Importance of welding work
Pressure vessels have an explosion hazard, and if an explosion occurs, it will be catastrophic. It turns out that most of the leaks and explosions of pressure vessels originate from the fracture of welded joints. Therefore, welding quality is the key to ensuring the safety and reliability of pressure vessels.
Welding Requirements
The welding requirements for stainless steel pressure vessels are as follows:
1. The groove surface of the welded joint must be constructed by mechanical methods.
2. Welding materials must be dehydrogenated and strictly cleaned.
3. The operator who undertakes the welding joint pairing must wear clean gloves, and must not touch the groove and its vicinity on both sides.
4. Welding should be carried out immediately after the cleaning of the weldment group is completed.
5. The purity of argon and helium for welding should not be lower than 99.99%, and the dew point should not be higher than minus 50℃.
6. Before the welding of titanium materials, strict mechanical cleaning and degreasing treatment should be carried out on the groove and within 25mm on both sides. Measures should be taken to prevent contamination of the groove during the welding process.
7. Effective measures should be taken to avoid mutual dissolution of steel and titanium during welding. When the drawing requires, the iron pollution test shall be done.
8. During the welding process, the color of the surface of the welding layer must be checked after each welding. The surface color of the welding seam and the heat-affected zone is silvery white or golden yellow. If the surface color is unqualified, all should be removed and then re-soldered. Surface color inspection should refer to the provisions of relevant standards.
9. Inert gas double-sided shielded arc welding or plasma welding must be used. The connection between the titanium pipe and the tube sheet should be welded by strength welding or post-expansion welding.
10. The surface of the welded seam after welding is not allowed to have defects such as undercut, pores, arc craters and cracks.
Concluding remarks
Although it is impossible to determine how many times a welder "spots" a weld bead or a container, it is certain that the quality of the weld is inseparable from the welder's "spots". Welding quality is more important than Mount Tai, this is not an alarmist, no matter how good a company will be blown up by a crisis. Therefore, as a tungsten argon arc welder, you must not only have operational skills, but also have quality awareness and sense of responsibility to ensure welding quality, ensure the safety of pressure vessels, and be responsible for yourself, the enterprise, and the society.
