How to choose the quality of the thermal insulation steel pip
Jul 23, 2018
The insulation steel pipe is very important when selecting material, it determines the service life and maintenance cost of the project. The selection of steel pipes is whether the quality of the steel pipe, the density and distribution of polyurethane foam are uniform, whether the outer pipe is damaged or not, and so on.
The polyurethane insulation pipe is divided into three layers from the inside to the outside.
First floor: working steel pipe layer
According to design and customer requirements, seamless steel tube, spiral steel pipe and straight seam steel pipe are generally selected. After the steel tube surface is treated with advanced blasting technology, the grade of steel pipe rust removal can reach Sa2 level in GB8923-1988 standard, and the surface roughness can reach R=12.5 micron in GB6060.5-88 standard.
Second layer: polyurethane insulation layer:
In the cavity formed between the steel tube and the outer protective layer, the high pressure foaming machine is injected into the original liquid of rigid polyurethane foam plastic in one time, that is, the commonly known "tube in tube foaming".
2. Before construction, it is necessary to investigate the manufacturers producing prefabricated thermal insulation directly buried pipes, and seriously inspect them after entering the field, and refuse to use unqualified insulation pipes.
3. In the construction of directly buried pipeline, welding is a key work to ensure the quality of the project.
4.The construction quality of fixed supports and all kinds of well chambers will directly affect the quality of the project and the service life of the pipelines, so the construction should be carefully constructed to ensure the quality of the construction.
5. Pay great attention to the pressure of directly buried pipes and satisfy the pressing conditions.
6. The insulation construction of the spot joint. The quality of the construction directly affects the service life. The heat preservation pipe field joint insulation must be carried out after the test pressure is qualified. There are two methods of field foam construction and insulation tile construction. No matter which method is used, there is no ring space, cracking, delamination and so on. The protection layer must ensure the whole joint. Body, tightness and waterproof.
7. Test pressure, joint, completion survey, back fill after cleaning, and must fill in the thickness sand according to the construction characteristics of the direct buried pipe.
8.Engineering acceptance, because buried buried heating pipes buried underground, problems are not easy to solve and will affect the future service life. Therefore, every construction link should be carefully checked.
