When and where to fill onboard propane

As to the 'when' part of your question, bear in mind that not all propane really is "propane". I say 'when' because in the northern areas of North America you often get a blend (in varying ratios) of propane and butane. More butane in the summer, less in the winter.

Sometimes you find nearly straight butane, this is very common in the southern US

This is why most place call it "LPG" (liquid petroleum gas) and not "propane".

This is important because the boiling point (the reason there's gas not just liquid in the tank) of butane is a LOT higher than that of propane. At anything warmer than -44 F. propane is boiling, therefore making vapour.

Butane however stops boiling at about 32 F. so if you are camping somewhere that the temp drops below freezing and you have butane in your tank, you too will be freezing, no heat, no cooking, no hot water.

The trick is to fill your tank, whenever possible, in cold season.

jplante4 wrote:
Remember that they only fill the tank to about 80% to allow for expansion.

If they fill it properly, they'll fill it until liquid instead of gas flows out of the fixed liquid level gauge, sometimes erroneously called a "vent". And yes, that occurs at the 80% liquid level. The OPD (Overfill Prevention Device) valve may shut off the fill slightly before or at about the same time that the gauge spits liquid.

Remember that they only fill the tank to about 80% to allow for expansion.

Thanks very much for the responses. Y'all helped me understand how it works and I feel a lot better about it...

I called the station we usually go to and they said yes they have the fitting and it shuts off automatically when full. We just have to go when there are at least 2 people on duty - between 10 and 2. :)

Well I like to let it get down a bit (half or less) but where.. Well that all depends on several things

Many RV parks offer Propane fill, around me about 3.00/gallon
In Flint, MI Parker's propane 1.36/gallon
In Tekonsha, MI (Home of Tekonsha Engineering) Carmichaels, don't knwo the price though. Do know how to get there (Kind of out in the sticks).

MOST Flying-J truck stops as well as a lot of others

Many gas stations also have propane

Even ACE hardware in some states.

Generally any place that fills cylinders can fill mounted tanks. You do not need to be empty to refill although you may get dirty looks if you pull in and the guy has to go out in the weather to pump 2 gallons into your rig.....

Your onboard tank is filled by the measured gallon, and can be filled at any time. Many cylinder refillers are equipped to refill your fixed tank, but not all. Many campgrounds, Flying J, U-Haul, Tractor Supply, RV dealers, etc., are equipped to fill your tank. If a campground does not fill tanks, they will be able to tell you where to get it filled in their area.