標準編號:	SH/T 3210-2020
中文名稱:	石油化工裝置安全泄壓設施工藝設計規范
英文名稱:	Process design specification forpressure relieving devicesin petrochemical industry
行業分類:	SH    石油化工行業標準
發布機構:	中華人民共和國工業和信息化部
發布日期:	2020-08-31
實施日期:	2021-1-1
標準狀態:	valid
翻譯語言:	英文
文件格式:	PDF
中文字符數:	39000 字
翻譯價格(元):	3500.0
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 Specification was prepared after repeated discussion and research by the preparing group according to the requirements of Notice on the Plan for the development and revision of the third batch of professional standards in 2017 (GONGXINTINGKE [2017] No.106) issued by the Ministry of Industry and Information Technology of the People's Republic of China, through extensive investigation, careful summarization of practical experience, reference to relevant domestic and international standards and extensive solicitation of opinions. This Specification comprises 8 Clauses and 3 Annexes. The main technical contents of this Specification are: basic requirements of pressure relieving devices, setting principles and requirements, requirements of set pressure and overpressure, analysis of overpressure operating conditions, calculation and selection of relief flowrate and relief area, etc. China Petrochemical Corporation (SINOPEC) is in charge of the administration of this Specification, SINOPEC Technology Center Station of Technologic System Design is responsible for the daily management, and SINOPEC Engineering Incorporation is responsible for the explanation of the specific technical contents. In case of any opinion and suggestion in the process of implementing this standard, please send it to the daily management organization and the chief development organization. This Specification was issued in 2020 for the first time. Process design specification for pressure relieving devices in petrochemical industry 1 Scope This Specification specifies the process design requirements for pressure relieving devices in petrochemical industry. This Specification is applicable to the process design of pressure relieving devices in petrochemical industry, but not to the process design of pressure relieving devices in compressor chambers which are self-contained or as components in power boilers heated directly by flames, transportable pressure vessels and rotating or reciprocating-motion mechanical equipment. 2 Normative References The following referenced documents are indispensable for the application of this Specification. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 150.1 Pressure vessels — Part 1: General requirements GB/T 567.1 Bursting disc safety devices — Part 1: Basic requirement GB/T 12241 Safety valves — General requirements GB/T 12242 Performance test code — Pressure relief devices 3 Terms and Definitions 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 12241, GB/T 12242, GB/T 567.1 and the following apply. 