Spheres tanks are typically used to store below ambient temperature liquids and pressurized gases such The stress concentration in a spherical shape will be minimal while storing pressurized gases as the stress resistance will be uniform over the total surface. And have a smaller surface area per unit volume than any other shape of vessel.So they are preferred for large capacity storages.
The spherical shell plates are the formed segment to install spherical storage tanks on the site. Optimize the segments arrangement and control the dimensional accuracy of each segments size are important .