serial number | Check content | Check basis | actual situation | Conformity |
1. | In the areas of production facilities and storage and transportation facilities that produce or use combustible gases and toxic gases, when the concentration of combustible gases in the leaked gas may reach the alarm setting value, combustible gas detectors should be installed; the concentration of toxic gases in the leaked gas may reach When the alarm setting value is set, a toxic gas detector should be set up; Combustible gas is also a single-component gas medium of toxic gases, and toxic gas detectors should be installed; in the case of multi-component mixed gases where flammable gases and toxic gases exist at the same time , the concentration of combustible gas and the concentration of toxic gases may reach the alarm setting at the same time when leaking. For fixed values, combustible gas detectors and toxic gas detectors should be set separately. | GB/T50493-2019 Article 3.0.1 |
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2. | The detection and alarm of flammable gas and toxic gas should adopt two-level alarm. When toxic gases and combustible gases of the same level alarm at the same time, the alarm level of toxic gases should take priority. | GB/T50493-2019 Article 3.0.2 |
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3. | The combustible gas and toxic gas detection alarm signals should be sent to the on-site control room, central control room, etc. that are on duty for display and alarm; the combustible gas secondary alarm signal and the fault signal of the combustible gas and toxic gas detection alarm system alarm control unit should be sent to Fire control room. | GB/T50493-2019 Article 3.0.3 |
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4. | The control room operating area should be equipped with sound and light alarms for flammable gases and toxic gases; on-site area alarms should be set according to the area occupied by the device, the layout of the equipment and buildings, the physical and chemical properties of the release source, and the on-site air flow characteristics. The alarm should have sound and light alarm functions. | GB/T50493-2019 Article 3.0.4 |
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5. | Combustible gas detectors must obtain the measuring instrument type approval certificate, explosion-proof certificate and fire product type inspection report from the national designated agency or its authorized inspection unit; the alarm control unit participating in the fire linkage should adopt the product standard of the dedicated combustible gas alarm controller Special combustible gas alarm controllers must be manufactured and obtained with test reports; toxic gas detectors required by national regulations must be obtained from nationally designated agencies or their authorization. The type approval certificate of the computing device from the authorized inspection unit. Specified gas detectors installed in explosive hazardous locations should also obtain explosion-proof certificates from nationally designated agencies or their authorized inspection units. | GB/T50493-2019 Article 3.0.5 |
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6. | Where combustible gas and toxic gas detectors need to be installed, fixed detectors should be used; where flammable gas and toxic gases need to be temporarily detected, mobile gas detectors should be installed . | GB/T50493-2019 Article 3.0.6 |
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7. | On-site workers who enter explosive gas environments or toxic gas environments. Portable flammable gas and/or toxic gas detectors should be provided. When the environment you enter contains explosive gases and toxic gases. Portable combustible gas and harmful gas detectors are available in multi-sensor types. | GB/T50493-2019 Article 3.0.7 |
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8. | Combustible gas and toxic gas detection and alarm systems should be set up independently from other systems. | GB/T50493-2019 Article 3.0.8 |
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9. | Power supply load for gas detectors, alarm control units, on-site sirens, etc. of combustible gas and toxic gas detection and alarm systems. It should be considered as a particularly important load among the first-level electrical loads. , it is advisable to use UPS power supply device for power supply. | GB/T50493-2019 Article 3.0.9 |
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10. | When determining occupational exposure limits for toxic gases. Sichuan should be selected according to the priority of maximum allowable concentration, time- weighted average allowable concentration and short-term exposure allowable concentration. | GB/T50493-2019 Article 3.0.10 |
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11. | The characteristics of common flammable gases and vapors should be adopted in accordance with Appendix A of this standard; the characteristics of common toxic gases and vapors should be adopted in accordance with Appendix B of this standard. | GB/T50493-2019 Article 3.0.11 |
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12. | The detection points of combustible gas and toxic gas detectors should be based on the physical and chemical properties of the gas, the characteristics of the release source, the layout of the production site, geographical conditions, environmental climate, characteristics of the detector, detection and alarm reliability requirements, operation inspection routes, etc. Comprehensive analysis of factors. Choose a place where combustible gases and toxic gases are easy to accumulate and where sampling, testing and instrument maintenance are convenient. | GB/T50493-2019 Article 4.1.1 |
