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For excerpts from documents and regulations regarding the installation of emergency shut-off valves in tank areas where major hazard sources are present, please refer to the following documents: Excerpts from documents and regulations concerning the installation of emergency shut-off valves in tank areas for Class I and Class II major hazard sources. **Order No. 40 issued by the State Administration of Work Safety, Article 13: Hazardous chemicals enterprises shall, based on the types and quantities of hazardous chemicals that constitute major hazard sources, as well as the production and usage processes (methods) or related equipment and facilities, establish a comprehensive safety monitoring system in accordance with the following requirements in order to enhance control measures: (1) Major hazard sources shall be equipped with systems for continuous collection and monitoring of information such as temperature, pressure, liquid level, flow rate, and composition, as well as detection and alarm devices for leaks of flammable gases and toxic and harmful gases. Such systems shall also have functions such as remote data transmission, continuous recording, accident early warning, and information storage； Class 1 or Class 2 major hazard sources are equipped with an emergency shutdown function. The electronic data recorded shall be retained for no less than 30 days ； **Notice of the General Administration of Work Safety on Further Strengthening the Safety Management of Chemical Storage Areas, GAWS No. 3 [2014] 68. II. Further Strengthening the Safety Management of Chemical Storage Areas (1) Further improve the monitoring and control facilities in chemical storage areas. In accordance with regulatory requirements, high and low liquid level alarms are installed in the storage tank; automatic interlocks are employed to shut down the tank’s feed valve when the liquid level is too high, and to stop material transfer when the liquid level is too low. Notice from the General Office of the State Administration of Work Safety on Carrying Out Special Rectification Actions Regarding the Safety of Fireworks and Firecrackers Operations, No. An Jian Zong Guan San (2016) 62. (II) Strengthen risk control and the identification and rectification of potential hazards. 3. Proactively advance special rectification efforts regarding hazardous chemicals, and implement comprehensive key prevention and control measures: (2) Improve the intrinsic safety level of major hazard sources. As of January 1, 2017, all hazardous chemical storage areas that constitute major hazard sources of level 1 or 2 and do not have an emergency shutdown (emergency isolation) function must cease to be in use ； Guiding Principles for the Campaign to Rectify Hazards in Sinopec’s Tank Farm Areas, Group Work Order Anfeng [2016] No. 39 III. SIS Interlock System 1. Enterprises shall conduct safety assessments of their major hazard sources and determine their risk levels. Tank farm areas that are classified as level 1 or level 2 major hazard sources must be equipped with an emergency shutdown system. The safety functions of this emergency shutdown system can be implemented through basic process control (DCS or SCADA) systems, or through a Safety Instrumented Systems (SIS) system ； IV. Low-low level interlock, high-high level interlock: 2. For storage tanks that are classified as major hazard sources of level 1 or 2, in addition to alarms for high and low liquid levels, corresponding alarms and interlock protection measures should also be implemented for low-low and high-high liquid levels. For storage tanks that require a separate SIS system, valve stems on their inlet and outlet pipelines (emergency shut-off valves must have fire protection measures, be capable of manual operation, and also have fire protection features) should be installed; the SIS system is used to interlock and shut off feed in emergency situations such as high liquid levels in the tank or fires ； For storage tanks that do not require a separate SIS system, the tank base valves on their inlet and outlet pipelines should be control valves equipped with manual operation capabilities; in emergency situations such as high liquid levels in the tank or fire incidents, feed can be shut off through interlocks in the basic process control system. AQ 3053-2015 Safety Technical Specifications for Vertical Cylindrical Welded Steel Storage Tanks 3.1.6 Large storage tanks: Tanks with a nominal diameter of 30 m or more, or a nominal volume of 10,000 m3 or more. 6.13 Isolation Valve: A main isolation valve should be installed near the tank body on the inlet and outlet pipes for the material in the storage tank. For large storage tanks, valves equipped with pneumatic, hydraulic, or electric actuators should be used. When the actuator is of electric type, its power cable, signal cable, and electric actuator shall be provided with fire protection. The cut-off valve should have automatic and manual shutdown functions, with manual shutdown including remote manual shutdown and on-site manual shutdown. 