Prepreg for repairing pipelines containing defects

Abstract

The invention discloses a prepreg for repairing pipelines containing defects, and relates to the technical field of pipeline systems. The prepreg is fiber or fiber cloth pre-impregnated with a specialresin system; and the special resin system comprises 45 to 55 percent of epoxy resin, 2.5 to 15 percent of modified fatty amine curing agent, 2.5 to 30 percent of low molecular polyamide curing agent, 0.5 to 2.5 percent of 2,4,6-tris(dimethylaminomethyl)phenol accelerator, 0.5 to 3.5 percent of imidazole accelerator and 0 to 7.5 percent of epoxy reactive diluents. The prepreg is used for the repair of the pipelines containing the defects, and has the advantages of excellent material properties, high-content and uniform fiber, long service life and high reliability.

Description

technical field [0001] The invention is a prepreg for repairing defective pipelines. 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 resin-based composite materials for ...

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

However, due to the particularity of buried long-term oil and gas pipelines, the above-mentioned prepregs cannot meet the requirements of course.