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Girgaon, Mumbai - 400004
Duplex Steel Welded Tubes Manufacturer in India
Trusted Global Manufacturer & Stockist of Duplex Steel Welded Tubes
Kamal Steels is a leading Duplex Steel Welded Tube Manufacturer and Stockist in India, supplying high-quality welded tubes for industrial applications worldwide. We offer Duplex Steel Welded Tubes in grades UNS S31803, UNS S32205 and Super Duplex UNS S32750 in accordance with ASTM A789, ASTM A790, ASTM A928 and ASME SA789 specifications.
Our Duplex Steel Welded Tubes are produced from premium duplex stainless steel coils and strips using advanced welding technology to deliver excellent strength, dimensional accuracy and corrosion resistance. These tubes are widely used in heat exchangers, condensers, offshore platforms, oil and gas processing, petrochemical plants, marine applications, chemical processing, desalination, pharmaceutical equipment and power generation systems.
As a trusted Duplex Steel Welded Tube manufacturer and stockist, we maintain ready inventory in multiple diameters, wall thicknesses and lengths for fast delivery across India and international markets. Our welded tubes offer strong resistance to chloride stress corrosion cracking, pitting and harsh operating conditions while remaining a cost-effective tubing solution.
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Certifications & Compliance
- ISO 9001:2015 Certified
- ISO 14001 Certified
- ISO 45001 Certified
- PED Approved Materials
- MSME Registered Company
- IEC Export Certification
- GST Registered Business
Duplex Steel Welded Tube Specifications
| Product Name | Duplex Steel Welded Tubes |
|---|---|
| Brand | Kamal Steels |
| Material | Duplex Steel |
| Type | Welded Tube |
| Grades | UNS S31803, UNS S32205, UNS S32750, UNS S32760 |
| Outer Diameter | 6 mm to 219 mm |
| Wall Thickness | 0.5 mm to 12 mm |
| Length | Single Random, Double Random, Cut Length |
| Tube End | Plain End, Beveled End |
| Surface Finish | Annealed, Pickled, Polished, Bright Annealed |
| Standards | ASTM A789, ASTM A790, ASME SA789 |
| Tube Shapes | Round, Square, Rectangular |
Duplex Steel Welded Tube Size Chart & Dimensions
Available Grades of Duplex Steel Welded Tubes
Kamal Steels manufactures the following grades of Duplex Steel Welded Tube:
Duplex Steel Welded Tube vs Stainless Steel Welded Tube
Duplex Steel Welded Tubes and Stainless Steel Welded Tubes are widely used across industrial applications. However, Duplex Steel Welded Tubes provide significantly higher strength and improved corrosion resistance, making them suitable for aggressive and high-pressure environments.
| Property | Duplex Steel Welded Tubes | Stainless Steel Welded Tubes (304/316) |
|---|---|---|
| Strength | Higher Yield & Tensile Strength | Moderate Strength |
| Corrosion Resistance | Excellent | Good |
| Chloride Resistance | Excellent | Moderate |
| Pitting Resistance | Superior | Standard |
| Stress Corrosion Cracking Resistance | Excellent | Lower |
| Service Life | Longer in Corrosive Conditions | Moderate |
| Seawater Applications | Highly Suitable | Limited |
| Cost | Higher Initial Cost | Lower Initial Cost |
Duplex Steel Welded Tubes are preferred in offshore, marine, petrochemical, desalination and chemical processing industries where superior corrosion resistance and high mechanical strength are required.
Why Duplex Steel Welded Tubes Are a Better
Duplex Steel Welded Tubes are widely used in industrial applications because they offer excellent dimensional accuracy, cost-effectiveness and reliable performance. Modern welding technologies ensure strong weld integrity and consistent quality suitable for a wide range of engineering applications.
| Feature | Duplex Steel Welded Tubes | Duplex Steel Seamless Tubes |
|---|---|---|
| Manufacturing Process | Formed and Welded from Steel Strips | Manufactured from Solid Billets |
| Dimensional Accuracy | Excellent | Good |
| Availability | Wide Range of Sizes | Limited in Some Sizes |
| Cost | More Economical | Higher Cost |
| Surface Finish | Smoother & Uniform | Good |
| Production Time | Faster | Longer |
| Custom Length Availability | Easy to Manufacture | Limited |
| Best Applications | Heat Exchangers, Condensers, Structural & Process Tubing | High Pressure & Critical Service Applications |
Duplex Steel Welded Tubes provide an excellent balance of performance, corrosion resistance and cost efficiency, making them a preferred choice for heat exchangers, process tubing, instrumentation systems, marine applications and industrial fabrication projects.
