(See Fig. A, below, to find the wind zone you live in.) It won't cost a fortune, either. A little elbow grease and the building materials will all but guarantee your family's injury-free survival in any storm that comes down the pike. Keep in mind that a safe room can be more than just a storm shelter.
Expansion Tanks. The expansion tank is a vital part of your car's cooling system and acts as an overflow reservoir catching the water/coolant mix that is forced from your radiator as it heats and builds pressure in the system. cooling systems would explode under pressure or the coolant would be forced from the overflow tube on the radiator and leak onto the road. If your find yourself having to replace coolant too regularly then check your expansion tank and the rest of your system for leaks.
Water Heater Thermal Expansion Tanks. A thermal expansion tank is designed to help protect potable (drinkable) hot water systems, helping to maintain them and keep them working efficiently. They are used to absorb excess water pressure, which can be caused by thermal expansion as water is heated. With a properly installed tank, the system pressure will be maintained, and will help prevent added stress to various components, saving you headaches - and money - down the road.