1. Galvanized steel pipes with a pipe diameter greater than 100mm should be connected by flanges or ferrule-type special pipe fittings.
2. In order to ensure the welding quality, the galvanized steel pipes and flanges should be galvanized, and the galvanized layer should be treated with a hand wheel or sandpaper, or the galvanized layer should be removed with a gas welding flame.
3. The weld between galvanized steel pipe and flange should be galvanized twice.
Measures to ensure welding quality include
1. The human factor is the main point of control for welding gas galvanized pipes. Because of the lack of necessary post-weld manipulation methods, it is easy to cut corners and affect the quality; at the same time, the welding particularity of the galvanized pipe makes it difficult to ensure the welding quality. Therefore, before the start of the project, it is necessary to select skilled welders with corresponding boiler and pressure vessel or equivalent welder certificates, conduct necessary technical training and clarification, and perform on-site welder verification and approval according to the boiler pressure vessel welder examination rules, and then grant them Permission to enter the site for welding. And do not change at will, to ensure that the welder welding the pipeline is relatively stable.
2. Control of welding consumables: ensure that the welding consumables purchased from regular channels have quality assurance certificates and certificates that meet the process requirements; welding consumables must be inspected and received and dispatched in a formal and complete procedure, and the welding rod heads should be recycled and controlled strictly to ensure the flow direction , Dosage: Welding consumables must be baked strictly according to the process, and the amount of welding materials shall not exceed the half-time amount in one time.
3. Welding machine: The welding machine is a tool for welding, which must ensure reliable function and meet the needs of the process; the welding machine must have a qualified current and voltmeter to ensure the correct implementation of the welding process. The welding cable should not be too long, and the welding parameters should be adjusted when it is longer.
4. Welding process method: to ensure the strict implementation of the special operating methods for galvanized pipes, check the pre-weld groove according to the welding process, control the welding process parameters, operation methods, check the appearance quality after welding, and add non-destructive testing after welding if necessary. Control the welding level and the amount of welding consumables for each pass.
5. Welding environment control: to ensure that the temperature, humidity, and wind speed during welding meet the process requirements. No welding is allowed when unconditional.