3.1.1 pressure relieving device device designed to prevent the internal medium pressure from rising above a specified security value when the pressure system is in an emergency or abnormal condition Note: The pressure relieving devices in this Specification are limited to safety valves and rupture disk devices. Other pressure relieving devices, such as breathing valve, buckling pin valve, breaking pin, fusible plug are not within the applicable range of this Specification. 3.1.2 safety valve valve that uses the force of the medium itself to discharge a rated amount of fluid to prevent the pressure from exceeding a specified safety value When the pressure is reduced to a certain value, the valve closes automatically and prevents the medium from continuing to flow out. It is also known as pressure relief valve. 3.1.3 rupture disk device non-reclosing pressure relieving device actuated by the static pressure difference between the inlet and outlet of the medium and designed to realize the pressure relieving function by the rupture of a pressure containing disk 3.1.4 set pressure set opening pressure of pressure relieving device under use conditions, also known as level pressure Note: The pressures not specified in this Specification are all gauge pressures. 3.1.5 back pressure pressure at the outlet of pressure relieving device and is the sum of the built-up back pressure and the superimposed back pressure, also known as backpressure 3.1.6 built-up back pressure pressure formed at the outlet of the pressure relieving device due to the medium flowing through the discharge system when the pressure relieving device is discharged 3.1.7 superimposed back pressure static pressure that exists at the outlet of the pressure relieving device before it is about to operate, caused by other pressure sources in the discharge system 3.1.8 overpressure pressure increment in excess of the set pressure of the pressure relieving device, usually expressed as a percentage of the set pressure 3.1.9 relieving pressure set pressure plus overpressure, also known as relieving pressure 3.2 Main symbols For the purposes of this specification, the following major symbols apply. A——the heated surface area of the container; Cp——the liquid specific heat capacity at constant pressure; Cv—— the average specific heat at constant volume of gas at the relieving and operating temperatures; D——the diameter of the container; d——the inner diameter of feed pipe of gas storage tank; F——the relieving reduction coefficient; G——the relative density of liquid; GL—— the liquid relief flowrate; h——the wetting height of the container, which refers to the distance from the lower tangent line of the tank to the highest liquid level; L——the total length of the container; M——the molecular weight of the fluid; Pd——the relieving pressure (absolute pressure); Pn——the operating pressure (absolute pressure); Ps——the set pressure; Q——the maximum heat capacity of the system; r——the latent heat of vaporization of the liquid under the relieving pressure; T1——the relieving temperature; Tn——the operating temperature; TW——the wall temperature of equipment under fire condition; t——the saturated temperature of relieving liquid under the pressure relief condition; W——the relief flowrate of