Propane Tank Math Equation - Home Brew Forums

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10-15-2009, 04:29 PM   #1
Lodovico

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I'm still a little new to the whole propane tank brewing and I wanted to make sure I understand this. I'm trying to tell how much I have left in my tank.

Here's the info:

I have an Ameri-Gas Tank that says Net Weight- 15 pounds on front of tank

The Tare Weight on the handle of the tank says 17 pounds

I just weighed the tank and it weighs 26 pounds even.

How much propane do I have left??? Thanks!
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10-15-2009, 04:50 PM   #2
Catt22
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You have 9 lbs remaining in the tank. The Tare Weight is the empty weight of the container. The net weight is the weight of the contents. In this case your supplier is saying that 15 lbs is what the contents should be for a full tank. Normally, the 20 lb propane tanks hold 20 lbs of propane when full. The exhange places have been playing a shell game lately and only fill the tanks 3/4 full, or 15 lbs. This is a scam IMO. The suppliers claim they are doing this so that they don't have to raise the price. Duh? So, we get screwed out of 25% of the fuel and are required to fill the tanks more frequently. I guess they figure our time and effort are worth nothing to us.

The calculation is simply to subtract the tare weight from the total weight to arrive at the remaining gas weight. ie 26-17=9

It would weigh 32 lbs when filled with 15 lbs and 37 lbs if filled with the max 20 lbs.

To avoid this, take your empty tank to a refill station if you have one near where you live and they will normally give you a true fill of 20 lbs. You may also discover that the price will be lower than the exchange price. I get 20 lb fills for roughly \$20 currently. I am surprised and disappointed that the state bureau of weights and measures has not come down hard on the tank exchange people, but they have found a loop hole by putting up a sign saying that the net weight is 15 lbs for their tanks. It's still pretty slimy IMO and I refuse to give them my business. The average idiot on the street is usually too stupid to realize they are getting screwed and it's pretty obvious some in the government are getting kick backs somehow. You can bet on it.

10-15-2009, 04:54 PM   #3
SOB

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Wow, Catt...I never paid attention to the whole 15lbs vs 20lbs filling. I have noticed recently that my tanks dont last as long. I've also wondered why someone would go through the pain of taking a tank to get filled when it is the same price to exchange it and less hassle. Make sense...unfortunately there are no spots that fill tanks around here.

Good info...
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10-15-2009, 04:59 PM   #4
wildwest450
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And if you use blue rhino you are getting raped. I fill my own tanks, have been for years, and those blue rhino tanks do not hold #20lbs.

10-15-2009, 05:01 PM   #5
Lodovico

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Thanks Catt. Good information here.

So I should have plenty left to do at least 2 more 60 minute boils if I heat the mash and sparge water on my stove, right??
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10-15-2009, 05:10 PM   #6
Schnitzengiggle

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Does anyone know how many gallons of LP make ~20#, I have my tanks filled for the same reason, it is about \$30 after tax with an exchange here, and it costs me about 15 bucks or so to have my tank filled, normally I don't allow them to run dry, but when I have them filled they will take about 4 gallons give or take. Does 4 gallons equal ~20# of LP?
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10-15-2009, 05:14 PM   #7
Catt22
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Quote:
 Originally Posted by HarryHood1 Thanks Catt. Good information here. So I should have plenty left to do at least 2 more 60 minute boils if I heat the mash and sparge water on my stove, right??
Yes, but it might be close. A lot depends on your burner design and how you use it. It's possible to waste a lot of propane by turning the burner up higher than necessary. Some burners are more efficient than others. I have multiple propane tanks so always have a backup on hand. The damn things seem to accumulate. Someone's always giving me one and I occasionally find one discarded at the curb or buy them for a few bucks at garage sales. I think I have seven at the moment and I didn't buy any of them at retail price. I make a run with four at a time when I get them filled.

It's a real drag to run out of gas in the middle of a brew session. You should do some more looking for a bulk propane supplier. I'm almost sure there is one somewhere in your area.

10-15-2009, 05:21 PM   #8
Catt22
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Quote:
 Originally Posted by Schnitzengiggle Does anyone know how many gallons of LP make ~20#, I have my tanks filled for the same reason, it is about \$30 after tax with an exchange here, and it costs me about 15 bucks or so to have my tank filled, normally I don't allow them to run dry, but when I have them filled they will take about 4 gallons give or take. Does 4 gallons equal ~20# of LP?
The specific gravity of propane is about .495 which equates to roughly 4 lbs per gallon. It will vary some depending on the temperature, but that should be close enough for our purpose. So, your four gallons would be about 16 lbs. which indicates you still had about four lbs in the tank when you had it filled. The fill stations usually weigh the tanks when filling them in order to avoid overfilling. This is the other advantage of getting refills. Normally, the fill stations only charge you for what they put in the tank. The exchange places don't allow credit for any gas remaining in the exchanged tank. This is a PIA for some as you must run your tank completely dry before you exchange it or you get additionally screwed.

10-15-2009, 05:29 PM   #9
Catt22
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Quote:
 Originally Posted by SOB Wow, Catt...I never paid attention to the whole 15lbs vs 20lbs filling. I have noticed recently that my tanks dont last as long. I've also wondered why someone would go through the pain of taking a tank to get filled when it is the same price to exchange it and less hassle. Make sense...unfortunately there are no spots that fill tanks around here. Good info...

I just used the googles for "Propane Delaware Ohio" and came up with quite a few propane suppliers in your area. Here's one:

Delaware Rental Center
1050 Bowtown Rd, Delaware, OH
(740) 369-9661

and another:

Alum Creek RV & Marine
5742 State Route 37 E
Delaware, OH 43015
740-363-4068

There are some others also.

10-15-2009, 05:39 PM   #10
Lodovico

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So I just called a propane place in town and they refill tanks for \$1 per pound.

Is this a decent price for propane refills??
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Lodovico Brewing Co.

On Draft: Mild
On Draft: IPA
On Draft: Belgian Pale Ale
In Bottle: Brett Porter
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Fermentor: Belgian Amber Ale