1 Scope This standard stipulates the technical requirements and management requirements for the limited space operation of the production and business operation units. This standard applies to metallurgical, non-ferrous metals, building materials, machinery, light industry, textiles, tobacco, commerce and other industrial and trade industry limited space operations. 2 Normative references The clauses in the following documents have been adopted as references to this standard. For dated references, subsequent amendments (not including errata content) or revisions do not apply to this standard. However, parties that have reached an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. . For undated references, the latest version is applicable to this standard. GB 2893 safe color GB 2894 Safety Signs and Guidelines for Use GB/T 3787 hand-held power tools for the management, use, inspection and maintenance of safety technical regulations GB/T 3805 Extra Low Voltage (ELV) Limits GB 3836.1 Electrical apparatus for explosive gas atmospheres Part 1: General requirements GB4053.1 Safety requirements for fixed steel ladders and platforms - Part 1: Steel ladders GB4053.2 Safety requirements for fixed steel ladders and platforms - Part 2: Steel inclined ladders GB4053.3 Safety requirements for fixed steel ladders and platforms - Part 3: Industrial protective railings and steel platforms GB 8958 Hypoxia Hazard Operation Safety Regulations GB 9448 Welding and Cutting Safety GB 50016 Code for Design of Building Fire Protection GB 50140 Code for Configuration Design of Building Fire Extinguishers (with explanatory notes) GBZ 2.1 Occupational Exposure Limits for Harmful Factors in the Workplace Part 1: Chemical Harmful Factors GBZ 2.2 Occupational exposure limits for harmful factors in the workplace Part 2: Physical factors GBZ 158 Workplace Occupational Hazard Warning Signs GBZ/T205 Occupational Hazard Prevention Code for Confined Space Operations Selection, Use and Maintenance of GB/T 18664 Respiratory Protection Products GB11651 Personal Protective Equipment Selection Specification GB/T 18883 Indoor Air Quality Standard 3 Terms and Definitions This standard uses the following terms and definitions. 3.1 Limited space Refers to closed or partially closed, the entrance is relatively narrow, the operator can not work long hours, natural ventilation is poor, easy to cause toxic and hazardous, flammable and explosive material accumulation or lack of oxygen in the space. 3.2 Limited Space Types There are three types of limited space: closed semi-enclosed equipment, underground limited space, and limited space above ground. 3.2.1 Closed and Semi-enclosed Equipment Such as storage tanks, truck tanks, reaction towers (reactors), pressure vessels, pipelines, flue, boilers, industrial furnaces and so on. 3.2.2 underground limited space Such as underground pipes, underground ditch, tunnels, culverts, pits, waste wells, cellars, sewage pools (wells), digesters, septic tanks, sewers, etc. 3.2.3 Limited space on the ground Such as storage room, distillers pool, fermentation tank, garbage station, silo and so on. 3.3 Limited Space Operation Refers to the operation of workers entering a limited space. 4 Identification of dangerous and harmful factors 4.1 For the limited space, the production and business operation units should identify hazards and harmful factors. 4.2 The limited space hazards and harmful factors include: (1) The presence of acids, alkalis, poisons, dust, smoke, and other dangerous media, can easily cause suffocation, poisoning, fire and explosion accidents; (2) Hazardous and harmful factors such as lack of oxygen or oxygen, flammable gases and vapors, toxic gases and vapors, roof fall, high drop, object hit, various mechanical injuries, electric shock, drowning, etc. (3) The equipment and facilities are cut off from each other, between the equipment and the facility, resulting in poor ventilation of the working space, insufficient lighting, poor lighting, and poor communication; (4) The small space for activities and the narrow work space make it difficult for staff to enter and exit, and they are inconvenient to communicate with each other, which is not conducive to work custody and implementation of rescue; (5) High humidity and heat, energy consumption of operators, and fatigue; 5 Security Management Requirements 5.1 Responsibilities and Safety Responsibilities of Production and Business Units 5.1.1 Production and business units shall establish a responsibility system for safe production for limited space operations and implement: (1) The principal responsible person has overall responsibility for the safety production work of the unit; (2) The person in charge of safety is responsible for direct leadership; (3) The person in charge of the site bears direct responsibility; (4) The responsibility for the supervision and inspection of safety production management personnel; (5) The operator is obliged to obey the command, to abide by the responsibilities of the discipline, knowing that the law has a responsibility to refuse; (6) Occupational guardians should take responsibility for on-site monitoring. 5.1.2 The requirements for the contracting and contracting of production and business units for limited space operations are as follows: (1) If the production and business operation entity does not have limited space operation conditions, the limited space operation project shall be contracted to a qualified construction unit, and the project may not be contracted to units or individuals that do not have safe production conditions. (2) When producing and contracting limited space operations, the production and business operation entity shall sign a special safety production management agreement with the contracting unit, or stipulate their respective duties of safe production management in the contract. Where there are multiple contractors, the production and business operation unit shall coordinate and manage the safety production work of the contractor. (3) The contractor shall strictly abide by the safety agreement, abide by the operating rules, and strictly prohibit illegal command and illegal operations. 