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This post was last edited by “Hasty Passerby” on March 15, 2019, at 10:04. Oil depots are locations prone to fire and explosion; in accordance with **standards and relevant industry regulations, measures for fire and explosion prevention must be implemented. Special attention should be paid to lightning protection, static electricity prevention, and protection against ground potential surges. 【Surge protectors】Statistics show that in recent years, the scale and number of oil storage facilities have been continuously expanding. Instrumentation systems are developing rapidly toward networking and intelligence. However, information devices such as instruments generally suffer from weaknesses such as low insulation strength, poor tolerance to overvoltage and overcurrent, and sensitivity to electromagnetic interference. If these instrumentation devices are struck by lightning directly or if there is a lightning strike in the area surrounding them, it can result in severe casualties and economic losses. Therefore, the design of modern oil depot systems must place great emphasis on lightning protection. http://www.junhedianzi.cn/uploads/ueditor/image/20180918/1537253081264751.jpg II. Overview and Analysis of Lightning Protection for XX Oil Depot XX Oil Depot is located in XX City, and it is in an area with frequent lightning strikes. The oil depot is located in the suburbs of the city, with no tall buildings in the surrounding area. The oil tanks and office buildings constructed there are the tallest structures in the vicinity, making them highly susceptible to lightning strikes. The signal lines for instruments such as on-site level gauges and electric gate valves in the X newly built tanks at the oil depot lack lightning protection. All X tanks in the tank farm need to be grounded, and in addition, the information rooms and fuel dispensing control rooms within the oil depot also require grounding protection. The internal power distribution systems in the separate buildings in various areas are also lacking lightning protection. There is no lightning protection at the network, monitoring, or instrument control ends. If the aforementioned facilities are struck by lightning, it will inevitably affect the oil unloading operations at the tank farm; in severe cases, it can cause the network system to fail, and even lead to accidents such as fires and explosions. Therefore, comprehensive lightning protection for oil depots is an urgent necessity! http://www.junhedianzi.cn/uploads/ueditor/image/20180918/1537253237652973.jpg III. Lightning safety hazards existing at XX oil depot 1. There are no tall buildings around the oil depot; the oil tanks and office buildings constructed there are the tallest structures in the vicinity, making them highly susceptible to lightning strikes. In severe cases, this can lead to fires and explosions of the oil tanks, causing serious harm to people’s lives and property as well as significant economic losses. 2. The power supply system lacks lightning arresters; no lightning protection measures are installed at the low-voltage power distribution facilities, circuits, and electrical equipment in the oil depot. As a result, the static or electromagnetic charges generated along the power lines cannot be discharged into the ground, which leads to damage to the power supply facilities and the electronic devices connected to them. 3. The electronic information devices used in oil depots, as well as the cables connected to them, lack lightning protection measures; the charge released by induced lightning spreads along these cable lines, resulting in overvoltages and strong electromagnetic fields in the transmission lines, signal lines, and network communication lines, which in turn damages the electronic information devices. 4. Proper grounding is essential; it is the most important aspect of lightning protection technology. Whether it is direct lightning strikes, induced lightning, or other forms of lightning, in all cases the lightning current is directed into the ground. Without a proper and effective grounding system, it is not possible to provide reliable lightning protection. In summary, oil depots generally lack lightning protection for direct lightning strikes, power supply systems, electronic equipment, and signal systems. In the event of a thunderstorm, lightning strikes are likely to occur, causing damage to important devices such as level gauges, mass flow meters, and PLCs, which in turn hinders the smooth progress of tasks such as oil unloading and delivery, resulting in incalculable losses. IV. The lightning protection solution for XX Oil Depot is formulated in accordance with the relevant provisions of the **Standard of the People’s Republic of China GB50074-2002 \"Code for Design of Oil Depots\" and GB50343-2004 \"Technical Code for Lightning Protection of Electronic Information Systems in Buildings\", taking into account our investigations of China National Petroleum Corporation’s XX Oil Depot as well as the existing problems there. The following solutions are proposed: (1) Protection against direct lightning strikes – Implement appropriate measures to protect the oil depot from direct lightning strikes as well as ball lightning that accompanies such strikes, thereby reducing the likelihood of lightning striking within the depot area and preventing lightning from reaching inside it. (II) Grounding: In accordance with the **standard GB50074-2002 \"Code for Design of Oil Depots\" of the People’s Republic of China, for lightning protection grounding, anti-static grounding, working grounding of electrical equipment, protective grounding, and grounding of information systems within oil depots, it is advisable to use a common grounding system, with a grounding resistance not exceeding 4Ω. The areas within the XX oil depot that require grounding include the tank area, the train loading/unloading area, the fire control room, and several other locations; all other areas are interconnected through grounding systems. In addition, an equipotential bus bar must be installed inside each building and connected to the ground. At all grounding points within the reservoir area, trenches with a depth of not less than 0.8 meters must be dug to lay the grounding connection flat bars; the grounding electrodes should be placed at a depth of not less than 1.8 meters (with a length of 1 meter each), at a distance of not less than 1.5 meters from the buildings, and they must be connected to the building’s grounding system. 