How to completely refill a 1lb "disposable" propane Bottle

Picture of How to completely refill a 1lb
Summer Is here and its time to go camping! I go through a lot of the small 1lb cylinders of propane. They are used for my stove, Lanterns, Heaters, etc. At  $3 to $4 a Piece, they really start to add up, not to mention that when you are done with them, they are then thrown into a landfill. No more! for about $30 you can build a refill station and refill those bottles completely for about 50 cents a bottle!

I know what you are thinking, why build this when you can buy a refill adapter ready made for your tank. I used to use one, but you can only fill your bottles about 2/3rds full. This method allows you to completely fill a bottle. much the same way as they were originally filled in the factory. and with the quarter turn valve, the refill process is quick and easy.

Disclaimer: this is the way I refill cylinders. I do not claim to be an expert, and I take no liability for mistakes you make. BE SURE TO DO THIS OUTSIDE preferably with a bit of a breeze and no near, flames, sparks, cinders, etc. Propane is highly flammable and this can be dangerous if you don't use common sense. If you blow yourself up, don't blame me!
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Step 1: The Anatomy of a 1lb Cylinder

Picture of The Anatomy of a 1lb Cylinder
A 1lb Cylinder has a pressure relief valve. This is a safety feature that will vent excess pressure from a bottle. This is also used to vent the gas during the filling of the bottle. It looks much like a valve from a tire.

Step 2: The Valve

Picture of The Valve
The valve Consists of the appropriate propane connectors, a 1/4 turn valve and a street elbow to angle the bottle appropriately. I found all my parts at my local hardware store. I am sure they can be ordered on line as well.
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thedustycelt (author) 1 year ago

I no longer use the tire valve tool to vent the small tank. It is safer to use a needle-nose pliers to pull up the vent valve. The pressure relief valve is set at the factory. (as mentioned in some comments below.) it is difficult to get this back into the same setting and can lead to preventing the safety valve from working. the following is a link that I have since found that demonstrates the refill process with needle-nose pliers. (And yes it can be accomplished with a Harbor Freight valve adapter, but it is much easier to use an angled setup with more room.)

ken.mchale12 months ago

The plumbing above works. Only thing I did different was use a 1"-20 cylinder thread and soft nose excess flow POL with handwheel instead of the male POL fitting to 1/4 MIP above (top right in illustration) (Mr Heater sells them and Made in USA). The 1/4 street elbow was also changed to one end male one end female to accommodate !"20 excess flow POL. With the POL you can slide it into position and tighten without rotating entire fitting for easy alignment. I also don't mess with the relief valve, instead buy a pair of "curved" locking forceps (like medical) and pull up on the pressure valve (as described with vent tool above) while filling until you see a small burst of liquid vapor. The 1 lb bottles finish out within 2 oz. Be sure to use YELLOW thread tape designed for gas fittings. :)

thedustycelt (author)  ken.mchale12 months ago

Excellent modifications :-) You should post a pic of your setup :-)

I also went and changed up the text in my original instructable regarding venting the tank. some people don't read the stickies in the comments.

mmartin4011 months ago

Although too scared to do myself, but VERY nice! Do you know a good valve to stop the camp tanks once they are only used partially from expelling the rest of their gas ?

when you unscrew the 1 pound cylinder the valve should close automatically if it leaks gas you should throw the tank out.

Cleve546013 months ago

80% full is good for me. I have a huge propane tank out side that feeds my house and they only fill that to about 80% for gas expansion and same with the bbq tanks there only about 80%. On a nice hot day propane will expand my tank will go from 80% to sometimes 93% to 97% (being the highest its ever gotten) on the gauge out side. I am NO expert but the last thing I want is a couple of one pound bottles exploding in my suv as I am driving down the road. So the harbor freight adapter will work good for me and I would recommend it to everyone else. this is a good set up but don't mess with the relief valve you should only have to purge the tank when its a virgin.

sbaker285 months ago

For those of you so called "experts" it is clear that being "certified" has also Brainwashed you into believing that what you are taught is the only way. It is clear that you have been taught how to also not think for yourselves.

If you read the label on the bottle you will see the weight of the gas inside the cylinder. here in Australia it is 426g so there is just under 1L of propane in the cylinder. I have been filling these cylinders for around 2 years now.

What I will do is exactly what thedustycelt has shown. Before and after I have finished filling the cylinder I weigh it every time and I get a weight change of 400-420g in the cylinder. This is the 80% mark that you all bang on about with your wasted time becoming "certified".