5.1.3 The production and business operation units shall appoint corresponding management departments for limited space operations and shall be equipped with appropriate personnel. 5.1.4 The production and business operation entity shall create a construction environment that meets the requirements for safe operation for the construction unit. 5.1.5 The main person in charge of the production and business unit shall strengthen the safety management of the limited space operations and perform the following duties: (1) Establish and improve the safety production responsibility system for limited space operations, and clarify the duties of responsible persons, operators and guardians of limited space operations; (2) Organize the development of special space operation plans, safe operation procedures, accident emergency rescue plans, safety technical measures, and other limited space operation management systems; (3) to ensure the safety of limited space operations, provide ventilation, detection, protection, lighting and other safety protection facilities and personal protective equipment; (4) Supervise and inspect the safety production of the limited space operations of the unit and implement the safety requirements for the limited space operations; (5) Provide emergency rescue support and do emergency rescue work; (6) Report production safety incidents in a timely and truthful manner. 5.2 Job Management 5.2.1 The production and business operation entity shall identify each device, equipment or work area, determine the quantity and location of the limited space, and establish a limited space management ledger. The limited space statistics should be constantly updated according to the operating environment, process equipment changes, etc. 5.2.2 When entering the limited space for construction, maintenance, cleaning and other operations, the production and business operation unit shall implement the operation approval, which shall be subject to the approval of the person in charge of the safety and related management department. Without approval, no one may enter limited space operations. 5.2.3 The production and business operation unit shall inform the operator of the dangerous and harmful factors and the prevention and control measures of the limited space operations. 5.2.4 The operators of limited space shall have no impediments to the diseases and physiological deficiencies of the corresponding work, and shall meet the qualifications required for the operation of the corresponding work. 5.2.5 Before and after the operation, workers and work equipment shall be counted. 5.2.6 The production and business operation entity shall specify the responsible person, guardian and operator of the limited-space operation site and shall not operate without a guardian. 5.2.7 Workers shall not carry articles unrelated to the work into the limited space. No materials such as materials or work tools shall be thrown in the work. 5.2.8 Workers are strictly prohibited from escaping personal protective equipment in the limited space work area. 5.2.9 The limited space operation with high difficulty, high labor intensity and long time should be rotated. 5.2.10 After the operation, the person in charge of the site shall conduct safety inspections to eliminate hidden dangers and ensure that all personnel leave. 5.3 Safety Management System and Operation Procedures 5.3.1 The production and business operation entity should establish the following rules and regulations for safe production in a limited space: (1) Limited space operation approval system; (2) Training and education system for limited space workers; (3) Operating personnel health inspection system; (4) The supervision system for limited space safety facilities; (5) Detection system. 5.3.2 Safety operation regulations should be established according to job types. 5.4 Operator Education and Training 5.4.1 The production and business units shall annually conduct safety education and training for the responsible persons, guardians and operators of the limited space operations. The training includes: the hazardous characteristics of limited space and the requirements for safe operations; the procedures for entering limited space; the correct use of testing equipment, personal protective equipment and other equipment; accident emergency rescue measures and emergency rescue plans. There should be a record of training, and the personnel participating in the training should sign and confirm it. 5.4.2 Before a limited space operation, the production and business operation entity shall make a safe presentation of the guardian and the operator. The contents of the submission shall include the structure of the work space and related media, toxic and hazardous substances that may be present in the limited space, and accidents that may be encountered during the operation. Treatment, rescue methods, etc. 5.5 Emergency Rescue Management 5.5.1 The production and business operation entity shall formulate the emergency rescue plan and on-site disposal plan and on-site disposal plan for the limited space operation, specify the rescue personnel and their duties, implement the rescue equipment and equipment, master the accident disposal procedures, and improve the emergency handling capacity for emergencies. At least one rehearsal shall be conducted every year in the plan, and the on-site disposal plan shall be rehearsed once every six months. The rehearsal shall be kept in the rehearsal and shall be continuously revised and improved. 