標準編號:	GB/T 50493-2019
中文名稱:	石油化工可燃氣體和有毒氣體檢測報警設計標準
英文名稱:	Standard for design of combustible gas and toxic gas detection and alarm for petrochemical industry
行業分類:	GB    國家標準
發布機構:	中華人民共和國住房和城鄉建設部
發布日期:	2019-09-25
實施日期:	2020-1-1
標準狀態:	valid
替代舊標準:	GB 50493-2009 石油化工可燃氣體和有毒氣體檢測報警設計規范
翻譯語言:	英文
文件格式:	PDF
中文字符數:	33000 字
翻譯價格(元):	2310.0
交付時間:	付款后 1 個工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is revised from GB 50493-2009 Specification for design of combustible gas and toxic gas detection and alarm for petrochemical industry by Sinopec Guangzhou Engineering Co., Ltd. jointly with organizations concerned according to the requirements of Document JIANBIAO [2015] No.274 issued by the Ministry of Housing and Urban-Rural Development of the People's Republic of China - Notice on Printing and Distributing the ‘Development and Revision Plan on Engineering Construction Standards and Codes in 2016’. During the revision of this standard, the standard drafting group made extensive investigations and studies on the problems encountered in the design of combustible gas and toxic gas detection and alarm for petrochemical industry, summarized the experience in the use of combustible gas detectors and toxic gas detectors in petrochemical enterprises in recent years, and finalized this standard after examination finally by reference to the European standard EN 60079-29-2 Explosive atmospheres - Part 29-2: Gas detectors - Selection, installation, use and maintenance of detectors for flammable gases and oxygen and on the basis of soliciting opinions from design, production, scientific research, detector manufacturing enterprises and other relevant parties. The main technical contents of this standard are: general provisions, terms, basic requirements, location of detection points, design of combustible gas and toxic gas detection and alarm system, installation of combustible gas and toxic gas detection and alarm system, etc. The main technical contents of the revision of this standard are: 1. The scope of application of the standard is revised from “construction, extension and renovation engineerings of petrochemical industry" to "construction and extension engineerings of petrochemical industry"; 2. The scope of toxic gases is expanded from toxic gases listed in the Catalogue of highly toxic articles to common toxic gases; 3. The requirements for design compatibility, independence and reliability of combustible gas and toxic gas detection and alarm system (GDS) are added; 4. The requirements for separately setting the combustible gas and toxic gas detection and alarm system (GDS) and the fire fighting and fire automation system are added; 5. Open-path (laser, infrared) detectors, noise detectors and other contents are added, and the detection point and layout requirements of detectors are further improved; 6. Guide for the selection of common gas detectors as well as the arrangement plan of combustible gas and toxic gas detection and alarm system are added. The Ministry of Housing and Urban-Rural Development of the People's