What is the safe flow rate for filling cars with gasoline and diesel?

Relevant domestic standards regarding the safe flow rates for fuel-based products. 8. GB12158-1990 General Guidelines for Preventing Static Electricity Accidents, 4.3.3: When filling large containers such as tank trucks with hydrocarbon liquids, it is advisable to feed the liquid in from the bottom. If top feeding is unavoidable, the oil injection pipe should extend into the tank at a depth not exceeding 200 mm from the bottom of the tank. Before the oil injection pipe is submerged in the liquid, its flow rate should be limited to within 1 m/s. 4.3.4 Other incompatible second-phase impurities such as water should be avoided from mixing into acetylene liquids. And efforts should be made to minimize and eliminate water accumulation at the bottom of the troughs and within the pipes. When a second phase is clearly present in the pipeline, its flow velocity should be limited to within 1 m/s. GB13348-92 Regulations on Static Electricity Safety for Liquid Petroleum Products 4 Basic Methods for Preventing Static Electricity Hazards 4.2.1 In the operation of the production process, it is necessary to keep the oil products within a safe flow rate range. Reduce oil splashing, while preventing moisture and gases from entering the oil (see GB12158). 5.4.3 The initial oil filling speed shall not exceed 1 m/s; once the inlet pipe is submerged, the speed may be increased, but for pipes with a diameter of 100 mm, it shall not exceed 9 m/s ； For pipe diameters of 150 mm, the flow velocity shall not exceed 7 m/s, in accordance with SH/T3108-2000 – Design Code for Process and Thermal Piping in Oil Refineries. 3.2 Determination of Pipe Diameter and Flow Velocity – 3.2.3 The design flow velocity for process piping shall comply with the following requirements: (1) To prevent fires or explosions caused by static electricity, when the conductivity of the oil is less than 50 pS/m, the design flow velocity for oil pipelines shall be as follows: the flow velocity in the inlet pipes of light oil tanks shall be less than 4 m/s. The flow rate in the loading pipeline of the road tankers for light petroleum products shall meet the requirements of Equation 3.2.1-1, and the maximum flow rate shall not exceed 7 m/s. The flow rate in the loading pipeline of railway tank cars for vd light oil products shall meet the requirements of Equation 3.2.1-1, and the maximum flow rate shall not exceed 7 m/s. For oils to which antistatic additives have been added, the flow rate can be increased when their conductivity is greater than 50 pS/m, or when an electrostatic eliminator is installed near the pipe outlet; however, the flow rate must not exceed 10 m/s. When the content of free water or contaminants in the light oil is high, the flow rate should be less than 1 m/s. 3 4. For pipelines transporting liquids containing solid particles such as catalytic slurry, the flow velocity of the medium should not be less than 0.9 m/s. . China Petroleum and Chemical Corporation’s Occupational Safety and Health Management System (1995), Part II: Safety Technology Management, Section V: Regulations on Static Electricity Safety Management for Flammable and Combustible Liquids. Article 5: When liquids of Category A and B are introduced into storage tanks and tank cars, the initial flow rate shall not exceed 1 m/s. The flow rate can be increased when the inlet pipe is submerged by 200 mm, with a maximum value not exceeding 6 m/s. For liquids of categories A and B that contain free water, organic impurities, or a mixture of two or more types of oils, the initial flow rate must also not exceed 1 m/s. For Class A and Class B liquids, when antistatic agents are added, or when specialized static electricity eliminators along with static electricity alarms are used, the flow rate can be 6 m/s. According to GB/T15626-1995 – Technical Requirements for the Loading and Unloading of Bulk Liquid Chemical Products, Section 4.2 specifies the flow rate requirements: 4.2.1 During the loading and unloading of flammable liquids, the flow rate in the pipes should not exceed 1 m/s, while during normal operations it should not exceed 3 m/s. 4.2.2 For other liquid products, a more economical flow rate can be utilized. According to the \"Code for Design of Oil Depots\" (GBJ74—84), the outlet of the loading arm can have its filling flow rate increased only after it is submerged by the oil; moreover, the filling flow rate for oils such as gasoline, kerosene, and light diesel should not exceed 4.5 m/s, while the initial filling flow rate should be below 1 m/s. ?

The current value should be 4.5 meters per second, right? What could be the causes of this accident? Let’s discuss it!

The cause of the accident was the mixing of different types of oil in the tank truck. Gasoline was installed first, followed by diesel. Volatile oil products should have an oil vapor recovery system, whereas diesel does not. Therefore, during the loading of diesel, gasoline volatilized and spilled from the filling port, resulting in an explosion due to static electricity.