Well, this involves a piece of physics when you use the stove.
You do NOT actually apply heat to the tank, except as needed to prime the expansion chamber. The expansion chamber is the brass valve/burner assembly on top of the stove, there really is no expansion chamber, except in function. This heats the WG to evaporation (boiling.) The pressure sends the fuel out of the jet to be mixed with air & burned, AND, sends pressure back into the tank. Temperature and pressure are directly related in a closed system, so, the pressure is condensed in the liquid fuel, warming it. This supplies more fuel to the "expansion chamber." It sounds kludgey, but it works quite well. In open air, no pot, no windscreen, the tank warms as much from this as well as conduction through the metal parts (a given.)
This is the same mechanism as boiling water. Note that steam is created near the bottom, then, as bubbles rise through the water, they disapear and are re-absorbed into the water, releasing heat. Another, perhaps better example: The capuchino maker on many small expresso machines supplies steam to the milk. This will warm the milk simply by the milk absorbing some steam.
Anyway, it only requires a small bit of combustion to do this since the heat causes some expansion forcing raw fuel into the "expansion chamber."
Overheating is typically caused by large pots over a SVEA while using a wind screen. The simplest solution is to pour a bit of water on the stove. I know, this is counter to pouring water on oil flames, but we are not dealing with liquid fuel, here. Rather fuel vapour that is being vented. The water will simply reduce the heat in the tank, reducing the amount of vapour pressure, from overheating, being produced to vent out the safety valve. Hence, will pretty much reduce the stove output to normal conditions. The safety valve may stick, though. but it will eventually extinguish the stove, or, allow you to turn it off. Even the pot of water on the stove will be fine, boiling water is much cooler than the stove, IFF (if and only if) it overheats.
Did you ever boil-over a pot? It will put the stove out. I have done this several times, since I use a wind screen all the time. The stove will NOT explode. I recommend only low heat when using a wind screen. This is OK with me, since, lower heats are very efficient with fuel, anyway.
Generally, on low, fireballs cannot not happen. Even on 100F days in the sun, the stove will not overheat on low before you are done heating water. I have never gotten the stove to overheat with only a pot on top. Using a windscreen can cause ANY canister type stove to overheat. Canisters of compressed gas are much more risky, since, they have NO safety valve, like a SVEA has. Compressed gas canisters under the same conditions can explode, the SVEA will simply vent excess pressure, preventing the explosion.
You have to really misuse the SVEA to vent the safety. It is not recommended to use a wind screen, I do anyway. Knowing the parameters for any stove is the key to safe operation.