To ensure the minimum thickness required for the wall to store fluid, different parts of the tank are thickened.
The design of the tank should be such that it is not allowed to fill with water and part of the tank should be filled with water and tested by increasing the air pressure on the water surface.
According to the design, the whole tank can be filled with water and pressurized.
According to the design, the tank has a relative vacuum in the roof
All tank control equipment and pressure reducing devices should be approved for calibration and performance accuracy.