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Section 14: Work Permit Management I. Management of Permits for Hot Work and Work in Confined Spaces 【Example】On April 15, 2019, a pharmaceutical company carried out modifications to the refrigerant system pipes in its lyophilized injection production workshop while the plant was shut down; hot work was required for these modifications. According to the \"Safety Regulations for Special Operations in Chemical Production Units\" (GB30871), which of the following statements is correct regarding the safety requirements for hot work? A. Painting operations should not be carried out simultaneously within a radius of 15 meters from the area where welding is being performed. B. The oxygen cylinders and acetylene cylinders used for cutting must be kept at a distance of at least 5 meters from the welding area. C. The welding work permit can be approved by the company’s chief engineer. D. The distance between oxygen cylinders and acetylene cylinders should be at least 10 meters. 『Correct answer』C 『Answer explanation』This question relates to the management of work permits. A should be 10 meters ； B should be 10 meters ； D should be 5 meters ； For special hot work, the hot work permit is approved by the plant manager in charge or the chief engineer; for level 1 hot work, it is approved by the safety management department, while for level 2 hot work, it is approved by the workshop where the hot work will take place. Refer to GB308715.2.7: Flammable gases shall not be released within 30 meters of the welding area during welding operations ； Flammable liquids should not be discharged within 15 meters of the hot work area ； Cleaning with flammable solvents or painting and other similar tasks shall not be carried out simultaneously within 10 meters of the hot work area and below the area where fire is used. 5.2.9 When performing welding or cutting operations using gas, the acetylene cylinder should be placed upright; the distance between it and the oxygen cylinder should be no less than 5 m, and the distance between both cylinders and the site of the operation should be no less than 10 m. Sun protection measures should also be in place. Additionally, per 5.4.1, when performing hot work outside the equipment, a hot work analysis must be conducted within a radius of 10 meters from the point where the hot work is carried out ； The interval between the hot work analysis and the actual hot work should generally not exceed 30 minutes; if the site conditions do not permit, this interval can be extended slightly, but it should not exceed 60 minutes ； If the interruption time of the operation exceeds 60 minutes, re-analysis is required; a fire analysis must be conducted before starting any firework-related tasks each day ； Special: Monitoring should be carried out at all times during hot work. 【Example】A chemical company entrusted a contractor to repair the underground enclosed gas pipelines in one of its workshops. Since this work involved operations in a confined space, the company formulated safety measures for such operations in accordance with the safety requirements for working in confined spaces. Which of the following measures meet the safety requirements? A. When working in confined spaces, the contractor must monitor the gases at least once every 2 hours. B. In humid and enclosed confined spaces, the lighting voltage should be less than 12V, and explosion-proof lamps must be used. C. The permit for working in confined spaces is issued by the gas company. D. Welding work on underground pipelines is subject to the regulations for level 2 welding operations. E. Workers must wear anti-static work clothing while working. 『Correct answers』ABE 『Explanation』This question relates to the management of personal protective equipment. Option C is incorrect; the restricted operation permit is issued by the chemical company ； Option D is incorrect; it should be managed in accordance with the procedures for level 1 hot work. II. Management of Permits for Work at Heights and Lifting Operations 【Example Question】 In June 2018, a chemical manufacturing group company sent safety inspectors to check whether the work at heights carried out by its subsidiary companies complied with safety regulations. It was found that the company had the following safety management requirements: ① Any work at a height of 1.8 meters or more above the potential fall surface was classified as work at heights ； ②The validity period of a high-altitude work permit shall not exceed 10 days ； ③The work at height permit must be carried with you at all times ； ④A permit for working in a confined space is not required for work at heights inside such spaces. According to the \"Safety Regulations for Special Operations in Chemical Production Units\" (GB30871), which of the company’s practices is correct? A.① B.② C.③ D.④ 『Correct answer』C 『Explanation』This question tests knowledge regarding the management of personal protective equipment. Option A is incorrect; tasks with a risk of falling from a height of 2.0 meters above the reference surface for falls should be classified as work at heights ； Option B is incorrect; the work permit for working at heights does not specify an expiration date ； Option D is incorrect; a permit for working in a confined space is required when working in such spaces. III. Blind plate removal and installation operations and management of temporary power use 【Example】A company is constructing a shelf-type refrigerated warehouse with a cooling capacity of 5000 liters. A refrigeration system using liquid ammonia as a refrigerant is employed. The designed refrigeration temperature ranges from -10°C to -23°C. One day, while working in the cold storage, forklift driver Zhang suddenly smelled ammonia and immediately reported it to his supervisor. Upon investigation, the leak was caused by a weld defect in the elbow of the liquid ammonia supply pipe of the evaporator. The technicians reviewed the drawings. After joint discussion, a emergency repair plan was formulated. And a blind plate is installed at the valve at the upper end of the liquid supply pipe before the operation. In accordance with the \"Safety Regulations for Special Operations in Chemical Production Units\" (GB30871). Which of the following statements about blind plate removal and installation operations is correct? A. Anti-static work clothes and shoes should be worn during the operation, and non-explosion-proof lighting fixtures and tools should be used. B. Welding operations can be carried out 15 meters away from the location where blind flanges are removed or installed. C. Two separate blind flange removal/installation operations can be conducted on the same liquid ammonia supply pipeline at the same time. D. The pressure at the operation site must be reduced to atmospheric pressure, and a dedicated person should be assigned to supervise the operation. 『Correct answer』D 『Answer explanation』This question tests knowledge regarding the permit management for blind flange removal/installation operations. Options A and B are incorrect; when performing blind flange removal and installation tasks in flammable and explosive environments, workers should wear anti-static work clothes and shoes, as well as use explosion-proof lighting and tools ； No hot work is allowed within 30 meters of the blind plate removal and installation site ； Option C is incorrect; two or more blind flange removal and installation operations should not be carried out simultaneously on the same pipeline ； Option D is correct; during the operation, the pressure at the work site should be reduced to atmospheric pressure, and a dedicated person should be assigned to supervise. 【Example】During a maintenance operation, a chemical manufacturing company was able to set up a temporary platform 6 meters high, on which temporary electrical work could be carried out. According to the safety requirements for special operations specified in the \"Safety Regulations for Special Operations in Chemical Production Units\" (GB30871), which of the following is correct? A. When moving up and down on a 6m platform, insulated tools should be used. B. If temporary power use exceeds 1 month, it is necessary to register this with the power supply provider. C. The power and lighting circuits on the platform should be installed separately. D. If maintenance work on a 6m platform lasts more than 8 hours, it is necessary to take a break on the platform. 『Correct answer』C 『Answer explanation』This question relates to job permit management. Option A: When working at heights, one should not hold anything in hands while going up or down ； Option B: The duration of temporary power use is generally no more than 15 days; in special cases, it should not exceed one month ； Option D: For work at heights, a dedicated supervisor should be assigned, and workers must not rest at the work site