1. According to the temperature of the medium in the pipe, polyurethane foam is used as thermal insulation material, and acid ester foam with temperature ≤ 120℃ is an ideal thermal insulation material.
2. The outer protective sleeve is extruded from high-density polyethylene material, which has high strength and good waterproof and corrosion resistance.
3. The foam insulation layer, the inner steel pipe and the outer protective pipe are closely combined, and the interlayer shear strength is ≥0.2Mpa.
4. The compressive strength of the insulation layer is ≥0.2Mpa, which ensures that the insulation structure will not deform under the action of earth pressure and ground dynamic load. Directly buried thermal insulation pipe has high compressive strength, good anticorrosion and waterproof performance and long service life, which can be widely used in central heating, tap water transmission, power plants, refrigeration pipelines, etc. in cities, factories and building communities, and is suitable for directly buried laying.