1. Observe carefully with tools
The inspection can be carefully observed with the naked eye. Check the appearance and standard size of the steel pipe. During inspection, it is necessary to observe the above-mentioned defects in appearance, wall thickness, ends, etc. of seamless steel pipe, judging from experience. For the qualification rateseamless pipes,Supervision and inspection can also be carried out before installation. A regular inspection mechanism is established to regularly inspect the deformation, expansion, diameter, size and bending of seamless steel pipes.
2. Pay attention to the thickness of the inner walland corrosion
by hydrogen
During the use of seamless steel pipes, long-term operation at high temperature and high pressure will cause the entire pipe to burst. The cause of the pipe burst accident is that there is a deviation in the wall thickness of a part of the inner wall of the pipe. When the load cannot be satisfied, these deflection parts become weak links and it is easy to cause a breaking accident. Therefore, before inspection, it is necessary to inspect the surface of the pipe to be inspected to observe whether there is rust, oxidation, oil contamination, etc. If so, it should be addressed before checking. During inspection, the wall thickness of the parts is checked.
3. Improve the accuracy of ultrasonic testingwith the help of a variety of tools
Auxiliary Ultrasonic tests are necessary to detect defects in the inner wall. This detection technique can detect the wall thickness direction of the entire steel pipe. Especially for the defects of seamless steel pipes. Due to the simple shape of seamless steel pipes, a simple automatic water immersion method is basically used for ultrasonic testing in the manufacturing process, but this way of testing cannot be used for steel pipes in use. The direct contact method and the shear wave test method will be used.
4. Use magnetic particle and penetrant testing to judge the qualification rate of elbows
Because the cutting margin reserved at both ends of the manufacturing process is relatively small. In addition to the limitations of existing inspection equipment, inspection cannot be performed on elbows. However, this part is one of the parts where cracks usually appear. Especially during installation, if the crack problem is not checked in time, the crack will expand during welding. Therefore, for welded elbows, magnetic particle inspection and penetrating inspection can be used as inspection objects.