Republic of China is in charge of the administration of this standard, China Petrochemical Corporation is responsible for the routine management, and Sinopec Guangzhou Engineering Co., Ltd. is responsible for the explanation of specific technical contents. During the process of implementing this standard, you are kindly requested to send your opinions and advice (if any) to Sinopec Guangzhou Engineering Co., Ltd. (Address: F20, Tower A, Guangzhou Sinopec Building, No.191, West Tiyu Road, Tianhe District, Guangzhou City, Guangdong Province, 510620, China). Contents 1 General provisions 1 2 Terms 2 3 Basic requirements 4 4 Location of detection points 6 4.1 General requirements 6 4.2 Process units 7 4.3 Storage and transportation facilities 7 4.4 Other places where combustible gases, toxic gases diffuse and accumulate 8 5 Design of combustible gas and toxic gas detection and alarm system 10 5.1 General requirements 10 5.2 Selection of detector 10 5.3 Selection of field alarming units 11 5.4 Selection of alarm control unit 12 5.5 Measurement range and setting of alarm value 13 6 Installation of combustible gas and toxic gas detection and alarm system 15 6.1 Installation of detector 15 6.2 Installation of alarm control unit and field alarming unit 15 Annex A Properties of common combustible gases and vapors 16 Annex B Properties of common toxic gases and vapors 21 Annex C Arrangement plan of combustible gas and toxic gas detection and alarm system 22 Annex D Technical performance table of common gas detectors 23 Annex E Guide for selection of common gas detectors 25 Explanation of wording in this standard 26 List of quoted standards 27 1 General provisions 1.0.1 This standard is formulated with a view to ensuring the personal safety and production safety of petrochemical enterprises, monitoring combustible gases or toxic gases leaked during the production process and in storage and transportation facilities and timely alarming to prevent personal injury and fire and explosion accidents. 1.0.2 This standard is applicable to the design of combustible gas and toxic gas detection and alarm system for construction and extension engineerings of petrochemical industry. 1.0.3 In addition to the requirements of this standard, the design of combustible gas and toxic gas detection and alarm system for petrochemical industry shall also comply with those stipulated in the current relevant standards of the nation. ? 2 Terms 2.0.1 combustible gas combustible gas or vapour formed after gasification of Class A gas or Classes A and BA combustible liquids, which is also known as flammable gas 2.0.2 toxic gas toxic gas or vapor that may cause death or permanent health injury of workers through skin contact or breathing during professional activities 2.0.3 source of release location or place where explosive gas atmosphere and toxic gas atmosphere may be released and formed 2.0.4 detector an electronic device that converts the concentration of combustible gas, toxic gas or oxygen into electrical signals 2.0.5 open-path gas detector an open