Application of the hottest pipe automatic welding

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Application of automatic pipe welding machine in long-distance pipeline construction

first, the characteristics of welding in long-distance pipeline construction

1. Liquidity construction is the most economical and reasonable process scheme for welding quality; At the same time. The construction sites are constantly moving with the construction progress, which increases the difficulty of construction management, quality management, safety management and other aspects compared with the production of factory products; Because the welding operation is in a flowing state, it is relatively difficult to ensure the quality

2. Influence of landform on welding quality. The construction unit is unable to choose an ideal construction site. A long-distance pipeline may encounter a variety of terrain, such as the west to east gas transmission project, which passes through Gobi, desert, Loess Plateau, mountains, plains, water, etc. from west to East. Terrain and landform have a direct impact on welding, so different welding methods should be selected according to local conditions to meet the needs of the project

3. the influence of environment on welding quality will cause too high cost. Wind, rain, temperature, humidity and other natural environment have a certain relationship with the welding quality

4. In addition to on-site duplex pipe welding, welding equipment, process, materials, welder skills and other factors have a great impact on welding quality

5. Influence of human and social environment on welding quality. In the artificial intensive areas in the east of China, due to various reasons, the construction cannot be carried out continuously, which often brings difficulties to the on-site welding. Due to the interference of external factors, there are many joints left on site, the number of joints increases, and the quality is difficult to guarantee, which also increases the welding cost

II. Current situation of pipeline welding

with the progress of social technology, the welding technology of long-distance pipeline is also gradually improving

1. domestic situation:

1.1 in the 1970s and before, the traditional manual welding method was used for welding in pipeline construction. This welding method is no longer suitable for application in pipeline construction because of the slow industrialization system and low welding quality of intelligent robots using advanced magnetic materials, electromechanical and power electronic devices due to the welding speed

1.2 in the early 1980s, the pipeline bureau introduced the manual downward welding process from the United States and Europe, and gradually extended it to most construction enterprises, with the quality improved to a higher level. At that time, the quality was counted according to the length of weld, and the first pass rate of X-ray was more than 95%. This welding method has replaced the traditional manual welding method

1.3 self protective semi-automatic welding consumables are mainly imported. The pipeline administration has not achieved any results since it began the test in 1994. It is understood that several domestic welding materials research institutions have carried out research and development, and no formal products have been found so far, and no products have been found at all welding exhibitions

1.4 the disadvantages of automatic welding technology are as follows:

first, it requires high quality of pipe groove and butt joint, that is, it requires uniform butt joint of the pipe all around

second, the requirements for groove type are strict. When the wall thickness of the pipe is thick, composite or U-shaped groove is used when determining the process, which can not only reduce the workload, but also consider the guarantee of the groove to the welding quality. Although small angle V-shaped groove simplifies the construction procedure, from the perspective of quality assurance, composite slope L or U-shaped groove is better

third, it is greatly affected by the external climate, which is also a common problem of gas shielded welding

fourth, the problem of gas source in remote areas, especially argon. For example, the west of the west east gas transmission project is flat, which is suitable for automatic welding. However, the argon gas source is far away, and the mixed gas is only close to Xi'an, which virtually increases the project cost

through analysis, the best matching of automatic welding should be external welding, internal copper backing, root welding, forced molding and external automatic welding. Because the equipment is simple, it is easy to ensure internal molding. Tests have proved that the problem of copper infiltration is conditional, and the process is appropriate, which can completely avoid copper infiltration, or do not cause harmful results

based on the above analysis and the application of various welding methods, I personally believe that in general, the welding of long-distance pipelines should be dominated by self-protection semi-automatic welding. For pipeline projects such as the west east gas pipeline project, automatic welding should be promoted and applied in flat areas. Manual traditional welding methods and manual welding will be supplemented by the rectification methods of golf corruption courses named by the Central Commission for Discipline Inspection. If conditions permit, Partial duplex welding can be used. For this reason, Dongguan Novell welding and Cutting Technology Co., Ltd. has launched a series of products, pipe prefabrication welding machine, according to the market demand. The pictures are as follows. Please call us for specific parameters. (end)

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