To ensure safety during oil loading and unloading, proper grounding and electrical connections are essential. All parts of the system-such as loading arms, fueling hoses, metal platforms, and pipelines-must be reliably grounded. Special attention should be given to ensuring that these connections are secure and the grounding resistance does not exceed 100 ohms. A soft copper grounding cable with a minimum cross-sectional area of 4mm² should be used, equipped with a crocodile clip capable of penetrating paint to make firm contact with the tanker body.
Static electricity prevention also involves structural and equipment considerations. Oil tankers must be equipped with internal baffles to reduce turbulence, and only rubber dragging belts are permitted-metal ones are prohibited. The resistance between the tank body and the chassis should not exceed 1 megaohm, and the resistance between any two conductive points within the pipeline system must remain under 5 ohms to ensure safe dissipation of static charges.
During operations, strict procedures must be followed. Before opening the tank lid, the static grounding wire must be connected to a designated grounding point, avoiding any connection within 1.5 meters of the loading port. The connection must be secure, and twisting or wrapping the wire is not allowed. After refueling, the wire should only be removed after the lid is closed. When using a crane pipe for top loading, it must extend near the bottom of the tank-no more than 200mm above it-to avoid splashing flammable liquids.
Lastly, tankers switching between high-volatility and low-volatility fuels must undergo gas concentration testing. If the vapor concentration exceeds 25% of the lower explosive limit, proper ventilation or cleaning must take place before use. Operations that might generate sparks or electrostatic discharge, such as field testing or wiping surfaces, are strictly forbidden without prior approval to minimize ignition risks.