A propane tank should be stored outdoors and away from a house or garage. It should be kept upright, away from heat and in a dry location. Before storage, it should be inspected to be sure it is in good condition.
Propane tanks should never be stored in houses, attached garages or crawl spaces under houses. In some states, it is illegal to store them in these locations. A good alternative for propane tank storage is a shed or outbuilding that is not connected with the main house or garage. A well-ventilated area away from heavy activity is best. The tanks should be kept out of the sun and away from any sources of heat. They should stand upright on their foot rings on a dry surface such as concrete or non-flammable shelving. Damp surfaces such as grass or mud may cause rust. Storing propane tanks on their sides or upside down is not advisable because this may cause leaks.
Before storing a propane tank, it is important to check that the valve is closed completely and that the tank is not damaged or corroded. Light surface rust can be sanded and painted, but deep pits in the tank means it needs to be replaced. The collar on top of the tank and the foot ring on the bottom should be tightly fastened. It is important to be safety-conscious when storing propane tanks because the contents are under pressure and are very flammable. When the temperature increases, the pressure increases inside the tank. A relief valve prevents the tank from becoming over-pressurized, but natural disasters such as lightning can cause propane tanks to explode.