▎ 摘　　要

NOVELTY - The utility model claims a pipe, comprising a metal shell, graphene, expanded core layer and a polycarbonate layer, the graphene layer is coated in the metal shell, the graphene layer, expansion core layer and the polycarbonate layer are connected in turn from the outside to inside, said metal outer shell is provided with a groove, the groove section is semicircular; the groove is distributed, the polycarbonate is provided with round hole, the round hole is distributed, the metal shell is provided with a baffle; the baffle is L-shaped configuration, the baffle plate is provided with a reinforcing block, the reinforcing blocks are welded with the baffle and the metal shell, the pipe of the utility model can be quickly heated and expanded, the fire retardant effect is good, the structure strength is high.