Underground piping system types

Other electrical equipment is either directly buried or installed in underground conduit systems. In this type of environment, the extremes of temperature are less often experienced however localized and transient heating is experienced when power loads are high or when equipment runs near steam pipes for example. In underground installations, corrosive conditions are found based on road salts, lime extraction from concrete, and other minerals that become concentrated as water dries away. Exposure to microbes, oil run-off, decaying vegetation and other materials suggests that very stable polymers are required for this service. 

Traced pipe performs better with a nonwicking insulation which has low thermal conductivity. Underground systems are very difficult to keep dry permanently. Methods of insulation include factory-preinsulated pouring types and conventionally applied types. Corrosion can occur under wet insulation. A protective coating, applied directly to the metal surface, may be required. 

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