Are the propane exchanges underfilling their tanks?

[willingtorelocate]

Just figured out that you can actually go to local hardware stores and get tanks refilled, rather than going to Wamart or home depot, or whichever to do a propane exchange. I've got three propane tanks right now. Two for cooking, and one for heat. Was actually pretty proud of myself for figuring this out, and I got what I thought was a great deal on the refill, at least as compared to the other places I've been doing to swap my tanks out. 

Then I put the cans in my truck, and I noticed something. They're ALL a lot heavier than they've ever been before. Nearly twice as heavy as they usually are when you do a propane swap. Really took some effort to get them to the car. 

Am I crazy?
Or have I been getting handed half full tanks all along?

 

[jimindenver]

A propane exchange such as Blue Rhino puts only 15pounds in a tank that could hold 20 pounds. It is usually much less expensive to get them completely full by having it refilled yourself.

 

[willingtorelocate]

I'm seeing that.
This place also had taller tanks that might be worth investing in. The fewer propane runs I need to do in the dead of winter, the happier I'll be.

 

[rectalogic]

“In 2008, to help control these rising costs, Blue Rhino followed the example of other consumer products companies with a product content change. We reduced the amount of propane in our tanks from 17 pounds to 15 pounds.”
https://bluerhino.com/propane-info/faqs/buying-blue-rhino-tanks-faqs

 

[tx2sturgis]

If you have the tolerance for a bit more weight, the 30 pounders are only a little bit taller but hold (in theory) 50% more fuel.

Thirty pounders weigh around 65 pounds when full.

 

[wayne49]

Exchange around Pahrump priced at 21.95-22.95 plus tax.

20 pounds is 4.85 gallons.

4.85 gallons at 3.50/gal (most common rate in Pahrump area) would be $16.98+tax.

Exchange rate/gallon is 21.95/4.85 = $4.53/gallon.

A tank is not really empty when the usable flow stops.

Exchange makes sense for out of date tanks that require re-certification.

 

[wayne49]

And with underfilled exchange tanks the cost difference is worse.

 

[broken ed]

WOW :exclamation:

 

[ZoNiE]

Heh,
Having propane tanks refilled is the "normal" way. The exchange is the "new" way.

They under fill them. That is how they cover the cost of the transportation and refurb of the tanks. The only good thing about tank exchange is when your tank comes up for expiration, you can swap it for a new one and get some gas with it.

 

[Weight]

There is the safety issue with exchange services hauling, handling, storing, all by clerks with limited experience. 15 pounds of gas is less likely to pressure release in the Walmart parking lot. I exchange until I get a good tank, then refill that. The advantage of a 20 pound tank is it can be exchanged at so many places that stay open late or all night. Refill services are harder to find. But I did find many gasoline stations have refill services in areas with limited NG available for home owners.

 

[Weight]

If the sign says 15 pounds for $17.95, they are not under filling if they give you 15 pounds.

 

[Seminole Wind]

A tank is not really empty when the usable flow stops.

while that is technically true, it just means there is a small amount of vapor left to fill the "space" other wise you would have to suck a vacuum on it. the stated weight of propane is for when it is in liquid form and at a specific temp. in most reasonable temps once all the liquid has been converted to vapor. their is still enough pressure to run your appliace a bit. when the pressure drops below what is needed to run the appliance then the flame goes out. with that tiny bit of vapor in there you wont be able to measure any weight of the remaining propane on any scale normally used to measure propane. you can consider it empty for all practical purposes

as far as someones comment about 15# being safer than 20# that is just lack of knowledge or straight up propaganda being spread by stores and dealers. these tanks, all propane tanks are spec'd out with an air space to allow room in the tank for the liquid to expand if it warms up

as long as a tank has some liquid remaining in it. the pressure will be determined by the temp of the propane. the hotter the temp of the propane the higher the pressure. so if you put a bottle in the sun up against a dark colored wall in phoenix in july it does not matter if there is 1# or 20# the pressure will be the same. of course the one with 20# will take a little more time to reach that internal temp as there is more thermal mass to heat up. there is no realistic safety benifit to under filling a propane bottle.

now, over filling the bottle beyond the design capacity can lead to catastrophic failure of the tank due to rupture. then you have problem

 

[broken ed]

This  reminds me of back in the 1970's when companies would partially fill aerosol cans. It could deoderant, hair spray, what ever. But a small can could weigh more then a can twice the size. The correct ounces where labeled on the can, but people looked at the size.

It might be legal but it's deceptive plain and simple.

This guy wrote a pretty good article on the whole thing. http://www.elivermore.com/propane.htm

Including: "I do not know if these still exist.  I have not seem them locally, and most online discussions on them seem pretty old.

Blue Rhino apparently has their own proprietary “TS2” valve. The purpose of this is to prevent you from refilling one of those cylinders at your local propane refiller. The tank can only be refilled by them due to some sort of magnetic interlock, for which they have the key."

 

[Weight]

The propane dealer in my area has a magnetic key they made. They refill any bottle I bring them. When I have a bottle with 20 pounds sitting in the sun, it vents more often than when it has 15 pounds. My observation, I haven't done any research or math. So I could be wrong. Do whatever you want to leave the gene pool.

 

[Seminole Wind]

i believe the blue rhino proprietary key has been legally prohibited. when they were doing it so places would try and defeat the valve by tipping or inverting the tank to fill it and was unsafe. back when i delivered propane for a living 10-15 years back i was told by our company reps there had been several lawsuits regarding the fact the bottle was owned and it being improper to force someone to restrict who they buy from. can you imagine if when you bought a ford you could only buy fuel from ford? same deal...

 

[Weight]

A little bit, sort of like Tesla.