Keeping propane flowing in cold temperatures

[noteven]

In cold temperatures there is a point where the propane stops boiling into vapor and supply will stop to your appliances. Sometimes people refer to this as “freezing up” but it is actually lack of boiling...

Charts are available with vessel sizes, btu/hr demand, outside temperature limits.

Around -20F cylinders are getting to their limit to supply my trailer’s furnaces. The 80gal pig is ok.

Edited October 28 by noteven
too many words

[TXiceman]

Pure propane stops vaporizing at -44.42 deg, at 14.7 psia.

At -20 degF, the heat absorbed by the bottle has to exceed the refrigerating effect of the vaporizing propane. The liquid propane will reach -44-42 degF and stop vaporizing.  You can always put a heat lamp on the tank to raise the temperature.

Edited October 28 by TXiceman

[Ray,IN]

3 hours ago, TXiceman said:

Pure propane stops vaporizing at -44.42 deg, at 14.7 psig.

At -20 degF, the heat absorbed by the bottle has to exceed the refrigerating effect of the vaporizing propane. The liquid propane will reach -44-42 degF and stop vaporizing.  You can always put a heat lamp on the tank to raise the temperature.

Exactly!

[Jinx & Wayne]

17 hours ago, noteven said:

round -20F cylinders are getting to their limit to supply my trailer’s furnaces.

We had to laugh.  One of the reasons we have a RV is never having to see -20 again.

Wayne  and Jinx from Maine

[Darryl&Rita]

12 hours ago, TXiceman said:

Pure propane stops vaporizing at -44.42 deg, at 14.7 psig.

At -20 degF, the heat absorbed by the bottle has to exceed the refrigerating effect of the vaporizing propane. The liquid propane will reach -44-42 degF and stop vaporizing.  You can always put a heat lamp on the tank to raise the temperature.

 

8 hours ago, Ray,IN said:

Exactly!

Not quite. The pressure isn't measured in psig, but psia. 14.7 psig would still be enough pressure for RV appliances to operate. Sadly, they won't operate in those temperatures.

[Kirk W]

What's the Difference Between PSI, PSIA, & PSIG?

[DJohns]

I wonder how many  folks would still be in the camper at -20 to -40?

[Darryl&Rita]

21 minutes ago, DJohns said:

I wonder how many  folks would still be in the camper at -20 to -40?

Done it. Didn't enjoy it. It almost turns into work, just existing. Add a full time job at the same temperatures, makes winter long.

[rpsinc]

I wonder if a cheap furniture blanket around the tanks in the compartment would be helpful.  A lamp also can help as long as it isnt LED.

[TXiceman]

My bad, I know the difference between PSIA and PSIG and mis-typed.  Corrected the original post to read PSIA.

Ken

[bigjim]

Not  fat fingers, brain outrunning fingers.

[Dutch_12078]

Propane cylinder/tank heater blankets are commonly used in the colder parts of the US and Canada:

https://www.amazon.com/Powerblanket-PBL20-Cylinder-Propane-Charcoal/dp/B00PKKHC2Y/

[noteven]

5 hours ago, Jinx & Wayne said:

We had to laugh.  One of the reasons we have a RV is never having to see -20 again.

Wayne  and Jinx from Maine

That’s not funny you guys😆. 
 

Signed,

Snowbird grounded in western Canada. 

[noteven]

I started the thread hoping someone with proper knowledge would contribute which they are. The situation has altered lots of wintering plans for people.

Yes you can blanket and heat cylinders - I’ve done that. That kind of weather also adds needing to fill frequently chores which is a nuisance.

I have a 80gal pig at base camp. It is large enough to supply adequate fuel without cover or heating it. Delivered to my location my supplier charges 1/2 of cylinder fill price. It’s 25miles one way to fill cylinders.

[Star Dreamer]

I can "Freeze up" my 30# tank for my generator in about 6 hours of running at 50 degrees outside temp. A 20# tank does it in about 3 hours. Basically the generator is sucking more gas than the tank can convert from liquid to gas. I may have to try a tank heater next.

[bigjim]

Too bad there is not a way to use the exhaust from the generator to heat the thank.  Safely of course.

[Jinx & Wayne]

On 10/28/2020 at 2:18 PM, noteven said:

Snowbird grounded in western Canada

My sympathies. Is there any way to get a really big pig and delivery?

[noteven]

6 hours ago, Jinx & Wayne said:

My sympathies. Is there any way to get a really big pig and delivery?

Thanks.  My 80gal (320 lbs) lasts quite a while and refills are delivered. 

20 hours ago, bigjim said:

Too bad there is not a way to use the exhaust from the generator to heat the thank.  Safely of course.

You could do that with some aluminum dryer vent pipe.  I've used a small electric heater under a blankie.

Edited October 30 by noteven

[Ray,IN]

On 10/29/2020 at 4:55 PM, Star Dreamer said:

I can "Freeze up" my 30# tank for my generator in about 6 hours of running at 50 degrees outside temp. A 20# tank does it in about 3 hours. Basically the generator is sucking more gas than the tank can convert from liquid to gas. I may have to try a tank heater next.

The small surface area is the problem LP only vaporizes at the surface of the liquid form, which is why larger horizontal tanks are preferred.

[bigjim]

1 hour ago, Ray,IN said:

The small surface area is the problem LP only vaporizes at the surface of the liquid form, which is why larger horizontal tanks are preferre

I am fairly sure propane forklifts us a horizontal cylinder for that reason.

[beemergary]

Smaller the tank the bigger the problem. You want them cold to fill but warm to empty.

 

[rynosback]

On 10/28/2020 at 11:51 AM, Dutch_12078 said:

Propane cylinder/tank heater blankets are commonly used in the colder parts of the US and Canada:

https://www.amazon.com/Powerblanket-PBL20-Cylinder-Propane-Charcoal/dp/B00PKKHC2Y/

$160......... a heating pad and a ace bandage should keep that tank warm. As a fulltime RVer sometimes I have to come up with  creative solutions with what I carry with me.

Edited October 31 by rynosback

[Ray,IN]

2 hours ago, bigjim said:

I am fairly sure propane forklifts us a horizontal cylinder for that reason.

Forktrucks run on liquid propane only. Appliances use vaporized propane, the cylinder/tank valving must be above the liquid level. High output appliance burners consume propane faster than it can vaporize in containers with a small diameter during cold weather.

[Kirk W]

10 hours ago, bigjim said:

I am fairly sure propane forklifts us a horizontal cylinder for that reason.

From propane 101:

Quote

Propane powered forklifts primarily use 33 pound cylinders as their fuel source and are equipped for liquid service. Because the cylinders are designed for liquid service, they have to be placed properly on the lift truck to operate correctly.

 

[Dutch_12078]

11 hours ago, rynosback said:

$160......... a heating pad and a ace bandage should keep that tank warm. As a fulltime RVer sometimes I have to come up with  creative solutions with what I carry with me.

Make sure it's a weatherproof heating pad unless your cylinders are enclosed.