5.5.2 Production and business operation units should be equipped with comprehensive personal protection and emergency rescue equipment, such as full-faced positive pressure air respirator or long tube masks and other isolated respiratory protection devices, emergency communication alarm equipment, on-site rapid detection equipment, high-power mandatory Ventilation equipment, emergency lighting equipment, safety ropes, lifelines, safety ladders, etc. 5.5.3 Protective equipment and emergency rescue equipment and facilities shall be properly kept and tested and maintained regularly as required to ensure the normal operation of the facilities. 5.6 Other Management Requirements (Other management requirements that were not included in the above content after consultation with experts) 6 Safety Technical Requirements 6.1 Inspection and Monitoring 6.1.1 The principle of “ventilation, re-testing, and after-operation†must be strictly implemented in the limited-space operation. It is forbidden for operators to enter the limited space without ventilation and testing. 6.1.2 When the working environment conditions may change, the hazard factors in the workplace shall be continuously or regularly detected. For limited space operations that may generate harmful gases or carry out internal preservation at any time, the analysis must be performed every 30 minutes. If there is a failure or other abnormality, the operation shall be immediately stopped and the operator shall be evacuated; After the test meets the requirements, it will be re-approved before continuing operations. 6.1.3 When testing, the inspectors should be in a safe environment. Test records should be made when testing, including the time, place, type of gas, and concentration of detection. The indicators include oxygen concentration, inflammable and explosive substances (flammability). Gas, explosive dust) concentration, toxic gas concentration, etc. 6.1.4 The application of a detection device with an alarm device and a qualified test device shall be used for the detection and evaluation of the limited space; the detection and sampling methods shall be performed in accordance with the relevant specifications. The test sequence and items shall include: 6.1.4.1 Normal oxygen content is 18% to 22%. The limited space for oxygen deficiency should comply with the stipulations in GB8958. Mechanical ventilation must be used for short time operation. 6.1.4.2 The concentration of flammable gases in the limited space air shall be less than 10% of the lower explosive limit. For the maintenance of fuel tanks, oil tanks, etc., the concentration of flammable gases in the air shall be less than 1% of the lower explosion limit. 6.1.4.3 The concentration of toxic gases shall be less than the concentration required by GBZ2. If it is higher than this requirement, mechanical ventilation measures should be taken. 6.2 Security isolation 6.2.1 Reliable cut-off (isolation) measures must be taken to isolate limited space from other pipes or other spaces that may endanger safety operations. Prevents the influx of harmful gases, dust or other free-flowing liquids such as mud, water, and solids into confined spaces. 6.2.2 Other openings where hazardous gases or vapours may flow back into a confined space shall be closed. 6.2.3 The limited space should be isolated from the sources of fire that are not related to the operation. 6.3 Cleaning, emptying or replacement 6.3.1 The limited space shall be cleaned, emptied or replaced according to the characteristics of the material contained in the limited space and the safety operation requirements shall be met. 6.3.2 Water vapor cleaning or inert gas replacement may be used. 6.3.2.1 Water Vapor Cleaning (1) It is suitable for the cleaning of water vapor volatile substances in a limited space; (2) When cleaning, ensure that there is enough time to completely remove the harmful substances in the limited space; (3) During the cleaning period, sufficient vents should be provided for water vapor and condensate in order to prevent the creation of dangerous pressure in a limited space; (4) After cleaning, adequate ventilation shall be provided to prevent any "vacuum" in the limited space due to heat dissipation and condensation. Before the operator enters the high temperature limited space, the space should be cooled to room temperature; (5) After the cleaning is completed, all remaining liquid in the limited space shall be properly drained or pumped away, and the import and export shall be opened in time for ventilation; (6) The limited space that has been cleaned by water vapor should be tested again after it has been left for a long time. It does not meet the safety requirements and should be cleaned again by steam; (7) Before corrosive or non-volatile substances are cleaned with water vapor, water, or other suitable solvent or neutralizing agent is repeatedly washed and pretreated. 6.3.2.2 Inert gas replacement (1) When the limited space contains flammable gas or evaporative liquid, replace it with inert gas (such as nitrogen or carbon dioxide); (2) Replacing the limited space with inert gas. After the detection reaches the lower limit, the fresh air should be used for ventilation after the operator enters or approaches, and the oxygen content of the limited space should be continuously tested to ensure that there is enough oxygen in the limited space to maintain life. . 6.4 Ventilation 6.4.1 Into a limited space where natural ventilation and ventilation are not effective, mechanical ventilation should be used. Ventilation should meet the need to dilute toxic and hazardous substances. 6.4.2 Mechanical ventilation should be provided with local ventilation of the post, supplemented by full ventilation. When operating positions are not fixed, mobile local ventilation or full ventilation should be used. 6.4.3 Suction outlets in limited spaces shall be provided in the lower part. When there is a contaminant with the same or less air density than the air density, an air intake should also be added at the top. 6.4.4 Do not use pure oxygen for ventilation. 6.4.5 When the ventilation is abnormal, stop the operation and withdraw the personnel. 