Lightning protection for Class A, B, and C chemical warehouses

According to the \"Code for Design of Lightning Protection of Buildings in the People’s Republic of China\": Article 2.0.1 Buildings shall be classified into three categories based on their importance, nature of use, likelihood of lightning accidents, and consequences thereof, in accordance with lightning protection requirements. Rule 2.0.2: Buildings shall be classified as Category I lightning protection buildings in any of the following situations: 1. Buildings that manufacture, use, or store large quantities of **, **, explosives, and other pyrotechnic materials, where an explosion caused by electric sparks could result in severe damage and casualties. II. Buildings in areas with explosion hazards of Zone 0 or Zone 10. III. In buildings with Zone 1 explosion hazards, explosions caused by electric sparks can result in severe damage and casualties. Article 2.0.3 Buildings shall be classified as Category II lightning protection buildings in any of the following circumstances: 1. Buildings that are under first-level protection as key cultural relics. II. Particularly important buildings such as **-grade auditoriums, office buildings, large exhibition and expo venues, large railway stations, state guesthouses, **-grade archives, and major water supply pumping stations in large cities. III. Buildings such as **level computing centers and international communication hubs that are of great significance to the national economy and are equipped with a large number of electronic devices. IV. Structures of **quality that are manufactured, used, or stored in such a way that electric sparks are unlikely to cause explosions or significant damage as well as casualties. V. Buildings in Zone 1 explosive hazard environments where electric sparks are unlikely to cause an explosion or result in significant damage or casualties. VI. Buildings in areas with explosion hazards of Zone 2 or Zone 11. VII. Open steel enclosed gas tanks in industrial enterprises that pose an explosion risk. VIII. Departmental and provincial office buildings, as well as other important or densely populated public buildings, where the expected number of lightning strikes is greater than 0.06 times per year. IX. Ordinary civil buildings such as residential houses and office buildings, where the expected number of lightning strikes is greater than 0.3 times per year. Note: The expected number of lightning strikes should be calculated according to Appendix 1 of this specification. Article 2.0.4 Buildings shall be classified as Category III lightning protection buildings in any of the following circumstances: 1. Buildings under provincial-level key cultural heritage protection and provincial archives. II. Departmental and provincial office buildings, as well as other important or densely populated public buildings, where the expected number of lightning strikes is greater than or equal to 0.012 times per year and less than or equal to 0.06 times per year. III. Ordinary civil buildings such as residential houses and office buildings, where the expected number of lightning strikes is greater than or equal to 0.06 times per year and less than or equal to 0.3 times per year. IV. General industrial buildings with an estimated number of lightning strikes of 0.06 or more times per year. V. Based on the impact of lightning strikes on industrial production and the resulting consequences, and taking into account factors such as local weather conditions, topography, geology, and the surrounding environment, the fire-hazardous areas of Zones 21, 22, and 23 that require lightning protection are identified. VI. In areas with an average number of thunderstorm days exceeding 15 days per year, isolated tall structures such as chimneys and water towers at a height of 15 m or more ； Isolated tall structures such as chimneys and water towers at a height of 20 m or more, in areas where the average number of thunderstorm days is less than or equal to 15 days per year.