pressure relieving device; WG——the relief flowrate of gas storage tanks of pressure relieving device; ΔT——the temperature difference between the relieving temperature and operating temperature; δ——the insulation thickness; λ——the heat conductivity coefficient of thermal insulation material at room temperature; ρ——the density; ρG——the gas density under relieving pressure Pd; v——the flow rate in the feed pipe of gas storage tank; ω——the volume expansion coefficient, which refers to the volume expansion of liquid for every 1°C increase. 4 Basic rules 4.1 The pressure relieving devices shall be set up in accordance with the requirements of the pressure system under abnormal conditions to determine the overpressure analysis: 4.2 The independent pressure system of the pressure relieving devices shall be able to meet the system's relief requirements. Note: Independent pressure system refers to the system separated from other systems with isolating devices. When a pressure system consisting of multiple containers is provided with shut-off devices (such as shut-off valves and control valves, or although there is a pipeline connection, the pipeline is not enough to relieve pressure), it is necessary to divide the pressure system into several independent pressure systems according to the position of the shut-off devices, and each independent pressure system is provided with pressure relieving devices. 4.3 When the system design pressure of the independent pressure system is greater than or equal to the highest possible pressure under the working conditions, the independent pressure system may not set up pressure relieving devices. 4.4 In addition to the reliability of protective instrument system reaches the reliability of pressure relieving device or the pressure relieving device cannot be used, the automatic interlock system, automatic shutdown system and other conventional instrument systems with anti-overpressure function shall not replace the protective effect of pressure relieving device on pressure system. 4.5 The setting of pressure relieving devices shall meet the requirements of its inspection cycle. 4.6 If the medium is viscous, strong corrosive or the toxicity degree is highly harmful or above, the auxiliary safety valve should be set up, and the auxiliary safety valve shall be of the same specification as the safety valve in use. 4.7 The inlet and outlet shut-off valves of safety valves in use shall remain opened then locked or car seal open; the inlet shut-off valve of auxiliary safety valves shall be closed then locked or sealed, and the outlet shut-off valve should be opened then locked or car seal open. 5 Principles and requirements of safety relief device setting 5.1 Setting principles 5.1.1 The safety valves shall be provided in the following situations: a) The design pressure of the system is less than the pressure at the pressure source; b) Except that the equipment itself has a safety valve and its set pressure and relieving capacity meet the relieving requirements of the system, the outlet of each section of