OK I am officially confused.I took one of my 40lb. propane cylinders out of my new RV to have it filled. A note on the door of the propane compartment said do not fill over 80%, could cause fire,explosion etc.I told the guy that was filing the bottle to fill to 80%, he didn't know what I was talking about and since I didn't know what I was talking about we filled it to 65 total lbs where his info showed it full at 75 lbs.Anyhow since this is a safety issue can anyone help me out. since this is a 10 gallon tank am I only supposed to put 8 gallons in it?I have always taken them to the guy, he puts it non a scale and fills it to the total weight on his chart. Is this 80% or is it over filled?For those of you that want me to do a search, I did and got 503 pages and although I am retired I don't have enough time to read all of the info.

80% is the normal fill quota. Mine are by volume, and I know little about weight.As for searching, your comment reminds me of a gal who won't use google because she can't read 1,108,455 responses.

Modern propane tanks are considered full at 80%, to allow expansion room. They fill with liquid propane, which turns into a gas that will flow to your burners and such. Modern tanks have a internal shut-off to prevent over filling. On non-portable tanks, an overflow vent valve is opened, and then the tank is filled until liquid propane comes out or the valve shuts off, at 80% full.

I have been told, so I can not state with authority, that each gallon of liquid will result in about 65 gallons of gas. Anyone else know the exact value??

Tank has an OPD valve to prevent over fill. Tank is already designed to stop at 80%. No need to short fill to 80% of 80%.100% filled to capacity (40 lbs.) is 80%.

Depending on the age of the tank there are two over fill indicators that go off at 80%Modern tanks have a float type valve. at 80% it closes and filling ceases. HARD.Older and modern tanks have a "Visual Overfill indicator Valve" Yes that is the name of the valve.Many people, will tell you you need to open this valve to let the air out of the tank becaus you can not compress air... I have no idea where thy went to school but...Well.. I will forgoe some serious insults (1 Air is easily compressed.. I mean what is filling your tires and 2: No air IN the tank aftr the first (PROPER) filling,,,only propane liquid and gas and some contaminats).When that valve starts spitting liquid (Comes out as a white cloud,like 40 degrees below white cloud)the tank is 80% full.

Propane fill question | Good Sam Community

SaltiDawg
Explorer
Mar 27, 2015
RinconVTR wrote:
...
Holy cow...no!

Use this chart to compare fuels.

He didn't say gasoline he said gas. I think he trying to equate a gallon of liquid propane to a number of gallons of gaseous propane.

By using the gallon as the unit of volume measure of a gas, I don't think the conversion he is proposing has any useful value. Volumes of gasses require a stated temperature and pressure.

PS It is my experience that a full 20# propane bottle will produce the same amount of work as 4-5 gallons of gasoline.
RinconVTR
Explorer
Mar 27, 2015
12th Man Fan wrote:
OK I am officially confused.

I took one of my 40lb. propane cylinders out of my new RV to have it filled. A note on the door of the propane compartment said do not fill over 80%, could cause fire,explosion etc.

I told the guy that was filing the bottle to fill to 80%, he didn't know what I was talking about and since I didn't know what I was talking about we filled it to 65 total lbs where his info showed it full at 75 lbs.

Anyhow since this is a safety issue can anyone help me out. since this is a 10 gallon tank am I only supposed to put 8 gallons in it?

I have always taken them to the guy, he puts it non a scale and fills it to the total weight on his chart. Is this 80% or is it over filled?

For those of you that want me to do a search, I did and got 503 pages and although I am retired I don't have enough time to read all of the info.

This is the information you are looking for, and I'd like to confirm the 80% fill is indeed a full LP tank.

http://www.missiongas.com/lpgascylinders.htm
RinconVTR
Explorer
Mar 27, 2015
Johno02 wrote:
I have been told, so I can not state with authority, that each gallon of liquid will result in about 65 gallons of gas. Anyone else know the exact value??

Holy cow...no!

Use this chart to compare fuels.

http://www.afdc.energy.gov/fuels/fuel_comparison_chart.pdf

http://www.afdc.energy.gov/fuels/fuel_comparison_chart.pdf
wa8yxm
Explorer III
Mar 26, 2015
Depending on the age of the tank there are two over fill indicators that go off at 80%

Modern tanks have a float type valve. at 80% it closes and filling ceases. HARD.

Older and modern tanks have a "Visual Overfill indicator Valve" Yes that is the name of the valve.

Many people, will tell you you need to open this valve to let the air out of the tank becaus you can not compress air... I have no idea where thy went to school but...Well.. I will forgoe some serious insults
(1 Air is easily compressed.. I mean what is filling your tires and 2: No air IN the tank aftr the first (PROPER) filling,,,only propane liquid and gas and some contaminats).

When that valve starts spitting liquid (Comes out as a white cloud,like 40 degrees below white cloud)the tank is 80% full.
time2roll
Nomad
Mar 26, 2015
Tank has an OPD valve to prevent over fill. Tank is already designed to stop at 80%. No need to short fill to 80% of 80%.

100% filled to capacity (40 lbs.) is 80%.
Johno02
Explorer
Mar 26, 2015
I have been told, so I can not state with authority, that each gallon of liquid will result in about 65 gallons of gas. Anyone else know the exact value??
Johno02
Explorer
Mar 26, 2015
Modern propane tanks are considered full at 80%, to allow expansion room. They fill with liquid propane, which turns into a gas that will flow to your burners and such. Modern tanks have a internal shut-off to prevent over filling. On non-portable tanks, an overflow vent valve is opened, and then the tank is filled until liquid propane comes out or the valve shuts off, at 80% full.
2oldman
Explorer II
Mar 26, 2015
80% is the normal fill quota. Mine are by volume, and I know little about weight.

As for searching, your comment reminds me of a gal who won't use google because she can't read 1,108,455 responses.

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