I would suggest you few modifications for successful and better results,
As your model consists of many solids, contact should be defined between them.
But in this case, you can simply combine all different part of solids into one. Make use of this forum post for merging solids.
Then during simulation, there is no need for the contact definitions.
Another tip is about the prescription of temperature to the pipe.
You can provide fluid temperature inside and ambient temperature for the outer surface and define convection heat flux.
You can look at the similar projects [like this] (https://www.simscale.com/projects/ahmedhussain18/thermostructural_analysis_of_a_cracked_pipe/) for more understanding.
Hope you get good results with these modifications, feel free to comment for more queries.