Material of duct pipe

Cables in ducts which have been completely filled with a pumpable material having a thermal resistivity not exceeding that of the surrounding soil, either in the dry state or when sealed to preserve the moisture content of the filling material, may be treated as directly buried cables.

IdMaterial name
PEPlastic duct made of PE (Polyethylene)
PPPlastic duct made of PP (Polypropylene)
PVCPlastic duct made of PVC (Polyvinylchloride)
WPEPlastic duct filled with water
MetalPipe made of steel
FibrePipe made of fibrous material
EarthPipe made of earthenware
CemPipe made of cement