Material failures occur in products due to changes in the original characteristics that prevent satisfactory performance of a functional system for its intended purpose and could produce losses to human life and economic infrastructure. Metals’ characteristics change due to cyclic stress, strain, and corrosion. This paper presents a case study that deal with the application of corrosion fundamentals in the determination of the origin of failures in a metallic part—galvanic corrosion failure in a water supply plumbing system. Metallographic examination, chemical analysis of the parts, and fractography were conducted, and the cause of failures was determined as a galvanic corrosion.