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13. | To determine whether the leaked gas medium is heavier than air, the ratio of the molecular weight of the leaked gas medium to the molecular weight of ambient air should be used as the benchmark, and the judgment should be based on the following principles: 1. When the ratio is greater than or equal to 1.2, the leaked gas is heavier than the air; 2. When the ratio is greater than or equal to 1.0 and less than 1.2. The leaked gas is slightly heavier than air; 3. When the ratio is 0.8-1.0, the leaked gas is slightly lighter than air; 4. When the ratio is less than or equal to 0.8, the leaked gas is lighter than air. | GB/T50493-2019 Article 4.1.2 |
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14. | Detection points should be arranged around the following flammable gas and/or toxic gas release sources: 1. Dynamic seals of gas compressors and liquid pumps; 2. Liquid sampling port and gas sampling port; 3. Liquid (gas) drain (water) port and vent port; 4. Frequently disassembled flanges and frequently operated valve groups. | GB/T50493-2019 Article 4.1.3 |
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15. | When detecting flammable gases and toxic gases, the detector probe should be close to the release source and in a location where gases and vapors are easy to accumulate. | GB/T50493-2019 Article 4.1.4 |
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16. | When the leakage of combustible gases and toxic gases in the production facilities and storage and transportation facility areas may have an impact on the safety of the surrounding environment and need to be monitored, combustible gas detectors or toxic gas detectors should be arranged at appropriate intervals along the perimeter of the production facilities and storage and transportation facility areas. Detectors, or linear gas detectors installed along the perimeter of production facilities and storage and transportation facilities. | GB/T50493-2019 Article 4.1.5 |
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17. | During the production process, the ambient oxygen concentration may change, and if there is a lack of oxygen or over-oxygen and people enter the active place, oxygen detectors should be installed. When the relevant gas release source is a combustible gas or toxic gas release source, the oxygen detector can be arranged together with the relevant combustible gas detector and toxic gas detector. | GB/T50493-2019 Article 4.1.6 |
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18. | The release source is located in the equipment area of an open-air or open factory building. The horizontal distance between the combustible gas detector and any release source within its coverage should not be greater than 10m. The horizontal distance between the toxic gas detector and any release source within its coverage should not be greater than 10m. The horizontal distance between sources should not be greater than 4m. | GB/T50493-2019 Article 4.2.1 |
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19. | The release source is in a closed factory or a semi-open factory with poor local ventilation. The horizontal distance between the combustible gas detector and any release source within the cover range of the combustible gas detector should not be greater than 5m; the distance between the toxic gas detector and any release source within its coverage range should not be greater than 5m. The horizontal distance between any release source should not exceed 2m. | GB/T50493-2019 Article 4.2.2 |
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20. | The release source of flammable gases or toxic gases that are lighter than air is in a closed or semi-open factory with poor local ventilation. In addition to setting up a detector above the release source, the combustible gas should also be set up at the highest point in the factory where gas is likely to accumulate. or toxic gas detectors . | GB/T50493-2019 Article 4.2.3 |
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twenty one. | Detectors should be installed in the fire dikes of liquid storage tanks that generate flammable gases, such as liquefied hydrocarbons, Class A B, B , and A liquids . The horizontal distance between a combustible gas detector and any release source within its coverage should not be greater than 10m, and the horizontal distance between a toxic gas detector and any release source within its coverage should not be greater than 4m. | GB/T50493-2019 Article 4.3.1 |
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twenty two. | For loading and unloading facilities for liquefied hydrocarbons and Category A B and B A liquids, the detector settings should comply with the following regulations: 1. For railway loading and unloading pallets, a detector should be installed in each parking space on the ground, and the horizontal distance between the detector and the loading and unloading port should not be greater than 10m; 2. The horizontal distance between the loading and unloading truck crane at the vehicle loading and unloading station and the detector should not be greater than 10m. | GB/T50493-2019 Article 4.3.2 |
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twenty three. | The detector settings in the pump or compressor area of the loading and unloading facility shall comply with the provisions of Section 4.2 of this standard. | GB/T50493-2019 Article 4.3.3 |
