Core TradesQuestion 92 of 700
A contractor plans to join copper tubing to galvanized steel pipe directly. The BEST practice to avoid a common failure is to:
a.Weld the two metals together
b.Use extra pipe dope only
c.Wrap the joint in tape
d.Install a dielectric union or fitting to prevent galvanic corrosion between dissimilar metals
Explanation
Directly coupling copper and galvanized steel creates a galvanic cell that corrodes the connection; a dielectric union or fitting isolates the metals electrically to prevent this. Welding dissimilar metals, extra dope, or tape does not stop galvanic corrosion.
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