Duplex Steel Welded Tube Manufacturing Process
Understanding the Duplex Steel Welded Tube Manufacturing Process
Duplex steel welded tubes are manufactured using high-quality duplex stainless steel coils or plates through advanced forming and welding processes. These tubes offer excellent corrosion resistance, high strength and superior dimensional accuracy for industrial applications.
| Step 1 |
Raw Material Selection High-quality duplex stainless steel coils or plates are selected according to ASTM standards, required grade, size and application requirements. |
|---|---|
| Step 2 |
Strip Uncoiling & Slitting The duplex steel coils are uncoiled and slit into the required strip width based on the specified tube dimensions. |
| Step 3 |
Tube Forming The strip passes through multiple forming rolls that gradually shape the material into a tubular form. |
| Step 4 |
Welding Process (HF/ERW) The formed strip edges are welded using High Frequency (HF) or Electric Resistance Welding (ERW) technology to create a strong and uniform weld seam. |
| Step 5 |
Sizing & Calibration The welded tube is passed through sizing rolls to achieve accurate diameter, wall thickness and dimensional consistency. |
| Step 6 |
Heat Treatment Tubes undergo solution annealing and rapid cooling to improve mechanical properties, corrosion resistance and weld integrity. |
| Step 7 |
Pickling & Surface Cleaning The tube surface is pickled to remove oxide scale, welding discoloration and impurities, ensuring a clean and smooth finish. |
| Step 8 |
Straightening & Cutting Tubes are straightened using precision machines and cut into required lengths according to customer specifications. |
| Step 9 |
Testing & Inspection Each welded tube undergoes hydrostatic testing, eddy current testing, ultrasonic testing, PMI testing, dimensional inspection and visual examination to ensure quality compliance. |
| Step 10 |
Marking, Packing & Dispatch Finished tubes are marked with grade, size and heat number, then securely packed in bundles or export packaging for safe transportation and dispatch. |
Chemical Composition of Duplex Steel Welded Tubes
The chemical composition of duplex steel welded tube grades plays an important role in corrosion resistance, mechanical strength and long-term industrial performance. Duplex grades provide superior resistance against chloride stress corrosion cracking, pitting and crevice corrosion.
| Grade | Cr % | Ni % | Mo % | N % |
|---|---|---|---|---|
| UNS S31803 | 21.0–23.0 | 4.5–6.5 | 2.5–3.5 | 0.08–0.20 |
| UNS S32205 | 22.0–23.0 | 4.5–6.5 | 3.0–3.5 | 0.14–0.20 |
| UNS S32750 | 24.0–26.0 | 6.0–8.0 | 3.0–5.0 | 0.24–0.32 |
Duplex Steel Welded Tube Standards
| ASTM Standards | ASME Standards |
|---|---|
| ASTM A789 | ASME SA789 |
| ASTM A790 | ASME SA790 |
Mechanical Properties of Duplex Steel Welded Tubes
Tensile Strength
Tensile strength indicates how much stress the welded tube can withstand before breaking. Duplex steel welded tubes provide reliable tensile performance for industrial, structural and heat exchanger applications.
Yield Strength
Yield strength shows the stress level at which the tube starts permanent deformation. Good yield strength ensures safe performance in pressure and load-bearing applications.
Elongation
Elongation reflects the ductility and forming capability of duplex steel welded tubes. Higher elongation allows easier fabrication, bending and installation.
| Grade | Tensile Strength (MPa, min) | Yield Strength (MPa, min) | Elongation (% min) |
|---|---|---|---|
| UNS S31803 | 620 | 450 | 25% |
| UNS S32205 | 655 | 450 | 25% |
| UNS S32750 | 800 | 550 | 15% |
Features of Duplex Steel Welded Tubes
- Excellent Corrosion Resistance: Duplex steel welded tubes provide excellent resistance against corrosion, pitting and chloride stress corrosion cracking, making them suitable for aggressive industrial and marine environments.
- High Strength: These tubes offer higher mechanical strength compared to standard stainless steel tubes, allowing them to perform efficiently under high pressure and heavy-duty applications.
- Superior Durability: Manufactured using high-quality duplex steel material and advanced welding technology, these tubes ensure long service life and reliable industrial performance.
- Good Weldability: Duplex steel welded tubes support easy fabrication and welding for industrial tubing systems and structural applications.
- Excellent Pitting Resistance: The higher chromium and molybdenum content improves resistance against pitting and crevice corrosion in chloride-rich environments.
- High Pressure Handling Capability: Duplex steel welded tubes are designed to handle high internal pressure and heavy-duty industrial operations.
- Smooth Surface Finish: Smooth internal and external surfaces improve flow efficiency and reduce contamination, scaling and pressure loss.
- Accurate Dimensions: Precision manufacturing ensures uniform wall thickness and dimensional accuracy for reliable installation and performance.
- Low Maintenance Requirements: Due to their superior corrosion resistance and strength, duplex steel welded tubes require minimal maintenance during service.
Applications of Duplex Steel Welded Tubes
Duplex steel welded tubes are widely used in industrial applications where corrosion resistance, high strength and pressure handling capability are required.
Oil & Gas Industry
Used for transporting oil, gas and high-pressure fluids in offshore and onshore operations with reliable performance.
Petrochemical Industry
Widely used in petrochemical plants for handling corrosive chemicals and high-temperature processing systems.
