1. Watch 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 the appearance, wall thickness, ends, etc. of the seamless steel pipe, so as to judge by experience. For the qualification rate of seamless 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 inner wall thickness and hydrogen corrosion

During the use of seamless steel pipes, long-term operation under high temperature and high pressure will cause the whole 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 deviation parts become weak links, and it is easy to cause a burst accident. Therefore, before the inspection, it is necessary to inspect the surface of the pipeline to be inspected to observe whether there is rust, oxidation, oil pollution, etc. If so, it needs to be dealt with before checking. During inspection, the parts are checked for wall thickness.

3. Improve the accuracy of ultrasonic testing with the help of a variety of auxiliary tools

Ultrasonic testing is required to detect inner wall defects. 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 form of testing cannot be used for steel pipes in use. The direct contact method and the shear wave test method shall be used.

4. Use magnetic particle and penetrant testing to judge the qualification rate of elbows

Because the cutting allowance reserved at both ends of the manufacturing process is relatively small. In addition to the limitations of existing inspection equipment, inspection cannot be performed at elbows. However, this part is one of the parts where cracks often 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 penetrant inspection can be used as inspection objects.