I'm not into extruded pipes, but I would think the outer tube would be designed for tension due to 300 psi and the inner tube would be designed for compression of 250 psi. You can use the elastic shortening of the 'ribs' to get a handle on the tensile force, as a guess... else you can do an FEM analysis to get more correct values. Just a WAG...
Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?
-Dik