聚氨酯保温管在国外一些兴隆国度已成为一项比较成熟的技术。近十几年。正推进着国内管网敷设技术向更高的层次展开。十几年来的理论效果充沛证明了聚氨酪保温直埋管敷设方式与传统的地沟及架空敷设相比，国供热工程技术人员经过消化、吸收这项技术。具有诸多优点。这也正是聚氨酪保温直埋管在国供热工程上得以迅猛展开的内在动力。
Polyurethane insulation pipe has become a mature advanced technology in some prosperous countries abroad. Over the past decade. It is pushing domestic pipeline network laying technology to a higher level. Over the past decade, the theoretical effect has proved that the laying method of polyurethane tyre thermal insulation buried pipe is better than the traditional trench and overhead laying method, and the national heating engineers and technicians have digested and absorbed this advanced technology. It has many advantages. This is precisely the internal power of the polyurethane thermal insulation directly buried pipe in the national heating project.
1.降低工程造价。据有关部门测算，双管制供热管道，普通情况下可以降低工程造价的25%采用玻璃钢做维护层）和10%采用高密度聚乙烯做维护层）左右。
1. Reduce the cost of construction. According to the calculation of relevant departments, double-pipe heating pipeline can generally reduce the cost by 25% using FRP as maintenance layer and 10% using high density polyethylene as maintenance layer).
2热损耗低，节约能源。由于直埋管采用聚氨酪硬质泡沫塑料中止保温，其导热系数为：λ=0.0130.03kcal/mhoC比其他过去常用的管道保温资料低得多，保温效果进步4~9倍。再有其吸水率很低，约为0.2kg/m2吸水率低的缘由是由于聚氨酯泡沫的闭孔率高达92%左右。低导热系数和低吸水率，加上保温层和外面防水性能好的高密度聚乙烯或玻璃钢维护壳，改动了激进地沟敷设供热管道“穿湿棉袄"状况，大大减少了供热管道的整体热损耗，热网热损失为2%小于10%规范恳求。
2. Low heat loss and energy saving. The thermal conductivity of the directly buried pipe is 0.0130.03kcal/mhoC, which is much lower than that of other commonly used pipes, and the thermal insulation effect is improved by 4-9 times. In addition, the water absorption rate is very low. The reason for the low water absorption of 0.2kg/m2 is that the closure rate of the polyurethane foam is about 92%. Low thermal conductivity and low water absorption, together with high density polyethylene (HDPE) or fiberglass reinforced plastics (FRP) maintenance shell with good insulation layer and external waterproof performance, have changed the situation of radical trench laying heating pipeline "wearing wet cotton jacket", greatly reducing the overall heat loss of heating pipeline, and the heat loss of heating network is less than 2% of the International 10% code request.
3.防腐，绝缘性能好，运用寿命长。直埋保温管由于聚氨酯硬质泡沫保温层紧密地粘结在钢管外皮，隔绝了空气和水的渗入，能起到良好的防腐作用。同时它发泡孔都是闭合的吸水性很小。高密度聚乙烯外壳、玻璃钢外壳均具有良好的防腐、绝缘和机械性能。因此，工作钢管外皮很难遭到外界空气和水的腐蚀。只需管道内部水质处置好，据国外资料引见，聚氨酪保温管道的运用寿命可达50年以上，比传统的地沟敷设、架空敷设运用寿命高3~4倍。
3. Anti-corrosion, good insulation performance and long service life. The directly buried insulation pipe is tightly adhered to the outer skin of the steel pipe because of the rigid polyurethane foam insulation layer, which can isolate the infiltration of air and water, and can play a good anti-corrosive effect. At the same time, the foaming holes are closed and the water absorption is very small. High density polyethylene shell and FRP shell have good anti-corrosion, insulation and mechanical properties. Therefore, the outer skin of working steel pipe is very difficult to be corroded by external air and water. According to foreign data, the service life of polyurethane thermal insulation pipeline can reach more than 50 years, which is 3-4 times longer than that of traditional trench laying and overhead laying.
4.占地少，施工快，有利环境维护。直埋供热管道不需求砌筑庞大的地沟，只需将保温管埋人公开，因此大大减少了工程占地，减少土方开挖量约50%以上，减少土建砌筑和混凝土量90%同时，保温管加工和现场挖沟平行中止，只需现场接头，可以缩短工期约50%以上。
4. It occupies less land, constructs quickly and maintains favorable environment. Directly buried heating pipelines do not need to build huge trenches. They only need to bury insulating pipes openly. Therefore, the construction area is greatly reduced, the excavation amount of earthwork is reduced by more than 50%, and the amount of civil construction and concrete is reduced by 90%. At the same time, the processing of insulating pipes and the excavation of trenches on site are stopped in parallel, and the construction period can be shortened by more than 50% with only the on-site joints.
5.国外消费聚氨酪保温预制管，均设有渗漏报警线，一旦管道某处发作渗漏，经过报警线的传导，便可在专用检测仪表上显现出保温管道渗水、漏水的准确位置及渗漏程度的大小，以便通知检渗人员疾速处置漏水的管段，保证供热管网的平安运转。国内消费的保温管目前末设渗漏报警线，有待补上这一空白。总之，聚氨酯保温直埋管不只具有激进地沟和架空敷设管道难以比较的技术、适用性能，而且还具有显著的社会效益和经济效益，也是供热的有力措施。采用直埋供热管道技术，标志着我国供热管道技术展开曾经进入了新的起点。随着这项技术的进一步完善和展开，供热管道直埋取代地沟和架空势在必行。
5. Foreign consumer polyurethane insulation prefabricated pipes are equipped with leakage alarm lines. Once leakage occurs somewhere in the pipeline, through the transmission of the alarm lines, the exact location and degree of leakage of the insulation pipes can be displayed on the special testing instruments, so as to inform the inspectors to quickly dispose of the leakage pipeline section and ensure the safe operation of the heating network. At present, the leakage alarm line for domestic consumer heat preservation pipes has been set up, which needs to be filled in. In a word, polyurethane thermal insulation buried pipe not only has advanced technology and applicability which is difficult to compare with radical trench and overhead pipeline laying, but also has significant social and economic benefits. It is also a powerful measure for heating energy saving. The adoption of directly buried heating pipeline technology marks a new starting point for the development of heating pipeline technology in China. With the further improvement and development of this advanced technology, it is imperative to replace underground ditches and overhead by burying heating pipelines directly.
