Duplex Steel Seamless Tubes Manufacturer in India

Duplex Steel Seamless Tube Manufacturer in India

Kamal Steels is a leading Duplex Steel Seamless Tube Manufacturer, Supplier and Exporter in India, supplying high-quality duplex steel seamless tubes for industrial, commercial and engineering applications. Established in 1984, we have decades of experience in stocking, supplying and exporting duplex steel seamless tubing solutions to customers across domestic and international markets.

We maintain a large stock of duplex steel seamless tubes in various grades, sizes, wall thicknesses and specifications to suit diverse industrial applications. Our duplex seamless tubing products are widely used in oil & gas, petrochemical, chemical processing, power generation, marine, desalination, offshore and other demanding industries.

Our Duplex Steel Seamless Tubes are sourced from approved manufacturers and supplied with excellent corrosion resistance, high tensile strength, superior durability and long service life. All products are supplied according to international ASTM, ASME and ANSI standards with strict quality control and testing procedures.

As trusted duplex steel seamless tube suppliers and exporters in India, we provide seamless tubes with accurate dimensions, smooth surface finish and reliable performance for high-pressure and aggressive corrosive applications. Our commitment to product quality, ready stock availability, timely delivery, competitive pricing and customer satisfaction has made Kamal Steels a preferred choice in the duplex steel seamless tubing industry since 1984.

duplex-steel-welded-pipes-tubes

Why Duplex Steel Seamless Tubes?

Duplex Steel Seamless Tubes are known for their high strength, excellent corrosion resistance and superior resistance to chloride stress corrosion cracking. These tubes combine the properties of ferritic and austenitic stainless steels, making them suitable for aggressive industrial environments.

Duplex Steel Seamless Tubes are widely used in applications requiring high mechanical strength, pressure handling capability and resistance against pitting and crevice corrosion. These tubes are commonly used in offshore, marine, chemical processing, heat exchanger and oil & gas industries where reliable performance is critical.

Why Choose Kamal Steels?

  • Manufacturer & Stockist Since 1984
  • Large Ready Stock Available
  • ASTM & ASME Standard Tubes
  • Third Party Inspection
  • Mill Test Certificates Provided
  • PAN India & Export Supply
  • Competitive Prices
  • Fast Delivery Support
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Duplex Steel Seamless Tube Specifications

Product Name Duplex Steel Seamless Tubes
Brand Kamal Steels
Material Duplex Steel
Type Seamless Tube
Grades UNS S31803, S32205, S32750, S32760
Outer Diameter 6 mm to 219 mm
Wall Thickness 0.5 mm to 20 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 Thickness 0.5 mm to 20 mm

Available Grades of Duplex Steel Seamless Tubes

Kamal Steels manufactures the following grades of duplex steel seamless tube:

Duplex Steel Seamless Tube Manufacturing Process

duplex-steel-seamless-tube-manufaturing-process

Understanding the Duplex Steel Seamless Tube Manufacturing Process

Duplex steel seamless tubes are manufactured using premium quality duplex stainless steel billets through a hot extrusion and rotary piercing process. Since seamless tubes are produced without any welded joint, they offer excellent strength, superior corrosion resistance, high pressure handling capability and long service life for critical industrial applications.

Step 1 Raw Material Selection
High quality duplex steel billets such as UNS S31803, S32205 and S32750 are selected according to ASTM standards and application requirements.
Step 2 Billet Heating
The duplex steel billet is heated uniformly in a rotary hearth or walking beam furnace to achieve the required forming temperature.
Step 3 Piercing Process
The heated billet is pierced using a rotary piercing mill and mandrel to create a hollow shell.
Step 4 Elongation & Rolling
The hollow shell is elongated and rolled through mandrel mills to obtain the required tube diameter and wall thickness.
Step 5 Sizing Process
The tube passes through sizing mills for accurate outside diameter, wall thickness and dimensional consistency.
Step 6 Heat Treatment
Tubes undergo solution annealing and rapid water quenching to improve mechanical strength, toughness and corrosion resistance.
Step 7 Pickling & Straightening
Tubes are pickled to remove oxide scale and then straightened using precision equipment for smooth finish and dimensional accuracy.
Step 8 Cutting Process
The seamless tubes are cut into required lengths as per customer specifications and industry standards.
Step 9 Testing & Inspection
Tubes are tested through hydrostatic testing, ultrasonic testing, PMI testing, eddy current testing and visual inspection to ensure quality compliance.
Step 10 Marking & Packaging
Finished duplex steel seamless tubes are marked with grade, size and heat number, then packed securely in bundles or wooden boxes for safe dispatch.

Chemical Composition of Duplex Steel Seamless Tubes

The chemical composition of Duplex Steel Seamless Tubes plays an important role in corrosion resistance, mechanical strength and long-term industrial performance. Duplex and Super Duplex grades are widely used for highly corrosive and high-pressure applications.

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
UNS S32760 24.0–26.0 6.0–8.0 3.0–4.0 0.20–0.30

Duplex Steel Seamless Tubes Size Chart & Dimensions

duplex-steel-seamless-tube-size-chart

Duplex Steel Seamless Tube Standards

ASTM Standards ASME Standards
ASTM A789 ASME SA789
ASTM A790 ASME SA790
ASTM A928 ASME SA928

Mechanical Properties of Duplex Steel Seamless Tubes

Tensile Strength

Tensile strength indicates how much stress the Duplex Steel Seamless Tube can withstand before breaking. Duplex Steel Seamless Tubes provide reliable tensile performance for industrial 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 Seamless Tubes. Higher elongation allows easier fabrication, bending and installation.

Grade Tensile Strength (MPa, min) Yield Strength (MPa, min) Elongation (%)
UNS S31803 620 450 25%
UNS S32205 655 450 25%
UNS S32750 800 550 15%
UNS S32760 750 550 25%
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Features of Duplex Steel Seamless Tubes

  • Excellent Corrosion Resistance: Duplex Steel Seamless Tubes offer excellent resistance against pitting, crevice corrosion and chloride stress corrosion cracking in aggressive industrial environments.
  • High Mechanical Strength: These tubes provide higher tensile and yield strength compared to standard stainless steel grades for demanding applications.
  • Superior Durability: Manufactured without welding joints, Duplex Steel Seamless Tubes offer superior durability and long service life.
  • Leak-Proof Construction: The seamless manufacturing process minimizes leakage risks and improves reliability in critical service applications.
  • Smooth Surface Finish: Smooth internal and external tube surfaces improve flow efficiency and reduce contamination during service.
  • High Pressure Handling Capability: Duplex Steel Seamless Tubes are suitable for high-pressure and heavy-duty industrial operations.
  • Accurate Dimensions: Precision manufacturing ensures consistent wall thickness and dimensional accuracy for reliable installation.
  • Excellent Heat Resistance: Duplex tubes maintain good mechanical properties under elevated temperature operating conditions.
  • Long Service Life: Duplex Steel Seamless Tubes provide dependable long-term performance in offshore and corrosive environments.
  • Low Maintenance Requirements: Due to their corrosion resistance and strength, these tubes require minimal maintenance during operation.

Applications of Duplex Steel Seamless Tubes

Duplex Steel Seamless Tubes are widely used in industrial applications where high strength, corrosion resistance 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 chemical processing applications requiring excellent corrosion resistance and durability.

Power Generation Plants

Used in thermal and power generation systems for steam handling and heat transfer applications.

Heat Exchangers

Preferred for heat exchanger systems because of their corrosion resistance and high strength properties.

Desalination Plants

Suitable for seawater desalination systems because of excellent chloride corrosion resistance.

Water Treatment Plants

Used in water treatment systems where corrosion-resistant and hygienic tubing solutions are required.

Pharmaceutical Industry

Ideal for pharmaceutical applications requiring clean, durable and contamination-free tubing systems.

Food Processing Industry

Widely used in food and beverage industries due to hygienic surface finish and corrosion resistance.

Marine Industry

Marine environments require corrosion-resistant tubing systems capable of handling seawater exposure.

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 Seamless Tubes to various industries worldwide for corrosion-resistant and high-pressure applications.

Refineries

Our Duplex Steel Seamless Tubes are widely used in refinery applications for handling corrosive fluids and high-pressure operations.

Fertilizer Plants

Fertilizer industries require corrosion-resistant tubing systems for chemical processing and industrial operations.

Cement Plants

These seamless tubes are suitable for demanding cement manufacturing and industrial handling systems.

Engineering Industry

Engineering sectors use Duplex Steel Seamless 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 seamless tubes in fluid transportation and industrial engineering applications.

Packaging, Testing & Inspection

Packaging

  • Wooden Boxes: Duplex Steel Seamless 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 handling.

Testing & Inspection

  • Hydrostatic Testing: Ensures the tube can withstand high internal pressure without leakage or failure.
  • Ultrasonic Testing: Detects internal defects and confirms structural integrity of Duplex Steel Seamless 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

Kamal Steels is a leading duplex steel seamless tube manufacturer in India supplying high-quality duplex stainless steel tubing for industrial and engineering applications.

A duplex steel seamless tube is manufactured without any welded seam and offers superior corrosion resistance, strength and pressure handling capability.

We supply Duplex 2205, Super Duplex 2507, UNS S31803 and UNS S32750 seamless tubes.

These tubes are widely used in offshore, marine, chemical processing, oil & gas and desalination industries.

Our duplex steel seamless tubes are manufactured according to ASTM A789, ASTM A790 and ASME standards.

We offer duplex seamless tubing in different diameters, wall thicknesses and custom specifications.

We perform hydro testing, ultrasonic testing, PMI testing and third-party inspections.

Duplex steel tubes provide higher strength and better chloride corrosion resistance compared to standard stainless steel grades.

Yes, we supply Super Duplex 2507 seamless tubes for highly corrosive and offshore applications.

You can request a quote by sharing your grade, tube size, quantity and application details with our sales team.

Speak to Our Sales Team