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What Different Materials Are Used for Duplex Flanges, Their Applications, and Benefits?

Steel duplex flanges are a popular industrial flange used in diverse applications across industrial sectors. They are from a distinct type of steel known as duplex steel. It is a micro-structure formed by combining austenitic and ferritic stainless steel. 

Duplex

When a material gets melted, it solidifies from the fluid state into the complete ferritic structure. However, when duplex steel is cooled, half transforms into an austenitic structure. 

Duplex steel contains high chromium (19-28%), lower nickel, and molybdenum. 

What are the most popular types of duplex stainless steel?

The most used industrial grade duplex stainless steels are 2507 comprising twenty-five percent chromium and seven percent nickel, and 2205, which stands for twenty-two percent chromium and five percent nickel.

The low nickel percentage of duplex steel makes it an improved thermal conductor compared to the other austenitic grades. Hence, these steel flanges are often considered a better choice for any project. 

Duplex steel forged flanges are popular due to their distinct characteristics like high resistance, strength, durability, and robustness. Forged flanges have a microstructure of austenitic and ferritic grade.

It comprises higher molybdenum, nickel, copper, and chromium contents making these flanges suitable for functioning in aggressive environments because of their low thermal expansion, high heat conductivity, and immunity to corrosion. Forged flanges find extensive usage in several industrial sectors. 

Moreover, different metals are combined in the duplex steel to help create a metallurgical structure ensuring superior corrosion resistance, high strength, and toughness, making it an ideal choice in demanding environments. Such properties of duplex steel create a high demand for it in heavy industries. 

How does duplex steel arrive?

The concept of duplex steel alloy became evident in the 1920s. However, its production started in 1930. Earliest specimens are limited to cast production and other specific uses because it contains a high amount of carbon.

By the end of the 1960s, metal foundries started creating low-carbon steels that had high chromium and nickel content. As a result, they were able to balance ferrite and austenite structures. It made better duplex steel with the high-performance ability and lower downsides.

Even though much has changed since then, the new age duplex steel owes its roots to that originated in the 1970s. The steel used today includes different ranges of chromium, molybdenum, and nickel. 

What is duplex steel flanges application?

Duplex steel flanges are widespread in applications where high strength and corrosion resistance are required, such as in the oil and gas industry, chemical processing, and marine environments. 

Some of the industrial sectors where duplex steel flanges are extensive include the following:

  1. Petrochemical
  2. Oil and Gas
  3. Chemical Process
  4. Geothermal
  5. Water Desalination
  6. Pharmaceutical
  7. Natural Gas
  8. Biomass
  9. Mining
  10. Solar Power
  11. Nuclear Power
  12. Utilities
  13. Construction
  14. Pollution control equipment
  15. Pulp and paper production
  16. Hot water and brewing tanks

These flanges are available in varying sizes and configurations. Hence, it helps meet the specific needs of each application.

What are the benefits of duplex flanges?

One of the distinctive advantages of duplex steel flanges is their ability to resist corrosion. This type of steel contains higher levels of chromium, molybdenum, and nitrogen, providing excellent resistance to pitting and crevice corrosion. It makes duplex steel flanges ideal for harsh environments where other materials quickly degrade.

Duplex stainless steel often provides better toughness under pressure than other ferritic grades. Often, they offer lower values than austenitic steels, but their unique characteristics and structures often outweigh any other concerns.

Another advantage of duplex steel flanges is their high strength. Duplex steel is twice as strong as conventional austenitic stainless steel, thus making it an excellent choice for applications where high strength is an essential requirement.

In addition, duplex steel flanges provide excellent toughness, making them ideal for applications where impact resistance is a critical ask.

Duplex steel offers all the above qualities and uses lower quantities of molybdenum and nickel. Moreover, it is a much more affordable option in the market than other traditional austenitic stainless steel varieties. 

What are the different types of duplex steel flanges?

Duplex steel flanges are available in various sizes and configurations. 

You can contact a reputable manufacturer with your individual requirements to get better guidance on the selection.

The choices include weld neck, slip-on, threaded, and socket weld flanges. Each variety of industrial flange is designed to meet individual needs. The choice of flange type will depend on its application.

Weld neck flanges are the most common type of duplex steel flange used in high-pressure applications featuring an elongated neck welded to a pipe helping to distribute stress evenly across the flange. Weld neck flanges are widespread in applications where the flange gets subjected to higher stress, like oil and gas pipelines.

Slip-on flanges are another popular type of duplex steel flange. They are easy to install and ideal for applications requiring frequent disassembly.

Slip-on flanges are usual in applications where the flange gets subjected to moderate stress levels, such as in chemical processing plants.

Threaded flanges are similar to slip-on flanges but feature a threaded connection instead of a slip-on connection. As a result, they are extensive in low-pressure applications where disassembly is required.

Socket weld flanges are usual in applications with higher pressure and temperature. They feature a socket welded to a pipe used in high-temperature applications, such as steam piping systems.

In conclusion, steel duplex flanges are popular industrial flanges used in diverse applications designed of a distinct type of steel known as duplex steel providing superior corrosion resistance, high strength, and excellent toughness.

Duplex steel flanges are found in diverse sizes and configurations to help meet the specific needs of each application.

For users, the choice of flange type will depend on the individual nature of the application. Whether you need a flange for usage in the oil and gas industry, chemical processing, or marine environments, duplex steel flanges are an excellent choice that will provide reliable performance and long-lasting durability.

 

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Peter
Peter
8 months ago

Duplex steel’s unique combination of austenitic and ferritic structures provides it with remarkable corrosion resistance, making it a top choice for challenging industrial environments.

Sam
Sam
8 months ago

The versatility of duplex steel flanges is evident in their widespread usage across sectors like petrochemicals, oil and gas, and even solar power, showcasing its adaptability to various applications.

Tony
Tony
8 months ago

What are the most common types of duplex steel flanges, and where are they typically used?

Peter
Peter
8 months ago
Reply to  Tony

Some common types of duplex steel flanges include weld neck, slip-on, threaded, and socket weld flanges. Weld neck flanges are used in high-pressure applications like oil and gas pipelines, while slip-on flanges are ideal for frequent disassembly needs. Threaded flanges work well in low-pressure situations, and socket weld flanges are suitable for high-temperature applications such as steam piping systems.

Susan
Susan
8 months ago

What distinguishes duplex steel flanges from other types of steel?

Sam
Sam
8 months ago
Reply to  Susan

Duplex steel flanges are characterized by their microstructure, formed by combining austenitic and ferritic stainless steel. This unique structure provides them with superior corrosion resistance, high strength, and excellent toughness.

Susan
Susan
8 months ago

The historical evolution of duplex steel from its early high-carbon versions to the modern, well-balanced compositions underscores its enduring importance and relevance in today’s industrial landscape.