Final answer:
The connection device between copper and galvanized piping is a Dielectric union, which prevents galvanic corrosion by keeping the metals from direct electrical contact.
Step-by-step explanation:
The connection device between copper and galvanized piping that prevents corrosion is called a Dielectric union. This device is essential in plumbing to prevent the galvanic corrosion that occurs when two dissimilar metals are in contact with each other in the presence of an electrolyte. Without a dielectric union, a galvanic cell would be created, with the less noble metal (galvanized steel) acting as the anode and the more noble metal (copper) acting as the cathode, which would lead to rapid deterioration of the galvanized steel.
Corrosion is indeed a galvanic process that can be mitigated using cathodic protection. This protection strategy involves using sacrificial anodes, such as zinc or magnesium, which are more easily oxidized than the metal being protected. For example, zinc is used to protect galvanized steel through galvanization, providing a protective coating that prevents the steel from rusting. In the case of different metallic pipes joined together, a dielectric union is used to ensure that these metals don't come into direct electrical contact, thus preventing galvanic corrosion.
Answer: B. Dielectric union.