If I was to buy new cylinder every time @ $10 a go, the cost of using these would be beyond reasonable. I see it as a way camping and chain stores gouge you for the convenience of having a portable gas cylinder. I also refill my regular cylinders myself using an adapter mounted in my car and go to the local service station, a camping store will charge $28 to refill a 9kg bottle a 9 kg bottle will hold 18L of gas here in Australia gas is currently $0.74/L there is an immediate cost saving. there is an even bigger saving with the 45KG bottles a local gas supplier charges $130 for a full cylinder. I can refill the same cylinder for around $67 as fuel prices fluctuate this changes.

I don't know about you but and extra $60-$70 in my back pocket is worth the trouble of a small bit of math and a little plumbing. Two refills of the 45kg bottle and I have paid for the filling hardware, so it pays for its self very quickly.

The gas at the service station is more refined than the BBQ gas your local camping and hardware stores sell, so its better for your equipment

TSellers225 months ago

When using dichotomous cooling of the slave and donor tanks, it is possible to overfill the 1lb tank using the conventional adapter, that's why a scale should be used. The connection fittings are best if bridged with a flexible hose which then allows you to float the receiving 1lb tank on the scale. Once you place the bottle on the scale and zero it out, you can then monitor the net weight as the bottle fills and halt the process at 16.4 oz. Then confirm the gross weight which should be the sum of the tare (the weight of the empty bottle), and the net. If it is over, you then use the pressure relief valve to adjust to your target volume.

Nunofyourb6 months ago

I just use the HF refill kit but leave the 1lb bottle on the 20lb donor tank for about an hour and I beleive this fills it to about 90% +.I have had no bulge problems and refill most bottles about 6 times before they decide they no longer want to be refilled.Also helps to warm the larger donor (grill tank) and keep the smaller 1lb tanks cold before you refill.Good luck and keep refilling......


Thank you all very much. I just started using a Buddy heater in my truck and I asked several people when I was buying them and was told no way are they refillable. I've probably thrown away a dozen cylinders. Now I know better.
YumasunbumA8 months ago

Do not fill a bottle past 80% under any circumstances. You need the expansion room when the gas expands. Been filling them for years and learned from a propane tech the right way to do it.

Overkill. The Harbor Freight bottle refill kit works really well, and will refill the "disposable" bottle as full as the elaborate setup. The limiting factor with either is the pressure in the donor bottle, which is a function of how full it is and temperature of the bottle.

I'm with you. 1/2 full, 2/3's full... who cares. The entire reason I started using the refill adapter doohicky was so I didn't have to buy a new dang 1 lb tank for my grill whenever it ran out. Plus the thought of throwing away steel containers simply made no sense - since they are good for many refills!

thedustycelt (author)  Snidely704481 year ago

the trouble with the harborfreight valve is that you can not get to the relief valve to vent the bottle as you fill it.

I forgot. The recipient bottle can be filled to a higher pressure than the donor bottle with the use of a pump. Which is, of course, prohibitively expensive for this use.

I was pretty interested in this instructable until I started reading
the comments. I found the barbed comments between you guys to be
off-putting, and will look for another source of information on this

Food for thought... If you have a pissing contest,
and fill your thread with barbed comments, you're likely to lose your
potential audience. I'm disappointed that I wasted as much time as I
did reading comments that had little to no informational value to them.

Have a nice day, and thanks for the Instructable.

GeeDeeKay2 years ago
While this works -- I have one of these adapters myself -- it is very important to understand that any propane canister is only as good as its hydrostatic test results. This method should have significant safety warnings attached beyond "don't blow yourself up." Ignition during the transfer process is only one concern. If the receiving canister is somehow weakened by age or handling, it could explode unexpectedly with catastrophic results.

My local gas dealer will always check the hydrostatic test date on my 20# grill tank before refilling, and if there's any question, they will not refill the tank. They're the experts so I respect their professional opinion. I go and swap the tank out for a new one at my local orange or blue mega-store.

Pressurized, flammable gas is nothing to fool around with, and any time one refills a container under pressure without a way to measure the resulting pressure of the container, especially in reference to its maximum safe internal pressure, could create a massive safety hazard.

Yes, perform this at your own risk, but understand that the larger tank could impart a significant amount of pressure on the smaller one, beyond its capacity. This could create a timebomb in a 1-lb propane canister.
This is incorrect.
A bulk tank does not have greater pressure than a 1lb canister,
and can not possibly impart excessive pressure to it.
Also, your local gas dealer is *not* an "expert"
but simply obeys the law which mandates the expiry date for any inspection.
Checking that date gives him no information
regarding possible handling damage, etc.
Safety is Priority One,
but ignorance is a poor guide.
I appreciate the care with which you crafted your response. You clearly know lots about me from a few paragraphs. I especially liked the part where you called me ignorant...

