Intermediate-frequency heating repaired opening construction technology for thermal contraction band of buried steel pipeline

Abstract

The invention relates to an intermediate-frequency heating repaired opening construction technology for a thermal contraction band of a buried steel pipeline. The construction technology comprises the following steps: 1) cleaning flaws of a welded junction and an anticorrosive layer prefabricated in a factory; 2) performing sand-blasting and de-rusting on a pipe body, wherein a de-rusting level is Sa2.5 level and an anchoring grain depth is 50 microns to 100 microns; 3) performing intermediate-frequency heating on the pipe body, wherein a preheating temperature is at 50-90 DEG C; 4) painting a primer, wherein the thickness of the primer is above 200 microns; 5) performing napping treatment on the surface of the anticorrosive layer prefabricated in the factory, in a flame manual steel wire brushing napping mode; 6) mounting the thermal contraction band: winding the thermal contraction band at the repaired opening, sticking a fixing sheet, and baking the surface till the thermal contraction band is completely and seamlessly covered on the pipe body; 7) secondarily intermediate-frequency heating under a secondary heating temperature at 100-130 DEG C, till fully melting a hot melt adhesive; and 8) removing air bubbles. According to the construction technology provided by the invention, the heating temperature is uniform, the influences of personal factors on construction quality are reduced and the efficiency and quality of repaired opening construction are greatly increased.

Description

technical field [0001] The invention relates to a joint construction process for buried steel pipeline heat shrinkable with intermediate frequency heating suitable for intermediate frequency heating, and relates to the technical fields of general anticorrosion of metal materials and pipeline systems. Background technique [0002] At present, the heat-shrinkable tape joints of buried pipelines are generally heated by manual flames. The existing problems are: direct flame heating will cause secondary pollution on the surface of the pipe body, resulting in a decrease in the adhesion of the epoxy primer; flame heating is difficult. Ensure that the pipe body is heated evenly and the heating temperature is insufficient due to human factors, often resulting in insufficient or partial melting of the hot melt adhesive, resulting in a decrease in the sealing performance of the heat shrinkable tape or even a failure of the seal; especially in winter construction, due to the low ambient ...

AI Technical Summary

Problems solved by technology

[0002] At present, the heat-shrinkable tape joints of buried pipelines are generally heated by manual flames. The existing problems are: direct flame heating will cause secondary pollution on the surface of the pipe body, resulting in a decrease in the adhesion of the epoxy primer; flame heating is difficult. Ensure that the pipe body is heated evenly and the heating temperature is insufficient due to human factors, often resulting in insufficient or partial melting of the hot melt adhesive, resulting in a decrease in the sealing performance of the heat shrinkable tape or even a failure of the seal; especially in winter construction, due to the low ambient temperature, the pipeline Fast heat dissipation, slow temperature rise, and long heating time seriously affect the efficiency of pipeline construction

However, this technology will still cause secondary pollution on the surface of the pipe body, resulting in a decrease in the adhesion of the epoxy primer and the lack of ensuring that the pipe body is heated evenly.

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