ANSI B16.5 DN150 Class 600 CNC Machining F51 Flat Flange

This flat flange is manufactured in strict accordance with the American standard ANSI B16.5, with a nominal diameter of DN150 and pressure class Class 600. It is fully precision CNC machined from ASTM A182 F51 duplex stainless steel forgings.Featuring a dual-phase microstructure consisting of austenite and ferrite, F51 delivers far higher yield strength than conventional 304 stainless steel. It offers outstanding resistance to chloride pitting corrosion, crevice corrosion and stress corrosion cracking, making it suitable for high-pressure and severely corrosive working conditions such as seawater, sulfur-containing oil and gas, and acid-base chemical media.All bolt holes and raised face sealing grooves are CNC milled to precise dimensional tolerances, ensuring excellent sealing flatness and stable pressure resistance to withstand long-term impact of Class 600 high-pressure media.Each product undergoes strict factory inspections including spectroscopic material re-verification, non-destructive testing and hydrostatic pressure testing. With good welding compatibility, the flange is widely used in overseas engineering projects such as offshore platforms, oil & gas transmission pipelines and high-pressure chemical heat exchangers. Customized sealing face types and surface treatment processes are available upon request.