Duplex Steel Seamless Pipes Manufacturer in India

Trusted Global Manufacturer & Stockist of Duplex Steel Seamless Pipes

Kamal Steels is a trusted Manufacturer and Stockist of Duplex Steel Seamless Pipes in India, supplying high-performance Duplex Stainless Steel Seamless Pipes for demanding industrial applications worldwide. We manufacture and stock Duplex Steel Seamless Pipes in grades UNS S31803, UNS S32205 and Super Duplex UNS S32750 according to ASTM A790, ASTM A928 and ASME SA790 specifications.

Our Duplex Steel Pipes are widely used in offshore platforms, oil & gas projects, petrochemical plants, marine systems, desalination plants and power generation facilities due to their excellent corrosion resistance, high strength and long service life.

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

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Duplex Steel Seamless Pipes

Certifications & Compliance

Kamal Steels adheres to internationally recognized quality standards and industry regulations, ensuring reliable manufacturing, consistent product quality, and compliance with global export requirements.

  • ISO 9001:2015 Certified
  • ISO 14001 Certified
  • ISO 45001 Certified
  • PED Approved Materials
  • MSME Registered Company
  • IEC Export Certification
  • GST Registered Business
  • EN 10204 3.1 Material Test Certificate

Duplex Steel Seamless Pipe Specifications

Product Name Duplex Steel Seamless Pipes
Brand Kamal Steels
Material Duplex Steel
Type Seamless Pipe
Grades UNS S31803, S32205, S32750
Outer Diameter 6 mm to 610 mm
Wall Thickness 1 mm to 40 mm
Length Single Random, Double Random, Cut Length
Pipe End Plain End, Beveled End, Threaded End
Surface Finish Annealed, Pickled, Polished
Standards ASTM A790, ASTM A928, ASME SA790
Pipe Schedules SCH 10 to SCH XXS

Duplex Steel Seamless Pipe Size Chart & Dimensions

duplex-steel-seamless-pipe-pipe-size-chart

Available Grades of Duplex Steel Seamless Pipes

Kamal Steels manufactures the following grades of Duplex Steel Seamless Pipes:

Duplex Steel Seamless Pipe Manufacturing Process

duplex-steel-seamless-pipe-manufacturing-process

Understanding the Duplex Steel Seamless Pipe Manufacturing Process

Duplex Steel Seamless Pipes manufactured according to ASTM A790 specifications are produced using high-quality UNS S31803, UNS S32205 and Super Duplex UNS S32750 billets through a hot extrusion and rotary piercing process.

Step 1 Raw Material Selection
High-quality duplex stainless steel billets are selected as per ASTM standards and customer requirements.
Step 2 Heating Process
The billet is heated at high temperature in a furnace to achieve uniformity and make the material soft and workable.
Step 3 Piercing Process
The heated billet is pierced using a rotary piercing mill to create a hollow shell.
Step 4 Elongation & Rolling
The hollow shell is elongated and rolled through mandrel mills to achieve the required diameter and wall thickness.
Step 5 Heat Treatment
The pipes undergo heat treatment such as solution annealing to improve mechanical properties, strength and corrosion resistance.
Step 6 Sizing & Straightening
The pipes are sized accurately and straightened using precision machines to maintain dimensional accuracy and smooth finish.
Step 7 Testing & Inspection
Each seamless pipe is tested through hydrostatic testing, ultrasonic testing, PMI testing, flattening tests, and visual inspection to ensure international quality standards.
Step 8 Finishing & Packaging
The finished pipes are cleaned, marked, polished (if required) and packed securely in bundles or wooden boxes for safe delivery.

Chemical Composition of Duplex Steel Seamless Pipe

The chemical composition of Duplex Steel grades plays a major role in corrosion resistance, mechanical strength and resistance to chloride stress corrosion cracking. Grades UNS S31803, UNS S32205 and Super Duplex UNS S32750 are widely used in offshore, marine, petrochemical and chemical processing industries.