Chemical Processing Plants
Suitable for industrial chemical processing applications requiring strong corrosion resistance and durability.
Power Generation Plants
Used in thermal and power generation systems for steam handling and high-temperature tubing applications.
Heat Exchangers
Preferred for heat exchanger systems because of their smooth finish and temperature resistance properties.
Boilers
These tubes are suitable for boiler systems operating under high pressure and demanding temperature conditions.
Water Treatment Plants
Used in desalination and water treatment systems because of their corrosion-resistant and hygienic properties.
Pharmaceutical Industry
Ideal for pharmaceutical applications requiring clean, contamination-free and durable tubing systems.
Food Processing Industry
Widely used in food and beverage industries due to hygienic surfaces and corrosion resistance performance.
Marine Industry
Marine environments require corrosion-resistant tubing systems capable of handling seawater exposure efficiently.
Construction Industry
Used in industrial and structural construction projects because of their strength and long service life.
Industries We Serve
Kamal Steels supplies duplex steel welded tubes to various industries worldwide for high-pressure and corrosion-resistant applications.
Refineries
Our duplex steel welded tubes are widely used in refinery applications for transporting high-pressure fluids and chemicals safely.
Fertilizer Plants
Fertilizer industries require corrosion-resistant tubing systems for chemical processing and industrial operations.
Cement Plants
These welded tubes are suitable for demanding cement manufacturing and material handling systems.
Engineering Industry
Engineering sectors use duplex steel welded tubes for fabrication and industrial tubing systems.
Offshore Industry
Offshore applications require durable and corrosion-resistant tubing solutions for marine environments.
Automobile Industry
Automobile industries use welded tubes in exhaust systems and industrial fluid transportation applications.
Packaging, Testing & Inspection
Packaging
- Wooden Boxes: Duplex steel welded tubes are packed securely in wooden boxes to prevent damage during transportation and export handling.
- Bundles Packing: Tubes are bundled properly for easy loading, unloading and safe storage during shipment.
- Plastic End Caps: Plastic caps are provided on tube ends to protect against dust, moisture and external damage.
- Export Standard Packaging: All products are packed according to international export standards for safe worldwide delivery.
- Bubble Wrap Protection: Bubble wrapping provides additional surface protection during transportation and material handling.
Testing & Inspection
- Hydrostatic Testing: Ensures the tube can withstand high internal pressure without leakage or failure.
- Eddy Current Testing: Detects weld seam and surface defects to ensure the structural integrity of duplex steel welded tubes.
- PMI Testing: Positive Material Identification verifies the chemical composition and material grade accuracy.
- Flattening Test: Checks tube flexibility and resistance to cracking under deformation conditions.
- Flaring Test: Evaluates tube expansion capability and forming performance for fabrication applications.
- Intergranular Corrosion Test: Confirms corrosion resistance performance in aggressive industrial environments.
- Third Party Inspection: Independent inspection agencies verify quality, dimensions and testing compliance.
Frequently Asked Questions
A Duplex Steel Welded Tube is manufactured by forming duplex stainless steel strips or coils into a tubular shape and welding the seam using advanced welding processes. These tubes offer high strength, excellent corrosion resistance and long service life in demanding industrial environments.
Duplex Steel Welded Tubes are commonly available in UNS S31803, UNS S32205, UNS S32750 and UNS S32760 grades. These grades provide excellent corrosion resistance and mechanical strength for various industrial applications.
Duplex Steel Welded Tubes provide higher strength and better resistance to pitting, crevice corrosion and chloride stress corrosion cracking compared to conventional stainless steel welded tubes such as 304 and 316 grades.
Duplex Steel Welded Tubes offer excellent dimensional accuracy, smooth surface finish, wider size availability and cost-effectiveness. Modern welding technology ensures strong weld integrity and reliable performance for most industrial applications.
Duplex Steel Welded Tubes are widely used in oil & gas, petrochemical, marine, offshore, desalination, heat exchangers, condensers, chemical processing, pharmaceutical and water treatment industries.
Yes, Duplex Steel Welded Tubes offer excellent resistance to chloride-induced corrosion, pitting and crevice corrosion, making them ideal for seawater handling systems, offshore structures and desalination plants.
Duplex Steel Welded Tubes are manufactured according to ASTM A789, ASTM A790, ASTM A928, ASME SA789 and ASME SA790 standards to ensure quality, dimensional accuracy and reliable performance.
Duplex Steel Welded Tubes undergo hydrostatic testing, ultrasonic testing, eddy current testing, PMI testing, flattening tests, flaring tests and visual inspections to verify quality and compliance with international standards.
Yes, Kamal Steels supplies Super Duplex Steel Welded Tubes in UNS S32750 and UNS S32760 grades for offshore, marine, desalination and highly corrosive industrial applications.
You can request a quote by providing details such as grade, outside diameter, wall thickness, length, quantity and application requirements. Our team will provide pricing, stock availability and delivery information based on your project needs.