type gas detector for detecting combustible gas or toxic gas clouds in a straight path. Commonly used open-path gas detectors include: infrared gas detectors, laser gas detectors, etc. 2.0.6 field alarming unit/audible and visual alarm unit an electronic device installed on the site to alert personnel on or near the site by sound, light, or optical rotation. Common ones include: the integrated audible and visual alarm unit on the detector, and the field alarming unit set by zone 2.0.7 alarm control unit an electronic device that receives the output signal of the detector, displays and records the concentration of the detected gas, emits audible and visual alarm signals, and can send gas concentration alarm signal and alarm control unit fault information to equipment such as graphic display device in the fire control room. When the combustible gas alarm signal is involved in the fire control linkage, the alarm control unit usually adopts a special combustible gas alarm controller that is manufactured according to the product standard for the special combustible gas alarm controller and has been provided with the detection report 2.0.8 sensible range the concentration range of the detected gas that the detector can detect, which is also called measurement range 2.0.9 alarm set point the preset alarm concentration value, which is divided into primary alarm set point and secondary alarm set point 2.0.10 response time the time from the detector contacting the detected gas to reaching stable indication under test conditions. Usually, the response time is the time required for reaching 90% of the stable indication, and the recovery time is the time required for returning to 10% of the stable indication 2.0.11 vertical height vertical distance from the suction inlet of the detector sensor to the specified reference 2.0.12 lower explosion limit (LEL) the lower concentration (V%) limit of a combustible gas when it explodes 2.0.13 upper explosion limit (UEL) the upper concentration (V%) limit of a combustible gas when it explodes 2.0.14 occupational exposure limit (OEL) the allowable exposure level of a worker that will not cause harmful health effects on the majority of contacts during his/her long-term repeated exposure in the occupational activities. The occupational exposure limits of chemical factors can be divided into three types: maximum allowable concentration, permissible concentration-short term exposure limit and permissible concentration-time weighted average 2.0.15 maximum allowable concentration (MAC) the concentration of toxic chemicals that cannot be exceeded at workplace at any time within a working day 2.0.16 permissible concentration-time weighted average (PC-TWA) the average permissible exposure concentration for 40h per working week (i.e., 8h per working day), with time as the weight 2.0.17 permissible concentration-short term exposure limit (PC-STEL) the permissible short term (15min) exposure concentration subject to the permissible concentration-time weighted average (PC-TWA) 2.0.18 immediately dangerous to life or health concentration (IDLH) certain dangerous level of the concentration of air pollutants in the environment at workplace, which may cause death or permanent health damage, or may make human immediately lose escape ability ? 