For a main steam piping system with cold spring, I made the load cases as follows:
L1: W (hanger design)
L2: W+D1+T1+P1 (hanger design)
L3: WNC+H (hanger design)
L4: W+D1+T1+P1+H+CS (OPE) (hot case, for restraints calculation only)
L5: W+H+CS (OPE) (cold case, for hanger/support design and equip. nozzle check only)
L6: W+P1+H (SUS) (for stress check only)
L7: W+P1+H+F2+CS (OCC, for stress check, hanger/support design and equip. nozzle check. F2 is the vent forces by relief valves)
L8: L4-L5 (EXP) (for EXP stress check only)
L9: L4-L6 (EXP) (for EXP stress check only)

Question:
1. Are these cases right/enough for the whole piping stress analysis?
2. Are L6,L8,L9 necessary for hanger/support design and equip. nozzle check? I think L6 is not a cold case or field installed case for the MS pipeline, because if P1 is considered in the load case, T1 and D1 should be considered at the same time. Either L8 or L9 is actual load case.
3. How to do analysis after the stress release for a piping system? I mean how to get forces and moments of the restraints under stress released condition?