What Went Wrong 3
Unusual Tank Explosion
During the construction of a new tank, the operators decided to connect the nitrogen line to the tank for safe hot job on the connected pipe line of the tank. They said they knew better; nitrogen was inert and therefore safe.
The new tank and an existing one were designed to be on balance with each other to save nitrogen (Figure 5-9), The valve to the new tank was closed but passing. Nitrogen and methanol vapours entered the tank, and the vapours were ignited by a welding job performed by a welder who was completing the inlet line to the tank. The roof was blown right off. By great good fortune, it landed on a patch of empty ground just big enough to contain it (Figure 5-10).