Users should pay attention to the following points in the use of flat-welded flange Products:
1, in order to prevent the flat welding flange cover heating and produce eye corrosion, welding current should not be too large, than carbon steel electrode less than 20%, arc should not be too long, between the layers of fast cold, to narrow the welding path is appropriate.
2, the electrode should be used to maintain its dry, titanium calcium should be maintained 150 ℃ dry 1 hours, low a hydrogen type should be maintained 200-250 ℃ dry 1 hours, to prevent the electrode oil and other dirt and other dirty, so as to avoid the weld increased carbon content and influence the quality of the welding pieces.
3, flat welding flange pipe welding, by repeated heating and precipitation of carbide, reduce corrosion resistance and product mechanical properties.
4, Chrome flat welding flange pipe welding hardening of the United States standard flange larger, easy to produce cracks. If the use of the same type of chromium stainless steel electrode (G202, G207) welding, must be 300 ℃ above preheating and welding after 700 ℃ cooling. If the welding parts can not be heat treatment after welding, you should use the flat welding flange pipe electrode (A107, A207).
5, flat welding flange, in order to improve corrosion resistance and weldability and appropriate increase in the amount of stability of the elements ti, Nb, MO and so on, welding more than chrome flat welding flange better. When using the same type of chrome welding flange electrode (G302, G307), should be 200 ℃ above preheating and welding after 800 ℃ tempering treatment. If the welding parts can not be heat treatment, you should use the flat welding flange pipe electrode (A107, A207).
The main function of the flat welding flange:
1, connecting the pipe and maintain the pipeline sealing performance;
2, facilitate the replacement of a section of the pipeline;
3. Easy to disassemble and inspect the pipeline;
4, convenient for a section of the pipeline closure.