Duplex Steel Flanges

Duplex steel flanges are pipe connection components manufactured from Duplex Stainless Steel grades, which carry a two-phase microstructure of austenite and ferrite. The composition falls roughly at 50% each phase, and this structure is what gives the material its characteristic combination of strength and corrosion resistance. They are used wherever standard stainless steel flanges fall short, particularly in chloride-heavy or mildly acidic environments.

The material handles stress corrosion cracking far better than austenitic grades. The tensile strength is also higher, allowing thinner wall sections without compromising pressure handling. In practical terms, that can reduce overall system weight and fitting costs.

Metracore Alloys is a trusted supplier of Duplex Steel Flanges. We provide these flanges in UNS S31803 (2205) and UNS S32750 (2507). Apart from these, 2205 has become the most common grade. For highly corrosive applications, 2507 is the more appropriate choice.

These flanges come in sizes ranging from 1/2 inch to 48 inches. Available flange types include Slip-On, Weld Neck, Blind, Socket Weld, Lap Joint, and Threaded. Finish is typically raised face (RF), though ring type joint (RTJ) and flat face (FF) can be arranged on request.