3 Basic requirements 3.0.1 In the areas of the process units producing or using combustible gases and toxic gases and the storage and transportation facilities for combustible gases and toxic gases, when the concentration of combustible gas in the leaked gas may reach the alarm set point, the combustible gas detector shall be set; when the concentration of toxic gas in the leaked gas may reach the alarm set point, the toxic gas detector shall be set; in case of the single-component gas medium that belongs to both combustible gas and toxic gas, the toxic gas detector shall be set; in case of the multi-component mixed gas containing both combustible gas and toxic gas, when the concentration of combustible gas and that of toxic gas may reach the respective alarm set points at the same time during leakage, combustible gas detector and toxic gas detector shall be set respectively. 3.0.2 Two-level alarm shall be adopted for detection and alarm of combustible gas and toxic gas. When an alarm is sent for the toxic gas and combustible gas at the same level at the same time, the alarm level of toxic gas shall take precedence. 3.0.3 The detection and alarm signals for combustible gas and toxic gas shall be sent to the attended field control room and central control room for display and alarm. The secondary alarm signal of combustible gas and the fault signal of alarm control unit in combustible gas and toxic gas detection and alarm system shall be sent to the fire control room. 3.0.4 The operation area of the control room shall be provided with audible and visual alarm for combustible gas and toxic gas; the field alarming unit should be set according to the occupied area of the unit, the layout of equipment, buildings and structures, the physical and chemical properties of the source of release and the field air flow characteristics, which shall have audible and visual alarm functions. 3.0.5 The combustible gas detectors must be provided with the type approval certificate for measuring instruments, the explosion-proof certificate and the type inspection report for fire-fighting products issued by the organization designated by the nation or its authorized inspection unit; the alarm control unit involved in fire control linkage shall be the special combustible gas alarm controller that is manufactured according to the product standard for the special combustible gas alarm controller and has been provided with the detection report; the toxic gas detectors required by the national regulations must be provided with the type approval certificate for measuring instruments issued by the organization designated by the nation or its authorized inspection unit. Toxic gas detectors installed in explosive hazardous areas shall also be provided with the explosion-proof certificate issued by organization designated by the nation or its authorized inspection unit. 3.0.6 Where combustible gas and toxic gas detectors need to be set, stationary detectors should be adopted. Where it is necessary to temporarily detect the combustible gas and toxic gas, transportable gas detectors should be equipped. 