ASTM / ASME / ANSI Certified

Duplex Steel Flanges Manufacturers in India

Unicorn Metal Industries is a leading Duplex Steel Flanges Manufacturers in India, offering high-performance flange solutions designed for corrosive and high-pressure environments. Duplex Steel Flanges are widely preferred in industries where a combination of strength and corrosion resistance is critical for long-term performance.

Our range includes slip-on, weld neck, blind, socket weld, and threaded Duplex Steel Flanges manufactured as per ASTM, ASME, ANSI, and international standards. These Duplex Steel Flanges are part of our industrial flanges manufacturers range and are extensively used in offshore, marine, oil & gas, and chemical processing industries. We also offer custom Duplex Steel Flanges based on project specifications, ensuring reliability and precision.

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15–1200 NBSize Range

150#–2500#Pressure Rating

F51 / F60Core Grades

Duplex Steel Flanges Manufacturers in India

Overview

Duplex Steel Flanges Overview

Duplex Steel Flanges are specialized piping components used to connect pipes, valves, and equipment in aggressive and high-stress environments. Known for their dual-phase microstructure, Duplex Steel Flanges offer excellent strength along with superior resistance to corrosion, especially in chloride-rich conditions.

One of the key advantages of Duplex Steel Flanges is their ability to resist stress corrosion cracking while maintaining high mechanical strength. These Duplex Steel Flanges are suitable for high-pressure and high-temperature applications. At Unicorn Metal Industries, Duplex Steel Flanges are manufactured using advanced forging and machining processes to ensure consistent quality, similar to high-performance solutions such as Inconel flanges and Hastelloy flanges used in critical industries.

Datasheet

Duplex Steel Flanges Specifications

Full mill-standard specifications, material grades, chemical composition, and mechanical properties for our Duplex Steel Flanges range.

Duplex Steel Flanges — Specifications

SHEET 01

Specification	Details
Product	Duplex Steel Flanges
Size Range	15 NB to 1200 NB
Pressure Rating	150# to 2500#
Standards	ASTM A182 / ASME SA182
Flange Standards	ANSI B16.5, B16.47, MSS, API
Types	Slip-On, Weld Neck, Blind, Socket Weld, Threaded
Face Types	RF, FF, RTJ
Finish	2B, BA, Polished

Duplex Steel Flanges Material Grades

SHEET 02

Grade	Standard	Equivalent	Application
F44	ASTM / ASME SA182	S31254	Chemical processing
F45	ASTM / ASME SA182	–	Specialized use
F51	ASTM / ASME SA182	S31803	General industrial
F60	ASTM / ASME SA182	S32205	Oil & gas
F53	ASTM / ASME SA182	S32750	Offshore
F55	ASTM / ASME SA182	S32760	Marine
F61	ASTM / ASME SA182	–	High strength

Chemical Composition

SHEET 03

Element	Range
Chromium	22–25%
Nickel	4.5–6.5%
Molybdenum	3–3.5%
Nitrogen	0.1–0.3%

Mechanical Properties

SHEET 04

Property	Value	Unit
Tensile Strength	≥620	MPa
Yield Strength	≥450	MPa
Hardness	≤290	HB
Elongation	≥25	%

Product Types

Types of Duplex Steel Flanges We Manufacture

We manufacture a comprehensive range of Duplex Steel Flanges designed for superior strength, corrosion resistance, and long service life in demanding industrial environments.

TYPE / 01

Slip-On Duplex Steel Flanges

Designed for easy installation, these flanges are suitable for low to moderate pressure systems and provide flexibility in alignment.

TYPE / 02

Weld Neck Duplex Steel Flanges

Engineered for high-pressure and high-temperature applications, these flanges offer excellent strength through a strong welded connection and tapered hub.

TYPE / 03

Blind Duplex Steel Flanges

Used to seal pipe ends and isolate piping systems, ensuring leak-proof closure in critical applications.

TYPE / 04

Socket Weld Duplex Steel Flanges

Ideal for small-diameter pipelines, providing strong and reliable connections in high-pressure environments.

TYPE / 05

Threaded Duplex Steel Flanges

Suitable for applications where welding is not feasible, offering secure connections through threaded joints.

TYPE / 06

Lap Joint Duplex Steel Flanges

Designed for systems requiring frequent dismantling, offering flexibility and ease of alignment.

TYPE / 07

Spectacle Duplex Steel Flanges

Used in piping systems to isolate sections, commonly applied in maintenance and inspection processes.

TYPE / 08

Custom Duplex Steel Flanges

Manufactured based on engineering drawings and specifications to meet specialized industrial requirements.

Where They're Used

Applications of Duplex Steel Flanges

Duplex Steel Flanges are widely used in industries where corrosion resistance and mechanical strength are essential. In offshore and marine environments, Duplex Steel Flanges are used in structures exposed to seawater and chloride conditions.

They are also extensively used in oil & gas, chemical processing, desalination plants, and power generation industries. Duplex Steel Flanges provide reliable performance in aggressive environments where standard materials may fail.

Our Commitment

Why Choose Our Duplex Steel Flanges

Selecting the right manufacturer is crucial for Duplex Steel Flanges used in critical environments. Unicorn Metal Industries ensures that Duplex Steel Flanges meet strict engineering and performance standards.

Our manufacturing process emphasizes precision, traceability, and quality control
Custom Duplex Steel Flanges tailored to project requirements
Ensuring durability, reliability, and timely delivery

Quality Assurance

At Unicorn Metal Industries, strict quality control procedures are followed to ensure the reliability of Duplex Steel Flanges.

Raw Material Verification

The process begins with raw material verification to confirm grade and composition before production starts.

Dimensional Inspection

Followed by dimensional inspection and in-process quality checks during manufacturing.

Mechanical Testing

Mechanical testing is conducted to confirm strength and performance against specification.

Final Inspection

Each flange undergoes final inspection before dispatch, ensuring compliance with international standards and consistent quality for industrial applications.

Full Catalogue

Our Flanges Product Range

Explore our complete portfolio of industrial flanges manufactured for strength, corrosion resistance, and long-term performance.

Stainless Steel Flanges Carbon Steel Flanges Alloy Steel Flanges Inconel Flanges Incoloy Flanges Hastelloy Flanges Monel Flanges Nickel Alloy Flanges Titanium Flanges

FAQ

Frequently Asked Questions

What are Duplex Steel Flanges used for?

Duplex Steel Flanges are used to connect pipes, valves, and equipment in piping systems exposed to corrosive and high-pressure environments. They are widely used in offshore platforms, chemical plants, and marine applications where both strength and corrosion resistance are critical.

What grades are available in Duplex Steel Flanges?

Common grades include F51, F60, F53, and F55 as per ASTM/ASME SA182 standards. These grades correspond to materials like S31803, S32205, and super duplex grades, offering varying levels of corrosion resistance and mechanical strength.

Why are Duplex Steel Flanges better than stainless steel flanges?

Duplex Steel Flanges offer higher strength and better resistance to stress corrosion cracking compared to Stainless Steel flanges. They also provide improved durability in chloride-rich and aggressive environments, making them more suitable for critical applications.

Are Duplex Steel Flanges suitable for marine applications?

Yes, Duplex Steel Flanges are highly resistant to seawater corrosion, making them ideal for marine and offshore use.

What types of Duplex Steel Flanges are available?

Types include slip-on, weld neck, blind, threaded, socket weld, and lap joint Duplex Steel Flanges.

Can Duplex Steel Flanges handle high pressure?

Yes, Duplex Steel Flanges are designed to perform in high-pressure systems due to their superior mechanical properties.