Basic Principles
Penetrating testing uses the ability of liquid penetrants to penetrate and visualize open defects on solid surfaces. The penetrant penetrates into open defects such as cracks, pores, shrinkage holes, etc. on the surface of API 5L X52 pipes under capillary action, and then removes excess penetrant by cleaning, and then applies a developer to the surface. The developer uses the same capillary action principle to attract the penetrant in the defect to the surface, and shows the morphology and distribution of the defect through fluorescence or coloring.
Testing Steps
Prepare the workpiece: Scrub the surface of the API 5L X52 seamless and welded pipe to be tested to remove stains, grease and other impurities that may affect the test results.
Apply penetrant: Apply the penetrant to the surface of the pipe to make it fully contact and form a wet film layer. This step is the key to the test, and it is necessary to ensure that the penetrant can fully penetrate into the open defects.
Cleaning and Drying: Use a suitable cleaning agent to remove excess penetrant on the surface of the pipe, and then dry it to prevent moisture from affecting the test results.
Apply developer: Apply the developer to the dried pipe surface. The developer will absorb the penetrant in the defect through capillary action, thus showing the trace of the defect on the surface.
Detection and evaluation: Observe the pipeline surface under an appropriate light source (such as black light or white light) to find and evaluate the morphology, size and distribution of defects. For fluorescent penetrants, black light is usually used; while colored non-fluorescent penetrants can be directly observed under white light.
