Spiral common defect detection method

Common defects of submerged arc welding magnetic particle testing or penetration testing. Spiral steel magnetic particle testing or penetration testing can effectively detect surface cracks, folding, heavy skin defects, hair lines, pinholes. For ferromagnetic materials, magnetic particle testing method for the detection of high sensitivity, priority should be given to magnetic particle inspection; for non-ferromagnetic materials, such as stainless steel spiral tube, using penetration detection method.


In-line austenitic steel spiral pipe, when the insulation is damaged or rain may infiltrate the site, pay attention to the penetration test to find defects such as stress corrosion cracking or pitting. However, magnetic particle inspection or penetration testing can only detect the outer surface of a pipe to detect internal defects. Detector inner surface, especially crack-type defects must be detected by ultrasound.


When there is less trimming at the end of the coil, the coil tip can sometimes not be detected effectively for structural reasons and the tip is the site most likely to crack or other defects. If the ends of the spiral pipe have a tendency to crack, the welding heat during the installation may also cause potential cracks. Therefore, it should be noted that, in the detection of a welded spiral zone, to detect the spiral tip defects.