No. The pipe leg is welded to a piece of 1/8" stainless steel that was formed to match the shape of the tank and then welded all the way around it's edge.. This panel is about 8 inches in diameter, and can be seen in he pictures. A crack in this panel will not penetrate the tank. It is a very clever idea, and makes working on the tank legs much less problematic.
I still don't understand why the tank legs are steel and not stainless steel, but maybe in the 1960's in England Stainless steel was really expensive, so they only used it where they had to.