Non standard flange refers to the parts used when connecting pipes, pipes and valves. There are holes and bolts on it to tightly connect the two flanges. Non standard flange is widely used in many industries because of its excellent performance. It is one of the mechanical parts widely used in industrial equipment and production. At the same time, it is also one of the connecting parts. The main application part is between the two ends of the pipeline or at the entrance of the equipment. The following describes the precautions for using non-standard flanges.
1. In order to prevent the inter eye corrosion caused by the heating of the flange cover, the welding current should not be too large, about 20% less than the carbon steel electrode, the arc should not be too long, the cooling speed between layers is fast, and the weld is relatively small. Narrow genghao.
2. Electricity Ji should be kept dry during use. The perovskite type shall be dried at 150 ℃ for 1 hour, and the low hydrogen type shall be dried at 200-250 ℃ for 1 hour (do not repeat drying for many times, otherwise the coating is easy to crack) and peel off, so as to prevent the welding rod coating from sticking oil and other dirt, so as not to increase the carbon content of the weld and affect the weld quality.
3. When welding non-standard flange pipe fittings, repeated heating will precipitate carbides, thus reducing corrosion resistance and mechanical properties.
4. Non standard flange pipe fittings have large quenchable flanges after welding, which are easy to break. If the same kind of chromium stainless steel electrode is used for welding, bixu preheat more than 300 ℃ after welding and slow cool at about 700 ℃. If the weldment cannot be subject to post weld heat treatment, non-standard flange pipe shall be used Ji.
5. In order to improve the corrosion resistance and weldability, appropriate stabilizing elements Ti, Nb, Mo, etc. should be added to the non-standard flange, and the weldability is better than that of chromium non-standard flange. When the same type of chromium non-standard flange electrode is used, it shall be preheated to more than 200 ℃ and tempered to about 800 ℃ after welding. If the weldment cannot be heat treated, non-standard flange pipe welding rod shall be used.
6. Non standard flange fittings have good corrosion resistance and oxidation resistance when welding flange electricity Ji, and are widely used in chemical industry, chemical fertilizer, petroleum and medical machinery manufacturing.
