MCC-NH Gas Fitters Practice Exam

The recommendation of using copper pipes for underground installation to prevent corrosion is based on the natural properties of copper. Copper has a high resistance to corrosion, especially when buried underground. This is because copper forms a protective layer of patina (copper oxide) when exposed to moisture, which inhibits further corrosion from the surrounding soil. Additionally, copper is also relatively lightweight and easy to work with for installation purposes.

In contrast, steel pipes are prone to rust and corrosion when exposed to moisture and soil conditions over time. Galvanized pipes, while coated to resist corrosion initially, can still suffer from corrosion at the joints and cut ends, which often leads to leaks. Cast iron pipes, although durable, can also corrode, especially if they come into contact with acidic soils.

Thus, the durability and corrosion-resistant qualities of copper make it the ideal choice for underground piping applications.