6.5 Electrical Equipment and Lighting Safety 6.5.1 For limited space workplaces where flammable gases are present, all electrical equipment facilities and lighting shall comply with the relevant provisions in GB 3836.1. To achieve the overall electrical explosion-proof and anti-static measures. 6.5.2 It is prohibited to use open flame lighting and non-explosion-proof equipment in a limited space where flammable gases are present. 6.5.3 When the installation height of the fixed lighting fixture is 2.4m or less from the ground, safety voltage should be used. The safety voltage should meet the relevant requirements in GB/T 3805. When mobile lighting fixtures are used on wet floors and other places, the rated voltage should not exceed 36V when the mounting height is 2.4m or less from the ground. 6.5.4 For the narrow workplaces such as boilers, metal containers, and pipelines, the rated voltage of hand-held lamps shall not exceed 12V. 6.5.5 Portable lamps shall have insulated handles and metal shields, and the metal parts of the lamp shall not be exposed. 6.5.6 Step-down transformers used for running lights should use isolation transformers, and the safety voltage should comply with the relevant provisions of GB/T 3805. Transformers for running lamps are not allowed to be placed in metal containers such as boilers, heaters, and water tanks, and in particularly humid places; the insulation resistance should not be less than 2 MΩ and they should be regularly tested. 6.5.7 Hand-held power tools shall be inspected regularly and recorded. The insulation resistance shall comply with the relevant provisions in GB 3787. 6.6 Mechanical Equipment 6.6.1 The movements and moving parts of machinery and equipment shall all be enclosed and shielded. All transmissions shall be provided with guards. 6.6.2 Safety lighting should be used for local lighting on mechanical equipment. 6.6.3 The metal components on mechanical electrical equipment should have a solid and reliable PE wire. 6.6.4 The ladders and maintenance platforms attached to the equipment shall meet the requirements of GB 4053.1, GB 4053.2, GB 4053.3 and GB 4053.4. 6.7 Regional Alert, Warning and Fire Protection 6.7.1 The entrances and exits of limited space shall be provided with guard rails, grid screens, covers and warning signs. When the visibility is not high, warning lights shall be provided. When it is necessary to set the grid screen protection, the specifications of the grid screen holes shall meet the requirements for preventing falling objects above. 6.7.2 Caution areas, cordon lines, and warning signs should be set up in conspicuous areas outside the limited space. Its settings should comply with the relevant provisions of GB 50016, GB 2893 and GB 2894. Without permission, no entry is allowed. 6.7.3 When the operator is working inside a closed semi-enclosed equipment connected to the transmission pipeline, the valve shall be closed tightly, and the blind plate shall be installed. Warning information such as “Prohibited to start†shall be set. 6.7.4 Locations with flammability factors In the alert area, fire extinguishing equipment should be set up in accordance with GB 50140 and remain in an effective state. Full-time safety personnel and fire fighters should regularly go through inspections and guardians in the warning area and have inspection records. Fire or combustibles are strictly prohibited from falling into limited space. 6.7.5 The power machinery equipment and tools should be placed outside the limited space and keep a safe distance to ensure that the gas or smoke discharges away from the potential fire source. At the same time, the exhaust gas or hydrocarbon fumes of the equipment should be prevented from affecting limited space operations. 6.7.6 When welding and cutting operations, the welding equipment, welding machine, cutting equipment, cylinders, cables and other apparatus placement, arc radiation and splash damage protection shall comply with the relevant provisions of GB 9448. 6.8 Personal Protection and Emergency Equipment 6.8.1 The selection of respiratory protection products shall meet the requirements of GB/T18664. In the absence of oxygen, it should meet the requirements of GB8958. 6.8.2 In the absence of oxygen or poisonous limited space, a protective mask should be worn. If necessary, the operator should carry the lifeline. 6.8.3 When working in a flammable and confined limited space, wear anti-static overalls and work shoes, use suitable explosion-proof low-voltage lamps and tools that do not generate sparks, and use combustible gas alarms. 6.8.4 When working in limited space with corrosive media such as acid and alkali, wear protective clothing such as anti-acid and alkaline work clothes, work shoes, and gloves. 6.8.5 Noise protection equipment such as earplugs or earmuffs shall be worn in limited space when noise is generated, and reliable contact methods shall be agreed upon. 6.8.6 When wearing a long tube respirator, air tightness should be carefully checked and the ventilated long tube should be prevented from being squeezed; the suction port should be placed on the upper air outlet of fresh air and be monitored by special personnel. 6.8.7 In the event of an accident in a limited space, the guardian shall promptly report and report to the relevant person in charge of the enterprise. The rescue personnel shall do their own protection and be equipped with the necessary breathing apparatus and rescue equipment. It is strictly forbidden to rescue them blindly and cause the accident to expand. 6.9 Other technical requirements This website solemnly declares: This article is the reprint of the online media, only represents the author's point of view, has nothing to do with this site. If news articles and comments infringe your legal rights, please call us and we will handle it in a timely manner. Build In Led Driver, Led Driver 48W,Led Driver Transformer,Led Driver Replacement Effort Semiconductor Lighting Ltd. , https://www.effortem.com