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twenty four. | The detector settings of the liquefaction filling station should comply with the following regulations: 1. In a closed or semi-open bottle filling room, the horizontal distance between the filling port and the detector should be 5m-7.5m. 2. Closed or semi-open bottle storage warehouses should comply with the provisions of Article 4.2.2 of this standard; open bottle storage warehouses should be equipped with a detector every 15m-20m around the perimeter. When the total length of the surrounding perimeter is less than 15m hour. A detector should be provided; 3. The horizontal distance between the buffer tank drain outlet or valve group and the detector should be 5m-7.5m. | GB/T50493-2019 Article 4.3.4 |
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25. | The closed or semi-open hydrogen filling room should be at the best point indoors above the filling port. Install detectors where gas is likely to accumulate. | GB/T50493-2019 Article 4.3.5 |
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26. | For loading and unloading docks that may emit flammable gas, a detector should be installed within 10m of the horizontal plane of the oil transfer arm. | GB/T50493-2019 Article 4.3.6 |
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27. | For other storage and transportation facilities that store and transport flammable gases and toxic gases, flammable gas detectors and/or toxic gas detectors should be set up in accordance with the provisions of Section 4.2 of this standard. | GB/T50493-2019 Article 4.3.7 |
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28. | A combustible gas detector should be installed between the open flame heating furnace and the combustible gas release source. The horizontal distance between the detector and the edge of the heating furnace should be 5m---10m. When there is a solid wall of non-combustible material between the open flame heating furnace and the combustible gas release source, a detector should be installed on the side of the solid wall close to the release source. | GB/T50493-2019 Article 4.4.1 |
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29. | The online analysis instrument room located within Zone 2 of the explosion hazard area should be equipped with flammable gas and/or toxic gas detectors, as well as oxygen detectors. | GB/T50493-2019 Article 4.4.2 |
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30. | Combustible gas and/or toxic gas detectors . | GB/T50493-2019 Article 4.4.3 |
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31. | In places such as process valve wells and pipe trenches where someone enters for inspection operations and may accumulate flammable or toxic flammable gas and/or toxic gas detectors should be installed. | GB/T50493-2019 Article 4.4.4 |
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32. | The combustible gas and toxic gas detection and alarm system should be composed of combustible gas or toxic gas detectors, on-site alarms, alarm control units, etc. | GB/T50493-2019 Article 5.1.1 |
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33. | The second level alarm signal of combustible gas and the fault signal of the alarm control unit. It should be sent to the fire control room for graphic display and alarm. Combustible gas detectors cannot be directly connected to the input circuit of the fire alarm controller. | GB/T50493-2019 Article 5.1.2 |
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34. | When the combustible gas or toxic gas detection signal is used as the input of the safety instrument system, the detector should be set independently. The detector output signal should be sent to the corresponding safety instrument system, and the hardware configuration of the detector should comply with the relevant provisions of the current national standard "Petrochemical Safety Instrument System Design Specification" GB/T 50770. | GB/T50493-2019 Article 5.1.3 |
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35. | The configuration diagram of the combustible gas and toxic gas detection and alarm system is shown in Appendix C of this standard. | GB/T50493-2019 Article 5.1.4 |
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36. | The output of the detector can be selected from 4mA-20mA DC signal, digital signal, and contact signal. | GB/T50493-2019 Article 5.2.1 |
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37. | The selection of combustible gas and toxic gas detectors should be based on the technical performance of the detector, the physical and chemical properties of the gas being measured, the component types and detection accuracy requirements of the medium being measured, the compatibility of the detector material with the on-site environment, and the production environment. Characteristics etc. determined. | GB/T50493-2019 Article 5.2.2 |
