Archer ,, i have used high strength flex LP line ,, it is good to 200 psi ,, and it all weather type line ,, u can get it at lowes ,, HD ,, but the draw back is ,, it takes special fittings for it ,, and "from what i have done" they do not match up to black pipe or copper ,, but what i did was re plumb the whole rv with the flex pipe ,, it makes it more easier to work on ,, and it is about 99% leak free from the manufact ,,, ( with the right fitting of course) but i hop this helps u ,, have a Merry Christmas and Happy New Year ,,, and Nash ,, same to u