It depends on the purpose of the line, the storage fields i worked on ran around 1200 psi iirc, some are more, most less. The problem is that since it's compressible it also expands. Water and other incompressible fluids can be run at higher pressures more safely, because if the pipe fails it doesn't expand. Gases expand so they basically act like a bomb. This is how most injuries happen when someone tries to weld on a 55 gallon drum, the vapor ignites which easily overpressurizes the drum, which is designed for atmospheric pressure only. Also why you never weld a plate on the end of a pipe and why blind flanges are so thick, if it's too thin it can't withstand the force. You ever blow down an air compressor tank, and notice how much energy that is? That's a small volume at 150 psi or so, going thru an 1/8 inch or less sized hole.
A contractor i used to work for made the mistake of testing 36" ductile chilled water lines with air, had about 80 psi on it when it cut loose. They were running a large compactor over the 5 feet of gravel and sand used as fill, which likely helped shake the joint loose since a toothed o ring was the only seal. 1 stick almost came completely out of the ground, they were insanely lucky no one died, some were injured but recovered.
I have a story.
I was helping a friends husband drop some trees. He was working at a gravel pit and used one of their massive wheel loaders to yard out a 43” oak tree whole. Amazing power! After the tree work was over we went back to his shop and I see this 55gallon drum that was almost turned into a sphere. I asked him what the story was behind that. So he tells me he needed a pressure washer for something and filled the drum with water and ran air into the drum at 75psi and that is what happened. When in reality he only needed to run 5psi into the drum to make it work. He was lucky to be alive. He told me not to tell his wife for obvious reasons.