Duplex steel flanges
Forged Duplex Steel Flanges Manufacturer and Supplier in UAE
Duplex flanges are forged from duplex stainless steel (DSS) with a dual austenite–ferrite microstructure. They resist pitting, crevice and chloride-induced corrosion better than standard stainless steel flanges.
At a glance
- Microstructure: roughly equal austenite and ferrite
- Strength: higher than standard austenitic stainless steel
- Weldability: good, so fabrication and installation stay simple
- Types: weld neck, slip-on, blind, socket weld, threaded, reducing
Leading Supplier of Duplex Flanges in the UAE
DuplexPipeline manufactures duplex steel flanges in Mumbai for high-pressure and corrosive service.
Parameter | Details |
Material | Duplex stainless steel (UNS S31803 / F51) |
Size range | 1/2″ – 48″ |
Pressure class | 150 – 2500 |
Face types | RTJ, RF, FF, T&G |
Finish | Anti-rust painting |
Supply | Made in India, shipped to the UAE and worldwide |
Why Choose Duplex Flanges?
- Corrosion resistance: performs well in aggressive chloride environments and extends service life
- High strength: excellent yield, tensile and fatigue strength
- Thinner sections: lighter piping without losing strength
- Lower lifecycle cost: duplex flanges cost more upfront than carbon steel but cut maintenance and replacement costs
Types of Duplex Stainless Steel Flanges
Our duplex flanges are available in these types for UAE projects:
Flange type | Key details | Typical use |
Slip-on | 1/2″ – 48″ | General piping, easy alignment |
Weld neck | Smooth butt-welded joint | High-pressure piping |
Socket weld | Pressure class 150 – 2500 | Small-bore, high-pressure lines |
Blind | Anti-rust painting | Closing pipe ends |
Threaded | Custom sizes available | Joints where welding is not preferred |
Reducing | Connects different pipe sizes | Pipe size transitions |
Duplex Steel Flanges Specification
Chemical composition (UNS S31803 / F51)
Element | % |
Carbon (C) | 0.030 max |
Manganese (Mn) | 2.00 max |
Silicon (Si) | 1.00 max |
Phosphorus (P) | 0.030 max |
Sulphur (S) | 0.020 max |
Chromium (Cr) | 21.0 – 23.0 |
Nickel (Ni) | 4.5 – 6.5 |
Molybdenum (Mo) | 2.5 – 3.5 |
Nitrogen (N) | 0.08 – 0.20 |
Mechanical properties
Property | Value |
Tensile strength | 620 MPa min |
Yield strength | 450 MPa min |
Elongation | 25% min |
Hardness | 293 HB max |
Size chart: keep your existing size chart image here.
Duplex Steel Flanges Stock in Mumbai for the UAE
- Our duplex steel flanges stock covers slip-on, weld neck, socket weld, blind, threaded and reducing types
- Sizes from 1/2″ to 48″, pressure classes 150 – 2500
- Face types: RTJ, RF, FF and T&G
- Custom sizes available for UAE project needs
- To check current duplex steel flanges stock for the UAE, send your size, class, face type and quantity
Buy Duplex Steel Flanges in the UAE from DuplexPipeline
When you buy duplex steel flanges from us, you get:
- Heat-treated material checked for phase balance and grain structure
- Rockwell hardness testing
- Custom sizes to fit your project
- Quality assurance and worldwide shipping, including the UAE
How to order
- Share size, pressure class, flange type and quantity
- Receive datasheet and quote
- Confirm the order
How Duplex Flanges Are Tested
- Optical microscopy and SEM: check phase balance, grain structure and harmful phases
- Metallographic analysis: verifies grain structure after heat treatment
- Rockwell hardness test: measures resistance to indentation
What Affects Cost and Corrosion Resistance
Factor | Effect |
Nominal pipe size (NPS) | Larger flanges use more material and cost more |
Thickness | Thicker flanges weigh more and cost more |
Molybdenum content | Improves resistance in chloride and acidic environments |
Service environment | Temperature, pH and chloride level affect corrosion |
Forged Duplex Steel Flanges Manufacturer
Duplex steel flanges are a class of stainless steel flanges made from DSS material prized for excellent resistance to pitting, crevice, and chloride-induced corrosion. They’re called duplex because, unlike single-phase steel flanges, they carry a dual microstructure of roughly equal austenite and ferrite content.