reciprocating compressor or the outlet of positive displacement pump such as electric reciprocating pump, gear pump and screw pump shall be equipped with safety valves; c) The system is connected with the outlet of blower, centrifugal compressor, centrifugal pump or steam reciprocating pump, and the design pressure of the system is less than its maximum outlet pressure; d) The medium of the system expands or vaporizes when heated, and the system pressure may exceed the system design pressure. 5.1.2 The rupture disk device should be set separately in the following situations: a) The system pressure increases rapidly, and the opening of the safety valve cannot meet the requirements of fast response time; b) The safety relief flowrate required by the system is large, and the selection of safety valves is difficult; c) The operating pressure of the system is very low or high, and the safety valve is difficult to manufacture; d) The temperature during the safety relief of the system is low, and the operating characteristics of the safety valve may be affected when the process medium is relieved; e) For the disposable pipeline system, the rupture of rupture disk device will not affect the operation and production. 5.1.3 The combination of safety valves and rupture disk devices should be set up in the following situations: a) Under vacuum condition, no gas or air outside the system is allowed to enter the system through pressure relieving devices; b) The system does not allow the process medium to leak through the safety valve during normal operation; c) Long-term contact between the relief medium and the safety valve may lead to failure of the safety valve in the system; d) The process medium is corrosive, so it is necessary to use corrosion-resistant materials or lined with anti-corrosion materials, and the safety valve has a high manufacturing cost; e) The system has multiple and complicated overpressure conditions. 5.1.4 The setting of rupture disk devices shall meet the following principles: a) Rupture disk devices should not be set for systems with frequent overpressure; b) Rupture disk devices are not suitable for systems with large temperature fluctuations; c) Apart from having a follow-up treatment system and meeting the requirements of safety and environmental protection, rupture disk devices shall not be used alone in places where the discharged medium is liquefied petroleum gas or explosive, or of extreme toxicity or high hazard. 5.2 Setting requirements 5.2.1 When the safety valve and rupture disk device are used in combination, the combined relief flowrate shall not be less than the safety relief flowrate of the protection system. 5.2.2 Safety valves and rupture disk devices used in series shall meet the following requirements: a) There shall be measures to detect rupture or leakage of rupture disk devices between rupture disk device and safety valve. b) When the rupture disk device is connected in series on the inlet side of the safety valve: 1) The marked bursting pressure of rupture disk device should not be greater than the set pressure of safety valve. 