3 meters away from the tank body (depending on actual conditions); each tank body requires 2 grounding test terminals. These terminals are made by bending galvanized flat steel at right angles at both ends – one end is welded firmly to the tank body, while the other end has two bolt holes for connection to the grounding system. The length of these terminals should be around 0.6 meters (determined based on the tank’s insulation layer), and they should be located 0.5 meters above the ground level. Calculations show that, with a soil resistivity of 100 Ω·m, a single building requires 20 oil-specific grounding electrodes of type KS-SYD-1000/T in order to achieve a grounding resistance of 4 Ω. With the combined use of grounding corrosion inhibitors (which wrap around horizontal grounding electrodes to prevent corrosion and thus extend their lifespan) and horizontal grounding electrodes, an average of about 12 grounding electrodes per location are sufficient to achieve a grounding resistance of 4 Ω or less. Depending on the varying distances from various grounding points and their respective usage purposes, the number of grounding electrodes can be appropriately increased or decreased. The KS-SYD-1000/T grounding product can be widely used in areas where grounding and cathodic protection coexist, and it can also be used as either a grounding product or a cathodic protection product. This product combines the advantages of zinc strip anodes and conventional galvanized steel; it possesses the high strength and good thermal stability of steel, as well as the function of cathodic protection. It avoids the waste and hassle of duplicate investment and construction for grounding systems and cathodic protection. This product is a new type of grounding solution specifically designed for petrochemical engineering. (III) Protection of the power supply system: In accordance with the relevant provisions of the **standard GB50074-2002 \"Code for Design of Oil Depots\" of the People’s Republic of China, where the distribution circuits of information systems in oil depots need to be connected to electronic devices at both the beginning and end of these circuits, overvoltage protection (surge protection) devices that are compatible with the voltage tolerance levels of those electronic devices should be installed. Installing line surge arresters on distribution lines allows them to activate when the overvoltage caused by lightning strikes exceeds a certain level. These arresters provide a low-impedance path for the lightning current to flow into the ground, thereby limiting the increase in voltage and ensuring the safety of the lines and equipment. 5 sets of KSP-25KA/350/40/M are installed at each primary power supply, 6 sets of KSP-80KA/4P/M are installed at the secondary power supplies, and 10 sets of KS-CP-01A-10A are installed at the front ends of the information equipment in the control room and office buildings. (IV) The protection of signal circuits shall comply with the relevant provisions of GB50343-2004 \"Technical Code for Lightning Protection of Electronic Information Systems in Buildings\": Signal cables entering and leaving buildings should preferably be cables with metal shielding layers, and they should be laid underground. At the boundary between the direct lightning strike unprotected zone (LPZ0A) or the direct lightning strike protected zone (LPZOB) and the first protection zone (LPZ1), the metal shielding layers of the cables must be equipotentially connected and grounded. At the corresponding ports of the core wires of the signal cables in the electronic information system equipment room, appropriate surge protectors for signal lines should be installed; the grounding terminal of the surge protector should be connected to the unoccupied ground wires within the cable. The electronic devices found in oil depots include: level gauges, differential pressure transmitters, mass flow meters, network switches, server hosts, and video surveillance systems. These devices are crucial for the informational management of oil depots; their signal lines not only transmit signals, but lightning strikes can also invade electronic equipment through these signal cables. Therefore, surge protectors must be used to protect the interfaces of the signals and communication circuits of various system devices, in order to ensure the proper transmission of signals along these lines. 1. Lightning protection for on-site instrument signals: Explosion-proof control circuit lightning protectors KS-EX-24V/2S/M are installed in the control circuits such as those for level gauges, differential pressure transmitters, thermometers, electric gate valves, flow meters, and the on-site operation display panels in the fueling area; a total of X units are used. 2. Lightning protection for network signals: Network signal lightning protectors of the KS-RJ45-24E/M type shall be installed on all network switches and service terminals, in a total of X units; network signal lightning protectors of the KS-RJ45-E100/4S/M type shall be installed at the network input points of the computer hosts used in the control room and offices; gigabit network signal lightning protectors, with the model KS-RJ45-2E/1000/M, shall be installed at the network input points of the computer hosts. 3. Lightning protection for monitoring signals: KS-3/24/M three-in-one surge protectors for video, pan-tilt controls, and power supplies are to be installed at all monitoring points; a total of X units are required ； Lightning protectors for control circuits are installed on the control lines in the monitoring host control room; product model: KS-K-12V/4S/M ； Install a video surge protector at the video interface; product model KS-TV/16B/M. Grounding protection is provided at each monitoring site; for each site, a well 5 meters deep must be drilled (24 wells in total), with 4 grounding electrodes installed in each well (96 electrodes in total). Connect to the equipment using 16mm2 copper wire. (Drilling must avoid underground cables)