Advantages of polyurethane seamless steel pipe direct buried insulation pipe

1. Reduce project cost

According to calculations by relevant departments, double-pipe heating pipelines can generally reduce the project cost by about 25% (using glass fiber reinforced plastic as a protective layer) and 10% (using high-density polyethylene as a protective layer).

2.Low heat loss and energy saving

The thermal conductivity of the direct buried insulation pipe is: λ=0.013-0.03kcal/m·h·oC, which is much lower than other commonly used seamless  steel pipe insulation materials in the past, and the insulation effect is improved by 4~9 times. In addition, its water absorption rate is very low, about 0.2kg/m2. The reason for the low water absorption rate is that the closed-cell rate of polyurethane foam is as high as about 92%. Low thermal conductivity and low water absorption, coupled with the insulation layer and the high-density polyethylene or glass fiber reinforced plastic protective shell with good waterproof performance on the outside, have changed the situation of "wearing a wet cotton jacket" in the traditional trench laying of heating pipelines, greatly reducing the overall heat loss of the heating pipeline, and the heat loss of the heat network is 2%, which is less than the standard requirement of 10%.

3. Anti-corrosion, good insulation performance and long service life

The direct buried insulated pipe has a polyurethane rigid foam insulation layer that is tightly bonded to the outer skin of the steel pipe, isolating the infiltration of air and water, and can play a good anti-corrosion role. At the same time, its foaming holes are closed and have low water absorption. Both the high-density polyethylene shell and the fiberglass shell have good anti-corrosion, insulation and mechanical properties. Therefore, the outer skin of the working steel pipe is difficult to be eroded by external air and water. As long as the water quality inside the pipeline is well treated, according to foreign data, the service life of the direct buried insulated pipe can reach more than 50 years, which is 3 to 4 times higher than the service life of traditional trench laying and overhead laying.

4. Small footprint, fast construction, beneficial to environmental protection and reducing construction disturbance

Direct buried heating pipes do not need to build huge trenches, only need to bury the insulation pipes underground, thus greatly reducing the project area, reducing the amount of earthwork excavation by about 50% or more, and reducing the amount of civil engineering masonry and concrete by 90%. At the same time, the insulation pipe processing and on-site trenching are carried out in parallel, and only on-site joints are required, which can greatly shorten the construction period. Since the transportation of bricks, cement, sand, gravel, and surplus soil is reduced, the amount of automobile exhaust emissions, dust, and noise emissions during the construction process are reduced, thus protecting the environment.

5. Safety

At present, all direct-buried insulated pipes produced outside China are equipped with leakage alarm lines. Once a leakage occurs somewhere in the pipeline, the alarm line conducts, and the exact location and degree of leakage of the insulated pipe can be displayed on the detection instrument, so as to notify the leakage inspection personnel to quickly deal with the leaking pipe section and ensure the safe operation of the heating pipe network. Domestically produced insulated pipes are currently not equipped with leakage alarm lines, and this gap needs to be filled.

Summary of direct-buried insulated pipes

In short, direct-buried insulated pipes not only have the best technology and practical performance that traditional trenches and overhead pipelines cannot match, but also have significant social and economic benefits, and are also a powerful measure for heating energy saving. The use of direct-buried heating pipe technology marks that the development of China's heating pipe technology has entered a new starting point. With the further improvement and development of this best technology, it is imperative to replace trenches and overheads with direct buried heating pipes.

Article source: https://article-realm.com/article/Business/67388-Advantages-of-polyurethane-seamless-steel-pipe-direct-buried-insulation-pipe.html