Since August 1994, the security company has undertaken and engaged in the work of underpressure sealing of pressure pipelines. The company attaches great importance to the development of this business and cooperated with the School of Mechanical and Power Engineering of Nanjing University of Technology to carry out the "non-stop pipeline and equipment" "Research and engineering application of pressurized hole technology", "Localized design and development of gate valve for pressurized hole opening", "Research and application of pressurized hole opening and plugging technology for continuous transmission", "Pressure open hole" A number of scientific research and development projects such as "Research on Online Welding Technology in Hole and Sealing Operations" have simulated and studied the pressure pipeline plugging technology and process under pressure, and obtained some scientific research conclusions and data with practical application value. In 2002, our company's "Application and Promotion of Pipeline Sealing Technology under Pressure" won the second prize of Excellent Achievement in the Sinopec Young Workers Innovation and Benefit Achievement Competition. Since the company engaged in pressurized sealing and opening business, it has conducted pressurized sealing in different media such as jet fuel, crude oil, methanol and different pressure occasions. So far, the largest opening and plugging diameter has been DN900 and the maximum working pressure is 4.0MPa .