DSS flanges deliver higher strength than standard austenitic stainless steel flanges. Across every flange type we manufacture including weld neck flange, slip-on, and blind styles good weldability keeps fabrication and installation straightforward.
DuplexPipeline – Leading Supplier of DSS Slip-On/Weld Neck Flanges in India
How are the effects of thermal processing on duplex flanges evaluated during heat treatment testing?
DSS manufacturers use optical and scanning electron microscopy (SEM) to examine heat-treated duplex steel flanges. This microstructural analysis lets manufacturers evaluate phase balance, grain structure, and any detrimental phases before a weld flange or neck flange batch ships out.
Metallographic processes such as optical and electron microscopy check the grain structure of DSS flanges, while Rockwell hardness testing measures resistance to indentation across all flange types produced.
Duplex Pipeline – Leading Supplier of Duplex Steel Forged Flanges in Mumbai with Advanced Thermal Processing
Duplex steel reducing flanges
DSS weld neck flange
Duplex steel threaded flanges
What are the advantages of using Duplex stainless steel flanges?
DSS reducing flanges resist corrosion exceptionally well in aggressive chloride environments, lowering degradation risk and extending the service life of the DSS slip-on flange and every other flange type in our range.
A DSS weld neck flange offers excellent yield strength, tensile strength, and fatigue resistance, allowing thinner wall sections. Stainless steel flanges may cost more upfront than carbon steel alternatives but deliver strong long-term savings through durability.
Duplex Stainless Steel Flanges Available in Custom Sizes to Fit Your Project Needs
Table of Content
- Specification of duplex steel flange
- Types of duplex stainless steel flanges
- Chemical composition of duplex pipe flange
- Mechanical properties of duplex ss flanges
- Size chart of duplex stainless steel flanges
Specification of duplex steel flange
We are a top duplex flange manufacturer in India check our stock of steel flanges and full specification sheets here, including detailed data for every weld neck flange and neck flange size we carry.
Types of duplex stainless steel flanges
Duplex slip on flanges
- Size: 1/2″ – 48″
- Application: airpspece industry
- Yield Strength: 290 MPa
Duplex steel socket weld flanges
- Pressure class: 150 – 2500
- Type: blind,slip on, weld neck
- Face type: Rtj, RF, FF, T&G
Duplex blind flanges
- Coating: anti-rust painting
- Size: Tensile strength: 415 MPa
- Elongation: 50mm
We stock a wide range of flange types, so whether your project calls for a standard neck flange or a specialised weld flange configuration, the right stainless steel flanges are available from inventory.
Chemical composition of duplex pipe flange
Mechanical properties of duplex ss flanges
Size chart of duplex stainless steel flanges
How do the dimensions and sizes of duplex blind flange affect their weight and cost?
The nominal pipe size (NPS) of a duplex blind flange directly impacts weight and cost. Larger-diameter steel flanges use more material during manufacturing, which drives up the price compared to smaller flange types.
The thickness of DSS threaded flanges also affects overall weight and cost; thicker weld flange sections need more material and raise production costs accordingly.
Which Factors Influence the Corrosion Resistance of Duplex Slip-On Flanges?
The alloy composition of DSS used in slip-on flanges plays a major role in corrosion resistance. Molybdenum enhances resistance, especially for stainless steel flanges exposed to chloride and acidic environments.
The service environment also matters temperature, pH, and chloride concentration all affect corrosion behavior across duplex steel socket weld flanges and other flange types.
Is DSS RTJ flanges magnetic?
DSS ring joint flanges are typically magnetic due to their ferrite content, since DSS is duplex in nature with both ferrite and austenite phases present.
Magnetism varies by grade and heat treatment; some duplex steel flanges show stronger magnetic properties than others depending on ferrite content.
Frequently Asked Questions
Duplex Steel Flanges — Questions Buyers Ask Most
What makes duplex steel flanges different from regular steel flanges?
They have a dual austenite-ferrite microstructure, giving higher strength and better corrosion resistance than standard steel flanges.
What flange types are available?
Slip-on, blind, socket weld, weld neck flange, threaded, and reducing all flange types are stocked in duplex grade.
What is a weld neck flange used for?
A weld neck flange (or neck flange) suits high-pressure piping needing a smooth, butt-welded connection.
Is a weld flange stronger than a slip-on flange?
Why choose stainless steel flanges over carbon steel?
Stainless steel flanges resist corrosion far better, reducing maintenance costs over the equipment’s service life.
