During the regular inspection of spherical tanks in a large chemical enterprise, there are a lot of weld cracks on the internal and external surfaces of the 3 000 m³ propylene spherical tank. The cracks are found classified and counted according to the location and category, and the appearance of typical crack defects are analyzed. The causes of weld cracks are analyzed in depth, and the five major causes of weld cracks on the spherical tank are summarized, The targeted treatment suggestions, precautions for the construction, installation and regular inspection of spherical tanks in the future and preventive measures to avoid weld crack are given. The results show that poor welding technology, on-site heat treatment not meeting the specification requirements, and welding residual stress are the main causes of spherical tank cracking. During the manufacturing process of spherical tank, the quality of raw materials and manufacturing quality of spherical shell plate shall be strictly controlled, and the quality of welding process and non-destructive testing of welds after welding shall be controlled. In the regular inspection process, the upper and lower circumferential welds shall be focused on. The method of UT+TOFD can be used for weld testing.
关键词
球罐储罐对接焊缝裂纹定期检验上、下级环焊缝
Keywords
spherical tankbutt weldcrackperiodic inspectionupper and lower circumferential welds
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