Pressure Sealing and Continuous Flow Sealing: This method involves sealing the original pipeline using pressure, while simultaneously installing or replacing pipeline components through bypass lines under continuous flow conditions. The technical process includes: welding four-way fittings at the locations requiring pipeline sealing; using a piercing machine to create openings in the pipeline; connecting sealers and other sealing devices to the pipeline and initiating the sealing operation; mating the bypass pipeline with the original pipeline; unsealing the pipeline post-mating and backfilling pipe blocks; applying anti-corrosion treatment to the four-way fittings and using double-sealing diversion to temporarily reroute the operating medium through the bypass line; replacing the severely corroded original pipeline with new anti-corrosion pipeline; and then redirecting the operating medium to the new pipeline. The Continuous Flow Pressure Sealing technique allows the entire construction process to be carried out under conditions of continuous pipeline operation.

The continuous pressure-sealing technology for pipeline shutdown not only allows for the relocation, replacement, installation, and even addition of branch pipelines under conditions where the pipeline medium is continuously transported, but also enables safe and rapid repair in the event of pipeline leaks, promptly restoring normal pipeline operation. This technology boasts features such as no temperature drop, no pressure reduction, and no production halt, ensuring the normal operation of process industry transportation. Therefore, it offers high comprehensive benefits and practical value. Although the construction process of this continuous pressure-sealing technology can be complex for longer pipelines, with reasonable planning, standardized operations, and strict control, it can safely and efficiently meet the timeliness and cost-effectiveness requirements of pipeline modification, and also significantly mitigate risks.