Thread Content
1. Brief description of the incident: At 7 a.m. on August 31, 2020, Zhao Mouhua, the operator of the electric-heated dewaxing tank in the dewaxing workshop of a certain technology company (Hubei), and Chen Mouyin, the assistant worker, arrived at their posts on time to start working. Zhao Mouhua closed the lid of the pot and turned on the switch of the electric heating integrated dewaxing pot to heat the inner tank. At 7:03, Zhao Mouhua reported in the company’s WeChat group that the electric heating integrated dewaxing tank was not working, and asked the equipment technician, Wang Mou, to carry out repairs. During an on-site inspection, it was found that the high water level alarm light of the electric-heated integrated dewaxing tank was on and the water level was high; the fault was resolved by draining excess water, and Zhao Mouhua was advised to drain water again if a high water level alarm occurred in the electric-heated integrated dewaxing tank. At around 8 o’clock, Li Moushan, the company’s production supervisor, went to the site to check the status of equipment maintenance and operation, and by then the electric heating integrated dewaxing furnace was already working properly. According to the operating procedure, after heating the rear chamber for over an hour until it reached the set temperature of 160 °C, Zhao Mouhua opened the vent valve to heat the front chamber. While waiting for the pre-reactor to heat up, Zhao Mouhua and Chen Mouyin violated regulations by clearing away waste generated during prior operations at a point approximately 6 meters directly opposite the reactor door. At 9:15, the kettle door, which had not been fully closed, suddenly broke free and flew out, knocking down Zhao Mouhua and Chen Mouyin, resulting in Chen Mouyin’s death and Zhao Mouhua’s injury. 2. Direct cause of the accident: First, Zhao Mouhua, the operator of the electric-heated integrated dewaxing tank, failed to close the tank door fully when doing so (the circumferential engagement length between the clamping teeth of the tank door and the teeth on the door itself was measured at 110 mm on-site; at the time of the accident, this engagement length was only 10 mm, resulting in a circumferential engagement degree of just 9.1%) ； Secondly, the connection bolts of the \"horizontal pin (mechanical limit post)\\" in the safety interlock device for rapid door opening of the electric-heating integrated dewaxing kettle had been completely broken for a long time due to neglect, which resulted in the failure of the safety interlock function that requires pressure to be applied only after the door has reached its predetermined closed position. As a result, since the quick-opening safety interlock device of the integrated electric-heating dewaxing tank could not effectively control the air intake into the front tank, the increasing pressure in that tank caused the actual meshing area between the clamping teeth of the tank door and the teeth on the door itself to be unable to withstand the normal operating pressure. This led to the tank door being ripped off and flying out, hitting Zhao Mouhua, the operator of the integrated electric-heating dewaxing tank, and Chen Mouyin, an assistant worker, who were illegally cleaning waste materials about 6 meters away from the tank door; one person died and another was injured. 3. Indirect causes of the accident: Causes related to the entities involved in the accident: 1) Certain Technology (Hubei) Co., Ltd. Enterprises lack awareness of safe production, have significantly inadequate safety management capabilities, and possess insufficient understanding of the concept of special equipment as well as related regulations; moreover, the use and management of such equipment are not standardized or strict enough. First, the electrothermal integrated dewaxing kettle failed to register its use as a special equipment with the department responsible for the supervision and management of special equipment safety in Gong’an County in accordance with the law; thus, it illegally used special equipment without a permit ； Second, the operators of the electrothermal dewaxing kettle do not hold certificates for pressure vessel operation; there is a serious issue of operating without proper certification ； Third, the operating procedures for the electric-heating integrated dewaxing kettle are not standardized ； Fourth are the records of daily inspection and maintenance for the electrothermal integrated dewaxing tank ； Fifth, the equipment maintenance staff noticed a problem with the \"horizontal pin (mechanical limit post)\\" on the safety interlock device of the electric-heated integrated dewaxing kettle, but neither addressed it promptly nor reported it ； Sixth, Zhao Mouhua, the operator of the electric-heating integrated dewaxing kettle, and Chen Mouyin, the assistant worker, violated the clear warnings by carrying out operations in front of the kettle door in an unauthorized manner. This is one of the main causes of accidents. 