Propane Tank Questions

jrhamel

Has anyone tried to Mopeka Blue Tooth tank gauges?

https://mopeka.com/

jkjenn

jrhamel said:

Has anyone tried to Mopeka Blue Tooth tank gauges?

https://mopeka.com/

Yeah, I didn't find it very effective. You have to put the tank on these rubber feet they got lost pretty quickly.

grubbster

jrhamel said:

Has anyone tried to Mopeka Blue Tooth tank gauges?

https://mopeka.com/

I have one and like it.  As jkjenn references, you have to raise the tank to put it on the bottom.  I didn't use rubber feet but put together some plastic blocks to raise the tank enough.  The gauge itself works well and tells you the % gas left.

Cbusguy

@Mrlaroo. The trailer is amazing frugal with propane use, even using the fridge on propane.   We have used nearly a tank in about a year.  

Arizonayeti

@tybladesmith  Yes, I have the Truma LevelCheck and really like it.  It's compact, lightweight, gives reproducible results, and very easy to use.  After using it the past year, it can give you a clear gauge on how much propane is left. It's small enough to check the side of the tank while it is in the storage tub. Since I have lots of other stuff crammed into the bin, and I have the tank secured with the retaining bracket, I didn't think a weight-based monitor was the best option.  It appears the Truma website is running a discount and would be cheaper than Amazon, but not sure about shipping.  Cheers!

Dutch061

There are 4.26 pounds of propane per gallon. So a 20 pound tank has approximately 4.6 gallons of propane in it. The Blue Rhino exchange tanks are 15 pounds, 25% less per tank, I also carry a spare 20 pound tank. I use the spare for the grill and camp stove both rather than cooking inside.

The issue with a 30 pound tank will be height, they are approximately 50% taller because they are the same diameter.

The best method is to weigh it, there is a "Tare Weight" stamped on all tanks. Empty tank weight for a 20 pound tank is approximately 17 pounds.

Brad

MuttonChops

Dutch061 said:

There are 4.26 pounds of propane per gallon.

So a 20 pound tank has approximately 4.6 gallons of propane in it.

The Blue Rhino exchange tanks are 15 pounds, 25% less per tank,

Believe DOT rules set the maximum fill at around 80% of rated capacity so fuel can expand on hot days. Even if you have a propane dealer fill your tank; a 20# tank will have ~ 16# of usable fuel when it is sold/called full.

falcon1970

That 80% rule is why the big box stores only fill to 16 pounds.  However, they misunderstand the rule.  A 20 pound tank is rated to fill to 20 pounds--and that is 80% of the tank capacity.  A propane dealer will fill your tank to 20 pounds.

ScottG

My convenient local hardware store typically puts 4.0 gallons in an empty tank. When I weight my tanks (before and after filling) this translates into 17.5 to 19+ pounds--and it's not clear why it is not always consistent.

In the past, they have sometimes filled based on the final weight of the cylinder--not a real good approach since cylinder tare weights can vary by a couple pounds. When they would do this I would end up with as little as 15 pounds in my "fill." I pay by the gallon so I wasn't getting cheated from a $$$ perspective, but it was aggravating to start out with 3/4s of tank.

Bottom line is I think it depends on the place and the attendant. The only way you can know exactly what you are getting is to weigh the tank yourself before and after, and factor in the tare weight as well if the tank is not completely empty.

falcon1970

@ScottG
Zackly right!  I fill at a propane dealer (one that fills propane tanks for people out in the county who do not have a gas line to the house) not a store that also fills propane bottles.  A propane dealer knows the rules about filling as well as recertifying those 20 pound bottles.  Unless your tank is rusted and dented it should only require a visual inspection and that should cost less than $5.00.  If your tank is in bad shape it may require a water column test and then it would probably be cheaper to buy a new tank.  They also fill the tank on a scale so they know when 20 pounds is in the tank and only charge for the propane they add--not a flat fee for the filling operation regardless of how much propane they added.
Propane dealers may be hard to find in the middle of a large (or even medium sized) city.  Look around on the outskirts of town.  They are easier to find in small towns.

Dutch061

MuttonChops said:

Dutch061 said:

There are 4.26 pounds of propane per gallon.

So a 20 pound tank has approximately 4.6 gallons of propane in it.

The Blue Rhino exchange tanks are 15 pounds, 25% less per tank,

Believe DOT rules set the maximum fill at around 80% of rated capacity so fuel can expand on hot days. Even if you have a propane dealer fill your tank; a 20# tank will have ~ 16# of usable fuel when it is sold/called full.

Respectfully, you are not correct in your information. ALL modern Tanks (Under 40 Lb Capacity) are equipped with Overfill Protection Devices (Triangular Knob) to prevent you from going past the 80% liquid fill point and potentially causing problems. When the tank is full, there is a float that closes the valve and stops additional propane from being added. A 20 pound tank will hold 20 pounds of liquid propane.

I doubt anyone has an older tank (Pre-OPD) that is being filled anymore. I had a couple but it has been years ago, like at least 10 at this point.

Here is a link with some pictures and additional information for reference.

https://www.comparepropane.com/20-lb-propane-tank-bbq-guide-facts/

N7SHG_Ham

You can't legally get a non OPD tank filled, so everyone who gets a tank filled should be getting close to 20 pounds of propane or around 4.7 gallons. They hold this amount and still have a 20% safety margin for expansion.

Blue Rhino fills their tanks to 15 pounds, so about 1.1 gallons less than full. You only get a 3/4 full tank with Blue Rhino and I suspect most other exchange services.

At the local Lowe's right now the exchange Blue Rhino tanks with 15 pounds are $19.97 which works out to be about $5.59/gal.

I can get my tank filled locally several places with 10 minutes of the house and I just saw $1.59/gallon today, so savings of $4 a gallon filling my tank.

A tank exchange is convenient if you have no other close by option, but certainly isn't the most economical.

Bayliss

Here's the math, if anyone is interested.

A gallon of propane weighs 4.24 lbs. (at the industry standard of 60° F.)

Thus, 20 lbs. ÷ 4.24 = 4.7 gal.

The below site explains the relationship between propane temperature and volume.  It is interesting reading and helpful in understanding why a propane tank is designed to leave room for expansion caused by temperature changes.

https://www.propane101.com/propanevolumecorrection.htm

I found the site while trying to figure out why I kept seeing slightly different values for the weight of a gallon of propane.  I have seen it discussed as 4.2, 4.22, 4.23, 4.24 and 4.25.  I assume those slight differences are based upon the temperature being used as a reference point. 

NOTE:  I found an identical copy of the info provided on that web post on a Texas propane company's website (dated two years earlier), so I do not know the original source of the information.

elbereth

In addition to cost, the other downside of a propane exchange is that their bottles are often pretty beaten up - made the mistake of exchanging our nice new bottle that came with our T@B, and so now have one where it is obvious the rust is covered up by light grey paint.  Hoping for a better exchange next time, and then will just refill the nice bottle at our local UHaul.

ScottG

@elbereth, U-Haul sells a reasonably priced 20lb tank with an integrated float gauge. If you are going there anyway, you might just cut your losses and pick up one of those.

Marceline

ScottG said:

@elbereth, U-Haul sells a reasonably priced 20lb tank with an integrated float gauge. If you are going there anyway, you might just cut your losses and pick up one of those.

Costco also usually has them in the summer.