Propane Weight per Gallon

[Buford445]

The Question always comes up and everyone says " I think it's"
So I figured it out (With Google's Help )

The density of propane at 25 degrees C is .493 grams per cubic centimeter. Converting gives 4.11 pounds per gallon.

SOOoooo

20# tank = 4.87 gal
30# tank = 7.3   gal
40#   tank = 9.73 gal
100# tank = 24.33 gal

[georgeshannon]

Now that's useful information. Thanks for doing the conversion Buford.

[Jims1dodge]

ok, so the 250 gallon tank in the backyard weighs 

Thanks for the conversions.

[Kilch123]

Thanks!

Now I know how much I'll be spending in the next few days (100# and a 30# are empty) 

Price was $2.50/gallon last year, it's $3.50/gal this year! 

[kenz]

That would be 5.84 gallons for a 30# tank..... Can only fill to 80%.    Cool info though.    Also a good thing to remember is that as the temp gets colder, the pressure goes down, vaper goes down. Thus you need to burn more to get the same btu's as when it was warmer. Don't understand the whole deal, but an old timer told me this. And to check it out while camping in the fall/early winter a 100# tank will last almost twice as long as the comparable amount in 30# tanks.

[Kilch123]

When I get my 30# tank filled, I regularly get at least 7 gallons (usually like 7.1 or 7.2)

the guy filling opens the bleed screw to allow the vapors to vent off, and closes when liquid comes out

[noplugs]

That would be 5.84 gallons for a 30# tank..... Can only fill to 80%.    Cool info though.    Also a good thing to remember is that as the temp gets colder, the pressure goes down, vaper goes down. Thus you need to burn more to get the same btu's as when it was warmer. Don't understand the whole deal, but an old timer told me this. And to check it out while camping in the fall/early winter a 100# tank will last almost twice as long as the comparable amount in 30# tanks.

Actually, you dont need to burn more, as 1 gallon of propane has the same number of BTU's whether its 100 degrees or 0 degrees. What does happen though is the vapor pressure is lower at colder temperatures and you end up having a smaller flame so you have to run the heater longer to get the room up to temp. You would use more electricity as the heater is running longer.