3.0.7 Field workers entering explosive gas atmosphere or toxic gas atmosphere shall be equipped with portable combustible gas and (or) toxic gas detectors. When explosive gas and toxic gas coexist simultaneously in the atmosphere entered, the multi-sensor type portable combustible gas and toxic gas detectors may be adopted. 3.0.8 The combustible gas and toxic gas detection and alarm system shall be set independently of other systems. 3.0.9 The gas detectors, alarm control units, field alarming units, etc. in the combustible gas and toxic gas detection and alarm system shall be considered as particular important power supply loads among Class I electrical loads, and should be powered by UPS device. 3.0.10 The occupational exposure limit of toxic gas shall be selected in priority order of the maximum allowable concentration, the permissible concentration-time weighted average and then the permissible concentration-short term exposure limit. 3.0.11 The properties of common flammable gases and vapors shall be adopted according to Annex A hereto; and the properties of common toxic gases and vapors shall be adopted according to Annex B hereto.

1 General provisions 2 Terms 3 Basic requirements 4 Location of detection points 4.1 General requirements 4.2 Process units 4.3 Storage and transportation facilities 4.4 Other places where combustible gases, toxic gases diffuse and accumulate 5 Design of combustible gas and toxic gas detection and alarm system 5.1 General requirements 5.2 Selection of detector 5.3 Selection of field alarming units 5.4 Selection of alarm control unit 5.5 Measurement range and setting of alarm value 6 Installation of combustible gas and toxic gas detection and alarm system 6.1 Installation of detector 6.2 Installation of alarm control unit and field alarming unit Annex A Properties of common combustible gases and vapors Annex B Properties of common toxic gases and vapors Annex C Arrangement plan of combustible gas and toxic gas detection and alarm system Annex D Technical performance table of common gas detectors Annex E Guide for selection of common gas detectors Explanation of wording in this standard List of quoted standards

1 總 則 1.0.1 為保障石油化工企業的人身安全和生產安全，監測生產過程及儲運設施中泄漏的可燃氣體或有毒氣體.并及時報警，預防人身傷害以及火災與爆炸事故的發生，制定本標準。 1.0.2 本標準適用于石油化工新建、擴建工程中可燃氣體和有毒氣體檢測報警系統的設計。 1.0.3 石油化工可燃氣體和有毒氣體檢測報警系統的設計，除應符合本標準要求外，尚應符合國家現行有關標準的規定。 2 術 語 2.0.1 可燃氣體 flammable gas 又稱易燃氣體，甲類氣體或甲、乙A類可燃液體氣化后形成的可燃氣體或可燃蒸氣。 2.0.2 有毒氣體 toxic gas 勞動者在職業活動過程中，通過皮膚接觸或呼吸可導致死亡或永久性健康傷害的毒性氣體或毒性蒸氣。 2.0.3 釋放源 source of release 可釋放并能形成爆炸性氣體環境、有毒氣體環境的位置或地點。 2.0.4 探測器detector 又稱檢測器，將可燃氣體、有毒氣體或氧氣的濃度轉換為電信號的電子設備。 2.0.5 線型氣體探測器 open-path gas detector 一種開放式、用于檢測直線路徑中可燃氣體或有毒氣體云團的氣體探測器。常用的線性氣體探測器有：紅外氣體探測器、激光氣體探測器等。 