Irrigation of LPG Spherical Storage Tanks at Summer

Hi,

There are several spherical storage tanks that will have or having external corrosion due to drainage of water at summer time through fire fighting system. I suspect, operators afraid of vapor pressure increase due to heat that is why at hot summer time they irrigate all tanks. What I believe is that it corrodes the tanks and weakens their soil foundations, causing structural problems. Is there any other alternative methods of cooling tanks or stabilize vapor pressure at hot weather?

P.S. At Platform we have typical Spherical Storage Tanks. Storage Tank contains LPG