How to detect the common defects in spiral welded pipe equipment

Spiral welded pipe equipment common defect magnetic powder inspection or saturated. Spiral welded pipe equipment magnetic powder inspection or saturated can be useful found crack appearance, folding, double skin, hair, such as pinhole appearance defects. Of ferromagnetic materials, should first choose magnetic particle test, because of its high detection sensitivity; On the ferromagnetic materials, such as spiral steel pipe, stainless steel is chosen to soak test.

When the spiral welded pipe equipment reserve two head resection margin is small, because the source of the layout of testing equipment, spiral steel pipe two head sometimes is not useful to detect, and end is the most able to crack or other defects. If the spiral welded pipe end there is a potential crack tendency, device at the time of the welding heat affected are able to make potential crack expansion. Therefore, also should pay attention to after butt spiral welded pipe must be area detection, timely find the drawback of the spiral welded pipe end expanding.

Line using austenitic spiral welded pipe, when thermal barrier damage or able to rain infiltration into parts, penetration tests should be paid attention to, to find stress corrosion cracking and pitting corrosion defect. But magnetic powder or penetration testing only to test the steel tube outer appearance, internal appearance defects are overstretched. For appearance of the spiral welded pipe unit testing, especially the crack defect detection, it is necessary after ultrasonic testing.