Liaoyang steel jacket steam prefabrication Thermal insulation pipe Large manufacturers Thermal insulation pipe is used for central heating, cooling and hot oil transmission and distribution Steel pipe Heju ethylene External protective tube, for both polyurethane Foam insulation materials are tightly integrated. The pipe diameter ranges from Φ 90 to Φ 1240. The full name of the insulation pipe is high-density polyethylene polyurethane rigid foam foam insulation pipe. Its function is to protect the temperature of the fluid inside the work pipe, prevent heat transfer with the outside world, and cause the loss of fluid temperature.
Polyurethane insulation pipe has the characteristics of small heat loss, strong compression resistance, good anti-corrosion and waterproof performance. Particularly suitable be launched High ranking areas. Compared with the traditional trench laying pipeline, it has a series of advantages such as good thermal insulation performance, corrosion prevention, good insulation performance, long service life, simple construction and installation, small floor area, low project cost, etc. It has been widely used in central heating, oil transportation, chemical industry, refrigeration, water supply in cold regions and other projects.
The polyurethane insulation pipe has low foam strength and soft foam, which is caused by the imbalance of the proportion of black and white materials. The proportion of * * * black materials can be appropriate (1:1-1.05). Note that the proportion of black materials should not be too large, otherwise the foam will become brittle and affect the foam performance.
The polyurethane directly buried insulation pipe has good insulation effect: the insulation effect of polyurethane is compared with that of other materials. 2. Compared with the traditional trench pipeline, the directly buried insulation pipeline with low engineering cost can save the cost of the whole trench and its auxiliary support devices. The construction cost of directly buried laying is lower than that of traditional perlite insulation trench laying. The service life is 60 years. According to the domestic data, the wet aging life is 16 years, and the thermal aging life is 60 years. Some data show that the service life of ordinary pipelines used as general thermal pipelines is less than 15 years in consideration of internal corrosion. Some data show that the service life of buried pipelines is 50 years, and that of empty pipelines is 20 years. Although the data are different, the service life of this directly buried anti-corrosion and thermal insulation pipeline is higher than that of the traditional trench pipeline. Its less useful life is 15 years.
The trench size of directly buried pipeline shall meet the requirements shown in the following figure:
1. When the bearing capacity of the upper layer at the bottom of the trench is ≤ 60KPa, the bottom of the trench shall be padded with plain concrete.
2. The soil layer at the bottom of the C15 plain concrete layer shall be compacted first and then poured with concrete. The surface of the concrete layer shall be smooth and flat. When the bottom soil layer is collapsible soil, it shall be replaced (about 1.0m deep) and compacted.
3. The trench width and * * * at the joint in the trench shall be 250~300mm more than that at the non joint.
4. For the position with corrugated compensator, the soil layer elevation at the bottom of the corrugated compensator shall be determined according to the actual arrival size of the compensator.
5. The slope of the upper layer of the trench bottom along the pipeline shall be consistent with that of the pipeline.
6. 100mm around the directly buried pipeline shall be compacted with fine sand. The diameter of sand particles shall not be greater than 8mm, and there shall be no clay, brick, stone, iron and other sundries in the sand layer.
7. When the pipe is located in the highly corrosive soil section such as slag and sundries, the backfill shall be replaced with less corrosive soil and compacted layer by layer.
8. The ditch must be well drained. Drainage ditch can be used, and the collecting pool can be drained by water pump.
Pipe installation
The installation of pipes must be carried out after the excavation of the pipe trench and the treatment of the soil layer at the bottom of the trench are qualified. Note during installation
The following requirements;
1. Before the pipeline is laid into the trench, the anti-corrosion coating on the surface of the pipeline shall be carefully checked. If the anti-corrosion coating is damaged, it shall be treated in time.
2. The design axis and gradient of the pipeline shall be ensured when the pipeline is connected.
3. Prefabricated insulation pipes can be hoisted into the trench for installation, or two or more * * * pipes can be hoisted after welding. When the assembly and welding pipe section is long, two or more cranes should be used to lift the pipe and lower the pipe, and the position of the lifting point should be selected according to the balance conditions. It is strictly prohibited to push the pipeline directly into the trench.
4. After the welding of the working steel pipe is completed and the inspection is qualified, the heat preservation of the joint and the connection of the outer sleeve can be handled. First, the formwork can be erected for polyurethane foaming, and then the joint part can be sealed as a whole with heat shrinkable tape. Both ends and the straight pipe are overlapped by 100mm respectively; The outer casing can also be butt welded first, and then opened for foaming after passing the sealing inspection.
5. When the project is completed on that day, the pipe end shall be blocked with a blind plate to prevent mud and water from entering the pipe.
6. Prefabricated insulation pipes can be installed in three ways: cold installation, thermal prestress installation and one-time compensator installation.
7. Cold installation is to directly connect the pipe sections and backfill according to the standard after passing the inspection;
8. The hot prestress installation is to preheat the pipe to 60% of the working temperature before welding, and then backfill and tamp.
9. The one-time compensator must be welded when the pipe temperature rises to 60% of the working temperature, and then backfilled and compacted.