I'm afraid you missed the point of my comment: to try to impress upon readers the idea that this is potentially a very dangerous process. The fact that my local gas dealer actually follows the law makes them far more expert than most. They do also inspect the condition of the container and will not refill a tank with visible condition issues. Forgive me for not making clear that the "any question" reference could also include a condition check.

I've seen the 1-lb tanks take more fuel from a 20-lb tank than they are rated to hold, so perhaps I used a term that's not scientifically precise, but my goal here is to use terms that get the point across rather than precise use of scientific jargon that could cause confusion.

Sometimes an idea is conveyed more effectively with simpler words.

Lighten up, and next time try to provide criticism that's more constructive than negative.

Safety third!
"Ignorant" is not an insult,
but rather "a descriptive term that gets the point across."
Please don't blame people for reading the words you post
rather than the meaning which you fail to state.

Ideas tend to be conveyed by accurate words.
It's difficult to correct incorrect information without using negatives.
Don't be defensive, and next time post accurate information.

Safety first!
Well, I'm pretty sure you intended it as an insult, but it seems you preferred the way I phrased it instead. I'll take that as a backhanded compliment. It's curious that nobody else in 15 months found my comment to be so egregious to warrant a correction until your castigation finally set me straight.

The meaning isn't just in the words themselves but in the spirit of the message, as well. It's absolutely possible to address what you perceive to be inaccuracies without being negative, but only if you choose to do so. Going negative is the cheap & easy path, but it's more of a challenge and ultimately more satisfying to be supportive and constructive. I'm satisfied, you just seem negative.

I'm trying to be nice, but you're not making it easy. So, good luck with your precision issues. I'm not sure why you decided this was a battle you wanted to fight, but this isn't the hill I choose to die on, so it's all yours. Enjoy your pyrrhic victory.

And I really did mean safety third. Look it up...
jtrzaska GeeDeeKay11 months ago


Aside from the exchange between you and shascho, I am grateful for your reference to Safety Third! It made me look it up, and I am glad I did. For anyone else who would like to read it direct from the source, here is a link to a letter about it by the man himself, Mike Rowe:

Alrighty thn, GDK.
If you choose to interpret my words
in ways that I have explicitly denied,
that's your choice and out of my hands.
Seems like a lot of writing for such a trivial offence,
but it's as big as you want to make it, I guess.

I stand by my corrections.
You stated that
"the larger tank could impart a significant amount of pressure on the smaller one, beyond its capacity."
but this is simply not the case.
Cylinder pressure does *not* increase with size.

If you choose to criticise an instructable
you should first make sure your criticisms are accurate.

Safety First, and peace out!
semibru1 year ago

I've had great success using the cheap Harbor Freight style adapter. What has made a HUGE DIFFERENCE, is to first FREEZE THE 1lb TANK. I think I saw this in a YouTube video somewhere. Someone smarter than me can probably explain why this works.

outdoorfun1 year ago


For those of you that use Propane powered stoves, lanterns
& heaters, there is finally a solution to having to keep buying those
disposable one pound propane cylinders.

Did you know? ...

Over 30 million empty 1 lb. non-refillable cylinders end up
in landfills every year.

The cost of a non-refillable cylinder is about 6-7 times the
actual cost of the propane in each cylinder.

A distributor called 'Flame King' is now selling DOT
certified refillable one pound (16.4 oz) cylinders and 14.1 oz cylinders.

They sell a complete refill kit that includes a 20 lb nurse
tank, the refill adapter/valve, and two refillable cylinders.

The cylinders are constructed like a miniature 20 propane
tank from heavy gauge steel, with a solid brass threaded top, and come with a
one year warranty.

No more buying disposable propane cylinders that will end up
in the land fill for me boys, I'll save a bundle being able to refill these
instead of buying the disposables ...

For more information go to go to their E bay site

Reiff1 year ago
I always thought it is a waste to use a nice little bottle and then throw it out. Although those little propane tanks only cost 3-4$.
pcooper21 year ago
Loosening the pressure relief valve with a valve core tool (Step 3) or any other tool to bleed the cylinder is a bad idea.

