Which method is used to join copper tubing by creating a flare at the end of the tube?

• A. Flaring
• B. Crimping
• C. Soldering
• D. Brazing

Answer: (A)

Creating a flare at the end of copper tubing is a flare-fitting process. The tube end is mechanically formed into a cone, usually about 45 degrees, so it can mate with a matching flare nut and fitting to make a tight seal when the nut is tightened. This method is chosen specifically for copper tubing when you want a strong, mechanically formed seal without using heat. Soldering or brazing join pieces by melting filler metal, which doesn’t produce the flared end, and crimping compresses a sleeve around the tube rather than shaping the end into a flare. So the described technique—forming that end into a flare—best matches the method of joining copper tubing by flare.