Testing Gasoline Transfer Tank Sealing Performance
Pressure Test
The pressure test is the most common and effective method. First, ensure the tank is clean and free of residual fuel. Close all valves and fittings tightly, then connect a calibrated pressure gauge and an air compressor to the tank's inlet.
Gradually pressurize the tank to the manufacturer's recommended pressure—with lower pressure levels for small tanks and higher levels for commercial ones. Once the target pressure is reached, turn off the compressor and seal the inlet.
Monitor the pressure gauge continuously for a set period—if the pressure remains stable, the tank's seal is intact. A pressure drop indicates a leak, which requires further inspection to locate the source.
Bubble Test (Soapy Water Test)
The bubble test is ideal for pinpointing small leaks identified during the pressure test. Mix a solution of water and mild dish soap in equal parts and apply it evenly to all seams, welds, valves, and connection points of the pressurized tank.
Watch closely for bubbles—even tiny, slow-forming bubbles signal a leak. Mark the leaking area immediately so it can be repaired later.
This method is especially useful for:
- Metal tanks with welded joints
- Plastic tanks with threaded fittings
- Detecting leaks that might be invisible to the naked eye
Static Liquid Test
For tanks designed for liquid storage, the static liquid test provides real-world sealing validation. Fill the tank with clean water (or a non-flammable test fluid similar to gasoline's viscosity) to a level that leaves sufficient space to avoid overflow.
Close all openings and let the tank stand undisturbed for an extended period. Check the exterior surface, especially the bottom and lower seams, for dampness, water stains, or puddles.
Additionally, weigh the tank before and after the test—if the weight decreases, it confirms a leak. This method simulates actual usage conditions, making it suitable for verifying long-term sealing performance.
Vacuum Test
For large commercial tanks, the vacuum test offers high precision. Use a vacuum pump to create a negative pressure inside the tank and seal the system.
Monitor the vacuum gauge for an extended period; a loss of vacuum indicates air is entering through a leak. This method is effective for detecting micro-leaks that might not show up in low-pressure tests, ensuring the tank meets strict industry safety standards.