The closed cell rate of the polyurethane foam is approximately 92%. With its low thermal conductivity and low water absorption rates, combined with a protective shell made of high-density polyethylene or glass fiber with excellent waterproofing properties, it alters the traditional practice of laying heating pipelines in trenches, which resemble "wearing a wet cotton coat." This significantly reduces the overall thermal loss of the heating pipelines, with a heat loss in the heating network of only 2%, which is below the international standard requirement of 10%. It offers good corrosion resistance and insulation properties, with a long service life. The pre-insulated pipe with polyurethane rigid foam is tightly adhered to the outer surface of the steel pipe, effectively preventing the infiltration of air and water, thereby providing excellent corrosion protection. PPR hot water pre-insulated pipe

Junru Insulated PPR Pipe, Flame Retardant 63*90