Duplex Stainless Steel Flange Manufacturer
When a Bill of Materials calls for F51/60, F53, F55, or F60 and the application sees chlorides, high pressure, and corrosive media all at once, standard 300 Series Stainless steel will not hold up.
As a duplex stainless steel flange manufacturer, MFC Flange forges, machines, heat treats, and tests every duplex flange in-house at our ISO 9001-certified facility in Sealy, Texas, so each one ships to your exact grade, dimensions, and pressure class.
ISO 9001-Certified Duplex Flanges, Forged in the USA
Duplex stainless steel flanges are made from a mixed austenitic-ferritic microstructure, typically a near-equal balance of austenite and ferrite. That dual-phase structure is what gives the material its defining advantage: roughly double the yield strength of conventional austenitic grades, paired with strong resistance to chloride stress corrosion cracking, pitting, and crevice corrosion. For procurement and materials engineers specifying to ASTM A182 and ASME standards, that combination means thinner wall sections, lower lifecycle cost, and reliable service in environments where standard stainless steel flanges fail prematurely.
Every flange we produce undergoes rigorous in-house testing and inspection, backed by our ISO 9001:2015 certification, ensuring dimensional accuracy, material integrity, and performance consistency across every order. Our 300 Series stainless steel flanges offer exceptional corrosion resistance, making them a reliable choice for high-exposure environments involving water, moisture, chemicals, and humidity.
With over 30 material grades in inventory and full DFARS compliance, including stainless steel grades 304/H, 304/L, 310/H, 316/H, 316/L, 317/L, 321/H, & 347/H. MFC Flange supports both domestic and global customers across a wide range of demanding applications.
Duplex Stainless Steel Grades We Manufacture
We supply duplex stainless steel forgings across the standard and super duplex grades specified for the most demanding service conditions:
- F51/60 (UNS S31803 / 2205): The workhorse duplex grade, offering high strength and dependable resistance to pitting and stress corrosion cracking in moderately aggressive environments.
- F53 (UNS S32750 / 2507): A super duplex grade with elevated chromium, molybdenum, and nitrogen for superior performance in chloride-rich and seawater applications.
- F55 (UNS S32760): A super duplex grade engineered for outstanding pitting resistance and mechanical strength in marine and high-chloride service.
- F60 (UNS S32205): A modern 2205 specification delivering consistent corrosion resistance and weldability across chemical and oil and gas applications.
Duplex Flange Types We Manufacture
MFC Flange manufactures a comprehensive range of duplex flange types to match your piping system and application. All types are available across our duplex grades and produced to ASME B16.5 and B16.36 specifications, made to order in any quantity.
- Weld-Neck Flanges: High-strength flanges that resist deformation under pressure and extreme temperatures
- Blind Flanges: Solid flanges that seal off the end of a piping system securely
- Slip-On Flanges: Easy-to-align flanges suited to lower-pressure applications
- Orifice Flanges: Allow accurate measurement of pipeline flow rates
- Lap-Joint Flanges: Engineered for systems that require frequent dismantling
- Socket-Weld Flanges: Compact flanges for small-diameter pipe, delivering a clean, secure weld
- Threaded Flanges: Feature internal threads for repeated assembly and disassembly
Our Duplex Flange Manufacturing Process
At MFC Flange, we operate as an integrated facility, handling every stage of production in-house at our Sealy, Texas, plant. Our process spans closed-die and open-die forging, precision machining, advanced heat treatment, and inspection, all under one roof.
With duplex stainless steel forgings, controlled heat treatment is critical: it preserves the austenite-ferrite phase balance that gives the material its strength and corrosion resistance. End-to-end control over that process means faster turnaround, tighter quality standards, and complete accountability on every order. See our full range on the commodity flanges page or review all grades on the materials overview.
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Our flanges are commonly used in industries like offshore drilling and nuclear power – industries where standards for performance, safety, and accuracy are extremely high. That’s why MFC Flange holds ourselves to rigorous standards on every product we manufacture. Whether you are sourcing a single super duplex grade for a capital project or building out a stocking program, our team can confirm grade availability and lead time.
Industries That Rely on Our Duplex Stainless Steel Flanges
Duplex stainless steel flanges are specified where both mechanical performance and corrosion resistance are non-negotiable. MFC Flange supplies the following sectors:
- Oil & Gas: Reliable duplex flanges for offshore, subsea, and topside production
- Petrochemical & Chemical Processing: Corrosion-resistant flanges built for aggressive media and high pressure
- Marine & Shipbuilding: Super duplex grades that hold up in seawater and chloride-rich environments
- Power Generation: High-strength flanges for conventional and offshore facilities
- Food & Beverage/Pharmaceuticals: Duplex flanges that meet hygiene and corrosion requirements
- Defense & Aerospace: DFARS-compliant flanges meeting strict government specifications
Frequently Asked Questions
What duplex grades do you manufacture?
We produce duplex stainless steel flanges in F51/60 (2205 / S31803), F53 (2507 / S32750), F55 (S32760), and F60 (S32205), covering both standard and super duplex materials and specifications. If your Bill of Materials calls for a specific UNS number, contact our team to confirm availability.
What standards do your duplex flanges meet?
All duplex flanges are manufactured to ASME B16.5 and B16.36, along with ANSI, ASTM A182, and DIN EN 1092 specifications, meeting requirements for pressure and temperature ratings, dimensions, tolerances, marking, and testing.
What is the difference between duplex and super duplex flanges?
Standard duplex grades such as F51 and F60 (2205) suit moderately corrosive service, while super duplex grades like F53 (2507) and F55 carry higher chromium, molybdenum, and nitrogen content for superior resistance in chloride-rich and seawater environments.
Are your duplex flanges manufactured domestically?
Yes. All duplex stainless steel forgings are produced at our facility in Sealy, Texas. Our inventory is 100% domestic and fully DFARS compliant, and we are AIS and BABA ready for federally funded infrastructure projects.