ASME Residential Propane Tank
ASME is a certification for tanks that are typically larger and used for home heating or additionally heating and appliances. These tanks are designed for stationary installation thus are not designed to be moved when containing propane. The design and standards are governed by American Society of Engineers aka (ASME).
Propane has a freezing point of -44 degrees Fahrenheit.
500 Gallon Propane Tank
A 500 gallon propane tank is a big domestic gas tank. It can contain up to 400 gallons of propane. The empty weight of a 500 gallon propane tank is approximately 949 pounds. A full 500 gallon propane tank weighs 2,649 pounds when filled to 400 gallons of propane.
Pressure inside an LPG tank does not change when the LPG level in the tank changes until the tank is almost completely empty, save from the impacts of temperature variations. The pressure in the tank will only be affected by the ambient temperature if there is enough LPG in the tank to make liquid LPG. Regardless of tank fill level, the pressure will be the same at -20F (seal level), or 11.5 psi. When the last of the liquid is nearly consumed liquid will boil in the tank to a vapor as pressure drops. In summary, a 500 gallon LPG tank at -20 F will have roughly 11.5 PSI.
Propane is a vaporous gas in its natural condition. LPG, or liquefied petroleum gas, is created by pressurizing propane gas below its boiling point of -44 degrees Fahrenheit. Propane pressure should generally be between 100 and 200 psi to guarantee that liquid propane gas remains liquid. At 70 degrees, a conventional 20-pound propane tank will have an internal pressure of 145 psi. On a 100-degree day, the same tank will have 172 psi of pressure.
To comply with the 80/20 rule for propane safety, a 500-gallon propane tank can only securely carry 400 gallons of propane. The 20% of vacant space in your propane tank offers that opportunity for expansion such as that from a hot summer day. You should never paint your gas tank a dark color for safety reasons. Lighter colors reflect heat from the exterior, while darker colors absorb it, resulting in harmful propane expansion.
