I thought LP Gas went Whhammmmummmmppppp not KkaaAAABOooOM. On the serious side copper tubing is extremely hard to reuse or salvage. When it freezes it swells and does not contract when it thaws, and being on the outside of the A/S it is apt to freeze quite often when in colder climates. The freezing point of Propane is minus 187.7 Celsius, of Butane minus 138.4 Celsius, so as long as you have the lines charged it shouldn't present a problem, but who hasn't let their tanks go empty at one time or other, you can't guarantee the lines haven't froze and therefor should be replaced if in question. I wadded mine up into a little ball, valves and all when I started my floor replacement project. Piece of mind and safety take precedent over the wallet in a situation like this.