What type of corrosion does a dielectric union stop?

A dielectric union is specifically designed to prevent galvanic corrosion. Galvanic corrosion occurs when two dissimilar metals are connected in the presence of an electrolyte, leading to the more anodic metal corroding more quickly than it normally would. This type of corrosion arises due to the electrochemical reactions that occur when different metals are in contact, promoting electron flow and subsequently corrosive activity.

The dielectric union acts as a barrier between the dissimilar metals by using a non-conductive material, such as plastic or rubber, to interrupt the electrical path. By preventing the two metals from directly contacting each other, the dielectric union effectively stops the electrochemical reaction that leads to galvanic corrosion. Hence, the integrity of the metals involved is maintained over time, which is crucial in water distribution systems where corrosion can lead to leaks, system failures, and contamination.

Understanding the mechanics of galvanic corrosion and the role of dielectric unions is critical for anyone involved in maintaining water systems, as it helps in ensuring the longevity and safety of the infrastructure.