Are duplex steel flanges cost-effective long-term?
Yes, higher upfront cost is offset by longer service life and lower maintenance versus standard steel flanges.
Frequently Asked Questions
Duplex Steel Flanges — Questions Buyers Ask Most
What are duplex flanges?
They have a dual austenite-ferrite microstructure, giving higher strength and better corrosion resistance than standard steel flanges.
What makes duplex steel flanges different from regular flanges?
Dual microstructure gives higher strength and better corrosion resistance
Which flange types are available?
Slip-on, blind, socket weld, weld neck, threaded and reducing
What is a weld neck flange used for?
Do you keep duplex steel flanges stock for the UAE?
Yes, contact us with your size and class to confirm availability
How do I buy duplex steel flanges in the UAE?
Send your requirements through the contact form, WhatsApp or phone for a quote
Duplex steel flanges are flanges made of DSS material that exhibits excellent resistance to various types of corrosion. It is named duplex as unlike other flanges it has a two microstructure that entails an equal composition of austenite and ferrite.
DSS flanges display higher strength as compared to austenitic stainless steel products. These stainless steel flanges generally have good weldability and allow for easy fabrication and installation operations.
DuplexPipeline – Leading Supplier of DSS Slip-On/Weld Neck Flanges in India
DSS manufacturers typically utilize various microscopy techniques such as optical microscopy and scanning electron microscopy or SEM to examine the heat-treated flanges. The microstructural analysis process employed in the DSS flange enables the manufacturers to evaluate the phase balance, grain structure, and the presence of any detrimental phases.
Steel manufacturers employ metallographic processes such as optical microscopy and electron microscopy to check the grain structure of DSS flanges. Hardness tests such as Rockwell hardness is usually conducted during the manufacturing process to measure the DSS resistance capacities to indentation.
DuplexPipeline – Leading Supplier of Duplex Steel Forged Flanges in Mumbai with Advanced Thermal Processing – Contact Us
Duplex steel reducing flanges
DSS weld neck flange
Duplex steel threaded flanges
DSS reducing flanges exhibit excellent corrosion resistance, particularly in aggressive environments containing chloride solutions. This resistance lowers the risk of material degradation and extends the service life of the DSS slip-on flange.
A DSS weld neck flange exhibits excellent yield strength, tensile strength, and fatigue strength, thereby allowing for the use of thinner sections. DSS flange may have a higher initial cost as compared to some other steel materials but it offers amazing long-term cost savings.
Duplex Stainless Steel Flanges Available in Custom Sizes to Fit Your Project Needs
We are top duplex flange manufacturer in India, check our stock here
DuplexPipeline’s DSS Blind Flanges Comply with Industry Standards and Offer Proven Corrosion Resistance
Duplex slip on flanges
- Size: 1/2″ – 48″
- Application: airpspece industry
- Yield Strength: 290 MPa
Duplex steel socket weld flanges
- Pressure class: 150 – 2500
- Type: blind,slip on, weld neck
- Face type: Rtj, RF, FF, T&G
Duplex blind flanges
- Coating: anti-rust painting
- Tensile strength: 415 MPa
- Elongation: 50mm
Refer to DuplexPipeline Datasheets for Complete Chemical & Mechanical Details of Duplex Orifice Flange
The diameter or nominal pipe size NPS of a duplex blind flange has a direct impact on its weight and cost. Unlike small-diameter flanges, large-diameter flanges involve more material during the manufacturing process which hikes up its costs.
The thickness of DSS threaded flanges impacts their overall weight and cost. Thicker flanges are heavier and require more material during manufacturing, thereby leading to higher costs.
The special alloy composition of the DSS employed in slip-on flanges plays a significant role in determining their corrosion resistance. Molybdenum can enhance the corrosion resistance of DSS products, especially in chloride and acid containing environments
The corrosive environment in which the slip-on flanges will be used significantly impacts their corrosion resistance. Factors such as temperature, pH level, chloride concentration, and other aggressive chemicals affect the corrosion of duplex steel socket weld flanges.
DSS ring joint flanges are typically magnetic due to their composition which includes a significant amount of ferrite phase. DSS are duplex in nature, consisting of both ferrite and austenite phases.
The magnetism of the DSS RTJ flanges can vary based on the specific composition and heat treatment process employed on the DSS. Some grades of DSS exhibit a higher ferrite content and therefore show stronger magnetic properties than other SS grades.