The depth to which the valve core is screwed into the body determines the preload on the spring and thus the pressure at which the valve opens.  There is no positive "stop" as in a tire valve core.  The correct depth is determined by calibrated factory tooling, which the average DIY person doesn't have.  If the valve core is screwed in too deep, the relief pressure setpoint may rise to a dangerously high value.  It is much safer to use a pair of needle nose pliers to grip the end of the relief valve core pin and pull it outward to open the valve.  Bent needle nose pliers are best, as they help keep one's hand out of the path of the icy cold LP gas discharge.  Wear safety goggles while doing this.

When the pin is released, it will snap into position and (hopefully) re-seat without leaking.  If it does leak, it may be due to freezing of the elastomeric valve seat, inaccessible at the bottom of the valve body, inside the cylinder.  Wait a few seconds for it to warm up, then try pulling the pin for an instant and letting it snap back.  If, after four or five attempts the valve doesn't seal, it may mean the valve seat is worn out and unusable.  Set it aside outdoors, away from ignition sources, where the propane can leak away harmlessly, and when it is empty, discard it.
thedustycelt (author)  pcooper21 year ago
This is good information. I have started only going a few turns past closed when I close the relief valve. I also only fill on site and use the tanks immediately. The hook idea is a good one. I will have to see if I can devise one...
manoweb1 year ago
Sooooo... I went again at HD and yes I was able to find a 1/4" ball valve, for 7.40$, in a remote corner, hidden. I guess they are not very popular. I also found the 1/4" street elbow but in galvanized steel, so I did not buy it, as you seem to have used all brass. I did not find the others. I know where there is an Ace Hardware and I'll try there next week. Let's hope they have what I need...
thedustycelt (author)  manoweb1 year ago
Here is the detailed parts list with links for where to buy if you can not find it locally...

1/4" Ball valve
1/4" Street Elbow
Male POL to 1/4: MIP
Female 1lb disposable to 1/4"
Tire Valve Core Tool
With the links above, I found the full parts list on amazon. In most cases the HD parts were cheaper on amazon. Total cost (not including shipping - I have prime for free shipping) was about $35 for the whole setup. Does that sound right? Here is the full amazon list of parts:

1/4" Ball Valve

1/4" Street Elbow

Male POL to 1/4: MIP

Female 1lb disposable to 1/4"

Tire Valve Core Tool

Oh, and did anyone figure out what the size bit was to bore out the vavle core tool?
thedustycelt (author)  manoweb1 year ago
I have also seen 1/4 turn valves at Harbor Freight. For about $3. The street elbow can be replaced with a standard elbow and a short nib of pipe. The main reason for using the street elbow is to keep the length between the bottle and valve to a minimum. I will see if I can create a parts list for mail order from amazon or McMaster Car and post it tomorrow.
An even more important reason for the elbow is to keep the relief valve on the disposable cylinder topmost, so that it vents vapor, not liquid while bleeding.
manoweb1 year ago
You are a HERO!!! Thank you! PS the street elbow looks different than the one you used... I assume it's fine. I assume you used Teflon tape on all the joints?
Ahh! There might be restrictions because HomeDepot says the street elbow is not sold and cannot be shipped to California! :( I'll have to find it somewhere else :(
If Home Depot doesn't have it, find a source on the Web. There's no reason for an ordinary brass fitting not to be shippable to California. if you can't find a street elbow, use a regular machined brass elbow and a brass close nipple; the combination will be nearly as compact.
thedustycelt (author)  manoweb1 year ago
Yes, Teflon on all the threaded pipe joints.
manoweb1 year ago
I was actually expecting HF would have the valve tool but it seems they do not... very strange, normally HF has all those tools. Sorry if I always reply with a "new" message but I think this website has a bug that does not allow me to "reply" correctly.
manoweb1 year ago
Hi! This is very interesting, my compliments! Among all the methods I've seen to re-fill propane tanks this is by far the best.
Anyway, could you help us a little with the components you used for the valve assembly? I haven't found those at HomeDepot - maybe I did not look in the right section? Are those in the picture the precise names I have to ask for? It would be nice to ... have more pictures or the name of the store where you have found those.
Thank you very much, this instructable is really great!
thedustycelt (author)  manoweb1 year ago
Thanks :-) Homedepot will have the 1/4 turn valve and street elbow should be available at a Home Depot. The harder to find parts are the gas connectors. These I found at an ace hardware. You might have to go to a propane supply store. And then there is always the Internet. The names of the parts should be exact as each describes one side or the other of the connector. The last part, the valve tool I bought at autozone. Any car parts place should sell them. One other thing I have done since I wrote this was added a lanyard to the tool so I can tie it to the valve setup so they stay together when not in use... I lost my original valve tool somewhere along the way ;-)
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