Copper gas 🤯💯🔥 That copper was sleeved thru a concrete sidewalk and run to an outbuilding for a boiler system I installed a couple years ago. That why it’s moving around so easily while I was working on it. Here in MN we regularly use type L copper for natural gas and propane both. Type L copper is an approved piping material according to the IFGC. Specifically, according to the International Fuel Gas Code (IFGC) and similar standards, copper and copper alloy tubing (such as ASTM B88 or ASTM