2) The nominal diameter of rupture disk device shall not be less than the nominal diameter of the inlet flange of the safety valve. c) The rupture of rupture disk device shall not affect the normal operation of safety valve. d) When the rupture disk device is connected in series on the outlet side of the safety valve, it shall ensure that the safety valve can be opened at the set pressure. 5.2.3 When rupture disk devices are used in series, there shall be measures to detect rupture or leakage between the two rupture disk devices. 5.2.4 When the safety valve and rupture disk device are used in parallel, the marked bursting pressure of rupture disk device shall not exceed 1.05 times the design pressure of the system. 5.3 Installation requirements 5.3.1 Safety valves shall meet the following installation requirements: a) The safety valve shall be set on the part of the protection system which is easy to install, inspect and maintain. b) The safety valve shall be set near the pressure source. When it is used in gas medium, it shall be set in the gas-phase space (including the gas-phase space above the liquid) or the pipeline connected to this space. c) The flow sectional area of all pipes, valves and pipe fittings between the safety valve and the pressure source shall be greater than or equal to the inlet sectional area of the safety valve, and the connecting pipe shall be short and straight. When two or more safety valves are installed on one connector, the sectional area of the connector inlet shall be greater than or equal to the sum of the sectional areas of the inlets of these safety valves, excluding the auxiliary safety valves. d) The nominal diameter of safety valve inlet pipe shall not be smaller than that of safety valve inlet flange, and the nominal diameter of safety valve outlet pipe shall not be smaller than that of safety valve outlet flange. 5.3.2 The rupture disk devices shall meet the following installation requirements: a) The inlet pipe of rupture disk devices shall be short and straight, and the pipe diameter shall not be less than the nominal diameter of rupture disk devices. b) Shut-off valves should not be set on the inlet pipeline of rupture disk devices. When the process requires a shut-off valve, the shut-off valve shall be opened then locked or car seal open, and the circulation area of the shut-off valve shall not be smaller than the relief area of rupture disk device. 6 Rules for set pressure and overpressure 6.1 When an independent pressure system is provided with a single safety valve, the set pressure of the safety valve shall not be greater than the design pressure of the protection system. 