I still don't understand my propane situation. Any help appreciated.I have a "76 lb tank" which I take to be "full" at 80% or 61 lbs. I am used to having two "30 lb" bottles, but when they get filled I am charged for typically 30 lbs, and they are only filled to 80% as well?So it seems my "76 lb tank" is about the same as two 30s in real life?As an example my first time to refill the tank it was showing about half full, and they put in 26 litres to fill it. I got charged by the litre for the tank instead of by the pound as with cylinders.My Manchester hand- out says 4.24 lbs/gal (US gal no doubt) and that would be about 3.8 litres/gallon? so a 30 lb cylinder would be about 27 litres which is about what they put in my "76 lb" tank at about half full, so I am thinking all I have here is a sideways two 30 lbers same as I had in the 5er.Is that about right? Or how do you figure propane amounts?I also don't understand the "liquid propane" deal, where I had to go to a sort of gas pump that did propane to fill the tank instead of to the usual cylinder fill place. Don't cylinders get "liquid propane" too? But they charge by the pound to fill a cylinder, but by the litre to fill the tank.

The campground near my house in Virginia fills cylinders by the gallon.BFL13 wrote:I still don't understand my propane situation. Any help appreciated.I have a "76 lb tank" which I take to be "full" at 80% or 61 lbs. I am used to having two "30 lb" bottles, but when they get filled I am charged for typically 30 lbs, and they are only filled to 80% as well?So it seems my "76 lb tank" is about the same as two 30s in real life?As an example my first time to refill the tank it was showing about half full, and they put in 26 litres to fill it. I got charged by the litre for the tank instead of by the pound as with cylinders.My Manchester hand- out says 4.24 lbs/gal (US gal no doubt) and that would be about 3.8 litres/gallon? so a 30 lb cylinder would be about 27 litres which is about what they put in my "76 lb" tank at about half full, so I am thinking all I have here is a sideways two 30 lbers same as I had in the 5er.Is that about right? Or how do you figure propane amounts?I also don't understand the "liquid propane" deal, where I had to go to a sort of gas pump that did propane to fill the tank instead of to the usual cylinder fill place. Don't cylinders get "liquid propane" too? But they charge by the pound to fill a cylinder, but by the litre to fill the tank.

Yes, I gather there are two sets of rules in the States for that so they can do either lbs or gallons. When they fill an empty "30 lb" cylinder by the gallon, do they put in 7.2 gallons as the 80% "full" ? (Manchester says 7.2 gal per 30 lb cylinder)My 76 lb tank should be 17.9 gallons at 4.24 per. Does that seem right?

Our brochure for our Class C states a Propane Capacity of 17.5 USG or 66 Liters. Liquid Propane density is about 493 kG / 1000 Liters.66 Liters would be 32.54 kG or 71.6 Pounds.

around here they charge by liquid volume for filling everything, bottles or frame mounted tanks, i haven't pay by the pound in at least 20yrs, even when travelingframe tanks and bottle have different fittingsmaybe there is a regulation regarding who fills what up there in BC ?yes, even bottles get liquid LP 'pumped' from the 'tank' at the place of fill upis your tank marked in pounds, or in water volume gallons, my tank is is 24.0 gallon appox 100#, my last fill up Sunday the 10thwas 21 gallon, i was not dead empty, the fridge was still going up till the moment i turned if off and shut off the tank

I have not seen a size of the tank on it, but can look next time it stops raining! The MH brochure says it has a 76 lb tank. If they use different temperatures as the "standard" for tank size, I suppose that would explain minor differences in "sizes"I somehow thought I now had a huge amount of propane compared with before at two 30s. Maybe not? Same as?Actually, I only think he said it was 26 litres. After he filled the tank he looked at at the pump numbers, then went to a little terminal beside that and tapped in a bunch of numbers, and then that spit out a slip of paper, which I took in and the cashier did something or other, and it came out as $26 on my Visa. Propane is about a dollar a pound but it is also approx. a pound per litre so I don't know. I was not paying enough attention obviously. Next time for sure!

