Refilling 1lb Propane Bottles - Advise

[LandCruiserPhil]

Does anyone refill the small 1lb(16.4oz) bottles using a larger 20lb tank?
Several places sell the Propane Bottle Refill Kit and wonder if anyone was refilling and was looking for some feedback.The kit would pay for itself after about 10 refills. I have a 20lb on the trailer but I also have a few things the run more conveniently on the 1lb bottles so I would have no need to carry extra 1lb bottles. Thoughts...

 

[SoCal_80]

I refill. I bought the adapter from Harbor Freight and it works as advertised.

 

[Stumpalump]

I heard you have to put them on ice to get a good fill. Even then getting them just over half full is as good as it gets. Not that thats a deal breaker but thought you should know so you don't run out of gas faster than expected.

 

[DrMoab]

Guys...just a word of warning. Be very very very careful doing this. I have worked in the propane industry for awhile now and knowing the properties of that gas I can tell you that if you don't know what you are doing you can have a small but very deadly bomb on your hands.

You can not fill any propane vessel more than 85%. Propane expands at a very large rate and if you get one too full the tank can rupture.

If you are going to do this, go get a small scale and weigh a full 1Lb bottle that you bought from the store and whatever you do, don't fill one past that weight. If you do, you are playing with fire....literally.

 

[Rando]

I refill, and it works well. I use a standard blue rhino exchange tank. The key is to put the green bottle in the freezer for half an hour to lower the vapor pressure. The higher vapor pressure in the 20lb tank forces liquid into the smaller tank. If you repeat the process twice (ie freeze the bottle and fill it again) you can easily get the 1lb tank full if not overfull (careful - you don't want to overfill). I definitely inspect the tanks before filling and use a little spit of soap to ensure they aren't leaking after refilling.

Edited to add: You can use tanks with an OPD as long as they are at least half full. The OPD is a float on the liquid propane that shuts off when it gets to a certain height. If the tank is mostly empty, and you invert it, the OPD float will fall down to the shutoff height and it won't work. However if you have enough liquid propane the float will float 'down' relative to normal operation and keep the OPD valve open.

 

[Herbie]

Not sure about propane (and I'm not sure I'd be experimenting), but with CO2 when you do a fill, you're supposed to use a siphon tank as the source, so that you're putting LIQUID CO2 into the filled tank. Technically its gas-over-liquid, as putting say 8 ounces of CO2 (by weight) into an "8 ounce" bottle doesn't fill the volume of the bottle, it leaves room for the vapor.

And yes, you do this with the filled tank on a scale so that you can be sure to only fill the appropriate amount. The "propane refill" kits I've seen always mount the bottle directly to the filling tank. How do you weigh the bottle? (You don't? Oh, that sounds dangerous)

You could simulate a siphon arrangement by tipping the fill tank on its side, but its still a little tricky and I wouldn't be experimenting. If I were to do it, I'd definitely include a hose to that the filled bottle could be hung from a scale to ensure you didn't overfil.

 

[DrMoab]

You could simulate a siphon arrangement by tipping the fill tank on its side, but its still a little tricky and I wouldn't be experimenting. If I were to do it, I'd definitely include a hose to that the filled bottle could be hung from a scale to ensure you didn't overfil.

The one I have seen used has a hose coming off the big tank and the little bottle stands alone.

 

[ntsqd]

I heard you have to put them on ice to get a good fill. Even then getting them just over half full is as good as it gets. Not that thats a deal breaker but thought you should know so you don't run out of gas faster than expected.

A friend used to refill his small tanks and the freezer was his choice. Freeze the tanks overnight before filling them. I would think that you would want to fill with the supply tank inverted to get liquid instead of gas, but not having done it I don't know what the hazards might be. The 85% fill rule is a very important one.

Technically most of these tanks are considered one-time use tanks. Those intended to be refilled are painted white. Been a while since I've seen any for sale anywhere.

 

[SoCal_80]

whatever you do, don't smoke (no fumar)

Now you tell me..... :ylsmoke::costumed-smiley-007

 

[LandCruiserPhil]

Guys...just a word of warning. Be very very very careful doing this. I have worked in the propane industry for awhile now and knowing the properties of that gas I can tell you that if you don't know what you are doing you can have a small but very deadly bomb on your hands.

You can not fill any propane vessel more than 85%. Propane expands at a very large rate and if you get one too full the tank can rupture.

If you are going to do this, go get a small scale and weigh a full 1Lb bottle that you bought from the store and whatever you do, don't fill one past that weight. If you do, you are playing with fire....literally.

Thanks for your sharing your knowledge.

The safety factor is not to overfill by using a scale. With the bottle hooked to the tank weighting the bottle sounds difficult? Would it make the refilling safer it you used a hose between the tank and the bottle on a scale? If that works where would you find a hose for between the tanks and does it matter on what side the adapter is connected when a hose is used?

 

[ntsqd]

Propane hose has a PTFE liner because it will work it's way through normal hose, like typical automotive fuel hose.

My local real hardware store (remember those?) carries all of the various adapter fittings to go into and out of NPT. Were it me I'd go big tank fitting to NPT adapter, into teflon lined braided SS hose w/ NPT hose ends, to NPT x small tank adapter.

 

[DrMoab]

Thanks for your sharing your knowledge.

The safety factor is not to overfill by using a scale. With the bottle hooked to the tank weighting the bottle sounds difficult? Would it make the refilling safer it you used a hose between the tank and the bottle on a scale? If that works where would you find a hose for between the tanks and does it matter on what side the adapter is connected when a hose is used?

Propane shops like Amerigas, Suburban and the like should have any fitting or hose you would need. Just don't tell them what you are doing with it or they might refuse to sell it to you. :ylsmoke: