Duplex Steel Seamless Tubes Manufacturer & Stockist in India (Since 1984)

Trusted Global Manufacturer & Stockist of Duplex Steel Seamless Tubes

Kamal Steels is a leading Duplex Steel Seamless Tube Manufacturer and Stockist in India, supplying high-performance Duplex Stainless Steel Seamless Tubes for demanding industrial applications worldwide. We manufacture and stock Duplex Steel Seamless Tubes in grades UNS S31803, UNS S32205 and Super Duplex UNS S32750 according to ASTM A789 and ASME SA789 specifications.

Our Duplex Steel Seamless Tubes are widely used in heat exchangers, condensers, instrumentation systems, hydraulic lines, chemical processing plants, offshore platforms, marine applications and power generation facilities due to their excellent corrosion resistance, high strength and long service life.

As a trusted Duplex Steel Seamless Tube Manufacturer and Stockist, we maintain ready inventory in multiple sizes, wall thicknesses and lengths for immediate dispatch across India and international markets.

Get Quote / Best Price for Duplex Steel Seamless Tubes

  • Instant Quotation Support (Fast Response)
  • WhatsApp Inquiry Available
  • UNS S31803, S32205 & S32750 Seamless Tubes in Stock
  • Bulk Order & Project Pricing
  • Mill Test Certificate (MTC) Available
  • Third Party Inspection (TPI) Support
  • ASTM A789 Compliance
  • Export Documentation Support
  • Ready Stock Dispatch Worldwide
  • Custom Length Cutting Available
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duplex-steel-welded-pipes-tubes

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 Seamless Tube Price in India

Kamal Steels offers competitive Duplex Steel Seamless Tube Price solutions for domestic and international customers. We supply Duplex and Super Duplex Seamless Tubes in various grades, sizes, wall thicknesses and specifications at industry-leading prices with ready stock availability.

Looking for the latest Duplex Tube Price Per Kg or Duplex Steel Seamless Tube quotation? Our sales team provides customized pricing based on tube dimensions, quantity, grade, testing requirements and delivery destination.

Factors Affecting Duplex Steel Seamless Tube Price

  • Duplex Grade (UNS S31803, UNS S32205, S32750, S32760)
  • Tube Size & Outside Diameter (OD)
  • Wall Thickness
  • Length Requirements
  • Order Quantity
  • Testing & Inspection Requirements
  • Surface Finish Requirements
  • Raw Material Market Rates
  • Export Packaging Requirements
  • Delivery Location

Duplex Steel Seamless Tube Price Information

  • Duplex Steel Tube Price
  • Duplex Tube Price Per Kg
  • UNS S31803 Seamless Tube Price
  • UNS S32205 Seamless Tube Price
  • Super Duplex S32750 Tube Price
  • ASTM A789 Duplex Seamless Tube Price

For the latest Duplex Steel Seamless Tube Price in India, contact Kamal Steels today. We offer instant quotations, project pricing, bulk order discounts, Mill Test Certificates (MTC), and worldwide delivery support.

Duplex Steel Seamless Tubes Size Chart & Dimensions

duplex-steel-seamless-tube-size-chart

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 vs Stainless Steel Comparison

Duplex Steel and conventional Stainless Steel are widely used in industrial applications, but Duplex Steel offers higher strength and improved resistance to corrosion in aggressive environments. The following comparison highlights the key differences between Duplex Steel and standard Stainless Steel grades such as 304 and 316.

