A type of copper tube joint is:

• A. Soldered
• B. Flared
• C. Compression
• D. All of the above

Answer: (D)

Copper tube joints can be made in several reliable ways. Soldered (sweated) joints involve cleaning and fluxing the tube ends, heating with a torch, and filling the joint with solder to create a sealed metal connection. Flared joints require forming the tube end with a flare tool and tightening a flare nut to seal the joint; the flare provides a tight metal-to-metal seal as the nut compresses the flare against the fitting. Compression joints use a nut and ferrule (olive); as you tighten the nut, the ferrule clamps the tube against the fitting to create a seal without heat. Because each method is a valid, widely used way to join copper tubing, all of the above is correct.