Storage tank is designed for storing liquid materials. In spite of the fact that it is generally utilized in petroleum industry, it is also used in various sectors (food industry, fertilizer industry etc.). The stored products are generally petroleum-derived materials or chamicals used in petroleum industry. 

The operation pressure of these tanks is same as the atmosphere pressure (101,3kPa). The features of the stored liquid such as density, vapor pressure etc. should be known. 

Special tanks (double wall, underground tanks, insulated) 
They can also be classified according to the type of the stored material, insulation or diameters.