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This post was last edited by 68589544 on 2016-3-19 at 11:54. In response to the forum’s notice encouraging discussions on professional \"basic knowledge,\" and based on my own work experience, I have prepared a guide covering the basic requirements for working in high-risk environments. I studied this material myself and have now organized it to share with everyone. Since the content is compiled based on my actual work experience, there may be discrepancies in the standards and norms; I welcome any criticism or suggestions for improvement. Phase 1: Technical requirements for hot work. Everyone has many suggestions and additions – feel free to post them! Technical Requirements for Hot Work Operations I. Definitions 1. Fixed-site welding: Refers to welding operations carried out in designated fixed welding areas located in safe zones within the production facility, after obtaining approval. 2. Fire for production: refers to the use of fire in productive equipment such as boilers, heating furnaces, and incinerators. 3. Temporary use of fire: refers to temporary operations that can directly or indirectly generate an open flame. 4. Four situations where fire should not be used: referring to the situation where fire is not used when a fire operation permit has not been issued ； If the established safety measures are not implemented, fire should not be used ； Using fire in areas, at times, for purposes that do not match those specified in the fire use permit is prohibited ； No fire is needed if the guardian is not present. 5. Flammable and explosive areas: Refer to areas where items are produced and stored, which fall under categories A and B in the fire hazard classification as specified in GB50016. II. Classification of fire use 1. Fire for production: The safety management of fire used in production is carried out in accordance with operating procedures and safety regulations. 2. Fixed fire use: The applying entity shall conduct a risk assessment of the areas where fixed fire use is required, establish corresponding safety measures, draw a plan showing the boundaries of these areas for fixed fire use, and only after approval can fire be used there. The validity period for fixed-use fire is 6 months. The fixed fire area must meet the following requirements: a) There must be no flammable or explosive materials within 50 meters of its boundaries. b) Establish a management system for designated fire use areas and appoint a fire safety officer. c) Equip sufficient fire-fighting equipment in accordance with fire safety regulations. d) There are clear signs indicating the “designated fire use area,” with the boundaries of that area marked. e) Establish emergency contact methods and emergency measures. 2. Temporary use of fire: (Determining whether it falls under the category of hot work) a) Welding and cutting methods such as electric welding, gas welding, brazing, and plastic welding. b) Electric heat treatment, electric drills, grinding wheels, pneumatic hammers, as well as operations that generate sparks such as crushing, hammering, blasting, and striking ferrous metals. c) Open-flame operations such as torches, stoves, electric furnaces, asphalt boiling, and sand frying. d) Motor vehicles, fuel-powered machinery, and other equipment entering flammable and explosive areas. e) Temporary electricity use in flammable and explosive areas as well as hazardous materials warehouses. f) Digging ditches and pits in flammable and explosive areas. III. Classification of temporary fire use 1. Special-grade fire operations a) Fire use in towers, oil storage tanks, reactors, sewage systems, oil separation tanks, as well as in pipelines carrying flammable or toxic materials that have not been subjected to procedures such as purging, cleaning, steaming, or displacement. b) Use of fire in the sewage system and oil separator during the device’s shutdown for maintenance. c) Pressurized hole opening and leak sealing in steam systems with a pressure of 4.0 MPa or higher (including 4.0 MPa) that require the use of fire are permitted. d) Use of fire in specially confined spaces and in high-altitude work of the highest category. 2. Level 4 fire operations: a) Heat exchangers, containers, and pipelines of non-flammable and non-toxic media that are directly connected to flammable or toxic media without being isolated by blind plates. b) Use of fire in enclosed hydrogen compressor rooms and loading docks (areas within 10 meters of the loading/unloading points). c) Use of fire within the fire dike of the tank area. d) Use of fire in level 3 high-altitude work. 3. Level 3 fire use does not fall under special-level fire use or other temporary fire uses of Level 4. IV. Basic Requirements for Work Involving the Use of Fire 1. Whenever work involves the use of fire, except for fire used in production and fixed-fire applications, a fire use permit must be obtained. 2. The hot work permit serves as the basis for any hot work on site. It may only be used at designated locations and within specified time periods; it shall not be altered or signed by anyone other than the authorized person. A fire operation permit allows for fire use at only one location. Note: Use of fire: In areas prone to fire and explosion, it refers to the use of fire within a 7.5-meter radius centered on the fire point. Use of fire in areas that are not flammable or explosive is permitted within a 15-meter radius centered on the fire point. 3. When working with fire, the \"four no-fires\" principle should be followed. 4. In areas where fire is used during production, any fire-related components that can be removed should be taken to a safe location to be used there. 5. Hot work is strictly prohibited during the shutdown, emptying, and purging of the unit, as well as during material charging and startup. 6. During holidays (including Saturdays and Sundays), hot work is generally not permitted in production units, tank areas, and utility systems. If hot work is necessary, it must be subject to enhanced management procedures. 7. The valid period of a fire operation permit shall not exceed 12 hours; after extension, the total period shall not exceed 24 hours. 8. The facility shall be shut down for comprehensive maintenance; once it passes the inspection and acceptance carried out by the company, a three-level system for managing fire use will be implemented (this does not include fire use within the sewage treatment system, oil separation tanks, or the fire dikes in the tank areas). The duration of fire-related operations shall be determined by each unit based on the specific task at hand, but it must not exceed 72 hours. V. Comprehensive safety technical requirements 1. A perimeter barrier should be set up in areas where fire is used in construction; it is strictly prohibited for persons or vehicles unrelated to the fire-related work from entering such areas. Fire extinguishers should be placed at the site where fire is used, and all mobile and fixed fire-fighting equipment on site must be thoroughly inspected. 