What is the best practice for connecting dissimilar metals in plumbing?

Using isolation fittings or dielectric unions is the best practice for connecting dissimilar metals in plumbing due to the risk of corrosion that occurs when different metal types are in direct contact. This phenomenon, known as galvanic corrosion, can lead to significant deterioration of the metals involved, ultimately resulting in leaks and system failures.

Isolation fittings and dielectric unions create a barrier between the metals, preventing direct electrical connection and the electrochemical reactions that lead to corrosion. These fittings typically incorporate non-metallic materials that separate the dissimilar metals and significantly increase the longevity and reliability of the plumbing system.

In contrast, directly connecting dissimilar metals without precautions can result in rapid corrosion, which undermines the structural integrity of the connection. Welding dissimilar metals is often not feasible or recommended due to the differences in melting points and properties of the metals, which can cause weakness at the joint. Using a conductive adhesive might seem beneficial for flow but would also introduce direct contact between the metals, negating the protective benefits and potentially leading to corrosion issues.