Video footage of the furnace explosion

There is no video footage available; for more information, please refer to: Analysis of the flash explosion incident in Jinzhou Petrochemical’s atmospheric and vacuum distillation unit, dated September 12, 2003. On that day, after maintenance work was completed on Jinzhou Petrochemical’s 3 million tons per year atmospheric and vacuum distillation unit, operations were resumed at 17:10, when a flash explosion occurred during the ignition of the vacuum furnace. The accident resulted in 3 deaths, 1 serious injury, and 5 minor injuries; it also caused severe damage to the furnace walls and framework, leading to the complete destruction of the vacuum furnace and its rendering unusable ； The direct economic loss from the accident was 450,000 yuan. This accident occurred during a simple manufacturing process – one that we have carried out thousands of times before – and it was a serious casualty incident resulting from violations of regulations and poor management. It brought disaster to the employees who lost their lives and their families, and also put the company’s operations in a very difficult situation. Three years have passed, yet looking back on the sequence of events and causes of the incident, it remains deeply etched in my memory; the lessons learned are extremely profound. I. Accident Overview: On August 25, 2003, the 3 million tons per year atmospheric and vacuum distillation unit began its routine maintenance. At 8:00 on September 11, the maintenance was completed and the plant was put back into operation. From 8:00 to 17:00 on September 11, the unit underwent purging and pressure testing; at 17:00, the steam supply was stopped and the blind flanges for oil inlet and outlet were removed in preparation for operation. At 20:00, the fuel oil and high-pressure gas blind flanges were removed. At 8:30 on September 12, diesel circulation was initiated to test the instruments for dehydration ； At 14:00, the heating furnace is prepared for ignition. Stoker Lei Zhigang, upon instructions from Workshop Production Director Li Zhongling, contacted Safety Officer Cui Baoxian to arrange for the Central Laboratory to take samples and analyze the combustible gases in the atmospheric and vacuum distillation furnaces. The results showed that the analysis was satisfactory. Start crude oil circulation at 16:00. At 16:30, Li Zhongling, the production director of the workshop, instructed the furnace operators Zhang Liqun, Lei Zhigang, and Wang Jian to make preparations for starting the furnace as well as to conduct final checks before ignition. He also assigned team leader Pan Jianzhong to take charge of activating the gas system in order to prepare for ignition. After the ignition of the atmospheric pressure furnace was completed at 16:55, furnace operator Wang Jian went straight to the first-floor platform of the reduced-pressure furnace to prepare for opening the valves. When Lei Zhigang entered the bottom of the furnace to turn on burner No. 9 in the reduced-pressure furnace, a flash explosion occurred there. II. Analysis of the accident causes 1. Illegal command. At 14:00 on September 12, the workshop production director, without being aware of the process and without conducting an on-site inspection, mistakenly assumed that the gas system for the furnace was properly set up, and thus instructed the safety officer to contact the central laboratory to take samples in order to analyze the combustible gases in both the atmospheric-pressure furnace and the reduced-pressure furnace. In reality, the gas flow in the degassing furnace has not been properly set up; the blind flanges have not been removed yet, and the furnace is still in a maintenance state. With the blind flaps still in place and the process not properly set up, the laboratory was asked to collect furnace gas in order to analyze the level of combustible gases in the furnace. Although the analysis results indicated that everything was within acceptable limits, these results were completely false. After taking the furnace gas samples, the workshop production manager contradictively assigned operators to set up the gas flow process. 2 hours and 40 minutes after sampling, the operator was scheduled to start the furnace. According to the regulations: it is necessary to confirm that the burner valve is closed, divert the gas to the front of the furnace and remove the blind flange; sampling and analysis must be conducted within 1 hour before ignition to be valid. This operation exceeds the specified time limit, and no one has confirmed it. Incorrect sampling results and improper instructions laid the groundwork for the accident. 2. Illegal operation. At 16:55, driven by incorrect sampling results, the atmospheric pressure furnace and the reduced pressure furnace were started; at 17:10, a flash explosion occurred while starting the reduced pressure furnace. Following the accident, an on-site inspection revealed that there were 4 valves in the gas system of the decompression furnace that were open to varying degrees: one DN80 valve and 3 DN50 valves. It was determined that the DN80 valve served as a valve connecting high-pressure gas with low-pressure gas; after the process modification, this valve should function as a normally closed valve and should be sealed off using a blind flange. The three DN50 valves were low-pressure gas burner valves, which, after the process modification, also became normally closed valves. The opening degrees of these four valves are as follows: the DN80 connection valve is opened to 10% (6 turns), while the DN50 gas burner valves are opened to 40% (7 turns), 40% (7 turns), and 50% (8 turns) respectively. Based on an analysis of the scene, this accident occurred because the furnace operator of the pressure-reduction furnace failed to conduct thorough and meticulous inspections during the preparation and checking processes prior to ignition. He failed to detect that the valves connecting high-pressure gas with low-pressure gas, as well as the three valves controlling the low-pressure gas nozzles, were open, allowing high-pressure gas to flow into the furnace through the low-pressure gas pipelines before ignition, which resulted in a flash explosion during ignition. The operator failed to close the low-pressure gas burner valve of the vacuum furnace and the high/low-pressure gas connection valve in accordance with the correct procedures before ignition; this improper operation was the direct cause of this accident. 