Pex Piping Expansion VS Crimpby Derrick Mattson on 06/13/13
Pex piping comes with two main types of connections. Expansion and crimp.
Expansion connections are made with a tool that pumps up the pipe, stretching it out over a fitting. The pipe is designed with "memory" to re-compress back down tight. This can be problematic if the tool is not rotated when installing. After several pumps of the tool, a cut begins to form on the inside of the pipe. This is prevented by a constant rotating of the fitting/tool with each connection. Some plumbers skip this step and it will lead to leaks down the road, if not immediately.
Crimp connections are made with a tool that evenly presses a metal ring around the pex at the fitting. This requires different fittings than the expansion type. There are two types of crimp systems, Cinch clamps and copper rings. I recommend the rings. The tool can be calibrated to apply the proper pressure on the pipe to prevent leaks.
The crimp connection is much faster than the expansion and, in my opinion, a more secure connection.
Overall, pex is the future of plumbing. Whether you use rings, clamps, or expansion; the ease of installation, durability, and cost make it far superior to copper plumbing.