First, the welding of galvanized steel pipes should pay attention to:
1. Galvanized steel pipes with a diameter greater than 100mm should be connected with flanges or special ferrule-type pipe fittings.
2. To ensure the quality of welding, the galvanizing of the weld should be treated at the welding joint of the galvanized steel pipe and the flange. The galvanized layer should be cleaned with a hand-grinding wheel or sandpaper, or the galvanized layer should be removed with a gas welding flame.
3. The welding of galvanized steel pipes and flanges should be galvanized twice.
Second, the measures to ensure the quality of welding are:
1. The human factor is the control focus of gas galvanized steel pipe welding. Due to the lack of necessary post-welding control measures, it is very easy to cut corners and affect the quality; at the same time, the special welding of galvanized steel pipes makes it difficult to ensure the quality of welding. Therefore, before the start of the project, skilled welders who hold the corresponding boiler pressure vessel or equivalent welder certificates should be selected, and necessary technical training and disclosure should be carried out. After the on-site welder assessment and approval are carried out by the boiler pressure vessel welder examination rules, permission to enter the site for welding should be given. And it shall not be replaced at will, to ensure that the welders of the pipeline are relatively stable.
2. Control of welding materials: ensure that the welding materials purchased are from regular channels, with quality assurance books and certificates, and meet the process requirements; the acceptance and delivery procedures of welding materials must be formal and complete, and the recovery of welding rod heads must be strictly controlled to ensure the flow direction and amount; welding materials must be baked strictly according to the process, and no more than half a day’s consumption should be issued at a time.
3. Welding machine; A welding machine is a welding machine, and its performance must be reliable and meet the process requirements; the welding machine must have qualified current and voltage meters to ensure the correct implementation of the welding process. The welding cable cannot be too long, and the welding parameters must be adjusted when it is long.
4. Welding process method: ensure the strict implementation of special operation methods of galvanized steel pipes, conduct pre-welding groove inspection according to the welding process, control welding process parameters and operation methods, and post-welding appearance quality inspection, and increase post-welding non-destructive testing if necessary. Control the welding level and the amount of welding materials for each pass.
5. Welding environment control: Ensure that the temperature, humidity, and wind speed during welding meet the process requirements. Welding shall not be carried out if the conditions are not met.
Post time: Jan-08-2025