Modern plumbing systems for potable water are generally comprised of either copper or Pex tubing, with copper pipes still being the top-of-the-line accepted standard and Pex now promoted as more durable and easier to install. Pex is now a building code-approved plumbing line, with each brand having their own International Code Council-approved report. Properly installed, the lines and fittings of different manufacturing systems are not interchangeable. Pex has been promoted by its various manufacturers as being so robust they can’t even test it to failure, as one manufacturer claims. It is easy to install as it’s both somewhat flexible and does not require a skilled plumber to solder the joints with a torch.