Steel sleeve steel buried steam pipeline is a composite insulation pipe in underground buried pipelines, mainly used for conveying high-temperature steam, with a usage temperature of up to 150 ℃ -450 ℃. Pipeline ports are generally sealed with polyethylene film or three-layer PE cold winding tape to prevent moisture or water from entering before installation or during construction. The insulation material is wrapped with multiple layers of staggered seams, effectively reducing heat loss