If you open the valve to let the gas out (or whatever is in that thing), but you don't open the second valve on-top to let air replace the gas, it will create a vacuüm inside the tank. There are some safety tubes/valves which are supposed to prevent this from happening, but the forces are so strong they're not always able to handle it.
If you open the valve to let the gas out (or whatever is in that thing), but you don't open the second valve on-top to let air replace the gas, it will create a vacuüm inside the tank. There are some safety tubes/valves which are supposed to prevent this from happening, but the forces are so strong they're not always able to handle it.
Happened at my work once. But not with a small truck like this, but with an 60 feet high silo. Sounded like a warzone for a couple of seconds.