What is the detection method for butt-welded elbows after corrosion?
Butt-welded elbows can produce corrosion during improper use. After the butt-welded elbows are corroded, they are usually manifested as thinning of the pipe wall of the butt-welded elbows, and local pits and pitting appear. Detection method for butt-welded elbows after corrosion: The basic principle of leakage flux detection is based on the basic property of high magnetic permeability of ferromagnetic materials.
The magnetic permeability of the corrosion defect of the butt-welded elbow is much smaller than that of the butt-welded elbow. The butt-welded elbow is magnetized under the action of an external magnetic field. When there is no defect in the butt-welded elbow, most of the magnetic lines of force pass through the steel pipe, and the magnetic lines of force are evenly distributed at this time; when there is a defect inside the butt-welded elbow, the magnetic lines of force bend, and some of the magnetic lines of force leak out of the surface of the steel pipe. By detecting the leakage flux escaping from the surface of the magnetized butt-welded elbow, it can be determined whether the defect exists. Ultrasonic method The ultrasonic detection method uses the pulse reflection principle of ultrasonic waves to measure the thickness of the pipe wall after corrosion. This process adopts the method of self-propagating centrifugal casting to form, mainly using the chemical reaction of the substance itself, exothermic combustion to generate high temperature, and synthesizing new substances in the process of combustion wave propagation. During the detection, the probe emits ultrasonic pulses vertically to the inner wall of the butt-welded 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. The distance between this pulse and the reflected pulse from the inner surface reflects the thickness of the pipe wall. Bending: refers to processing the pipe into a butt-welded elbow, generally refers to metal pipes for water and electricity and electrical PVC threading pipes; Bending butt-welded elbow: mostly refers to metal butt-welded elbows for water supply and drainage, and small-diameter butt-welded elbows can be obtained by bending.
Cold bending/hot bending: Generally, small and medium-sized butt-welded elbows can be obtained by cold bending; large diameters require hot bending. Bending processing generally refers to on-site completion. Butt-welded elbows: Most of the butt-welded elbows used in engineering water supply systems (especially large diameters) can be purchased as finished products, and the processing method is stamping.
