What type of fittings are used to join dissimilar metallic piping materials in hydronic systems?

• A. Soldered Copper Joints
• B. Approved Dielectric Fittings And Brass Converter Fittings
• C. PVC Glue-On Adapters
• D. Plastic Compression Couplings

Answer: (B)

Galvanic corrosion is a key concern when two different metals are joined in a hydronic system, since water can carry an electrochemical reaction between the metals. To prevent this, dielectric fittings are used to electrically isolate the two metals at the joint, stopping the corrosion process. Approved dielectric fittings paired with brass converter fittings let you safely connect dissimilar piping materials while providing a reliable seal and proper material transition. Soldered copper joints are limited to copper-to-copper connections and don’t address galvanic isolation when other metals are involved. PVC glue-on adapters and plastic compression couplings are not suitable for metallic piping in hydronic systems and do not provide the necessary isolation between different metals.