New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

What type of copper are tube types K, L, and M typically available in?

1. Soft copper only

2. Hard copper only

3. Both soft and hard copper

4. Aluminum

The correct answer is: Soft copper only

The correct choice is that tube types K, L, and M are typically available in both soft and hard copper. Understanding the distinction is important for various applications in plumbing, HVAC, and other piping systems. Type K copper is known for its heavy wall and is generally used in underground applications and for more demanding plumbing systems. Type L, with a medium thickness, is suitable for both residential and commercial installations, offering a balance of pressure handling and strength. Type M has the thinnest walls and is often used for lighter applications like residential plumbing systems. All of these types can be manufactured in both soft (annealed) and hard (not annealed) forms. Soft copper is easier to work with and can be bent by hand, making it favored for applications requiring tight bends. Hard copper, on the other hand, is well-suited for applications where the pipes need to be straight and maintain a certain structural integrity, such as in rigid installations. Thus, stating that tube types K, L, and M are only available in soft copper is incomplete, as the availability of both forms significantly affects usage across different scenarios in the plumbing and piping industries.