The PE-RT II hot spring insulation pipe is insulated by rigid polyurethane foam, and the thermal conductivity λ = 0.013—0.03 kcal/m h oc, which is much lower than other commonly used pipe insulation materials in the past, and the insulation effect is improved by 4~9 times. Moreover, its water absorption is very low, about 0.2kg/m2. The reason of low water absorption is that the closed cell rate of polyurethane foam is as high as 92%.
The pe-rt II hot spring insulation pipe adopts fiber-wound pe-rt II pipe as the conveying pipe (working pipe), and the inner impervious layer adopts temperature-resistant and corrosion-resistant fiber-wound PE-RT II pipe. Its outer protective tube, insulation layer and working tube are composed of three parts, and the outer protective layer is made of high-density polyethylene. The insulating layer is made of rigid polyurethane foam.