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38. | The selection of commonly used flammable gas and toxic gas detectors should comply with the following regulations: 1. For light combustible gases, catalytic combustion or infrared gas detectors should be used; when the air in the place of use contains media such as sulfur, phosphorus, silicon, lead, and halogen compounds that can poison the catalytic combustion detection element, a detector should be used. Choose anti-toxic catalytic combustion detectors, infrared gas detectors or laser gas detectors; in places with anoxia or high corrosiveness, it is advisable to use infrared gas detectors or laser gas detectors; for heavy mercury vapors, light can be used Ionization type detector; 2. Hydrogen detection should use catalytic combustion, electrochemical, and thermal conductivity detectors; 3. Semiconductor or photoionization detectors should be used for organic toxic gases; 4. Electrochemical detectors should be used for detecting toxic gases; 5. Electrochemical detectors should be used for oxygen; 6. In places where the climate environment or production environment is special and the area that needs to be monitored is open, linear combustible gas detectors should be selected; 7. In places where the gas or vapor formed after the process medium leaks can significantly change the ambient temperature around the release source, infrared image detectors can be used; 8. In places where the noise generated when high-pressure process media leaks can significantly change the sound pressure level of the environment around the release source, a noise detector can be selected; 9. In places where flammable gases and toxic gases need to be temporarily detected during production and maintenance, mobile gas detectors should be equipped. | GB/T50493-2019 Article 5.2.3 |
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39. | The sampling method of commonly used detectors should be determined according to the following regulations according to the place of use: 1. Diffusion detectors should be used for the detection of combustible gases and toxic gases; 2. Due to limitations of installation conditions and medium diffusion characteristics, inhalation detectors can be used in places where it is inconvenient to use diffusion detectors; 3. When the detector is equipped with a sampling system, the lag time of the sampling system should not be greater than 30s. | GB/T50493-2019 Article 5.2.4 |
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40. | The technical performance of common gas detectors should comply with the requirements of Appendix D of this standard; common gas detectors should be selected in accordance with Appendix E of this standard. | GB/T50493-2019 Article 5.2.5 |
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41. | Combustible gas and toxic gas detection and alarm systems should be divided into alarm zones according to the devices or units of production facilities and storage and transportation facilities, and each alarm zone should be equipped with on-site regional alarms. The start signal of the regional alarm should use the second level alarm set value signal. The number of area alarms should be such that the alarm can be perceived by on-site personnel anywhere in the area . | GB/T50493-2019第5.3.1条 |
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42. | 报警控制单元应采用独立设置的以微处理器为基础的电子产品，并应具备下列基本功能： 1、能为可燃气体探测器、有毒气体探测器及其附件供电。 2、能接收气体探测器的输出信号，显示气体浓度并发出声、光报警。 3、能手动消除声、光报警，再次有报警信号输入时仍能发出报警。 4、有相对独立、互不影响的报警功能，能区分和识别报警场所信号。 5、在下列情况下，报警控制单元应能发出与可燃气体和有毒体浓度报警信号有明显区别的声、光故障报警信号： 1) 报警控制单元与探测器之间连线断路或短路。 2) 报警控制单元主电源欠压。 3)报警控制单元与电源之间的连线断路或短路。 6、具有以下记录、存储、显示功能： 1）能记录可燃气体和有毒气体的报警时间，且日计时误差不应超过30s; 2) 能显示当前报警部位的总数； 3) 能区分***报警部位，后续报警点按报警时间顺序连续显示； 4）具有历史事件记录功能。 | GB/T50493-2019第5.4.1条 |
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43. | 控制室内可燃气体和有毒气体声、光警报器的声压等级应满足设备前方lm处不小于75dBA,声、光警报器的启动信号应采用第二级报警设定值信号。 | GB/T50493-2019第5.4.2条 |
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44. | 可燃气体探测器参与消防联动时，探测器信号应先送至按专用可燃气体报警控制器产品标准制造并取得检测报告的专用可 燃气体报警控制器，报警信号应由专用可燃气体报警控制器输出 至消防控制室的火灾报警控制器。 可燃气体报警信号与火灾报警 信号在火灾报警控制系统中应付明显区别。 | GB/T50493-2019第5.4.3条 |
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45. | 测量范围应符合下列规定： 1、可燃气体的测量范围应为0-100 % LEL; 2、有毒气体的测量范围应为0-300 % OEL; 当现有探测器的测量范围不能满足上述要求时，有毒气体的测量范围可为0-30%IDLH；环境氧气的测量范围可为0-25%； 3、线利可燃气体测扯范围为0-5LEL ·m。 | GB/T50493-2019第5.5.1条 |
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46. | 报警值设定应符合下列规定： 1、可燃气体的一级报警设定值应小于或等于25%LEL。 2、可燃气体的二级报警设定伯应小于或等于50%LEL。 3、有讲气体的一级报警设定值应小于或等于lOO%OEL, 有毒气体的二级报警设定值应小于或等于200%0EL。 当现有探测器的测扯范围不能满足测量要求时．有毒气体的一级报警设定伯 不得超过5%IDLH. 有毒气体的二级报警设定值不得超过1O%IDLH。 4、环境氧气的过氧报警设定值宜为23.5%VOL, 环境欠氧 报警设定值宜为19.5%VOL。线型可燃气体测量一级报警设定值应为1LEL• m; 二级报警设定值应为2LEL• m。 | GB/T50493-2019第5.5.2条 |
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47. | 探测器应安装在无冲击、无振动、无强电磁场干扰、易于检修的场所．探测器安装地点与周边工艺管道或设备之间的净空不应小于0.5m。 | GB/T50493-2019第6.1.1条 |
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48. | 检测比空气重的可燃气体或有毒气体时，探测器的安装高度宜距地坪（或楼地板）0.3m-O.6m; 检测比空气轻的可燃气体或有毒气体时，探测器的安装高度宜在释放源上方2.Om内。 检 测比空气略重的可燃气体或有毒气体时，探测器的安装高度宜在 释放源下方0.5m-1.Om; 检测比空气略轻的可燃气体或有毒气体时，探测器的安装高度宜高出释放源0. 5m—l.Om。 | GB/T50493-2019第6.1.2条 |
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49. | 环境氧气探测器的安装高度宜距地坪或楼地板1.5m-2.Om。 | GB/T50493-2019第6.1.3条 |
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50. | Linear combustible gas detectors are installed in large open environments, and the length of the detection area should not be more than 100m. | GB/T50493-2019 Article 6.1.4 |
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51. | The human-machine interface of the flammable gas and toxic gas detection and alarm system should be installed in a building such as a control room where operators are resident. | GB/T50493-2019 Article 6.2.1 |
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52. | The on-site area alarm should be installed nearby the alarm area where the detector is located. | GB/T50493-2019 Article 6.2.2 |
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53. | The installation height of the on-site area alarm should be 2.2m higher than the ground or floor of the on-site area , and should be located in a place where staff can easily detect it. | GB/T50493-2019 Article 6.2.3 |
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54. | The on-site | GB/T50493-2019 Article 6.2.4 |
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