Inspection method of Ground Double Wall Diesel Fuel Storage Tank

Appearance inspection
Periodically conduct a comprehensive inspection of the appearance of the tank. Use the naked eye or tools such as a telescope to check whether there is obvious physical damage such as deformation, dents, cracks, etc. on the surface of the tank. Focus on the welds and check whether there are cracks, desoldering, etc. At the same time, pay attention to the coating condition on the surface of the tank. If the coating falls off, bubbles, rusts, etc. on a large scale, it may indicate that the tank has begun to corrode and requires further in-depth inspection.
Sealing inspection
Pressure test method: Close all inlet and outlet valves of the storage tank and fill the tank with a certain pressure of inert gas, such as nitrogen, through specific equipment. Maintain the pressure for a period of time, usually 24 hours, and observe the pressure gauge reading. If the pressure drops beyond the specified range, it indicates that there is a leak in the tank. It is necessary to use soap bubbles or professional leak detection fluid to apply to possible leaking parts, such as valve connections, pipe interfaces, etc., to find the specific leak location.
Liquid level monitoring method: During the storage of diesel in the tank, regularly monitor the liquid level changes. If the liquid level drops abnormally without normal use, there may be a leak. The leak location can be preliminarily determined by combining the presence of oil stains, odors, etc. on the surrounding ground, and then other means can be used to accurately locate it.
Internal structure detection
Non-destructive testing: Use ultrasonic flaw detectors, radiographic flaw detectors and other equipment to detect the inside of the tank. Ultrasonic flaw detection can detect whether there are defects such as cracks and holes inside; radiographic flaw detection can clearly present the internal structure, accurately detect minor defects, and evaluate the integrity of the internal structure of the tank.
Wall thickness measurement: Use an ultrasonic thickness gauge to measure the wall thickness at multiple points in different parts of the tank. Compared with the original design wall thickness data, if the wall thickness is significantly thinner, it means that the tank may be damaged due to corrosion and other reasons. It is necessary to judge the remaining service life of the tank and whether it needs to be repaired or replaced in time according to the degree of thinning.
Ancillary equipment detection
Perform functional testing on ancillary equipment such as pressure balance devices, ventilation systems, and valves. Check whether the pressure balancing valve can be opened and closed normally within the set pressure range; whether the vent is unobstructed; whether the valve opens and closes flexibly and whether the sealing is good, etc., to ensure the normal operation of the auxiliary equipment and indirectly guarantee the overall performance of the storage tank.