Due to this fact, water can be dripping on to the ground not from a PEX plumbing pipe, but from vapors that form among the two conduits. But, the metal tube cannot eliminate this difficulty, and the water onto it shall be producing corrosion to appear over the tube and may damage things all around, such as kitchen home furnishings. When compared with the iron water line, the PEX plumbing pipe really needs less fixtures as well as being much simpler to set up. PEX Tubing market popularity.