Duplex steel flanges are high-performance pipe connection components made from duplex stainless steel, which contains a balanced microstructure of austenite and ferrite phases. This dual-phase structure provides superior strength and excellent corrosion resistance, particularly against stress corrosion cracking, pitting, and crevice corrosion. Duplex grades such as UNS S31803 (Duplex 2205) and UNS S32750 (Super Duplex 2507) are commonly used in these flanges for applications in offshore oil and gas, petrochemicals, desalination, and chemical processing.
Duplex steel flanges are manufactured to standards like ASTM A182 F51/F53/F55, ASME B16.5, and EN 1092-1, and are available in all standard types—weld neck, slip-on, blind, socket weld, lap joint, and threaded. They offer higher yield strength (almost twice that of austenitic stainless steel), which allows for thinner sections and weight savings in pressure vessel and pipeline design. Additionally, duplex flanges are well-suited for harsh environments due to their excellent resistance to chloride-induced corrosion and high mechanical stress, making them a reliable choice for demanding industrial systems.
