保温钢管聚氨脂直埋保温管又称“管中管”其有“两步法”构成，是由高密度聚乙烯外维护层、聚氨脂硬质泡沫塑管和钢管组成。
Thermal insulation steel pipe polyurethane directly buried insulation pipe, also known as "pipe in tube", has two steps, consisting of external maintenance layer of high density polyethylene, rigid polyurethane foam plastic pipe and steel pipe.
保温层材料为密度60kg/m380kg/m3的硬质聚氨酯泡沫，充分添满钢管与套管之间的空隙，并具有必定的粘接强度，使钢管、外套管及保温层三者之间构成一个坚固的整体。 保温钢管泡沫具有出色的机械功用和绝热功用，通常状况下可耐温120℃经过改性或与其它隔热材料组合可耐温180℃。保温层材料为密度60kg/m380kg/m3的硬质聚氨酯泡沫，充分添满钢管与套管之间的空隙，并具有必定的粘接强度，使钢管、外套管及保温层三者之间构成一个坚固的整体。保温钢管泡沫具有出色的机械功用和绝热功用，通常状况下可耐温120℃经过改性或与其它隔热材料组合可耐温保温钢管
The insulating layer material is rigid polyurethane foam with density 60kg/m3 to 80kg/m3, fully filled the gap between the steel pipe and the casing, and has a certain bonding strength, so that the steel pipe, the outer sleeve pipe and the insulation layer can form a solid whole between the three. The insulation steel tube foam has excellent mechanical function and adiabatic function. Under normal conditions, it can withstand 120 degrees of temperature and is able to withstand temperature of 180 degrees after being modified or combined with other insulation materials. The insulating layer material is rigid polyurethane foam with density 60kg/m3 to 80kg/m3, fully filled the gap between the steel pipe and the casing, and has a certain bonding strength, so that the steel pipe, the outer sleeve pipe and the insulation layer can form a solid whole between the three. The insulation steel pipe foam has excellent mechanical function and adiabatic function. Under normal conditions, it can withstand 120 degrees of temperature and is modified or combined with other insulation materials.
1.防腐层：维护外钢管避免腐蚀物腐蚀钢管，延长钢管运用寿命。
1. Anti-corrosive coating: Maintain external steel pipe to avoid corrosion and prolong service life of steel pipe.
2.外护钢管: 维护保温层免受公开水腐蚀，支撑作业管并能承受必定的外部荷载，确保作业管正常作业。
2. External steel pipe protection: Maintain the insulation layer from open water corrosion, support the work pipe and can withstand certain external loads to ensure the normal operation of the work pipe.
3.聚氨酯泡沫层: 确保介质温度，确保外护管表面坚持常温。
3. polyurethane foam layer: ensure the temperature of the medium and ensure the surface of the outer tube is kept at normal temperature.
4.隔绝、反射层: 确保有机泡沫材料不进入无机硬质耐高温层;反射耐高温层局部热量。
4. isolation and reflective layer: ensure that the organic foam material does not enter the inorganic hard and high temperature resistant layer; reflects the local heat of the high temperature resistant layer.
5.无机硬质保温层：耐高温，确保与有机保温层之间的界面温度，确保泡沫不被炭化。
5. inorganic hard insulation: high temperature, ensure the interface temperature between the organic insulation layer and ensure that the foam is not carbonized.
6.减阻层: 确保作业钢管热胀冷缩自由运动。
6. Drag Reduction Layer: Ensure free movement of hot expansion and cold contraction of working steel pipe.
7.作业钢管：确保保送介质正常活动。
7. Working steel pipe: Ensure the normal activity of the delivery medium.
It is believed that after reading the introduction of http://www.sdhpgy.com, the polyurethane insulation steel pipe manufacturer in this paper, they will have their own understanding of this aspect, and other problems can be solved well in the future.
