I try to use PEX pipe to replace copper pipe for Aircorn units. I try to use R22 and R410. The result after 6 month still working and no leaking and cracking on the pipe. My question is : The PEX can stand the Refrigerant, Why no body apply it.

With ARC piping as the new standard for copper. And PEX can not take the high pressure from my understanding.
Question to you is the PEX still holding and what is the length and dia of the PEX?