1. For pipelines with high peak shaving requirements, due to the uneven gas consumption of users and frequent pipeline pressure fluctuations, the steel pipes bear great alternating stress, and the existing defects in the pipes will expand under the alternating stress. If you choose 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 a seismic fault zone or passes through a local high-intensity earthquake area. Due to the frequent geological activities in these areas, longitudinal or axial alternating stress 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 the action of long-term stress, the probability of accidents in spiral welded steel pipes is much higher than that of submerged arc steel pipes. Therefore, submerged arc steel pipes should be used in such areas.
3. Submerged arc steel pipes should be used for pipelines with high requirements for internal and external anti-corrosion layers. 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 performing internal and external anti-corrosion on the steel pipes, the combination of anti-corrosion materials and bare pipes is not as tight as that of submerged arc steel pipes, and the anti-corrosion effect is not as good as that of submerged arc steel pipes. The steel pipe is good.
4. For important crossing projects, submerged arc steel pipes should be used. Since future maintenance and management are more difficult than ordinary line sections, it is particularly important to use high-performance submerged arc steel pipes.
5. For weak links in pipelines, such as hot-simmering elbow pipes, submerged arc steel pipes should be used. Due to the change in direction, the hot simmering elbow bears greater internal and external forces than the straight pipe section of the general line. Due to the influence of various factors during the simmering process, its stress is not easy to eliminate, and it is a relatively weak link in long-distance pipelines. , the use of submerged arc steel pipes with good comprehensive performance can make up for these shortcomings.
Post time: Oct-09-2023