Hello people.
To know the forces in the restraints, and design the supports, what load case should be considered to obtain the real efforts? Sustained loads? Expansion Loads? Operating Loads?
I can see that in the case of expansion, the forces are always very high.
Thanks

The Expansion load case is a difference (range) load case.

For support design you should consider all possible configurations (load cases) that the piping system can experience. This would include OPE, SUS, and OCC cases.

Thank you very much.
Another question:
To obtain the forces in the supports, for the occasional load case, is it ok to add dynamic effect plus the operational loads? or dynamic effect plus the sustained loads?

Former would be correct.

But for stress calculation, you should subtract and add with sustained one.

I recommend you have a discussion with your structural department to decide who is responsible for calculating which loads. Many I have worked with in the past prefer to calculate their own wind loads, for example.

Expansion loads are going to be high if you do not have real-world gaps and real-world resistances input to guides, directional stops, and anchors that are set up to resist one another. It is generally up to the structural engineer to contest excessive loads, which can be reduced accordingly.