NCCER Plumbing Level 2 Practice Exam

Using black iron pipe underground necessitates additional protection because black iron is susceptible to corrosion when exposed to moisture and soil, which can lead to structural failure over time. Coating the pipe with a protective layer prevents direct contact with corrosive elements in the ground. Wrapping it adds an additional barrier against moisture and soil contaminants.

Cathodic protection is also vital; it is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. This protective measure is especially important for underground installations where pipes are exposed to continuous moisture, which accelerates the corrosion process. Thus, the combination of coating, wrapping, and cathodic protection effectively safeguards black iron pipe from environmental damage, ensuring longevity and reliability in plumbing systems buried underground.