Titanium Tubing Fatigue

[innovation2]

Has anyone ever had a problem with fatigue at a expanded double groove tube joint using titanium gr. 12. TS is fixed integral type constructed of Alloy 625. I know that titanium is susceptible to low ductility if over expanded.

 

[unclesyd]

The only problems we've had with fatigue in Ti tubes was where flow induced vibration, steam, caused failure of the tubes at the backside of the tubesheet. The Ti affected bundles were calandria used for process heating.
We normally roll tubes beyond the back edge of the tubesheet, so the failures waere in the rolled area.