The Code for Design of Fire Protection in Petrochemical Enterprises, GB50160-2008, contains certain regulations regarding lightning protection; these are presented here for discussion. 9.2 Lightning Protection: 9.2.1 The classification of buildings and structures within process units with regard to lightning protection, as well as the corresponding protective measures, shall be carried out in accordance with the relevant provisions of the Code for Design of Lightning Protection of Buildings (GB50057). 9.2.2 For towers, containers, etc. installed outdoors within process units, if the thickness of their top plates is 4 mm or greater, it is not necessary to install lightning rods or wires for protection; however, a lightning protection grounding system must be provided. 9.2.3 Steel tanks containing flammable gases, liquefied hydrocarbons, or flammable liquids must be equipped with lightning protection grounding, and shall comply with the following requirements: 1. For above-ground fixed-roof tanks containing Class A B and Class B flammable liquids, when the thickness of the roof panel is less than 4 mm, lightning rods or wires shall be installed, and their protection range shall cover the entire tank ； 2. Class C liquid storage tanks do not require lightning rods or wires, but must be equipped with a grounding system to protect against induced lightning ； 3. Floating roof tanks and internal floating roof tanks do not require lightning rods or wires, but the floating roof must be electrically connected to the tank body using two soft copper wires with a cross-sectional area of not less than 25 mm2 ； 4. Pressure storage tanks shall not be equipped with lightning rods or wires, but must be grounded. 9.2.4 Measurement devices for the temperature and liquid level of flammable liquid storage tanks shall use armored cables or steel pipes for wiring, and the cable insulation or the wiring steel pipes shall be electrically connected to the tank body. 9.2.5 The resistance requirements for lightning protection grounding systems shall be met in accordance with the relevant provisions of the \"Code for Design of Oil Depots\" (GB50074) and the \"Code for Design of Lightning Protection of Buildings\" (GB50057). Let’s discuss the classification of buildings for lightning protection as specified in the \"Code for Design of Lightning Protection of Buildings\". According to Article 2.0.2, buildings should be classified as Category 1 lightning protection buildings in any of the following situations: 1. Buildings that manufacture, use, or store large quantities of explosives, detonators, and other pyrotechnic materials, where explosions caused by electric sparks could result in severe damage and loss of life. II. Buildings in areas with explosion hazards of Zone 0 or Zone 10. III. In buildings with Zone 1 explosion hazards, explosions caused by electric sparks can result in severe damage and casualties. Article 2.0.3 Buildings shall be classified as Category II lightning protection buildings in any of the following circumstances: 1. Buildings that are under first-level protection as key cultural relics. II. Particularly important buildings such as **-grade auditoriums, office buildings, large exhibition and expo venues, large railway stations, state guesthouses, **-grade archives, and major water supply pumping stations in large cities. III. Buildings such as **level computing centers and international communication hubs that are of great significance to the national economy and are equipped with a large number of electronic devices. IV. Structures of **quality that are manufactured, used, or stored in such a way that electric sparks are unlikely to cause explosions or significant damage as well as casualties. V. Buildings in Zone 1 explosive hazard environments where electric sparks are unlikely to cause an explosion or result in significant damage or casualties. VI. Buildings in areas with explosion hazards of Zone 2 or Zone 11. VII. Open steel enclosed gas tanks in industrial enterprises that pose an explosion risk. VIII. Departmental and provincial office buildings, as well as other important or densely populated public buildings, where the expected number of lightning strikes is greater than 0.06 times per year. IX. Ordinary civil buildings such as residential houses and office buildings, where the expected number of lightning strikes is greater than 0.3 times per year. Note: The expected number of lightning strikes should be calculated according to Appendix 1 of this specification. Article 2.0.4 Buildings shall be classified as Category III lightning protection buildings in any of the following circumstances: 1. Buildings under provincial-level key cultural heritage protection and provincial archives. II. Departmental and provincial office buildings, as well as other important or densely populated public buildings, where the expected number of lightning strikes is greater than or equal to 0.012 times per year and less than or equal to 0.06 times per year. III. Ordinary civil buildings such as residential houses and office buildings, where the expected number of lightning strikes is greater than or equal to 0.06 times per year and less than or equal to 0.3 times per year. IV. General industrial buildings with an estimated number of lightning strikes of 0.06 or more times per year. V. Based on the impact of lightning strikes on industrial production and the resulting consequences, and taking into account factors such as local weather conditions, topography, geology, and the surrounding environment, the fire-hazardous areas of Zones 21, 22, and 23 that require lightning protection are identified. VI. In areas with an average number of thunderstorm days exceeding 15 days per year, isolated tall structures such as chimneys and water towers at a height of 15 m or more ； Isolated tall structures such as chimneys and water towers at a height of 20 m or more, in areas where the average number of thunderstorm days is less than or equal to 15 days per year.

Class C liquid storage tanks do not require lightning rods or wires, but must be equipped with a grounding system to protect against induced lightning；