LPG shelf life is unlimited. Storing LPG for 10 to 30 years or more would not be an unreasonable expectation, with the limiting factor being the container. Assuming that the LPG cylinder and valve are in good shape, you shouldn’t have a problem.
An LPG tank or cylinder typically need re-ispection every 10 years.
How does shelf-life of LPG compare with other fuels like petrol and diesel?
Unlike unlimited propane shelf life, petrol (gasoline) and diesel have a very limited shelf life. Quality petrol should be good for six months while diesel is good for six months to a year, when stored properly.
However, both fuels will break down slowly over time due to the separation of the components, with gummy, sticky resin deposits and layers of varnish. “Stale fuel” can cause corrosion of system components.
How can you extend shelf-life of LPG cylinders and tanks
High quality galvanised LPG cylinders (propane tanks) can last 30 years or more and the LPG-propane never goes bad. There is no water or oxygen inside a full sealed gas cylinder so they typically do not rust from the inside. If they are stored in a cool dry place, exterior rust would be slow to develop, particularly with a galvanised cylinder or tank.
There are also aluminium and the newer composite cylinders that simply cannot rust, as they do not contain steel.
Some composite cylinders are also translucent, meaning you can see the liquid LPG and very easily check the fill level.
Cylinder re-inspection requirements typically apply to the refilling of the cylinders but place no time restrictions on the use. These regulations can vary by country so it is best to check if this is the case for you, as well. High quality valves and fittings are also a must. Rubber hoses, that can perish, are best avoided in favour of copper tubing or piping.
Significance of LPG’s indefinite shelf-life
With an indefinite LPG-propane shelf life, LPG is the perfect fuel for emergency generators and survival in the events of catastrophic emergencies and other unforeseen circumstances. LPG can be used to power generators, but is can also be used directly for cooking, heating, hot water, and most machinery that is powered by small internal combustion engines.
There are LPG versions of water pumps, small tractors, and an assortment of tools. The list of LPG – propane – applications is almost endless. A larger storage tank could also be used as autogas, if the vehicle has had a gas conversion. You could literally provide your entire energy needs with just LPG and, with sufficient storage, you could do it for many years.
Nothing compares to LPG-propane shelf life for emergency fuel.