6.2 The percentage of set pressure and maximum overpressure of safety valve shall not exceed the values in Table 6.2. Table 6.2 Percentages of set pressure and maximum overpressure of safety valves (in %) Item Single safety valve Multiple safety valves Ratio of set pressure of safety valve to design pressure of protection system Maximum overpressure percentagea Ratio of set pressure of safety valve to design pressure of protection system Maximum overpressure percentagea Non-fire Primary valve 100 10Note 1 100 16Note 2 Other valves — — 105 16Note 2 Fire Primary valve 100 21 100 21 Other valves — — 105 21 Note 1: The greater of 10% of design pressure or 20kPa. Note 2: The greater of 16% of design pressure or 30kPa. a Maximum overpressure percentage refers to the ratio of the maximum overpressure to the design pressure of the protection system. 6.3 The maximum marked bursting pressure of rupture disk devices shall not be greater than the design pressure of the protection system.

Foreword I 1 Scope 2 Normative References 3 Terms and Definitions 4 Basic rules 5 Principles and requirements of safety relief device setting 6 Rules for set pressure and overpressure 7 Case of overpressure and calculation of relief device 8 Selection Annex A (Informative) Volume expansion coefficient of hydrocarbon liquid and water at 15.6°C Annex B (Informative) Calculation of relieving flowrate and relief area in chemical reaction runaway (temper system) Annex C (Informative) Calculation of relief area in gas-liquid two-phase relief Explanation of wording in this Specification

石油化工裝置安全泄壓設施工藝設計規范 1 范圍 本規范規定了石油化工裝置安全泄壓設施的工藝設計要求。 本規范適用于石油化工裝置安全泄壓設施的工藝設計，不適用于直接用火焰加熱的動力鍋爐、移動式壓力容器、旋轉或往復運動機械設備中自成整體或作為部件的受壓器室的安全泄壓設施的工藝設計。 2 規范性引用文件 下列文件對于本規范的應用是必不可少的。凡是注日期的引用文件，僅注日期的版本適用于本規范。凡是不注日期的引用文件，其最新版本(包括所有的修改單)適用于本規范。 GB/T 150.1 壓力容器 第1部分：通用要求 GB/T 567.1 爆破片安全裝置 第1部分：基本要求 GB/T 12241 安全閥一般要求 GB/T 12242 壓力釋放裝置性能試驗規范 3 術語和符號 3.1 術語和定義 GB/T 12241、GB/T 12242和GB/T 567.1界定的以及下列術語和定義適用于本規范。 3.1.1 安全泄壓設施 pressure relieving device 一種，用來在壓力系統處于緊急或異常狀況時防止其內部介質壓力升高到超過規定安全值的設施。 注：本規范中的安全泄壓設施限指安全閥和爆破片。其他安全泄壓設施如呼吸閥、爆破針閥、折斷銷、易熔塞等不在本規范適用范圍內。 3.1.2 安全閥 safety valve 利用介質本身的力來排出額定數量的流體，以防止壓力超過規定安全值的閥門。當壓力降低到一定值后，閥門自行關閉并阻止介質繼續流出。也稱壓力泄放閥。 3.1.3 爆破片 rupture disk device 一種由介質進出口靜壓差驅動的非重閉式安全泄壓設施，通過承壓片的爆破實現泄壓功能。 3.1.4 設定壓力 set pressure 在使用條件下，設定的安全泄壓設施開啟壓力，簡稱定壓。 注：本規范中未特別指出的壓力，均為表壓。 3.1.5 背壓力 back pressure 安全泄壓設施出口處的壓力，是排放背壓力和附加背壓力的總和，簡稱背壓。 3.1.6 排放背壓力 built-up back pressure 安全泄壓設施排放時，由于介質流經排放系統在安全泄壓設施出口處形成的壓力。 3.1.7 附加背壓力 superimposed back pressure 安全泄壓設施即將動作前，在其出口處存在的靜壓力，是由其他壓力源在排放系統中引起的。 3.1.8 超過壓力 overpressure 超過安全泄壓設施設定壓力的壓力增量，通常用設定壓力的百分數表示。 3.1.9 泄放壓力 relieving pressure 設定壓力加超過壓力。也稱排放壓力。 3.2 主要符號 下列主要符號適用于本規范。 A——容器受熱表面積； Cp——液體的比定壓熱容； Cv——氣體在泄放溫度和操作溫度時的平均比定容熱容； D——容器直徑； d——氣體儲罐進料管的內徑； F——泄放減低系數； G——液體的相對密度； GL——液體泄放量； h——容器的濕潤高度，指罐體下切線至最高液面的距離； L——容器的總長； M——流體的分子量； Pd——泄放壓力(絕壓)； Pn——操作壓力(絕壓)； Ps——設定壓力； Q——系統的最大受熱量； r——泄放壓力下液體的汽化潛熱； T1——泄放溫度； Tn——操作溫度； TW——火災工況時設備的壁溫； t——泄壓工況時泄放液體的飽和溫度； W——安全泄壓設施的泄放量； WG——氣體儲罐安全泄壓設施的泄放量； ?T——泄放溫度和操作溫度的溫差； δ——保溫層厚度； λ——常溫下絕熱材料的導熱系數； ρ——密度； ρG——泄放壓力Pd下的氣體密度； v——氣體儲罐進料管內的流速； ω——體積膨脹系數，指液體每升高1℃的體積膨脹量。 4 基本規定 4.1 安全泄壓設施的設置要求應根據壓力系統在非正常條件下的超壓分析確定。 4.2 獨立的壓力系統的安全泄壓設施應能滿足系統的泄放要求。 注：獨立的壓力系統，指用隔斷裝置與其他系統分開的系統。由多個容器組成的壓力系統，當其中設有隔斷裝置時(如切斷閥、調節閥等，或雖有管線連通，但管線不足以泄壓)，需要根據隔斷裝置的位置分為幾個獨立的壓力系統，每個獨立的壓力系統均設置安全泄壓設施。 4.3 當獨立的壓力系統的系統設計壓力大于或等于各工況條件下可能出現的最高壓力時，該獨立的壓力系統可不設置安全泄壓設施。 4.4 除保護性儀表系統的可靠性達到安全泄壓設施的可靠性或不能使用安全泄壓設施外，防超壓功能的自動聯鎖系統、自動開停車系統和其他常規儀表系統等，不應代替安全泄壓設施對壓力系統的保護作用。 