LNG full containment tankIt is a structure integrated with a main container and a secondary container technology, designed to effectively manage the collection of liquid and gas leaks. Similarly, the main container and the secondary container are made of separate steel tanks and steel or prestressed concrete, respectively, and can store LNG liquid and LNG vapor separately. This structure allows for the collection of leaked gases and liquids, while the outer box protects the inner box in case of danger. The distance between the main container and the secondary container is usually specified to be less than 2.0m.

What are the precautions for using LNG full containment tanks? Let's take a brief look.

1. LNG full containment tanks should not be transported with liquid; LNG liquid inside the tank should be discharged when not in use for a long time.

2. For double-root valve tanks, the valve near the tank should remain open.

3. When unloading, it is recommended that the maximum filling amount of the LNG full containment tank does not exceed 90% of the effective volume (the manufacturer specifies 85%-95% of the geometric volume), and the usable margin should not be less than 10%.

4. If the tank shows significant and prolonged "sweating" or frosting, and the pressure continues to rise, it should be considered a vacuum failure, and emergency measures should be taken, including manual pressure relief and transferring LNG liquid from the tank.

5. When the pressure of the LNG full containment tank is high, it does not necessarily indicate a problem with the LNG tank; one should consider the heat leakage of the entire system and the storage time of the liquid. Generally, when the pressure approaches 1.1MPa, pressure relief should be performed. Long-term high pressure in the LNG tank can affect the lifespan of the tank's interlayer vacuum.

5. It is recommended to conduct a vacuum test on the LNG full containment tank every year. For thermal tanks, the vacuum should be less than 1Pa, and for cold tanks, the vacuum should be less than 0.5Pa (0.00375TOF) to be considered qualified.

7,LNG full containment tankAs a pressure vessel device, according to the "Safety Technical Supervision Regulations for Pressure Vessels" implemented by the People's Republic of China, the installation, repair, and modification of pressure vessels must be reported to the local quality inspection department by a qualified unit, and installation, repair, or modification can only proceed after obtaining permission.

What are the maintenance and care procedures for LNG full containment tanks and their auxiliary facilities? Let's take a brief look.

1. Operating personnel should be familiar with the structure and working principle of the tank and operate strictly according to the work instructions.

2. Operators should be familiar with the direction of the tank's connecting pipelines and the process flow of the pipelines, mastering the correct usage of supporting facilities and their relationship with the tank.

3. Daily checks should be conducted on the operation of the tank and connecting pipelines, and any issues should be addressed promptly.

4. Daily inspections of the safety technical accessories of the tank should be conducted, such as monitoring the operation of pressure gauges and ensuring they display correctly.

5. Daily checks of the sealing performance of valves and connecting flanges should be conducted to ensure there are no leaks, and any air leaks should be addressed promptly.

6. It is stipulated that the pressure gauges and safety valves of the tank should be calibrated at least once a year to ensure they are functioning properly.

7. It is stipulated that the tank should be inspected at least once every six years to ensure normal operation.

8. Annual anti-corrosion treatment should be conducted on the tank and ladder platform to ensure a smooth paint surface.

9. The connecting pipelines, valves, flanges, bolts, etc., of the LNG full containment tank should be anti-corrosion treated as required, ensuring that the paint on the pipeline surface does not peel off, valves are not blocked, and flanges and bolts do not rust.