I used 3/4” dia PEX made by Sharkbite and Sharkbite PEX fittings. I bought everything at Home Depot. One word of caution, I would not recommend using PVC pipe because, over time and exposure to UV light PVC becomes brittle and under pressure can burst sending plastic shrapnel throughout the garage. Also PEX is not brittle like PVC but can become brittle if exposed constantly to UV light. So I primed and painted my PEX air lines to protect them from UV exposure. My system is over 5 years with no leaks or issues. And my air line runs are over 80ft long.