PEX connects to copper using a special copper fitting that solders onto the existing copper pipe and provides an O-ring fitting to connect to the PEX. A stab-in connector offers a second option, but some building codes require these connectors to remain exposed, making copper connectors a better choice for those who prefer to keep the plumbing looking neat, according to the Family Handyman.Continue Reading
PEX is less expensive than copper and is quicker and easier to install. It doesn't require soldering. The best way to make connections requires the use of an expensive tool that is specific to the size of the pipe. When installing a branched plumbing system, it may require more connections and eliminate many of the PEX advantages. Most installers choose a manifold system, which also solves the problem of connecting PEX to copper. They use manifolds that solder directly to the copper main and to the feed from the water heater. Manifolds then provide PEX connectors for separate lines to feed each fixture.
Plumbers cannot install PEX directly to a fixture. One of the most popular methods of installation is to connect the PEX to a valve and then use a standard fixture connector to connect to the valve.Learn more about Heating & Cooling