3. There is no supervision during the work process. In accordance with the requirements of the new operating procedures, after adjusting the gas flow and confirming that everything is in order, the furnace operator should open the shutters for direct ventilation and air preheating, start the blowers and exhaust fans to maintain an appropriate negative pressure in the furnace. After the steam has been dehydrated, the furnace and burners should be purged, and the systems should be turned off after ten minutes. However, investigations following the accident revealed that the decompression furnace exhaust fan was not turned on, and the blower was not turned on either. The omission of this important operational step, without any oversight, led to the gas in the furnace not being evacuated in time, which was the main cause of the accident. 4. The management of blind plates has not been confirmed. The accident investigation revealed that the plant startup plan did not include a blanking plate list; instead, blanking plates were inserted and removed by referring to the blanking plate list from the shutdown plan. The insertion and removal of blind flanges were solely the responsibility of one person, the blind flange supervisor. On August 26, after removing the blind flange from the high- and low-pressure gas connection valve for decoking in the pressure reduction furnace, the supervisor forgot to reinsert it prior to restarting operations. As required by the workshop’s task schedule for cleaning the pipelines before operation, one team leader and one furnace operator were responsible for cleaning, connecting, and testing the high-pressure and low-pressure gas pipelines. However, in practice, these two individuals were careless and irresponsible in their work; they did not carry out the cleaning, connection, and testing tasks thoroughly, and failed to notice that the valves connecting the high-pressure and low-pressure gases were open. By failing to ensure proper control at the earlier stages, they allowed potential accident risks to develop into a catastrophic reality. Firstly, the September 12 incident was a fatal accident caused by serious violations of commands and operating procedures. The operator was not diligent or careful in their work, was careless, lacked proficiency, and failed to thoroughly check the gas system before attempting to ignite it. Secondly, a step was omitted: the induced draft fan and blower were not turned on as required by the procedures ； Before ignition, the valves in the process flow were not checked or verified; it was not detected that the control valves for the three low-pressure gas nozzles sowie the valves connecting high-pressure and low-pressure gas were open, allowing high-pressure gas to enter the furnace. This constituted an illegal ignition procedure ； Third, the workshop failed to provide effective supervision and control over the operator’s procedures during the operation process ； Fourth, the workshop’s procedure for arranging furnace sampling and analysis was incorrect; it was not carried out in accordance with the prescribed procedures, which prevented the accident from being avoided in a timely manner. Fifth, the workshop process engineer was irresponsible and failed to insert blind flanges. Therefore, this is a liability accident caused by serious violations of regulations. III. Handling of those responsible for the accident The “9.12” accident was an accident caused by negligence. In accordance with safety production regulations and the group company’s rules regarding accident handling, and adhering to the principles of clear accountability and strict enforcement, we imposed corresponding sanctions on a total of 21 individuals who were directly or indirectly responsible at various levels. Among them, 6 were given public reprimands, 3 received administrative warnings, 4 were given administrative demerits, 1 was given a severe administrative demerit, 1 had their rank reduced, 2 were removed from their positions, and 4 were dismissed from the factory but allowed to remain on site under supervision. IV. Lessons from the Accident The \"9.12\" accident resulted in three deaths and six injuries, causing severe negative impacts on the enterprise as well as immense suffering to the employees who were hurt or killed and their families. From this tragic incident with its heavy costs, we must draw profound lessons from the following six aspects. 1. At all levels, from the company to the workshops, leading cadres fail to firmly establish the philosophy of \"putting people first and safety first\"; their safety awareness is weak, their work style is not solid, their management approaches are crude, rules and regulations are inadequate, and responsibility systems are not properly implemented. “Although the 9.12” incident occurred in the workshop and manifested at the operational level, its root cause lies with management; it is essentially a management issue. This incident revealed that the company and its production workshop lacked meticulous organization and strict management regarding major production operations, such as the startup of key equipment and the ignition of the decompression furnace. Responsibilities for the start-up and shutdown management of the plant were unclear; leadership failed to exercise proper oversight. Even during operations such as lighting the furnace, no one went to the site to ensure that safety measures were in place. As a result, irresponsible leadership, careless employees, flawed management practices, and ineffective regulations all contributed to this serious accident. 