Special Welding Techniques Used for Zirconium Expansion Joints

Senior Flexonics Pathway manufactures expansion joints out of several reactive metals including zirconium, titanium and tantalum. All of these materials require special welding techniques in order to assure predictable product performance.

In many cases these exotic metals are used as one ply in a ply testable bellows. In a ply testable design, the outer ply has a pressure tap welded to the neck region of the bellows to sense the pressure between the plies. The photo shows a Senior Flexonics Pathway welding specialist welding a zirconium pipe nipple to the zirconium outer ply of a ply testable bellows. The weld is performed inside of a plastic bubble that has been purged with the appropriate inert gas mixture to prevent oxidation and contamination of the weld area. Even trace amounts of oxygen in contact with a reactive metal will ruin the weld.

Titanium, tantalum and zirconium are relatively expensive metals, but their resistance to corrosion is so good that these materials should be considered any time that stainless steels or high nickel alloys are not practical.

To inquire about expansion joints made from zirconium, tantalum and titanium, contact Senior Flexonics Pathway, 2400 Longhorn Industrial Drive, New Braunfels, Texas 78130. Phone (830)629-8080, Fax (830)629-6899. E-mail: sales@pathway.flexonics.com