Which type of conduit is commonly used for underground installations?

Rigid PVC conduit is commonly used for underground installations due to its excellent resistance to moisture and corrosion, making it highly durable in subterranean environments. PVC is lightweight, which simplifies handling and installation compared to heavier materials like metal. Its non-metallic nature prevents issues such as galvanic corrosion, which can be a concern with metal conduits when they come into contact with moisture.

Additionally, rigid PVC conduit is typically easy to cut and join using solvent welds, creating strong, watertight connections essential for protecting electrical wiring from water intrusion and other underground hazards. This compatibility with various fittings and the ability to withstand certain physical stresses make it a preferred choice for underground electrical systems.

In contrast, while metal conduit and electrical metallic tubing are robust options, they are more prone to corrosion when buried and therefore less suitable for underground use. Non-metallic flexible conduit is designed more for above-ground applications where flexibility is necessary, and isn't typically used for extended runs underground.