Catastrophic failures of aboveground, atmospheric storage tanks can occur when flammable vapors in the tank explode and break either the shell-to-bottom or side seam. These failures have caused the tanks to rip open and, in some cases, hurled the tanks through the air. A properly designed and maintained storage tank will break along the shell- to-top seam.
Tanks that are poorly maintained, rarely inspected, or repaired without attention to design, risk catastrophic failure in the event of a vapor explosion. Either weakening of the shell- to-bottom seam through corrosion or strengthening the shell-to-roof seam relative to the shell-to-bottom seam will increase the vulnerability of the tank to failure along the shell-to-bottom seam. The practice of placing gravel and spill absorbants around the base of the tank, may increase the likelihood of bottom corrosion. Given years of this practice, the bottom of some tanks, especially older ones, may be below ground level, thereby trapping moisture along the tank bottom. This can weaken the bottom and the shell-to-bottom seam. Alternatively, changes to the roof seam such as modifications to or replacement of the roof, or attachments to the roof, could make the roof-to-shell seam stronger relative to the shell- to-bottom seam.
Interesting citation. Thanks. The author postulates a lot of pathways that could create an explosive mixture in a water tank. A couple of commenters suggest these are not plausible given the concentrations of chloramine in the water.
Given these possibilities, why aren’t explosive gas concentrations monitored in water tanks?
That’s exactly what I had in mind. Thanks for the link.
I forgot about H2S !