Precautions for the use of LNG storage tanks

1. When unloading, it is recommended that the limit filling capacity of LNG storage tank shall not exceed 90% of the effective volume (85% - 95% of the geometric volume given by the manufacturer), and the use margin of cryogenic storage tank shall not be less than 10%.

2. When the pressure of LNG storage tank is high, it is not necessarily a problem of the storage tank. The heat leakage and liquid storage time of the whole system shall be considered. Generally, when the pressure exceeds 1.1MPa, the pressure shall be discharged and released. If the cryogenic storage tank is under high pressure for a long time, the service life of the vacuum in the interlayer of the storage tank will be affected.

3. When there are a lot of "sweating" or frosting in LNG storage tank for a long time, and the pressure keeps rising rapidly, the vacuum failure shall be considered, and emergency treatment, manual pressure discharge and transfer of LNG liquid in the tank shall be carried out. 4. It is recommended to carry out vacuum inspection every other year for cryogenic storage tank. If the vacuum degree of the storage tank is hot, it is less than 1pA. If the vacuum degree of the storage tank is cold, it is qualified if it is less than 0.5pa (0.00375tof).

5. The tank shall not be transported with liquid, and the LNG liquid in the tank shall be discharged when it is out of service for a long time.
 
6. LNG cryogenic storage tank belongs to pressure vessel equipment. According to the requirements of Supervision Regulation on safety technology of pressure vessel, the installation, maintenance and transformation of pressure vessel should be informed by the qualified unit to the local quality inspection department, and the installation, maintenance and transformation can only be carried out after obtaining the permission.