When dissimilar metals are joined underground, what tool must be used?

When dissimilar metals are joined underground, an insulating coupling or fitting is required to prevent corrosion. This is crucial because when different metals come into contact in the presence of moisture or soil, galvanic corrosion can occur. This type of corrosion involves one metal corroding at an accelerated rate due to the electrochemical reactions triggered by the differing electrical potentials of the metals.

Using an insulating coupling or fitting effectively creates a barrier that separates the two metals and prevents direct contact, thereby minimizing the risk of corrosion and extending the life of the underground piping system. This practice ensures safety and integrity in LP gas systems, where reliability is paramount due to the potential hazards associated with gas leaks or failures in the pipeline.

Other options, such as compression fittings, solder joints, and sealing tape, may not effectively serve the purpose of preventing electrochemical reactions between dissimilar metals and do not provide the necessary insulation to mitigate these corrosion risks.