The 3-layer product is composed of inner pipe (water crosslinked), middle layer (irradiation crosslinked) and outer UV resistant PE film. It features: high temperature resistant(120℃,fire retarded), anti-abraision, anti impact and anti-aging. The close cell bubbles are foamed by cross linked PE (specially formulated).  The inner pipe is foamed continuously without seam and closely welded with the outer 2 layers. The insulation pipe has no air pocket among layers. The special structure ensures low water absorption and good thermal insulation.It contains no corrosive material to the copper pipe or aluminum. High Temperature Resistant Type features: The insulation pipe can work under -70-120℃. Its good thermal insulation performance ensures no dewing, which avoid contamination of condensed water.The fire retarded insulation can reach the Level of UL-HF-1 (US) and M1(France).