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The ammonia synthesis unit and urea production unit of Sichuan Lutianhua’s new system resumed normal operation successfully after completion of maintenance work. Author/Source: Sichuan Lutianhua Co., Ltd. Date: February 20, 2021. Clicks: 12. At 15:25 on February 15 and 14:21 on February 16, ammonia and urea were produced successfully by the new system’s ammonia synthesis unit and urea production unit respectively, marking the successful completion of the maintenance work on the new system and the return of the units to normal operation. This major overhaul of the new system involves numerous tasks over a wide range of areas and over a long period of time; it is complex, demanding high technical standards as well as strict quality requirements. During the major repairs, the various teams in the Equipment Management Department strictly adhere to the company’s repair standards and procedures as well as the established construction plans. They maintain a zero-tolerance attitude toward any deviation from these standards, ensuring strict compliance with them. Equipment that has not had its abnormal operating issues resolved cannot be reinstalled; equipment whose repair quality does not meet the required standards cannot be reinstalled either; and equipment with newly identified defects that have not been addressed cannot be reinstalled. Special emphasis was placed on strengthening the quality and process control of key maintenance tasks, including inspections and repairs of 120-F ammonia tanks, restoration and internal component modifications of 105JT cylinder bodies, repairs of internal components in 105-D synthesis towers, and repairs of furnace tubes in the rising tubes of the first-stage furnace. By leveraging technical advantages, selecting and strengthening the maintenance team, and paying close attention to detail in the process management, potential hazards and defects in components such as the 120-F ammonia tank, the 105-D synthesis tower, and the rising tubes of the first-stage converter were promptly addressed, ensuring that the quality of the overhauls was strictly controlled. For outsourced maintenance projects, the company strictly monitors to ensure that the contractors adhere to the relevant maintenance standards and plans, and it strengthens quality inspections at every stage in order to achieve full compliance with the quality requirements for maintenance work. During this major overhaul, the inspection and testing of special equipment is a key task as part of the upgrade of the new system. The safe and stable operation of these devices is directly related to the long-term operation of the facility, and they hold equal importance to the main equipment. The company’s pressure inspection station focused on conducting inspections and tests on 73 pipelines in the ammonia system, as well as on the main pipes, branch pipes, and drain pipes of the hydrogen and nitrogen systems – all of which are pressure pipelines – as well as 12 pressure vessels. During the major maintenance, the company’s supervisors of special equipment went to the site in a timely manner, and through external macro inspections as well as testing, they gained a comprehensive understanding of any changes in the material composition of the equipment. For any abnormal data detected during the inspections, special meetings were held promptly to analyze the situation and develop repair plans. During this major overhaul of the new system, significant equipment safety hazards were promptly identified and eliminated, including rust-induced thinning of the wall of the 120-F ammonia tank, damage to the internal components of the 105-D synthesis tower, circumferential cracks in the welds of the upcomer tubes in the first stage of the conversion furnace, as well as cracks in the pipes of the Prison system. This has laid a solid foundation for the continuous, safe, environmentally friendly, and stable operation of the chemical plant in the future. At present, the ammonia synthesis unit, urea production unit, and thermal coal boiler unit of the new system have successively been put into normal operation.