2.0.6 現場警報器 field alarming unit/audible and visual alarm unit 安裝在現場，通過聲、光或旋光向現場或接近現場人員發出警示的電子設備。常見的有：探測器自帶的一體化的聲、光警報器，按區域設置的現場區域警報器。 2.0.7報警控制單元 alarm control unit 接收探測器的輸出信號、顯示和記錄被檢測氣體的濃度、發出聲光報警信號，并能向消防控制室圖形顯示裝置等設備發送氣體濃度報警信號和報警控制單元故障信息的電子設備。可燃氣體報警信號參與消防聯動時，報警控制單元通常采用按專用可燃氣體報警控制器產品標準制造并取得檢測報告的專用可燃氣體報警控制器。 2.0.8檢測范圍 sensible range 又稱測量范圍，探測器能夠檢測出被測氣體的濃度范圍。 2.0.9報警設定值 alarm set point 預先設定的報警濃度值。報警設定值分為一級報警設定值和二級報警設定值。 2.0.10 響應時間 response time 在試驗條件下，從探測器接觸被測氣體至達到穩定指示值的時間。通常達到穩定指示值90％的時間為響應時間，恢復到穩定指示值10％的時間為恢復時間。 2.0.11 安裝高度 vertical height 探測器傳感器吸入口到指定參照物的垂直距離。 2.0.12爆炸下限lower explosion limit(LEL) 可燃氣體發生爆炸時的下限濃度(V％)值。 2.0.13 爆炸上限 upper explosion limit(UEL) 可燃氣體發生爆炸時的上限濃度(V％)值。 2.0.14職業接觸限值 occupational exposure limit(OEL) 勞動者在職業活動中長期反復接觸，不會對絕大多數接觸者的健康引起有害作用的容許接觸水平。化學因素的職業接觸限值分為最高容許濃度、短時間接觸容許濃度和時間加權平均容許濃度三種。 2.0.15 最高容許濃度 maximum allowable concentration(MAC) 工作地點在一個工作日內、任何時間有毒化學物質均不應超過的濃度。 2.0.16 時間加權平均容許濃度permissibie concentration-time weighted average(PC-TWA) 以時間為權數規定的8h工作日、40h工作周的平均容許接觸濃度。 2.0.17 短時間接觸容許濃度permissible concentration-short term exposure limit(PC-STEL) 在遵守時間加權平均容許濃度(PC-TWA)前提下容許短時間(15 min)接觸的濃度。 2.0.18 直接致害濃度 immediately dangerous to life or health concentration(IDLH) 在工作地點，環境中空氣污染物濃度達到某種危險水平，如可致命或永久損害健康，或使人立即喪失逃生能力。 3 基本規定 3.0.1 在生產或使用可燃氣體及有毒氣體的生產設施及儲運設施的區域內，泄漏氣體中可燃氣體濃度可能達到報警設定值時，應設置可燃氣體探測器；泄漏氣體中有毒氣體濃度可能達到報警設定值時，應設置有毒氣體探測器；既屬于可燃氣體又屬于有毒氣體的單組分氣體介質.應設有毒氣體探測器；可燃氣體與有毒氣體同時存在的多組分混合氣體.泄漏時可燃氣體濃度和有毒氣體濃度有可能同時達到報警設定值，應分別設置可燃氣體探測器和有毒氣體探測器。 3.0.2 可燃氣體和有毒氣體的檢測報警應采用兩級報警。同級別的有毒氣體和可燃氣體同時報警時，有毒氣體的報警級別應優先。 3.0.3 可燃氣體和有毒氣體檢測報警信號應送至有人值守的現場控制室、中心控制室等進行顯示報警；可燃氣體二級報警信號、可燃氣體和有毒氣體檢測報警系統報警控制單元的故障信號應送至消防控制室。 3.0.4 控制室操作區應設置可燃氣體和有毒氣體聲、光報警；現場區域警報器宜根據裝置占地的面積、設備及建構筑物的布置、釋放源的理化性質和現場空氣流動特點進行設置，現場區域警報器應有聲、光報警功能。 3.0.5 可燃氣體探測器必須取得國家指定機構或其授權檢驗單位的計量器具型式批準證書、防爆合格證和消防產品型式檢驗報告；參與消防聯動的報警控制單元應采用按專用可燃氣體報警控制器產品標準制造并取得檢測報告的專用可燃氣體報警控制器；國家法規有要求的有毒氣體探測器必須取得國家指定機構或其授權檢驗單位的計量器具型式批準證書。安裝在爆炸危險場所的有毒氣體探測器還應取得國家指定機構或其授權檢驗單位的防爆合格證。 3.0.6 需要設置可燃氣體、有毒氣體探測器的場所，宜采用固定式探測器；需要臨時檢測可燃氣體、有毒氣體的場所，宜配備移動式氣體探測器。 3.0.7 進入爆炸性氣體環境或有毒氣體環境的現場工作人員，應配備便攜式可燃氣體和(或)有毒氣體探測器。進入的環境同時存在爆炸性氣體和有毒氣體時，便攜式可燃氣體和有毒氣體探測器可采用多傳感器類型。 3.0.8 可燃氣體和有毒氣體檢測報警系統應獨立于其他系統單獨設置。 3.0.9 可燃氣體和有毒氣體檢測報警系統的氣體探測器、報警控制單元、現場警報器等的供電負荷，應按一級用電負荷中特別重要的負荷考慮，宜采用UPS電源裝置供電。 3.0.10 確定有毒氣體的職業接觸限值時，應按最高容許濃度、時間加權平均容許濃度、短時間接觸容許濃度的優先次序選用。 3.0.11 常見易燃氣體、蒸氣特性應按本標準附錄A采用：常見有毒氣體、蒸氣特性應按本標準附錄B采用。 4檢測點確定 4.1 一般規定 4.1.1 可燃氣體和有毒氣體探測器的檢測點，應根據氣體的理化性質、釋放源的特性、生產場地布置、地理條件、環境氣候、探測器的特點、檢測報警可靠性要求、操作巡檢路線等因素進行綜合分析，選擇可燃氣體及有毒氣體容易積聚、便于采樣檢測和儀表維護之處布置。 4.1.2 判別泄漏氣體介質是否比空氣重，應以泄漏氣體介質的分子量與環境空氣的分子量的比值為基準，并應按下列原則判別： 1 當比值大于或等于1.2時，則泄漏的氣體重于空氣； 2 當比值大于或等于1.0、小于1.2時，則泄漏的氣體為略重于空氣； 3 當比值為0.8～1.0時，則泄漏的氣體為略輕于空氣； 4 當比值小于或等于0.8時，則泄漏的氣體為輕于空氣。 4.1.3 下列可燃氣體和(或)有毒氣體釋放源周圍應布置檢測點： 1 氣體壓縮機和液體泵的動密封； 2 液體采樣口和氣體采樣口； 3 液體(氣體)排液(水)口和放空口； 4 經常拆卸的法蘭和經常操作的閥門組。 4.1.4 檢測可燃氣體和有毒氣體時，探測器探頭應靠近釋放源，且在氣體、蒸氣易于聚集的地點。 4.1.5 當生產設施及儲運設施區域內泄漏的可燃氣體和有毒氣體可能對周邊環境安全有影響需要監測時，應沿生產設施及儲運設施區域周邊按適宜的間隔布置可燃氣體探測器或有毒氣體探測器，或沿生產設施及儲運設施區域周邊設置線型氣體探測器。 4.1.6 在生產過程中可能導致環境氧氣濃度變化，出現欠氧、過氧的有人員進入活動的場所，應設置氧氣探測器。當相關氣體釋放源為可燃氣體或有毒氣體釋放源時，氧氣探測器可與相關的可燃氣體探測器、有毒氣體探測器布置在一起。 4.2生產設施 4.2.1 釋放源處于露天或敞開式廠房布置的設備區域內，可燃氣體探測器距其所覆蓋范圍內的任一釋放源的水平距離不宜大于10 m，有毒氣體探測器距其所覆蓋范圍內的任一釋放源的水平距離不宜大于4 m。 