First, clean the trailer tank from dust, oil, and other debris. Ensure the tank and its connections are clear. Focus on the tank's welds, joints, and valve-to-pipe connections. Observe for signs of oil infiltration, damp patches, or residual liquid. Any abnormal color or a fine oil film may indicate a leak caused by seal failure. At the same time, inspect the tank surface for deformation or cracks. These structural issues can easily compromise the seal integrity. Prioritize ensuring that the structure is intact before further inspecting the seal.

Close all the inlet and outlet valves of the trailer tank to ensure the tank is completely sealed. Slowly fill the tank with inert gas using a dedicated pressure device until the tank reaches a stable pressure. Stop pressurizing, close the pressure device, and record the initial pressure. After a period of stabilization, continuously observe the pressure monitoring device's display. If the pressure remains stable without decreasing, the tank's overall seal is good. If the pressure gradually decreases, a seal leak exists, requiring further locating the leak.

Prepare a specialized, foaming leak detection liquid and evenly apply it to key sealing areas such as the tank's welds, valve sealing surfaces, and pipe joints. Ensure a uniform coating thickness, covering all potential leaks. After a short period of stabilization, carefully inspect the applied area for bubbles. If small bubbles persist in a specific area, this indicates a seal defect. The area where bubbles appear is the leak. After the test is complete, wipe away any remaining leak detection fluid with a clean cloth to prevent corrosion on the tank surface.

Inspect all connections on the Trailer Tank individually, including valve-to-pipe connections and the connections between the tank and accessories. Remove any sealing components, such as seals and gaskets, and inspect them for signs of aging, wear, deformation, or damage. Poor seals can cause seal failure even when properly installed. When reinstalling sealing components, ensure the correct model and installation position. Tighten the connecting bolts evenly to avoid uneven tightening that can affect the seal and cause uneven stress on the connection. After installation, re-verify that there are no signs of leakage.