The amount of oil in the oil tank of the oil tanker should be appropriate
The amount of oil in the oil tank of the oil tanker should be appropriateIf the oil tank of the oil tanker is filled with too little oil, there will be a large shaking space during transportation, which is prone to generating static electricity. If too much is filled, it is likely to cause overflow for oil tankers with poorly sealed tank openings. Therefore, a filling volume of around 85% is appropriate. In addition, during transportation, medium-speed driving should be maintained to ensure that the oil in the oil tank of the oil tanker is relatively stable. Emergency braking should also be minimized as much as possible.
When changing the oil filling, all the original oil should be drained completely
The so-called change in oil filling refers to, for example, an oil tank that originally held gasoline is now filled with kerosene or diesel or the opposite. Changing the oil filling can easily form explosive gas mixtures in the tank, especially when the oil tank of an oil tanker was originally filled with gasoline and is now filled with kerosene or diesel. The reason is that both kerosene and diesel have the property of absorbing gasoline vapor. It will dilute the oil tank that was originally filled with gasoline vapor and reached an oil-rich state to an explosive range. This is especially true in winter. If static electricity sparks occur, serious accidents such as fire and explosion may happen.
According to an accident investigation report from the American Petroleum Institute, among 620 static electricity accidents involving oil tankers, 440 were caused by changes in oil loading. Therefore, when changing the oil loading of an oil tanker, it is necessary to drain as much of the accumulated oil in the tank as possible, open the tank opening, and allow the remaining oil in the tank to evaporate as much as possible. In addition, when filling the oil tank, the original amount of oil in the tank should also be informed to the oil dispatcher so that they can operate in accordance with the regulations, such as limiting the oil delivery flow rate, etc.
Keep the oil tank of the oil tanker clean
There must be no water or impurities in the oil tank of an oil tanker. This is because water in the fuel can significantly change the electrification tendency of the fuel, causing the voltage inside the tank to increase by tens or even hundreds of times. At the same time, it may also discharge in the form of sparks.
Impurities in the oil also have a significant impact on the generation of static electricity, especially some floating substances, such as wood chips, rubber, and isolated metal balls (the floating balls on the oil tank content gauge of some oil tankers fall off), which are extremely dangerous. The main reason is that this type of conductor has a capacitive effect, which can collect and store a large amount of static electricity. Moreover, there is no fixed movement track in the oil tank of the oil tanker, making it easy to approach the tank wall or other accessories inside the oil tank of the oil tanker, thus forming an appropriate discharge gap. According to tests, once this phenomenon occurs, as long as the potential difference from the liquid surface is between 1 and 2KV, spark discharge may occur (the normal liquid surface is 28 to 30KV), and the discharge energy is strong, which can release all the stored energy at one time.
Ensure the integrity of other accessories of the oil tanker
All valves on the oil tank, exhalation valves, and sealing rings of the oil tank cover of the oil tanker should always be in good condition to prevent fuel from leaking or overflowing, and to avoid fire caused by static electricity sparks.
The static electricity wires should be properly connected
Before loading and unloading oil, the oil tanker and the oil loading and unloading equipment should be connected together with electrostatic wires (electrostatic wires connected to the oil tanker are installed in all oil depots).
Function:
① Conduct away the static electricity induced by the oil tank to prevent sparks with external substances.
② Keep the oil tanker and the entire loading and unloading oil equipment at the same potential to prevent potential differences.
③ It has the effect of accelerating the leakage of electric charges in oil. When connecting static electricity wires, it is essential to choose the metal parts on the tanker that are free of rust and exposed. Do not connect them to areas with severe rust or paint.
Data shows that only when the resistance of the entire electrostatic grounding system is less than 10 ohms can good electrostatic conduction performance be achieved. A more ideal approach would be to install a dedicated copper connection plate at a certain part of the oil tanker, specifically for connecting the static electricity wires. In addition, the static grounding wire on the oil tanker cannot be used as the static grounding wire for loading and unloading oil. The reason is that during the loading and unloading of oil, the oil tanker is usually parked on a concrete ground or a relatively hard ground, and the resistance of its static grounding wire cannot be lower than 10 ohms. Therefore, it is difficult to ensure that it maintains the same potential as the oil loading and unloading equipment.
Ensure that the anti-static facilities on the oil tanker are in good condition
The anti-static facilities on oil tankers mainly consist of static grounding wires and oil separation plates inside the oil tanks. There are two types of static grounding wires: chain type and conductive rubber support belt type. The former has disadvantages such as the easy generation of sparks due to dragging and impact on the ground, intermittent grounding, and the increased leakage resistance caused by rust. Now, all newly produced oil tankers adopt rubber grounding strips. Therefore, the static grounding wire should be adjusted frequently to ensure good contact with the ground. It is also necessary to use a multimeter to check if it is unobstructed and if there is any breakage. Any problems found should be replaced in a timely manner. The function of the oil separator is to reduce the shaking and splashing of oil in the tank during transportation by the oil tanker, so as to reduce the generation of static electricity. If the oil separator plate is removed during the maintenance of the oil tank, it should be reinstalled in time. It must not be regarded as an optional device.
