I am not sure if this is the correct forum to ask this question therefore if anyone can assist or direct me to the correct forum, I would appreciate it. My question is about running piping for an air compressor. I have a 135 PSI compressor and need to run pipe about 70 feet from the compressor. I will probably use copper piping, but do not know what type to use (type l vs M). I also would like some input on pressure drop over 70 feet and whether I should use 3/4 inch vs 1/2. Copper is expensive therefore I would probably go with the 1/2 inch but if it will not be adequate, than 3/4. I will use the compressor for air tools (ratch, impact wrench, chisel); one tool at a time.

I wouldn't recommend using such thin-walled material for compressed air.

Personally, I would use threaded black iron pipe and fittings, graded back towards the compressor and with drip legs installed at the bottom of any long vertical runs.