Q. Design layout of Storage Tanks in plant?

Generally, tanks taking up large areas of the plot are located off-site and storage tanks containing the same product grouped together, spaced within a diked area to contain any leakage. A dike must be sized to have a volumetric capacity of not less than 110% of the capacity of the tank when the diked area contains one tank or when the diked area contains more than one tank, the dike area volumetric capacity must not be less than:

a) The capacity of the largest tank located in the diked area plus

b) 10% of the greater of

i. The capacity of the largest tank), or

ii. The aggregate capacity of all other tanks located in the diked area.

Sizing of diked areas should be established as a priority early in the site layout. Transfer pumps should be outside the berm. Since piping involved in ground fires usually fails within 10 or 15 min. of initial exposure, locate an absolute minimum amount of piping, valves and flanges within dikes. It is also important to install pumps, valve manifolds and transfer piping outside dikes or impounding areas. For the same reason piping for one tank (or group of tanks) should not pass through a dike enclosure of another tank or group of tanks.