Weld inspection of storage tank: 100% non-destructive inspection (RT) is carried out first, then penetration inspection and air pressure (pure nitrogen) test are carried out, and finally helium mass spectrometry leak detection is carried out on every weld and joint with "helium mass spectrometry leak detector".
The container in the storage tank adopts integral pickling, cleanliness is treated according to the oxygen standard, and the imported ultraviolet black light detection, to ensure that there is no oil pollution and other organic impurities.
The time interval between cleaning and drying in the storage tank and group alignment with the outer container should be less than 3 hours. After group alignment, the inner container and jacket should be filled with nitrogen to prevent dust and other organic impurities from entering and ensure the cleanliness of the inner container and jacket.
The inner and outer surface of the container outside the storage tank is sandblasted to meet the requirements of SA-2.5a standard. After the surface of the steel plate is metallic, the dust attached to the surface is completely removed by a vacuum cleaner, so as to ensure the stability of vacuum in the interlayer.
The finished paint film on the outer surface of the storage tank is compact, firm and reliable. The paint dry film thickness is greater than 250µm, ensuring that the color does not fade within at least 3 years.
The sandwich insulation material is made of domestic high quality pearlite, and the performance parameters are as follows:
Air pressure test, air tightness test and helium leak detection, after the inner tank is manufactured, air pressure test and air tightness test shall be carried out in the factory, and helium leak detection shall be carried out in the outer tank.