Selection requirements for submerged arc steel pipe

Selection requirements for submerged arc steel pipe

1. For pipelines with high requirements for peak shaving, due to the uneven gas consumption of users and frequent pipeline pressure fluctuations, the alternating stress on the steel pipe is very large, and the existing defects in the pipe will expand under the alternating stress. If you choose For spiral welded steel pipes with many welds and a high probability of defects, the operation of the pipeline will not be guaranteed.

2. The pipeline crosses the seismic fault zone or passes through the local high-intensity seismic area. Due to the frequent geological activities in these sections, longitudinal or axial alternating stresses will be generated on the pipeline. There are many spiral welds, and the probability of defects is higher than that of submerged arc steel pipes. Under long-term stress, the probability of accidents of spiral welded steel pipes is much higher than that of submerged arc steel pipes. Therefore, submerged arc steel pipes should be used in this area.

3. For pipelines that require high internal and external anti-corrosion coatings, submerged arc steel pipes should be used. Spiral submerged arc welded steel pipes have many weld beads, and the weld reinforcement is generally higher than that of submerged arc steel pipes. When the steel pipe is internally and externally anticorrosive, the combination of the anti-corrosion material and the bare pipe is not as tight as the submerged arc steel pipe, and the anti-corrosion effect is not submerged arc steel. The steel pipe is good.

4. For important crossing projects, submerged arc steel pipes should be used. As future maintenance and management are more difficult than general line sections, it is especially important to use high-performance submerged arc steel pipes.

5. For weak links of the pipeline, such as hot simmering elbow pipes, submerged arc steel pipes should be used. Due to the change of direction, the internal and external forces of the hot simmering elbow are greater than that of the straight pipe section of the general line. Due to the influence of various factors during the simmering process, the stress is not easy to eliminate, and it is a relatively weak link in the long-distance pipeline, The use of submerged arc steel pipes with good comprehensive performance can make up for these deficiencies.