Butt-welded elbow fittings can cause corrosion during incorrect use. After the butt-welded elbow is corroded, it usually shows that the butt-welded elbow’s pipe wall becomes thinner, and there are local pits and pits. Detection method of butt welding elbow after corrosion: The basic principle of flux leakage detection is based on the basic characteristic of high permeability of ferromagnetic materials.
The magnetic permeability of the corrosion defect of the butt welding elbow is much lower than that of the butt welding elbow. The butt welding elbow is magnetized under the action of an external magnetic field. When there is no defect in the butt welding elbow, most of the magnetic field lines pass through For steel pipes, the magnetic field lines are evenly distributed at this time; when there is a defect inside the butt-welded elbow, the magnetic field lines bend, and a part of the magnetic field lines leak out of the surface of the steel pipe.
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By detecting the leakage flux from the surface of the magnetized butt welding elbow, it can be judged whether the defect exists. Ultrasonic method Ultrasonic detection method uses the principle of ultrasonic pulse reflection to measure the thickness of the tube wall after corrosion. The process adopts the self-propagating centrifugal casting method to form, and mainly uses the chemical reaction of the substance itself, exothermic combustion produces high temperature, and the technology of synthesizing new substances in the process of combustion wave propagation.
During the inspection, the probe is transmitted perpendicular to the inner wall of the butt welding elbow. The probe first receives the reflected pulse from the inner surface of the pipe wall, and then the ultrasonic probe receives the reflected pulse from the outer surface of the pipe wall. This pulse is reflected from the inner surface. The distance between pulses reflects the thickness of the tube wall. Simmering bend: refers to the processing of pipes into butt welded elbows, generally refers to metal pipes for hydropower and electrical PVC threading pipes; simmering butt welded elbows: refers to metal butt welded elbows for water supply and drainage, small pipe diameter butt welding The elbow can be obtained by simmering.
Cold bending/hot bending: Generally, small and medium butt welding elbow diameters can be obtained by cold bending; large pipe diameters require hot bending. Simmering processing generally refers to completion on site. Butt welding elbow: Most of the engineering water supply system (especially large pipe diameter) can be purchased as a finished butt welding elbow, and the processing method is stamping.
