HASTELLOY FLANGE

https://www.nickelalloytubes.com/products/hastelloy-pipe-tube-flange.html

As Hastelloy is a corrosion-resistant nickel alloy, the Hastelloy flanges are widely used in the oil and gas industry.
HASTELLOY FLANGE PROVIDED BY YUHONG
Hastelloy flanges are often utilized in chemical processing applications where acid chlorides, solvents, formic and acetic acids, acetic anhydride, wet chlorine gas, hypochlorites, chlorine solutions, and phosphoric acid are used.