2. When working with fire near equipment, containers, or pipelines that contain flammable or toxic hazardous materials, it is necessary first to remove the materials from these areas and cut off their sources. The relevant sections must be thoroughly purged, cleaned, and replaced, and blind flanges should be installed on all connected parts (for those areas where blind flanges cannot be used, other reliable isolation measures must be taken or the parts removed) to prevent the flow of materials or the spread of fire to other areas. Blind plates must meet the pressure rating requirements; it is strictly prohibited to use iron sheets or asbestos boards as substitutes. (Energy isolation) 3. Containers, pipelines, and equipment used for storing oxygen should be isolated from areas where fire is used (by installing blind flanges). Before using fire, the oxygen content in the system must be reduced to no more than 23.5% (V/V). 4. There shall be no leakage of liquid hydrocarbons or oils with a low flash point within 30 meters of the fire source ； No other flammable materials are allowed to leak or be exposed within a radius of 15 meters ； All funnels, drains, various types of well openings, exhaust pipes, pipelines, gutters, etc., within 15 meters of the fire source must be sealed tightly. 5. Equipment and pipelines such as towers, tanks, containers, and tank trucks that require the use of fire must be cleaned, purged, and ventilated; thereafter, the concentrations of flammable gases, toxic and harmful gases, and oxygen must be measured. Work involving fire can only be carried out when these concentrations are within the allowable levels. 6. Before carrying out work involving fire, the combustible gases in the work area should be tested. When using a portable combustible gas detector or other similar devices for analysis, the concentration of the combustible gas or vapor of a combustible liquid being tested should be less than 10% of its lower explosive limit (LEL) in air. When using analytical methods such as chromatography, if the lower explosion limit of the combustible gas or combustible liquid vapor being tested is 4% or higher, its concentration should be less than 0.5% (V/V) ； When the lower explosion limit of the combustible gas or combustible liquid vapor being tested is less than 4%, its concentration to be measured should be less than 0.2% (V/V). 7. All gas sampling and analysis for operations involving fire are carried out by the analysis and testing center. The sampling locations are proposed by the safety director of the unit where the project is located, who then assigns personnel to accompany the staff from the analysis and testing center to the site for sampling. The sampling samples for level 4 fire use should be retained until the fire operation is completed. For welding operations that do not require sampling for analysis, the unit’s safety supervisors shall use a \"four-in-one\" detector to check for gases; however, such detectors must be within their calibration validity period and in proper working condition. 8. If a fire-related operation is interrupted for 30 minutes or more, before resuming the use of fire, the person carrying out the operation, the supervisor, and the company’s safety officer must jointly inspect the site where the fire is being used to ensure that all risk reduction measures have been implemented; only after gas testing shows satisfactory results can the fire be used again. 9. Gas testing must be conducted at least once every 2 hours during a fire-related operation. If the person carrying out the operation, the supervisor, or the project manager deem it necessary to conduct sample analysis, such analysis should be carried out at any time. 10. Personnel performing work involving fire should be located upwind of the fire site, and at the same time avoid the direction from which materials or obstructions may be ejected. 11. When performing gas welding or cutting operations involving open flames, the acetylene cylinder must be placed upright, with measures in place to prevent it from toppling over. The distance between the oxygen cylinder and the acetylene cylinder should be at least 5 meters, and both cylinders must be kept at a distance of at least 10 meters from any open flames. Oxygen cylinders and acetylene cylinders should be kept away from heat sources and electrical equipment, and must not be exposed to direct sunlight. When using welding, the welding tools must be in good condition, and the welding machine’s casing must be grounded. 12. At each site where fire is used, at least one person from the unit where the project is located and one person from the unit carrying out the fire-related work shall be assigned to supervise, with supervision by personnel from the project’s location unit being the primary approach. 13. Any change in the fire watchperson must be approved by the approver of the hot work permit. The newly appointed guardian signs the permit and conducts an on-site handover. 14. When performing fire-related tasks at heights, the relevant requirements of the regulations for working at heights must also be followed. Protective equipment such as safety belts and lifelines used for working at heights should be made of flame-retardant materials, and automatic locking mechanisms should be employed when necessary. 15. When using fire at heights (including use of fire on the second floor or above of multi-story structures), measures must be taken to prevent sparks from falling. The distance between the oxygen cylinder, acetylene cylinder, and the vertical projection point of the fire source must be at least 10 meters. 16. Outdoor work involving open flames should be stopped when the wind speed is at level 5 or above; all outdoor work involving open flames should be halted when the wind speed is at level 6 or above. 17. The use of fire in confined spaces must also comply with the relevant requirements of the \"Regulations on the Management of Work in Confined Spaces\". 18. Fire use in excavation work must also comply with the relevant requirements of the \"Regulations on the Management of Groundwork Operations\". 19. Do not perform hot work on pressurized systems without replacement; the flames resulting from combustible gases leaking from the pipes when exposed to an open flame should not be extinguished, unless there is a specific danger involved.