Propane Amount Question | Good Sam Community

BFL13
Explorer II
Dec 19, 2017
It starts with the 80% rule, where you must know "80% of what?"

So your tank size is one thing and your full amount of LP is another thing. Then some people call the tank size by the full amount "size"

I will think of mine as a "70 litre" tank if that is what it holds when "full" and they charge by the litre.

I got into this mess by trying to relate what my tank holds to what my 30lb bottles held. How naive! :(
time2roll
Nomad
Dec 19, 2017
BFL13 wrote:
I agree it is all too silly. Another case where the people who invent these things have never gone RVing.
Or maybe they have customers that would otherwise run out and find it is better to have a reserve.

Same with the fuel gauge. Vehicle does not stop at E but actually continues 10 to 40 more miles.

When the tank is on E by all means fill it up. If you have a long distance and feel more comfortable filling at half that is fine too.
MrWizard
Moderator
Dec 19, 2017
Full is full, and the volume posted on the tank, is the correct volume
Mechanical gauges on tanks do sometimes get out of calibration

Run until you run out, get it filled, make a note of the amount

Use it until the guage reads empty
Refill and make a note, that difference is your reserve
What you still have when the guage reads empty
A few fill ups, and a few trips, and you will know your use pattern

"Trends and tendencies"
BFL13
Explorer II
Dec 19, 2017
I tend to think now that 1/2 on the tank gauge is more like 2/3 of what LP the tank holds when "full" At that time, the range hood monitor was showing three lights out of four. (Shows four lights indicating full when the tank is full showing 3/4)

Somebody mentioned the confusion of "thirds" vs "quarters" between these two gauges in another thread. Anyway, it seems that the range hood monitor is a little "over" what is really there, while the tank gauge indicates less than what is there, so somewhere between should be close.

I agree it is all too silly. Another case where the people who invent these things have never gone RVing.
Jayco-noslide
Explorer
Dec 19, 2017
I think when the gauge says its half full, then its half full. But when you have it "filled" the gauge will only say around 80% full because that's all they are allowed to put in. So full isn't really "full" 100% but the gauge is accurate and says 80%. Could that be any more confusing.
MEXICOWANDERER
Explorer
Dec 18, 2017
https://www.youtube.com/watch?v=Sj4hqYFNRqY
BFL13
Explorer II
Dec 18, 2017
MrWizard wrote:
1995 34ft Safari 26 gal

1997 36ft Bounder 24 gal, 24*4.24=101.76, aka round off 100#

Yes, but "full" is 80 lbs. I have also seen 4.14 as the conversion factor. Marshall hand-out says 4.24. Apparently nobody is in charge! :)
ktmrfs
Explorer II
Dec 18, 2017
Dutch_12078 wrote:
ktmrfs wrote:
BFL

if your talking about a MH mounted tank, what happens if you fill it when you are slightly off level? I don't know how these tanks are constructed with the spit valve etc. but if how do they accomidate (or lack theroff) if your filled off level? that might account for the difference.

The dip tube for the fixed liquid level gauge "spit" valve is located at the center of the tank. Being off level has virtually no effect on the amount it takes to fill the tank.

that makes sense. seems like it would be designed from a safety standpoint to not rely on it being level when filling.
MrWizard
Moderator
Dec 18, 2017
1995 34ft Safari 26 gal

1997 36ft Bounder 24 gal, 24*4.24=101.76, aka round off 100#
BFL13
Explorer II
Dec 18, 2017
Gas station lots are fairly level, as where this one was. Another factor is at colder temps the tank holds more LP. It was around 40F at the time.

Have to get used to this way of doing propane. I liked the two bottles, where you knew when the first one went empty, about how long you had before the last one went. (Not quite as long as the first one of course)

I will have to learn when I should get a fill so I don't run out at an awkward time. That's why I have been trying to figure out how all this works. They don't make it easy---1/2 does not mean half etc? Who needs that? I think I have it sort of figured out now thanks to the help here.

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