A few thoughts.

WRT re-pads,

On an Elbow, i sometimes do not ask for a re-pad but try to bump up the (elbow) schedule, as the re-pads are hard to form.

On straight runs, same again with the pipe.

Although doing the above, i do not indicate a pad in my calculations, but show the increase in wall thickness.

WRT the photo

* That looks like bad welding to me, the break is far to clean.
*The pad looks too small and may well not be helping to spread the load.
* The pad is not circular and may be accentuating stress concentrations (De- Havalland Comet windows...)
* The Pin in the joint looks ok
*Pad not insulated - differential thermal growth?
*For the size of the pin joint on the bellows ( and that is some bellows) the attachments LOOKS way to small.
* The bellows looks old, cyclic fatigue could be a factor.