Introduction

There were presented some kind of material at the last years of the third millennium called Temperature Pert (Poly ethylene Resistance). Their aim was to increase the polyethylene pipe's function extant in the situations in which a higher thermal insistence in necessary.

This material is a copolymer made of ethylene and Acton and has some similar characteristics without necessity to being crosslink and net. These materials are used just like pet materials to make the five layer pipes which involve two layers of pert material in and out of the pipe and also an aluminum layer which is connected to the polymer layers via two glue layers.

The existing aluminum layer stop oxysion infiltration and decrease the pipe's linear expansion just as what