12.2.2 Level control accessories: Flammable liquid storage tanks shall be equipped with level gauges, as well as high and low level alarm devices and high-high level alarm devices, in accordance with the requirements of relevant specifications and operational needs; the alarm signals and level information shall be transmitted to the control room. Storage tanks that are operated frequently should be equipped with automatic interlock emergency shut-off devices. Large tanks should be equipped with low and high liquid level alarms, high-high liquid level alarm devices, and emergency shut-off devices. Interlocks should be established between the high-high liquid level alarm and the emergency shut-off devices, and interlock buttons for the emergency shut-off valves should be provided outside the fire dike as well as at the control room operation stations. In the event of a high liquid level alarm or a fire in the storage tank, it is possible to remotely or manually close the feed cut-off valve; once the cut-off valve is closed, the feed pump should be automatically shut down via interlock. There is also the latest update: Notice from the Office of the State Council’s Safety Committee regarding the chlorine poisoning incident at Hebei Lixing Special Rubber Co., Ltd. on May 13, Document No. Anwei Ban [2017] 17. II. Strengthen administrative approvals and enhance control at the source. Safety supervision departments at all levels should further strengthen control at the source, regarding factors such as personnel competence, safety management capabilities, and equipment standards as necessary conditions for companies to obtain safety approvals. First, in strict accordance with the requirements set out in the \"Key Assessment Contents for Safety Production Management Knowledge of Principal Persons in Charge of Chemical (Hazardous Chemicals) Enterprises\" and the \"Key Assessment Contents for Safety Production Management Knowledge of Safety Production Managers in Chemical (Hazardous Chemicals) Enterprises\" (Safety Supervision Administration Office Circular [2017] No. 15), rigorous assessments of the safety production knowledge of enterprise principal persons in charge and safety management personnel must be conducted. Second, those engaged in special operations involving hazardous chemicals must have a educational qualification of at least high school level. Thirdly, regarding the installations and storage areas, the safety distances from surrounding areas must comply with the \"Personal Acceptable Risk Standards and Societal Acceptable Risk Standards for Hazardous Chemical Production and Storage Installations (Trial)\" (**Announcement No. 13 of 2014 by the State Administration of Work Safety). Hazardous chemical storage areas that constitute Class I or Class II major hazard sources must be equipped with emergency shutdown (emergency isolation) functions, while such storage areas must also have detection and alarm systems for leaks of flammable and toxic gases. Those that fail to meet the above requirements shall be ordered to make corrections within a specified time limit in accordance with the law ； If the violation is not corrected within the prescribed time, the entity shall be ordered to suspend operations for rectification in accordance with the law. By comprehensively utilizing various measures, pressure is exerted on enterprises to accelerate their transformation and upgrading, thereby enhancing their inherent safety levels and safety protection capabilities. Here, we present the product description of the explosion-proof emergency shut-off valve for oil depots/chemical plants handling flammable liquids. Overview of the explosion-proof emergency shut-off valve for oil depots/chemical plants handling flammable liquids: The explosion-proof emergency shut-off valve (hereinafter referred to as the shut-off valve) is a new type of emergency shut-off valve. It serves as a reliable and essential safety device designed to prevent safety incidents such as oil leaks, spills, fires, and explosions in oil depots. It plays a particularly important role in ensuring the safety of property and personnel. It works in conjunction with level gauges, combustible gas alarms, and other safety instruments related to fire protection; in the event of an accident at an oil depot or chemical plant, the shut-off valve will close quickly either through an alarm signal or as a result of an emergency power cut, thereby stopping the flow of oil or chemical liquids and preventing the accident from worsening. II: Application scope and uses of the explosion-proof emergency shut-off valve. This product is suitable for the inlet and outlet pipelines of oil tanks in oil depots and chemical plants. In the event of an overflow or leakage of oil or chemical liquids, or in case of a fire, the emergency shut-off valve can be activated to cut off the flow of such oils or hazardous chemical liquids. Reduce the occurrence of explosion and fire accidents caused by leaks, and ensure the safety of lives and property of ** and the people. III: Working environment conditions 1. The isolation valve is suitable for use in areas with explosive mixtures of Category II, Division B, with a surface temperature not exceeding Group T4, such as gasoline, kerosene, diesel, aviation fuel, lubricants with a viscosity not greater than that of Engler oil, and various chemical liquids. 2. The power supply voltage fluctuation must not exceed ±10% of the rated voltage. 3. A filtering device must be installed on the inlet pipeline. 4. The ambient temperature range is from -40°C to +55°C. 5. The ambient humidity should not exceed 90%. V: Structural features of the explosion-proof emergency shut-off valve. Structure type: Piston-type. VI: Working principle of the explosion-proof emergency shut-off valve. The shut-off valve is of the normally closed type, and it is installed above the inlet pipe of the oil tank as well as below the outlet valve. When the oil flows normally, automatic or manual control can be employed. When automatic control is used, it can be integrated with various safety devices such as the oil pump motor controller, level gauge controller, and combustible gas alarm. In the event of a high level alarm, a combustible gas alarm, or any other safety incident, the shut-off valve will use the relevant alarm signals to immediately cut off the supply of oil or the hazardous chemical liquid, with the emergency shut-off valve closing rapidly. This prevents the possibility of the accident escalating further; this valve is a safety valve and should not be used as a service valve. Manual control is used for temporary emergency situations, such as during debugging. The manual valve should be closed after debugging is completed! It should not be used under normal circumstances to avoid loss of control.