Saturday, August 21, 2010


There are many people who take it for granted or simply don’t know the facts about propane. They think it is an excellent Survival fuel choice for heating and cooking and don’t have to worry about an abundant supply of foreign oil or be affected by a ‘Peak Oil’ meltdown. There are a number of common misunderstandings about propane including where it comes from and how long it can be stored?

Propane and Extreme Cold: How does cold weather affect Propane?
Propane is stored as a liquid under pressure and as the pressure is lowered it boils to produce a vapor that is drawn off at the top for a generator engine to use as the fuel.  Because propane boils at -44° (below zero), the gas will be frozen if it can not absorb enough ambient heat to compensate for the boiling process. The bigger the cylinder is compared to the amount of load, the warmer it is outside, the warmer the cylinder is kept, all are a determining factor in the likelihood of a cylinder freezing up. 
If a sweat or frost line forms around the cylinder at the level of the fuel, this is a telltale sign that the cylinder is over-worked and is in the process of freeze up.  If the gas does freeze, it will stop producing vapor and the pressure inside the cylinder will drop to as low as zero psi which will cause the engine to stop running. 

There are a number of steps that you can take to cold-weather protect propane systems:
Sheltering and insulating the propane tank and line is the most practical approach to prevent propane freeze-up. To beat even the coldest weather, install an explosion-proof light that can be turned on when needed for heat. A small, insulated frame shelter is adequate. Heat stripping can also be used. A commercial product similar to electric heat tapes, but designed for propane tanks, is also available. Loose snow piled all around the propane tank often proves to be an effective insulation. If you have a permanent bulk propane tank, bury it to protect its contents from periods of severely cold weather. To prevent propane regulator and line freeze-up, insulate the system. See the suggestions for sheltering and insulating oil-fired supply systems, above.

Propane Generators and super-cold temperatures:
If winter temps of ‘0’f and colder are common in your area propane generators when needed could be problematic. All propane generators need a specific volume of vaporized propane to start and run at and produce full power (watts). That’s why each of them has a pressure regulator to ensure the correct volume of propane is delivered to the motor.

Depending on the size of your propane generator (horsepower/watts) and using a horizontal or vertical tank during temps of let’s say ‘0’f and colder, the limited volume of vaporized propane available may not be enough to run the generator at full power or not at all if it’s close to 44f below! Now your stove may work appear to work fine including your furnace, although they will be at a lower BTU output.

If your temperatures get to minus 44f (-44f) and below, propane will not vaporize at all and turns back into a liquid again. Believe it or not, they sell electric blankets for propane tanks and heat tapes for the lines and regulators.

Where does Propane come from?
Propane is a hydrocarbon (C3H8) and is sometimes referred to as liquefied petroleum gas, LP-gas or LPG. Propane is produced from both natural gas processing and crude oil refining in roughly equal amounts. It is nontoxic, colorless and virtually odorless. As with natural gas, a strong identifying odor is added so the gas can be readily detected.

Liquefied petroleum gas (LPG) consists mainly of propane, propylene, butane, and butylene in various mixtures. However, for all fuels in the United States, the mixture is mainly propane. Chemical Properties: LPG, like natural gas and unlike gasoline, is a simple mixture of hydrocarbons, mainly propane/propylene (C3S) and butane/butylene (C4S).

The most important statement in the second sentence and is the one that shocks most people. Propane is produced only from OIL or NATURAL GAS! Propane does not come from drilling wells in the ground and pumping it out. It only comes from refining oil or natural gas. Bottom line; if there is no oil or natural gas available, there is no propane!

What is the Shelf-Life of Propane?
Propane has an indefinite shelf-life. It will last and be good to use literally forever. The only long term storage issue propane has is the container it’s stored in. Most all tanks are made from steel with some smaller RV tanks made from aluminum and lately some are now being made from a translucent fiber glass resin compound and they’re called ‘Clear-View’ which allows you to see the liquid propane level inside. As we know steel rusts and as the tank begins to rust it can cause a pin hole and the propane will leak out. Proper tank maintenance is needed and will allow many years of safe storage.

What is the Life of a Propane Tank?
Cylinders (tanks) are subject to recertification (also known as requalification) twelve years from their date of manufacture and every five years after that. For example, a cylinder manufactured in January of 2000 will have to be recertified in January of 2012 meaning if you take your bottle to the propane company in April of 2012 to be refilled, it will have to be re-qualified by authorized personnel before it can be filled. The tanks have the date of manufactured stamped on the protective top collar.

Painting Propane Tanks?
Propane tanks, like ASME stationary LP Gas tanks, must be painted a reflective color to avoid overpressure situations caused by the sun beating down on them and overheating the Propane inside.

How should smaller Propane tanks be stored?
Propane tanks should be stored outside. Do not store any propane tanks in the garage or any other indoor areas at any time, even during the winter months. If the tanks may be subjected to excessive heat, like from direct sunlight or desert high temperatures the tanks should only be filled to 80 percent of the tank's capacity. This is to allow for some liquid propane expansion that might occur during hot days.

Propane is stored under high pressure!
ASME propane tanks are built to 250# working pressure. Under normal circumstances, the vapor pressure at 100ºF is 172 psi. The colder it gets the lower the vaporized pressure is. By the time the temp gets to -44f there will be no vaporized pressure.
Propane is a gas that when compressed turns into a liquid for storage and transport. That’s why you can hear it slosh around inside the tank when you move it. A pressure regulator must always be used with propane as it reduces the tank pressure from approximately 172 PSI to an appliance working pressure of around 10-12 PSI then fed to the appliances, lanterns, etc for burning.

