Quality Control Technique in Welding of ERW Pipe

The quality control of longitudinally welded pipes can be used to safely carry out production operations and is also an inevitable element to ensure the personal safety of operators. The application fields are mainly in large-span grid engineering, construction steel structure engineering, electric power and ultra-high voltage transmission and distribution engineering, mechanical engineering, cross-sea bridges, bridges, (railroad station, airport, stadium steel structure engineering), municipal pipeline network, supporting facilities such as foundation piling, water gas pipeline and road construction.

1. Check whether the specifications of the welding wire and flux are correct according to the welding procedure regulations to prevent the wrong use of welding wire and flux and cause welding quality accidents.

2. Supervise the welding environment. When the welding environment is not good (the temperature is lower than 0℃, the relative humidity is greater than 90%), corresponding measures should be taken before welding.

3. Before pre-welding, check the groove dimensions, including gaps, blunt edges, angles and misalignments, whether they meet the process requirements.

4. Whether the welding current, welding voltage, welding speed and other process parameters selected in the automatic submerged arc welding process are correct.

5. Supervise the welding personnel to make full use of the length of the pilot arc plate at the end of the steel pipe during automatic submerged arc welding, and strengthen the use efficiency of the pilot arc plate during internal and external welding, which helps to improve the quality of pipe end welding.

6. Supervise whether the welding personnel clean up the slag first during repair welding, whether the joints have been thoroughly treated, and whether there is oil, rust, slag, water, paint and other dirt at the groove.