Zirconium Expansion Joints for Corrosive Service

For certain types of process media, particularly acids, there is no substitute for the excellent corrosion properties of zirconium. The corrosion properties of zirconium are particularly valuable for expansion joints because expansion joints are generally designed without any corrosion allowance.

Senior Flexonics Pathway manufactures expansion joints from unalloyed zirconium in accordance with ASTM B551, grade R60702. The grade R60702 material has the elongation properties that are best suited for manufacture of expansion joints.

Since zirconium is not easily welded to other materials that are commonly used for piping in the chemical process industries, most zirconium expansion joints are of van stoned fl ange construction. In the van stone process, the bellows tube is fl ared to form the fl ange gasket seating surface similar to the above sketch. The bellows material is not welded to any adjacent component. The bellows can be welded directly to fi ttings if the pipe fi ttings are made from zirconium.