PE-RT is a medium density polyethylene produced with special molecular designing and synthetic process; with copolymerization of ethylene and octylene, it improves the heat resistance of PE by obtaining the unique molecular structure via quantity and distribution control of side chains. Macromolecule of PE runs through several crystals, rather than being crystallized in one tabular crystal, thus linking crystals due to the existence of short-chain branch of octylene, it retains good flexibility of PE, high thermal conductivity and inertia and makes its resistance to pressure better. PE-RT pipe can satisfy all levels of hot water pipes specified in ISO10508.