594 is the usual match for S32750 and S32760, and ER2553 for S32550. The filler is chosen to keep the weld metal in the super duplex range.
Can super duplex welded pipe 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 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 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 chart above covers NPS 4 to 36 in 6, 8, 10 and 12 mm walls, and the schedule table covers common large-size walls. 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 Super Duplex Welded Pipes?
Grade is the main factor, because nickel, molybdenum, chromium and nitrogen content move the cost. Size, wall, weld class, radiography, testing, inspection, quantity 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 Super Duplex Welded Pipes?
We are both. We manufacture near Mumbai and supply ready stock of popular sizes from the same location, subject to availability.
Do you export Super Duplex Welded 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.