What temperature does propane stop flowing?

[BobsYourUncle]

Getting a tad nippy out, living here in the TT.

Supposed to get down to minus 32C tonight. (about -25.6F)

Cooking dinner just now, oven on baking some salmon, furnace trying to keep this thing warm and 2 burners on the stove going.

I noticed that although one burner was on high, the flame was only maybe 30% of what it should be. Furnace shut off and the flame jumped up to high.

Don't think the bottle is near empty yet, I've only had it in use for a day and a half.

I'm thinking maybe it is too cold for the propane to boil off and flow.

Anybody know what temperature that propane stops flowing without warming the bottles?

I should have listened to pianotuna and bought an electric blanket for the tanks. Meant to, but never got around to it - too busy trying to work outside in this cool weather.

[Grit_dog]

Since you must be plugged in at, wherever you can “camp” in Calgary in the winter, are you limited on power, or is there some other aversion to some electric heat?  Would seem to be an easier and likely cheaper short term solution since the LP furnace probably chews through the LP quickly anyways. 
Another option, have spare tanks stored inside to rotate into the mix and keep em on the full side to help with boiling a greater volume. 
or use some of your power to heat the tanks. Literally a small magnetic block heater on the tank you’re using and an old blanket around it will make the problem disappear. 
idk depends how long you need the solution for. 
good luck and stay warm!

[W8-4-me]

Taken from a web site.
-44 degrees Fahrenheit

 A propane tank's cold temperature limit is -44 degrees Fahrenheit — at that point, propane turns from a gas to a liquid. Propane can only heat your home when it's in a gaseous state, not when it's a liquid.

[naturist]

Don't forget, as propane (or LPG) evaporates to run your furnace/cooktop/etc., it cools the liquid in the tank. So while it might flow just fine at -39 under a light load, if you try to run a lot of stuff, it might stop being useful at much higher ambient temperatures. When it gets below -30, you might need a 'lectric blanket out there around the tank. And the problem would be much worse the smaller your tank is. Feeding all those appliances off a thousand gallon residential tank would work much better than off a 20 pound RV tank.

[dandysmack]

I remember our LP stopped flowing at 54643

[ktmrfs]

down home wrote:
probably not the case here but another thing to be watched.
Some suppliers not only put propane int their tanks but butane and other heavy and light ends. Works ok in warm weather but you are shortchanged since they don''t have the same energy. When colder the "propane" may not flow too well or at all.
Sometimes it pays to ask and make sure. Others the people filling the tank don't know.

bigger issue is that butane has a much higher boiling point and lower vapor pressure. If you can't get it to boil then no gas.

There is a difference between "propane" and LPG "liquified petroleum gas". propane is propane only. LPG can be either pure propane or a mix of propane, butane etc.

[ktmrfs]

MEXICOWANDERER wrote:
LPG needs an appropriately large SURFACE AREA to vaporize liquid into gas. I installed a large hydronic heating system in a repair garage in the Sierra Nevada Mountains many years ago. A one million BTU boiler. At -25C it took four 500 gallon tanks set to offer enough surface area to gasify fuel for the boiler.

A vertical tank offers a poor relationship of surface area to gas storage. But nothing can be done about it except heat the tank. I've seen folks use an infrared LPG heater placed a meter distant from a big tank in an emergency.

yes. In fact most propane suppliers have graphs that will show the max BTU/hr that can be drawn from a tank at a given min ambient temperature when the tanks is at a low level, say 10% off initial capacity.

They use those graphs to determine the minimum size tank to supply an application taking into account the maximum draw. And why the bigger tanks are horizontal cylinders. But even with a horizontal cylinder, as you get near empty, the surface area is going down as well as you get near the bottom of the tank.

IIRC while a 7.5 gallon vertical tank is common for RV applications, it is actually undersized for a typical furnace draw below about 40F. And it gets worse when the furnace and HWH turn on.

I know my 7.5 gallon tank will switch over with about 1.5 gallons left if the HWH and furance come on in the morning with temps in the low 40's. I just wait till late in the morning and switch back to get the last gallon or so out of the tank.

[down_home]

probably not the case here but another thing to be watched.
Some suppliers not only put propane int their tanks but butane and other heavy and light ends. Works ok in warm weather but you are shortchanged since they don''t have the same energy. When colder the "propane" may not flow too well or at all.
Sometimes it pays to ask and make sure. Others the people filling the tank don't know.

[MEXICOWANDERER]

LPG needs an appropriately large SURFACE AREA to vaporize liquid into gas. I installed a large hydronic heating system in a repair garage in the Sierra Nevada Mountains many years ago. A one million BTU boiler. At -25C it took four 500 gallon tanks set to offer enough surface area to gasify fuel for the boiler.

A vertical tank offers a poor relationship of surface area to gas storage. But nothing can be done about it except heat the tank. I've seen folks use an infrared LPG heater placed a meter distant from a big tank in an emergency.

[gmctoyman]

More than you wanted to know.
http://www.documentation.emersonprocess.com/groups/public/documents/bulletins/d4500147t012.pdf

Much easier.
http://countryplans.com/smf/index.php?topic=10186.0

[wa8yxm]

I have heard a few claims of temp for the vapor point of propane.

I like to research and it's running in another tab now. the round figure is -40 your choice of C or F but it turns out -44F (About -42 C) is right.

here is the link

http://www.propane101.com/aboutpropane.htm

[BobsYourUncle]

last night was the lowest temperature for the next little while.
As soon as it got to about -25C (-13F) it worked fine again.

But I will follow Don's suggestion and get a heating pad of some kind to keep in here for future cold weather.

I was a bit concerned when the furnace couldn't keep up and the temp was dropping inside here. I can stay warm no problem but it's my plumbing freezing that concerns me.

Moving on to Medicine Hat tomorrow or Monday for the next part of my adventure!!

[BobsYourUncle]

atlin wrote:
Bobs.........You have had plenty of responses to your LP problem so I've nothing to add. But, what I am interested in is, how did the Salmon turn out, and would you share your recipe for baking salmon?

Well, it was nothing elaborate for sure. It was a frozen salmon steak.

I smeared some butter all over the top of it, heavily sprinkled garlic powder on it, followed by some Montreal chicken spice and then I baked it in a foil pie plate that was lined with foil. I covered it by wrapping the top of the fish with the same foil it was sitting on.
From frozen, I baked it at 450 for 20 minutes.

Thats all! And it turned out awesome, so tender and flaky

[pianotuna]

Hi westend,

Draping a blanket over the tank insulates it--then when the propane boils the temperature of the tank drops even more than if it were uncovered.

[westend]

I bet if you draped a moving blanket or some other heavy wrap around your tanks before retiring at night, you wouldn't have a problem.

FWIW, I've spent many a frigid night out in fish hoses with the tanks outside, only blocked from wind on one side. Never experienced a lack of propane.

BTW, if you do opt for one of those magnetic heaters, you may want to monitor it so that you aren't super heating the gas inside the tank. There is little as unnerving as having the safety release open on a 20lb. tank.