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

Mechanical Properties of Duplex Steel Seamless Pipes

Tensile Strength

Tensile strength indicates how much stress the Duplex Steel Seamless Pipe can withstand before breaking. Duplex Steel Seamless Pipes provide reliable tensile performance for structural and industrial piping applications.

Yield Strength

Yield strength shows the stress level at which the pipe 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 Pipes. 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%
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Duplex Steel Pipe vs Stainless Steel Pipe

The difference between Duplex Steel Pipes and conventional Stainless Steel Pipes primarily lies in strength, corrosion resistance and suitability for aggressive industrial environments. Duplex grades combine ferritic and austenitic structures, providing enhanced mechanical and corrosion-resistant properties.

Property Duplex Steel Pipe Stainless Steel Pipe
Strength Higher Moderate
Corrosion Resistance Excellent Good
Chloride Resistance Excellent Moderate
Stress Corrosion Cracking Resistance Excellent Lower
Pressure Handling Capability Higher Standard
Marine Applications Highly Suitable Limited
Service Life Longer Standard
Cost Higher Initial Cost Lower Initial Cost

Custom sizes, wall thicknesses and cut lengths can be supplied based on project specifications and application requirements.

Features of Duplex Steel Seamless Pipes

  • Excellent Corrosion Resistance: Duplex steel seamless pipes offer excellent resistance against chloride stress corrosion, rust, chemicals and moisture, making them ideal for marine and aggressive industrial environments.
  • High Temperature Strength: These pipes provide significantly higher strength compared to standard duplex steel, allowing them to perform efficiently under high pressure and heavy load conditions.
  • Superior Durability: Manufactured without welding joints, duplex seamless pipes ensure excellent mechanical strength, toughness and long service life.
  • Leak-Proof Construction: The seamless structure reduces leakage risks and ensures reliable performance in critical fluid and gas transportation systems.
  • Smooth Surface Finish: Smooth internal and external surfaces improve flow efficiency and reduce scaling, friction and contamination.
  • High Pressure Handling Capability: Designed to withstand high internal pressure, making them suitable for demanding industrial operations.
  • Accurate Dimensions: Precision manufacturing ensures uniform wall thickness, tight tolerances and easy installation.
  • Easy Fabrication and Welding: Duplex steel seamless pipes can be easily cut, bent, fabricated and welded as per project requirements.
  • Long Service Life: Excellent resistance to corrosion and wear ensures long-term performance even in harsh environments.
  • Low Maintenance Requirements: Requires minimal maintenance due to strong corrosion resistance and structural stability.

Duplex Steel Pipe Testing Methods

All Duplex Steel Seamless Pipes supplied by Kamal Steels undergo strict quality control procedures and testing methods to ensure compliance with ASTM, ASME and international quality standards.

Testing Method Purpose
Hydrostatic Testing Verifies pressure handling capability and leak resistance
Ultrasonic Testing (UT) Detects internal defects and discontinuities
PMI Testing Confirms chemical composition and material grade
Flattening Test Checks ductility and resistance to cracking
Flaring Test Evaluates expansion and forming capability
Intergranular Corrosion Test Verifies corrosion resistance performance
Visual Inspection Checks dimensions, finish and workmanship
Third Party Inspection (TPI) Independent verification of product quality

Mill Test Certificates (MTC) as per EN 10204 3.1 and Third-Party Inspection reports can be provided upon request with every supply.

Applications of Duplex Steel Seamless Pipes

Duplex steel seamless pipes are widely used in industries where high strength, corrosion resistance and pressure handling capability are required.

Oil & Gas Industry

Used for offshore and onshore pipelines, transporting oil, gas and high-pressure fluids safely and efficiently.

Petrochemical Industry

Ideal for handling aggressive chemicals and high-temperature processing systems.

Chemical Processing Plants

Used in chemical industries requiring strong corrosion resistance and durability.

Power Generation Plants

Suitable for steam lines, heat transfer systems and high-pressure applications.

Heat Exchangers

Preferred for efficient heat transfer due to excellent thermal and corrosion resistance properties.