Interesting links:


  1. Good info. I did know that propane was a manufactured gas and have planned accordingly. Slowly phasing it out. Have work arounds for the few remaining items that use that fuel.

  2. i happened across your blog througfh the survivalist blog. im glad i did. i suscribed. you have some very good info here. thanks brad

  3. Hi Brad,
    Thanks for stopping by! You’ve probably noticed I’m not a daily poster mostly because my life’s not that interesting but I do post about what I actually do myself and feel are important needs of a self-reliant person and have them here for all to review and use what makes sense in their lives. Being a frugal (cheap) person and in product development, I tend to test and verify what I do or buy so it’s repeatable and dependable, then others don’t have to waste their money on the way to self-reliance and independence. If you ever have any thoughts or questions just drop an e-mail to me, Mike at

    I several friends who are owner operators and am a fan of truckers as their lives are far more difficult than it appears. Today’s operating costs are astronomical and sometimes can’t see how the average OO can keep moving.

    Be safe out there,


  5. Anon, you are free to prepare as you see appropriate. Propane is a very comfortable way to live but there is absolutely no guarantee that it will be available or more than likely unaffordable in the near future as propane is a derivative of oil. In other words the price and availability is purely based on oil; no oil, no propane!

    Wood is a sound way to heat and cook with and should be in everyone’s back-up plans. Wood is available to harvest until all the trees are gone and when oil or propane is no longer affordable, I see wood as the only fuel alternative to heat and cook with.


  6. I keep 125 gallons of propane on hand. I can rum my main cooking stove for 4 years so for me it is a perfect short term (3 year) solution. In a 3 to 4 year period I can cut enough wood to take over the cooking and canning functions that my stove currently provides. I also keep a rotating 10 gals of gasoline which equal 6 months of potable water.

  7. Larry,
    Sounds like you have it covered, nice job!
    I’m guessing the gasoline is to run a generator to pump 6 months of water?

  8. Hey Guys,
    I went with a propane generator (6000w) and I'm in the process of aquiring 100lb tanks for emergency power. My plan is to run aux power for up to one hour a day, roughly how long will a 100lb bottle last me? and should the bottles have a ridgid cover while being stored outside, as for a heat shield against the sun?
    Thanx Bill

  9. Hi Bill,

    Having trouble logging onto my own blogger account, but here’s your answer.

    You should be able to look up the fuel consumption of your generator to get a close approximation of usage. Or for a more exact number put the tank on a bathroom scale and run the generator for an hour under he planned load and note the pounds used per hour or convert it to gallons. 4.2 lbs equals one gallon. A 100 lb tank holds 23 gallons.

    Using a Generac 6kw generator for the data it is as follows:
    ½ load will consume 0.8 gallons per hour. A 100 lb tank will last 28 hours.
    Full load will consume 1.3 gallons per hour. A 100 lb tank will last 17 hours.

    Any reason why you didn’t choose diesel?

    Hope this helps.

  10. Six years ago I changed from home heating oil to propane when the price on a gallon of oil went to 4.25. I bought a 1000 gallon propane tank, new furnace and a whole house backup generator which uses 36 gallons of propane every 24 hours. I live in central southern michigan and after last winter I realized that had I had to use the generator the two times Michigan had major power outages I would have come close to running out of propane. With that in mind I just ordered a 500 gallon propane tank to add to my original tank. Not sure if I can take another winter like we just experienced!

    1. Wow what a spot you're in. The costs are so high for propane. Maybe you could rethink the propane generator for a diesel like a 7000 watt that uses only 1 quart per hour (6 gallons in 24 hours). If your house is all electric maybe a camp stove for cooking while the smaller generator takes care of running the heat.
      You need to look at "Off-Road" diesel as there are no road taxes on it so it is cheaper. Check out this web site for current pricing
      CURRENT PRICES - 06/09/2014
      Heating Oil: $3.089
      Kerosene: $3.659
      Gas Regular: $3.579
      Off-Road Diesel: $3.159
      Propane BASE Price 150g And over: $1.579

  11. can you put propane tanks below ground

    1. Yes, but,,,, lots of costs and special rules go along with it. You can start by looking at this link.

  12. Can I as a lay person fill bottles used on my RV from a 500 gallon propane tank if I wanted or needed to do that? What equipment and training if any would be needed? I recall years ago my Dad routinely filling the propane tank on his farm tractor from a 500 gal propane tank used for providing heat for the farm house and a dairy barn. He hooked up a special hose to the 500 gal tank and then to the tractor's tank while opening a relief valve on the tractor's tank then opening the valve on the 500 gal tank and waited for a vapor cloud to escape from the tractor tank indicating it was full. Obviously the head on the 500 gal tank has to be equipped to allow for such a connection and transfer. Is that pretty much the process?

    1. Sure, you'll just nee the same system RV and BBQ tank re-fillers use. This probably will require a transfer pump. Check with a propane bulk distributor for the correct information.

  13. I have sun dial 116 gallon ASME TANK about half full it's been sitting for 10 years with no usage. I was wondering does the propane lose its oder and dose the lp go bad? is it still ok to use if the valves are good and check out from the tech ? Or just get it new stuff ?

    1. Hi Robert,
      Propane never goes bad, loses its safety odor or becomes unusable, so on that point yours is still good to use. The only thing that can go bad with propane are the tanks/cylinders rusting through (pin holes in tank) or mechanical valves or regulators.

      If your tank is heavily rusted you may have to replace it. I suggest you have the tank topped off but before filling, have the propane company do an inspection of the tank, all lines, connections and components just to be safe.

  14. Thanks for sharing such a nice piece and useful information.

  15. this generator blog is so informative. I'm so happy

    1. Aleda, Glad you found it useful.

  16. Awesome information. Answered all of my questions. THANKS!