4.2.2 釋放源處于封閉式廠房或局部通風不良的半敞開廠房內，可燃氣體探測器距其所覆蓋范圍內的任一釋放源的水平距離不宜大于5m；有毒氣體探測器距其所覆蓋范圍內的任一釋放源的水平距離不宜大于2m。 4.2.3 比空氣輕的可燃氣體或有毒氣體釋放源處于封閉或局部通風不良的半敞開廠房內，除應在釋放源上方設置探測器外，還應在廠房內最高點氣體易于積聚處設置可燃氣體或有毒氣體探測器。 4.3儲運設施 4.3.1 液化烴、甲B、乙A類液體等產生可燃氣體的液體儲罐的防火堤內，應設探測器。可燃氣體探測器距其所覆蓋范圍內的任一釋放源的水平距離不宜大于10m，有毒氣體探測器距其所覆蓋范圍內的任一釋放源的水平距離不宜大于4m。 4.3.2 液化烴、甲B、乙A類液體的裝卸設施，探測器的設置應符合下列規定： 1 鐵路裝卸棧臺，在地面上每一個車位宜設一臺探測器，且探測器與裝卸車口的水平距離不應大于10m； 2 汽車裝卸站的裝卸車鶴位與探測器的水平距離不應大于10m。 4.3.3 裝卸設施的泵或壓縮機區的探測器設置，應符合本標準第4.2節的規定。 4.3.4 液化烴灌裝站的探測器設置，應符合下列規定： 1 封閉或半敞開的灌瓶間，灌裝口與探測器的水平距離宜為5m～7.5 m； 2 封閉或半敞開式儲瓶庫，應符合本標準第4.2.2條規定；敞開式儲瓶庫房沿四周每隔15 m～20m應設一臺探測器，當四周邊長總和小于15 m時，應設一臺探測器； 3 緩沖罐排水口或閥組與探測器的水平距離宜為5m～7.5 m。 4.3.5 封閉或半敞開氫氣灌瓶間，應在灌裝口上方的室內最高點易于滯留氣體處設探測器。 4.3.6 可能散發可燃氣體的裝卸碼頭，距輸油臂水平平面10m范圍內，應設一臺探測器。 4.3.7 其他儲存、運輸可燃氣體、有毒氣體的儲運設施，可燃氣體探測器和(或)有毒氣體探測器應按本標準第4.2節的規定設置。 4.4其他有可燃氣體、有毒氣體的擴散與積聚場所 4.4.1 明火加熱爐與可燃氣體釋放源之間應設可燃氣體探測器，探測器距加熱爐爐邊的水平距離宜為5 m~10m。當明火加熱爐與可燃氣體釋放源之間設有不燃燒材料實體墻時，實體墻靠近釋放源的一側應設探測器。 4.4.2 設在爆炸危險區域2區范圍內的在線分析儀表間，應設可燃氣體和(或)有毒氣體探測器，并同時設置氧氣探測器。 4.4.3 控制室、機柜間的空調新風引風口等可燃氣體和有毒氣體有可能進入建筑物的地方，應設置可燃氣體和(或)有毒氣體探測器。 4.4.4 有人進入巡檢操作且可能積聚比空氣重的可燃氣體或有毒氣體的工藝閥井、管溝等場所，應設可燃氣體和(或)有毒氣體探測器。 5 可燃氣體和有毒氣體檢測報警系統設計 5.1 一般規定 5.1.1 可燃氣體和有毒氣體檢測報警系統應由可燃氣體或有毒氣體探測器、現場警報器、報警控制單元等組成。 5.1.2 可燃氣體的第二級報警信號和報警控制單元的故障信號，應送至消防控制室進行圖形顯示和報警。可燃氣體探測器不能直接接入火災報警控制器的輸入回路。 5.1.3 可燃氣體或有毒氣體檢測信號作為安全儀表系統的輸入時.探測器宜獨立設置，探測器輸出信號應送至相應的安全儀表系統.探測器的硬件配置應符合現行國家標準《石油化工安全儀表系統設計規范》GB/T 50770有關規定。 5.1.4 可燃氣體和有毒氣體檢測報警系統配置圖見本標準附錄C。 5.2探測器選用 5.2.1 探測器的輸出可選用4 mA～20mA的DC信號、數字信號、觸點信號。 5.2.2 可燃氣體及有毒氣體探測器的選用，應根據探測器的技術性能、被測氣體的理化性質、被測介質的組分種類和檢測精度要求、探測器材質與現場環境的相容性、生產環境特點等確定。 5.2.3 常用可燃氣體及有毒氣體探測器的選用應符合下列規定： 1 輕質烴類可燃氣體宜選用催化燃燒型或紅外氣體探測器；當使用場所的空氣中含有能使催化燃燒型檢測元件中毒的硫、磷、硅、鉛、鹵素化合物等介質時，應選用抗毒性催化燃燒型探測器、紅外氣體探測器或激光氣體探測器；在缺氧或高腐蝕性等場所，宜選用紅外氣體探測器或激光氣體探測器；重質烴類蒸氣可選用光致電離型探測器； 2 氫氣檢測宜選用催化燃燒型、電化學型、熱傳導型探測器； 3 有機有毒氣體宜選用半導體型、光致電離型探測器； 4 無機有毒氣體檢測宜選用電化學型探測器； 5 氧氣宜選用電化學型探測器； 6 在氣候環境或生產環境特殊，需監測的區域開闊的場所，宜選擇線型可燃氣體探測器； 7 在工藝介質泄漏后形成的氣體或蒸氣能顯著改變釋放源周圍環境溫度的場所，可選用紅外圖像型探測器； 8 在高壓工藝介質泄漏時產生的噪聲能顯著改變釋放源周圍環境聲壓級的場所，可選用噪聲型探測器； 9 在生產和檢修過程中需要臨時檢測可燃氣體、有毒氣體的場所，應配備移動式氣體探測器。 5.2.4 常用探測器的采樣方式應根據使用場所按下列規定確定： 1 可燃氣體和有毒氣體的檢測宜采用擴散式探測器； 2 受安裝條件和介質擴散特性的限制，不便使用擴散式探測器的場所，可采用吸入式探測器； 3 當探測器配備采樣系統時，采樣系統的滯后時間不宜大于30s。 5.2.5 常見氣體探測器的技術性能應符合本標準附錄D的要求；常見氣體探測器應按照本標準附錄E選用。 5.3 現場警報器選用 5.3.1 可燃氣體和有毒氣體檢測報警系統應按照生產設施及儲運設施的裝置或單元進行報警分區，各報警分區應分別設置現場區域警報器。區域警報器的啟動信號應采用第二級報警設定值信號。區域警報器的數量宜使在該區域內任何地點的現場人員都能感知到報警。 5.3.2 區域警報器的報警信號聲級應高于110dBA，且距警報器1 m處總聲壓值不得高于120dBA。 5.3.3 有毒氣體探測器宜帶一體化的聲、光警報器，可燃氣體探測器可帶一體化的聲、光警報器，一體化聲、光警報器的啟動信號應采用第一級報警設定值信號。 5.4 報警控制單元選用 5.4.1 報警控制單元應采用獨立設置的以微處理器為基礎的電子產品，并應具備下列基本功能： 1 能為可燃氣體探測器、有毒氣體探測器及其附件供電。 2 能接收氣體探測器的輸出信號，顯示氣體濃度并發出聲、光報警。 3 能手動消除聲、光報警信號，再次有報警信號輸入時仍能發出報警。 4 具有相對獨立、互不影響的報警功能，能區分和識別報警場所位號。 5 在下列情況下，報警控制單元應能發出與可燃氣體和有毒氣體濃度報警信號有明顯區別的聲、光故障報警信號： 1)報警控制單元與探測器之間連線斷路或短路。 2)報警控制單元主電源欠壓。 3)報警控制單元與電源之間的連線斷路或短路。 6 具有以下記錄、存儲、顯示功能： 1)能記錄可燃氣體和有毒氣體的報警時間，且日計時誤差不應超過30s； 2)能顯示當前報警部位的總數； 3)能區分最先報警部位，后續報警點按報警時間順序連續顯示； 4)具有歷史事件記錄功能。 5.4.2 控制室內可燃氣體和有毒氣體聲、光警報器的聲壓等級應滿足設備前方1 m處不小于75 dBA，聲、光警報器的啟動信號應采用第二級報警設定值信號。 5.4.3 可燃氣體探測器參與消防聯動時，探測器信號應先送至按專用可燃氣體報警控制器產品標準制造并取得檢測報告的專用可燃氣體報警控制器.報警信號應由專用可燃氣體報警控制器輸出至消防控制室的火災報警控制器。可燃氣體報警信號與火災報警信號在火災報警控制系統中應有明顯區別。