4.5 安全泄壓設施的設置應滿足其檢驗周期的要求。 4.6 介質為黏性、強腐蝕性或毒性程度為高度危害及以上的安全閥宜設置備用，備用安全閥應與在用安全閥相同規格。 4.7 在用安全閥進出口切斷閥均應鎖開或鉛封開；備用安全閥進口切斷閥應鎖關或鉛封關，出口切斷閥宜鎖開或鉛封開。 5 設置原則和要求 5.1 設置原則 5.1.1 下列情況應設置安全閥： a) 系統的設計壓力小于壓力來源處壓力的系統； b) 除設備本身已有安全閥且其定壓、泄放能力滿足系統泄放要求情形外，往復式壓縮機的各段出口或電動往復泵、齒輪泵、螺桿泵等容積式泵的出口； c) 與鼓風機、離心式壓縮機、離心泵或蒸汽往復泵出口連接的系統，且系統的設計壓力小于其最高出口壓力； d) 介質受熱膨脹或汽化，系統壓力可能超過系統設計壓力的系統。 5.1.2 下列情況宜單獨設置爆破片： a) 系統壓力快速增長，安全閥的開啟不能滿足快速反應時間要求； b) 系統需要的安全泄放量大，安全閥選型困難； c) 系統的操作壓力很低或很高，安全閥制造困難； d) 系統安全泄放時的溫度較低，工藝介質泄放時可能導致安全閥的工作特性受到影響； e) 一次性使用的管路系統，爆破片的破裂不影響操作和生產。 5.1.3 下列情況宜組合設置安全閥和爆破片： a) 在真空工況下，不允許系統外部氣體或空氣通過安全泄壓設施進入的系統； b) 正常操作過程中不允許工藝介質通過安全閥泄漏的系統； c) 泄放介質與安全閥長期接觸可能導致安全閥失靈的系統； d) 工藝介質有腐蝕性，需要采用耐腐蝕的材質或內襯防腐蝕材料，安全閥的制造成本較高的系統； e) 有多個超壓工況，且超壓工況比較復雜的系統。 5.1.4 爆破片的設置應滿足下列原則： a) 經常超壓的系統不宜設置爆破片； b) 溫度波動較大的系統不宜設置爆破片； c) 除具有后續處理系統且滿足安全和環保要求外，爆破片不應單獨用于排放介質毒性程度為極度、高度危害或易爆及液化石油氣等場合。 5.2 設置要求 5.2.1 安全閥和爆破片組合使用時，組合泄放量不應小于被保護系統的安全泄放量。 5.2.2 安全閥和爆破片串聯使用時應符合下列要求： a) 爆破片和安全閥之間應有檢測爆破片破裂或泄漏的措施。 b) 爆破片串聯在安全閥進口側時： 1) 爆破片的最大標定爆破壓力不宜大于安全閥的定壓； 2) 爆破片的公稱直徑不應小于安全閥的進口法蘭公稱直徑。 c) 爆破片破裂后不應影響安全閥的正常動作。 d) 爆破片串聯在安全閥出口側時，應保證安全閥能在設定壓力下開啟。 5.2.3 爆破片和爆破片串聯使用時，兩個爆破片之間應有檢測爆破片破裂或泄漏的措施。 5.2.4 安全閥和爆破片并聯使用時，爆破片的標定爆破壓力不應超過1.05倍系統的設計壓力。 5.3 安裝要求 5.3.1 安全閥應滿足下列安裝要求： a) 安全閥應設置在所保護系統上易于安裝、檢查、維護的部位。 b) 安全閥應設置在靠近壓力源的位置。當用于氣體介質時，應設置在氣相空間(包括液體上方的氣相空間)或與該空間相連通的管線上。 c) 安全閥和壓力源之間的所有管道、閥門和管件的流通截面積應大于或等于安全閥的進口截面積，其接管應短而直。當一個連接口上裝設2個或2個以上的安全閥時，該連接口入口的截面積應大于或等于這些安全閥進口截面積的總和，不包括備用安全閥。 d) 安全閥入口管道公稱直徑不應小于安全閥進口法蘭公稱直徑，安全閥出口管道公稱直徑不應小于安全閥出口法蘭公稱直徑。 5.3.2 爆破片應滿足下列安裝要求： a) 爆破片的入口管道應短而直，管徑不應小于爆破片的公稱直徑。 b) 爆破片入口管線上不宜設置切斷閥。當工藝要求設置切斷閥時，切斷閥應鎖開或鉛封開，切斷閥的流通面積不應小于爆破片的泄放面積。 6 定壓和超壓 6.1 獨立的壓力系統設置單個安全閥時，安全閥定壓不應大于所保護系統的設計壓力。 6.2 安全閥定壓和最大超壓百分數，不應超過表6.2中的數值。 表6.2 安全閥定壓和最大超壓百分數 單位為％ 項目 單個安全閥 多個安全閥 安全閥定壓與所保護系統設計壓力之比 最大超壓百分數a 安全閥定壓與所保護系統設計壓力之比 最大超壓百分數a 非火災 第一閥 100 10注1 100 16注2 其他閥 — — 105 16注2 火災 第一閥 100 21 100 21 其他閥 — — 105 21 注1：設計壓力的10％或20kPa中的較大值。 注2：設計壓力的16％或30kPa中的較大值。 a 最大超壓百分數，指最大超過壓力與所保護系統設計壓力的比值。 6.3 爆破片最大標定爆破壓力，不應大于所保護系統的設計壓力。 7 超壓工況分析及計算 7.1 超壓工況分析 7.1.1 系統超壓工況分析及最小泄放量計算宜按表7.1.1進行。 7.1.2 兩個或兩個以上毫無關聯的超壓工況不宜考慮同時發生。 表7.1.1 系統超壓工況及最小泄放量a 序號 條件 液體泄放 氣體泄放 1 容器出口關閉 進入容器的最大液體量 進入容器的氣體和水蒸氣總量，加泄放條件b產生的蒸氣量和水蒸氣量 2 冷凝器供水中斷 — 在泄放條件下，冷凝器的總凝氣量 3 塔項回流中斷 — 進入塔的氣體和水蒸氣總量，加泄放條件下產生的蒸氣量，減側線回流冷凝的蒸氣量 4 側線回流中斷 — 泄放條件下進入和離開該側線部位的蒸氣量差值 5 吸收塔貧油中斷 — — 6 不凝氣積聚 — 在塔中，為泄放條件下冷凝器的總凝氣量 在其他容器內，為進入容器的氣體和水蒸氣總量，加泄放條件下產生的蒸氣量和水蒸氣量 7 高揮發性物質進入熱油： a)水進入熱油 b)輕質烴進入熱油 — 對于塔，應采取保護措施，盡量避免 對于換熱器，采用兩倍單根換熱管截面積計算換熱管破裂時，揮發性物質進入低壓側所產生的蒸氣量 8 儲罐或緩沖罐溢出 最大液體進入量 — 9 自動控制故障： a)進口調節閥和旁路 b)出口調節閥 c)故障保位閥 d)節流閥 — 應逐個對各種情況做分析 10 不正常的熱量或蒸汽輸入 — 過熱產生的最大蒸氣量，包括不凝氣 11 換熱器管破裂 按兩倍單根換熱管截面積計算進入低壓側液體量 按兩倍單根換熱管截面積計算進入低壓側氣體或水蒸氣量 12 內部爆炸 — 用常規安全泄壓設施不能控制，應避免事故的發生 13 化學反應失控 — 根據工藝特點進行分析 14 液體熱膨脹 見7.2.4條 — 15 外部明火 — 見7.2.2條 16 動力中斷(水蒸氣、電源或其他) — 應根據裝置的特點確定動力中斷的影響，按可能發生的最壞情況確定泄放量 分餾塔 — 按所有泵都停運，導致回流液和冷卻水中斷考慮 反應器 — 攪拌或攪動停止、急冷或抑制劑中斷時，反應失控產生的蒸氣量 空冷器 — 風扇停轉時，正常和事故工況蒸氣量之差 緩沖罐 — 進入罐的最大液體體積流量 a 表中列出的僅為工藝裝置常見的單一超壓工況。 b 泄放條件：指安全閥在最大超壓時入口的溫度和壓力。 7.2 泄放量的計算 7.2.1 出口切斷工況 a) 壓縮機儲氣罐由于出口閥關閉造成超壓時，安全泄壓設施的泄放量宜按壓縮機的最大生產能力計算。 b) 液體儲罐由于出口閥關閉造成超壓時，安全泄壓設施的泄放量宜按泄放條件下進入儲罐物料的最大流量計算。 c) 氣體儲罐由于出口閥關閉造成超壓時，安全泄壓設施的泄放量宜按式(7.2.1)計算。