2) A certain head container manufacturing company. The enterprise’s quality plan for the manufacturing of electric heating steam dewaxing reactors does not cover aspects such as the manufacturing, installation, and commissioning of quick-opening door safety interlocks. There is also no data regarding the quality assessment of the bolts used to connect the \"horizontal pins (mechanical limit posts)\\" in these safety interlocks. The product quality certificates lack records of performance tests for the quick-opening door safety interlocks, and the enterprise fails to exercise effective control over the manufacturing quality of such interlocks. As a pressure vessel manufacturing enterprise qualified under legal regulations, it failed to provide the manufacturer of the electric steam dewaxing tank, a certain automation equipment company, with installation and operation/maintenance instructions as required by the \"Safety Technical Inspection Regulations for Fixed Pressure Vessels\" (TSG 21—2016). It also failed to attach product nameplates in visible locations on the equipment, which hindered the proper installation and safe use of such electric steam dewaxing tanks. This is one of the main causes of accidents. 3) A certain automation company. There is a lack of awareness regarding the policies and regulations governing special equipment in these enterprises; they rely on the workshops of other companies for processing, resulting in poor production conditions and weak management. When customizing, processing, assembling, and selling electric heating integrated dewaxing tanks, important information regarding the fact that these products are special equipment was deliberately concealed. The specification product nameplates supplied by a certain head container manufacturing company were not installed in prominent locations on the equipment as required by the \"Safety Technical Inspection Regulations for Fixed Pressure Vessels\" (TSG 21—2016). Moreover, no guidance on the policies and regulations governing the use of special equipment, nor any technical support documents, were provided to users, which severely affected the users’ ability to use such equipment in compliance with the law ； The enterprise did not possess the necessary license for installing fixed-pressure vessels; it illegally installed electric-heated dewaxing reactors without first submitting a notification of commencement of installation to the department responsible for supervising the safety of special equipment in Gong’an County, as required by law. By doing so, it attempted to evade safety inspections, which made it difficult for the regulatory authorities to carry out their oversight tasks and created gaps in supervision. This is one of the main causes of accidents. Reasons for territorial **management: There are weaknesses in the implementation of the safety production responsibility system by local Party and government leaders in a certain town under the Public Security Bureau. Firstly, when organizing and hiring a third-party safety assessment agency, namely a certain technology company, to conduct a safety inspection of that technology (Hubei) Co., Ltd., insufficient attention was paid to the issues related to the lack of knowledge and expertise in policies and regulations concerning the safe use of special equipment on the part of this agency ； Secondly, the issues related to the safety management of special equipment identified during an inspection by a third-party safety assessment agency, namely a certain technology company, were not reported to the county’s market supervision and management department; furthermore, the safety production problems were not communicated to the Public Security County Bureau of Science, Technology and Economic Informatization, and there was a lack of timely oversight in ensuring proper follow-up actions for rectification ； Third, the Zhen’an Office and the Emergency Management Station lack sufficient staff; many of those assigned to these positions are beginners, and there is insufficient training for them. Reasons for supervision by the regulatory department: 1) The Public Security County Market Supervision and Administration Bureau failed to keep track in a timely manner of the special equipment in use at Technology (Hubei) Co., Ltd., resulting in gaps in the specialized supervision of such equipment. 2) The Public Security County Bureau of Science, Technology and Economic Informatization failed to implement the principle that \"those in charge of an industry must also be responsible for its safety\" adequately; it did not urge or guide this technology company (Hubei) Co., Ltd. to carry out safety risk analysis and control, as well as the identification and resolution of safety hazards.