The fuel tanks vary. Some of the fuel tanks can be removed so that you can fuel up the stove or heater outdoors more easily. Some of the fuel tanks are integral types and others are cartridge types.
Integral Fuel Tanks
The integral fuel tank has a slit in it and offers up the kerosene generously. In the event that a kerosene appliance gets tipped over, the fuel will be contained by the slit. However, leakage by caps and gaskets and gauges can cause the kerosene to escape when tipped over.
Cartridge Fuel Tanks
Cartridge fuel tanks use an o ring and spring mechanism so that the tank can be removed for filling. The o ring is sandwiched between the valve holder and the fuel cap assembly.
If the tank is tipped over, air will enter the fuel tank coupling making it impossible for kerosene to leak out.