Gas pipe corrosion defect under-pressure repair method

Abstract

The invention discloses a gas pipe corrosion defect under-pressure repair method. The gas pipe corrosion defect under-pressure repair method comprises performing surface cleaning on the pipe repair position; filling the pipe perforation leakage position or the outer surface corrosion position with a repairing agent; brushing the epoxy resin primer at the pipe surface position which needs to be wrapped, wherein the thickness of the epoxy resin primer is not less than 0.2 mm; enabling a carbon fiber band to wind the epoxy resin primer brushed pipe surface in a spiral mode, wherein the carbon fiber band winds the first to third layer, a special adhesive is bonded between the layers, and the drum rolling is adopted in the process of winding of the carbon fiber band to avoid the interlayer bulge; brushing the anticorrosive paint at the carbon fiber band wrapping position of the pipe surface. According to the gas pipe corrosion defect under-pressure repair method, the defects of the traditional repair method are overcome; the pipe corrosion and perforation defects are repaired in the running state of a gas pipe, the stress state of the pipe is not changed, the flame operation is not required, and accordingly the potential safety hazard is avoided and the service life is long; the stop operation is not required and accordingly the continuous production is ensured.

Description

technical field [0001] The invention relates to a method for repairing corrosion defects of gas pipelines under pressure. Background technique [0002] There are many large-diameter (φ1200-3800mm) gas pipelines in iron and steel enterprises, which involve a variety of gas media. The pressure of most of the gas medium is much lower than 0.1MPa, so it is not included in the pressure pipeline category of special equipment. [0003] Due to the complex composition of gas, there are mainly H 2 , CO, CO 2 、CH 4 , O 2 , N 2 、H 2 S, NH 3 , HCN, NO, and water, ammonium chloride, naphthalene, tar, etc., among which CO 2 、H 2 S, etc. combine with gas condensate to form an acidic corrosion environment, which can easily cause corrosion on the inner wall of the pipeline, which is usually pitting corrosion. As the service life of the pipeline increases, these pitting corrosion will cause perforation leakage; at the same time, the outer wall of the pipeline is often corroded by the...

AI Technical Summary

Problems solved by technology

[0004] For the corrosion leakage of such pipelines, the existing repair methods are plugging under pressure, large-area support of steel plates, epoxy resin coating or overall replacement. These repair methods have their own limitations, and plugging under pressure is a This temporary remedial method is suitable for a small amount of corrosion leakage points, but the service life is short, and the safety risk of the plugging operation under pressure is high; the large-area support of the steel plate increases the self-weight of the pipeline, which affects the stress distribution of the pipeline and the settlement of the support. Pressure welding, because the pipe wall is thin, the welding process is easy to perforate, and there are certain safety hazards; the epoxy resin coating aging speed is fast, the life is short, and it is easy to cause re-leakage; the overall replacement cost is high, requiring shutdown operations, affecting continuous production

Images