Plumber Red Seal · Question
What is the purpose of installing a dielectric union or fitting when connecting copper water pipes to a galvanized steel pipe or water heater?
When two different metals like copper and galvanized steel are connected in the presence of water (an electrolyte), a galvanic cell is created which corrodes th
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Question: What is the purpose of installing a dielectric union or fitting when connecting copper water pipes to a galvanized steel pipe or water heater?
Answer options:
- To allow for easy disconnection of the pipe ✅ To prevent electrolytic corrosion between the dissimilar metals
- To provide thermal expansion flexibility
- To increase the structural strength of the joint
Correct answer: To prevent electrolytic corrosion between the dissimilar metals
Explanation: When two different metals like copper and galvanized steel are connected in the presence of water (an electrolyte), a galvanic cell is created which corrodes the more reactive metal (steel). A dielectric fitting isolates the metals and breaks this electrical circuit, preventing corrosion.
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