Nondestructive testing method for pipeline welding joint of thermal power plant and flow detection hole blocking piece

Abstract

The invention discloses a nondestructive testing method for a pipeline welding joint of a thermal power plant. The nondestructive testing method is used for nondestructive testing of the pipeline welding joint of the thermal power plant; a ray source is arranged at the circle center of the pipeline through a flaw detection hole formed in the pipeline, and a negative film coats the outer side of the welding joint; and circumferential exposure flaw detection is carried out, and the flaw detection hole is sealed by utilizing a flaw detection hole blocking piece after the flaw detection is finished. The invention further discloses a structure of the flaw detection hole blocking piece, so that the sealing of the flaw detection hole can be ensured, and the normal working performance of the pipeline is ensured not to be damaged. According to the testing method, it can be guaranteed that rays pass through a relatively thick tube wall smoothly, and the ray energy level and the illumination timeare greatly reduced; in addition, the imaging on the negative film corresponds to a specific position, overlapping is avoided, and the imaging accuracy is ensured. Meanwhile, according to the relation between the design temperature and the creep temperature of the pipeline, different flaw detection holes and flaw detection hole blocking piece structures are provided; and when the design temperature of the pipeline is within the creep temperature range, a threaded connection pipe seat can be used for ensuring that the flaw detection hole is effectively sealed.

Description

technical field [0001] The invention relates to the technical field of non-destructive testing of pipeline welds in thermal power plants, in particular to a method for non-destructive testing of pipeline welds in thermal power plants and a flaw detection hole sealing piece. Background technique [0002] After the four major pipelines of thermal power plants (main steam pipeline, hot reheat steam pipeline, cold reheat steam pipeline, and high-pressure water supply pipeline) are welded on site, it is necessary to conduct non-destructive testing on the weld to ensure the welding quality of the weld. At present, it is common The detection method adopted is the double-wall transillumination method, that is, the radiation source is placed outside the weld, the film is placed at the weld on the opposite side of the radiation source, the radiation passes through the weld, and the flaw detection results are displayed on the film. As a result, the welding quality of the weld is judged...

AI Technical Summary

Problems solved by technology

This application solves the problem of ray source tripping, but when dealing with complex pipelines, such as the four major pipelines of thermal power plants with many turns or variable diameters, the carrying system will be difficult to move forward smoothly due to structural changes in the pipelines, reducing work efficiency, and even Unable to reach the flaw detection position, unable to realize non-destructive testing of pipeline welds

Images