Property Duplex Steel Stainless Steel (304/316)
Microstructure Combination of Austenitic and Ferritic Structure Mainly Austenitic Structure
Strength Approximately Twice the Yield Strength of Stainless Steel Moderate Strength
Corrosion Resistance Excellent Resistance to Pitting and Crevice Corrosion Good Corrosion Resistance
Chloride Stress Corrosion Cracking Excellent Resistance Lower Resistance
Pressure Handling Capability Higher Pressure Capacity Moderate Pressure Capacity
Seawater Applications Highly Suitable Limited Suitability
Service Life Longer Service Life in Corrosive Environments Good Service Life
Maintenance Requirements Lower Maintenance Moderate Maintenance
Cost Higher Initial Cost but Better Long-Term Value Lower Initial Cost
Common Applications Oil & Gas, Offshore, Marine, Chemical Processing, Desalination Food Processing, Pharmaceutical, General Industrial Applications

Due to their superior mechanical strength and corrosion resistance, Duplex Steel Seamless Tubes are often selected for critical applications where conventional stainless steel may not provide adequate performance. Industries such as offshore, petrochemical, marine and desalination commonly prefer Duplex Steel for enhanced reliability and longer service life.

Why Choose Seamless Tubes Instead of Welded Tubes?

Both seamless and welded tubes are widely used across industrial applications. However, Duplex Steel Seamless Tubes are often preferred for critical services due to their superior strength, uniform structure and ability to withstand high pressure and demanding operating conditions. Since seamless tubes are manufactured without a welded joint, they provide enhanced reliability and performance in corrosive and high-stress environments.

Feature Duplex Steel Seamless Tubes Duplex Steel Welded Tubes
Manufacturing Method Produced from solid billets without any weld seam Manufactured by welding formed steel strips or plates
Structural Integrity Uniform structure throughout the tube Contains a welded joint
Pressure Resistance Excellent for high-pressure applications Suitable for moderate pressure applications
Corrosion Resistance Consistent corrosion resistance across the entire tube Weld area may require additional inspection
Mechanical Strength Higher overall strength and durability Good strength for general applications
Leakage Risk Very low due to absence of weld seam Slightly higher at the weld area
Service Life Long service life in demanding environments Good service life in standard conditions
Best Applications Oil & Gas, Offshore, Marine, Petrochemical, Heat Exchangers Water Systems, Structural Applications, General Industrial Use
Cost Higher initial cost More economical option

Duplex Steel Seamless Tubes are commonly selected for critical applications where high pressure, corrosive media and long-term reliability are important. Their seamless construction eliminates weld-related concerns and provides superior performance in offshore, chemical processing, marine and petrochemical industries.

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 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.

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

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

A Duplex Steel Seamless Tube is a high-strength stainless steel tube manufactured without a welded seam. It combines the properties of austenitic and ferritic stainless steels, offering excellent corrosion resistance, superior mechanical strength and outstanding resistance to chloride stress corrosion cracking.

Duplex Steel Seamless Tubes such as UNS S31803 and UNS S32205 provide excellent strength and corrosion resistance, while Super Duplex grades such as UNS S32750 and UNS S32760 offer even higher resistance to pitting, crevice corrosion and seawater environments.

Duplex Steel Seamless Tubes are manufactured without a weld seam, which improves structural integrity and pressure-handling capability. The seamless construction reduces the risk of weld-related defects and corrosion.

Common grades include UNS S31803, UNS S32205, UNS S32750 and UNS S32760. These grades provide different levels of corrosion resistance and mechanical performance for various industrial applications.

Duplex Steel Seamless Tubes are widely used in oil and gas, petrochemical, chemical processing, offshore, marine, desalination, power generation and heat exchanger applications.

Yes, Duplex Steel Seamless Tubes offer excellent resistance to chloride-induced corrosion and are commonly used in seawater, marine and desalination environments. Super Duplex grades are especially suitable for these applications.

Duplex Steel Seamless Tubes are typically manufactured according to ASTM A789, ASME SA789 and other applicable international standards to ensure quality and performance.

Testing may include hydrostatic testing, ultrasonic testing, PMI testing, eddy current testing, flattening tests, flaring tests and visual inspections to verify product quality.

Duplex Steel Seamless Tubes provide higher strength and better resistance to pitting, crevice corrosion and stress corrosion cracking than 316 stainless steel tubes, making them suitable for more demanding environments.

You can request a quote by sharing your required grade, size, wall thickness, quantity and application details. Kamal Steels offers competitive pricing, ready stock availability and worldwide delivery support.

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