The 20" pipe is very unusual shape after the very effective transient event. The sketch/ the model does not give the distances between supports. I will assume that support distances are same as B31.1 tabled.

I am just trying to imagine where the transient load was generated;

1. I will assume that there is no condensation removal pot on the lower portion of the loop, and slug was generated and hit the loop many times.

2. Transient load was occurred in the different part of the piping and the pipe pushed axially one side.

In both cases I cannot imagine how pipe changed its shape as given. There must be enormous forced generated on the pipe and sheared all the supports unless supports were not designed to take this kind of forces. By looking at the support displacement and lift-offs, I believe, there are some plastic hinges produced on the pipe. I hope this is not the case but if this is true I am not sure how you are going to deal with them.

I guess Dave gave you the most possible modelling scenario. However first you need to determine the exact cause of the transient to be able to understand the pipe behavior under the current condition. Is the pipe still under axial load (thermal and/or transient event) or relaxed with the current shape? If the pipe is relaxed with current shape the pipe has already developed the plastic hinges under the occasional load. If the pipe still under the transient event axial load there the problem might be concentrated where the pipe holding restraint location is.

I wish you good luck, it is a difficult job, you will need more than stress analysis.