Uses for a plumbing crimping tool include connecting PEX piping to shutoff valves and manifolds and transitioning it to existing copper tubing. While professionals prefer using less expensive crimping rings and the tool, the cost of the crimper makes compression fittings a better for do-it-yourself homeowners completing small plumbing jobs.
PEX tubing consists of inner and outer layers of polyethylene sandwiched around a thin aluminum layer. It is relatively new in the United States, but it has a long history of use in Europe. It is easy to cut to length and connect, remains flexible, and is frost-resistant. Plumbers run pipes directly from the manifold to the fixture when installing PEX in a new home. They use the crimping tool to tighten a small copper ring around the outside of the flexible tube to secure it at each hard plumbing connection; however, as of 2015, tools that crimp a single size ring cost approximately $100 and tools that crimp multiple sizes cost more.
Compression fittings use a small soft metal ring to make the connection too, but they depend on the tightening of the compression nut to tighten the ring around the pipe and prevent leaks. Plumbers also use compression fittings on copper pipe, and consumers may be familiar with them from icemaker kits.