2. Regarding the production and operation of the equipment, especially during start-up and shutdown procedures, there is a lack of strict management and control in terms of the system framework, change procedures, process discipline, employee behavior, and on-site supervision. “The occurrence of the 9.12 incident was due to unauthorized commands and loss of control in management. It revealed lax operational discipline at the production workshop, incomplete rules and regulations, loopholes in their implementation, and arbitrary alterations to work procedures, all of which led to the accident. The safety production responsibility system in the production workshop is not implemented. We also have relatively strict regulations regarding the operating procedures, steps, and safety precautions for startup and shutdown of equipment. If management and implementation are carried out properly, accidents can be completely avoided. However, in reality, our commitment to safe production remains merely a slogan; there is insufficient follow-through in putting it into practice. We fail to make strict adherence to rules and regulations a part of our actions. As a result, rules are not implemented rigorously or thoroughly, and certain safety procedures are deliberately simplified or omitted during execution. People ignore established rules and laws, leading to a habitual pattern of violations. Consequently, safety management becomes progressively weaker at each level. These are all painful lessons paid for by employees with their blood and lives. Especially by comparing the old and new versions of the operating procedures in light of the \"Four Haves and One Card\" system implemented by the joint-stock company, we have gained a deeper understanding of the root causes of these accidents. In the “9.12” accident, we didn’t have even one of the “four requirements” outlined in the “four have ones and one card” operating procedure. Although there were instructions for sampling and analysis, they were incorrect instructions, which is equivalent to having no instructions at all ； Although there are procedures for starting the furnace, they are very general and rough, making it difficult to follow ； The furnace operator failed to confirm the operation of lighting the furnace with gas ； There was no monitoring during the startup process ； There are no operation procedure cards for employees’ job tasks. “The 9.12” accident revealed a lack of organizational, managerial, and personnel oversight in the operation of the production facilities, as well as a absence of operational verification procedures; this led to uncontrolled production operations and created serious safety hazards in that process. 3. Inadequate change management. Change management includes instruction changes, process changes, equipment changes, and personnel changes. With the commissioning of this unit, changes were made to the production process; high-pressure gas burners were added to the fuel system of the vacuum furnace. After the process change, the workshop lacked sufficient awareness; it failed to properly organize employees to familiarize themselves with the operation plan and procedures, did not provide instructions to the operators regarding the changes, nor organized any training for them on these changes. Operations were carried out ahead of schedule in a haphazard manner, and coupled with chaotic management, this led to operators failing to follow the process requirements and steps outlined in the operation plan and engaging in arbitrary operations. 4. The operating procedures are not scientifically formulated and lack practicality. Section 3.3.1 of the original operating procedures specified the requirements for lighting the heating furnace, such as \"thoroughly checking that the furnace tubes, hangers, elbow fittings, explosion-proof doors, burners, flue dampers, pressure gauges, thermocouples, valves, fans, preheaters, etc. are in good condition, and that all valves are closed.\" The regulations are quite vague ； Inaccurate location ； No concept of order ； There is even no confirmation requirement ； Only employees familiar with the process can operate it; those who are not may make mistakes or overlook items due to carelessness. The operational steps are not detailed, responsibilities are unclear, there are no procedural or quantitative mandatory regulations, and it is not specified how much time must pass after sampling before the furnace can be started. This results in unclear, insufficiently detailed, and inadequate prescribed actions, with poor operability. 5. Inadequate training for employees on operations. “The 9.12” incident revealed serious shortcomings in our training regarding job-specific operational skills; we failed to truly ensure that employees learned and became proficient in exactly what was required for their tasks” ； I haven’t achieved 100% mastery of what I should know and be able to do. The two stokers assigned to be in charge of starting the furnace in the workshop scored 61 and 63 respectively on their qualification tests, just passing the threshold; this reflects the lax standards in our training and assessment processes, resulting in poor proficiency and weak fundamental skills among them. 6. Inadequate management during the start-up process. Start work while carrying out final project tasks, with concurrent operations. The operating procedures for starting up the equipment specify that it is necessary to promptly clear away any personnel who are not involved in the ignition process and keep them away from the site before igniting. However, on September 12th, when ignition took place, the workshop failed to conduct proper inspections as required and did not organize the evacuation of unrelated personnel. Three workers from the company’s engineering department were still carrying out maintenance and valve replacement work on the pressure reducer, while three outsourced workers from Shihua Engineering Team were performing construction work 15 meters away from the pressure reducer. As a result, when the pressure reducer exploded, one of these six people died and five were injured, increasing the number of casualties and exacerbating the severity of the accident.

The accident occurred because the furnace operator of the vacuum furnace failed to carry out thorough, careful, and meticulous inspections before igniting the furnace; he failed to detect that the valves connecting high-pressure gas with low-pressure gas, as well as the three valves controlling the low-pressure gas nozzles, were open. As a result, high-pressure gas entered the furnace through the low-pressure gas pipelines before ignition, leading to a flash explosion during ignition