Homeowners who decide to install a propane tank on their property need to be aware of a few safety guidelines. The National Fire Protection Agency (NFPA) has established a set of rules that govern the requirements for the clearance around propane tanks in the NFPA 58 Liquefied Petroleum Gas Code. The size of the clearance radius will depend on the type of installation and the size of the tank.
The requirements for the clearance around vertical propane tanks under 125 gallons depends on the location of ignition sources, venting windows and doors. The tank itself may be placed against the house or building, but it has to be at least 10 feet from an ignition source such as a water heater and 3 feet from a venting window or door.
Horizontal tanks, also referred to as vessels, come in three main sizes: 330, 550 and 1,000 gallons. The size of the vessel normally depends on the propane requirements and the size of the structure using the fuel. The requirements for the clearance around the 330 and the 550 gallon propane tanks is at least 10 feet from the structure, 10 feet from the property line and 10 feet from any ignition source. The 1,000 gallon propane tank requires at least 25 feet of clearance from the structure, the property line and any ignition sources.
Subterranean tanks are generally available as 500 and 1,000 gallon vessels. After installation is complete, the only visible part of these tanks is the riser cover, which is about 1 foot high and 1 foot in diameter. Because of the type of installation, these tanks only need 10 feet of clearance between them and any ignition sources, structures or property lines.