Method for preparing repair prepreg for pipelines with defects

Abstract

The present invention provides a method for preparing repair prepreg for pipelines with defects. In the method, fiber or fiber cloth is infiltrated with a special resin system, wherein the special resin system comprises epoxy resin accounting for 45 to 55 percent of the total weight which is 100, a modified aliphatic amine curing agent accounting for 2.5 to 15 percent of the total weight, a low-molecular polyamide curing agent accounting for 2.5 to 30 percent of the total weight, a 2,4,6-trisphenol accelerator accounting for 0.5 to 2.5 percent of the total weight, an imidazole accelerator accounting for 0.5 to 3.5 percent of the total weight, and an epoxy reactive diluent accounting for 0 to 7.5 percent of the total weight. The steps of infiltrating the resin system are as follows: a, the epoxy resin, the curing agents, the accelerators and the diluent are mixed well and then poured into a glue groove (3) with a heating element; b, fiber fabric (1) is wound on a paper tube; the paper tube is put on a rotating shaft (2); and the fiber fabric (1) is passed through the glue groove (3) under traction to infiltrate the fiber fabric (1) with resin; c, the obtained fiber fabric (1) infiltrated with the resin is dried via a blast drying channel (5) and then is wound on a roller; and d, a prepreg coiled tape (6) obtained in a step c is sealed and refrigerated.

Description

technical field [0001] The invention relates to a preparation method of a defect-containing pipeline repair prepreg. It relates to the technical field of piping systems. Background technique [0002] According to statistics, the total length of long-distance oil and gas pipelines currently in service in my country exceeds 5×10 4 km, a considerable part of which has been in service for many years and has defects of varying degrees and needs to be updated, modified, overhauled or depressurized. Therefore, the repair of pipelines has become an indispensable and regular work in the process of oil and gas gathering and transportation. , need to invest a lot of manpower and financial resources every year. Traditional pipeline repair methods include repair welding, repair plate, sleeve, etc. From the perspectives of safety, economy and reliability, these methods can no longer meet the higher requirements of the oil industry for repair technology. In recent years, the use of resi...

AI Technical Summary

Problems solved by technology

The disadvantages of this technology are: firstly, due to the high rigidity of the composite sleeve, it is not easy to deform, and it is difficult to ensure the tight fit between the composite sleeve and the pipe body during the construction process, which affects the overall load-bearing effect, and this technology can only be used Due to the large curvature of the circular pipe, it is impossible to repair the irregular parts of the structure, such as tee joints, etc.; second, due to the use of glass fibers with low modulus and strength, the recovery efficiency of the pipe body is limited. Moreover, the wet heat aging performance of the glass fiber composite material is poor, and it is not easy to be used in an environment with high humidity and high temperature; third, because the composite sleeve is produced in a series of processes such as extrusion, drying, heat treatment and curing in the factory come out, its cost is higher and its efficiency is lower

This repair technology also has obvious deficiencies: first, because the glue solution is prepared and wound on the construction site, the proportion of each component in the glue solution, the ratio of resin to fiber, the degree of infiltration of resin to fiber, and the smoothness of fiber cloth It is difficult to control the consistency of parameters such as degree of repair. They are all affected by factors such as the proficiency of the construction personnel, the amount of repair, the construction environment, and the initial state of raw materials. Therefore, the effectiveness and durability of the repair layer are unpredictable. The stiffness and strength of the layer fluctuate greatly, which is not suitable for the repair of high-temperature and high-pressure pipelines; in addition, the working environment and labor efficiency during the implementation of this technology are poor, and the volatile components in the resin and the fibers that fall off the fiber cloth Hair is easy to cause skin allergies, which is harmful to human health and pollutes the environment; finally, the contact between carbon fiber and metal is likely to cause potential corrosion of the metal, which is more obvious in a humid environment, which has a great effect on the anti-corrosion effect of the pipeline. big impact

[0005] However, due to the particularity of buried long-distance oil and gas pipelines, the above-mentioned prepregs are of course not applicable.

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