How to Connect Copper Pipes to Threaded Fixtures

Consider pipe sweating as option one. Preferred by many plumbers due to its solid and reliable bond, soldering with flux and a gas torch is required. Sweating copper to another metal is problematic for those less experienced in soldering techniques, because the alloys heat up at different speeds. Transition unions are employed in this situation. One side of the transition union is sweated onto the copper, while the other side is threaded onto the fixture.

Sweating pipes presents safety issues when working in confined areas: there can be health concerns if the solder contains lead and many people aren't comfortable working with an open flame. Compression connectors (also known as compression fittings) are used in these instances. They rely on the tension of internal fastening rings called ferrules to maintain the connection. Always lubricate the nut threads before installation, make sure there is ample fit between the pipes, and use compression connectors only for stationary jobs; many leaks can be traced back to compression connectors that were installed improperly.

Embrace the possibility of push-in connectors when pipes are a mix of copper, threaded and various polymer fixtures utilized on the market today. Known by a number of trademarked brand names, they're akin to the transition union as one side is threaded, but the copper side simply snaps into place. Like compression connectors, they're an excellent option for fittings that will in time need to be replaced with normal use, as no cutting with a hacksaw is required. However, being a fairly new product, there are still unknowns about the long-term durability of these connectors. Compatibility between competing brands is also an issue, as internal mechanisms of designs vary.