Boilers

Used in high-pressure boiler systems operating under extreme temperature conditions.

Water Treatment Plants

Ideal for desalination and water treatment systems due to corrosion resistance and hygiene.

Pharmaceutical Industry

Used in clean and contamination-free piping systems for critical applications.

Food Processing Industry

Suitable for hygienic processing environments requiring clean surfaces and durability.

Marine Industry

Highly resistant to seawater corrosion, making them ideal for shipbuilding and offshore structures.

Construction Industry

Used in structural and industrial piping applications for strength and durability.

Industries We Serve

Kamal Steels supplies duplex steel seamless pipes & tubes to various industries worldwide for high-pressure and corrosion-resistant applications.

Refineries

Used for safe transportation of oil, gas and chemical fluids under extreme conditions.

Fertilizer Plants

Suitable for handling corrosive chemicals and industrial processing systems.

Cement Plants

Used in heavy-duty industrial and material handling systems.

Engineering Industry

Widely used for fabrication and mechanical engineering applications.

Offshore Industry

Ideal for marine and offshore structures exposed to seawater environments.

Automobile Industry

Used in exhaust systems and fluid handling applications.


Packaging, Testing & Inspection

Packaging

  • Wooden Boxes: Duplex Steel Seamless Pipes are packed securely in wooden boxes to prevent damage during transportation and export handling.
  • Bundles Packing: Pipes are bundled properly for easy loading, unloading and safe storage during shipment.
  • Plastic End Caps: Plastic caps are provided on pipe 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 pipes withstand high pressure without leakage or failure.
  • Ultrasonic Testing: Detects internal defects and ensures structural integrity.
  • PMI Testing: Confirms correct chemical composition and material grade.
  • Flattening Test: Checks ductility and resistance to cracking under stress.
  • Flaring Test: Evaluates pipe expansion and forming ability.
  • Intergranular Corrosion Test: Ensures resistance in aggressive industrial environments.
  • Third Party Inspection: Independent agencies verify quality, dimensions and compliance standards.

Frequently Asked Questions

Duplex Steel Seamless Pipes are manufactured without welded joints using duplex stainless steel grades. These pipes provide excellent corrosion resistance, high mechanical strength and superior durability for demanding industrial applications.

Duplex Steel Seamless Pipes are widely used in oil & gas, offshore platforms, petrochemical plants, marine systems, desalination plants, chemical processing facilities and power generation projects.

We supply Duplex Steel Seamless Pipes in grades UNS S31803, UNS S32205 and Super Duplex UNS S32750 according to ASTM and ASME specifications.

ASTM A790 is the standard specification covering seamless and welded ferritic/austenitic stainless steel pipes, commonly known as Duplex Stainless Steel Pipes, for general corrosion-resistant and high-temperature service applications.

UNS S31803 is a Duplex Stainless Steel grade offering excellent strength, corrosion resistance and resistance to chloride stress corrosion cracking. It is widely used in chemical, marine and offshore applications.

UNS S32205 is an enhanced Duplex Stainless Steel grade with improved corrosion resistance and mechanical properties. It is one of the most commonly used Duplex Pipe grades worldwide.

Super Duplex Pipes contain higher chromium, molybdenum and nitrogen content than standard Duplex Pipes, providing greater strength and improved resistance to pitting, crevice corrosion and chloride attack.

Duplex Steel Seamless Pipes are available in sizes ranging from 6 mm to 610 mm outer diameter with multiple wall thicknesses and schedules including SCH 10, SCH 40, SCH 80 and SCH XXS.

Duplex Steel Seamless Pipe Price depends on grade, size, schedule, quantity, testing requirements and delivery location. Contact Kamal Steels for the latest Duplex Pipe Price and stock availability.

Yes, all Duplex Steel Seamless Pipes can be supplied with Mill Test Certificates (MTC) as per EN 10204 3.1 and Third-Party Inspection (TPI) reports from approved inspection agencies upon request.

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