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Accident of Converted Coke Oven Gas Leakage I. Accident Overview: At 0:40 on November 7, 2008, a loud noise suddenly shattered the quiet night sky in a company located in Hebei. In the chaos that followed, the workers rushed towards the source of the noise. Upon inspection, it was found that there was a leakage at the flow meter where the highly desulfurized coke oven gas was sent to the conversion unit. It was initially assumed that the gasket of the flow meter might be damaged, resulting in the leakage of coke oven gas. The control room was informed, and after it was confirmed that the flow rate of coke oven gas was decreasing significantly, the system was shut down urgently. A notification was issued for synthesis; the conversion system was switched to dispersed mode. It was also ordered that the oxygen supply be reduced and the pressure lowered, while the coke oven gas compressor had its output reduced and it was put into self-circulation mode. The conversion system was disconnected from the oxygen supply as well as from the process gas, and steam was used for protection during the normal shutdown process. Upon thorough inspection, it was found that the flow meter was not damaged; instead, the gasket of the DN50 vent valve located before the flow meter was broken. Maintenance was promptly notified to carry out emergency repairs. After restoration, when the furnace was prepared to be heated up, a problem with the gasket in the desalinated water unit arose, which forced the conversion system to adjust its process parameters again, switching to cooling mode, stopping the burner protection pump, and maintaining insulation and pressure. II. Cause of the accident: 1. Due to a damaged gasket on the vent valve located before the flow meter for coke oven gas flowing from precision desulfurization to conversion, coke oven gas leaked, resulting in the shutdown of the entire system. 2. The on-site personnel failed to conduct proper inspections and failed to detect potential safety hazards in a timely manner. 3. Maintenance personnel must work carefully and thoroughly, regularly checking for wear and tear on operating equipment and components, and performing timely calibration or replacements to ensure zero safety incidents. III. Preventive measures: 1. Operators must be familiar with the site so that they can accurately and quickly identify the cause of an accident and take timely action to address it. 2. On-site inspections must be thorough and comprehensive to promptly identify and eliminate safety hazards. 3. Contact the maintenance team promptly to keep the equipment and components on site in good condition; conduct regular inspections or replacements. The technicians performing maintenance must be highly skilled and must not be careless. 4. Purchasing staff must be diligent and responsible, ensuring quality control at every stage. 5. Operators must operate carefully, must not violate the process specifications, and there should be no frequent fluctuations within the specified range.