How to Completely Refill a 1lb "disposable" Propane Bottle

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!

Step 1: 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

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.

Step 3: The Vent Tool

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.)

Step 4:

Attach the Valve that we have built to a 5 gallon propane tank. Close the quarter turn valve and open the tank valve. Then invert the entire setup.

Step 5:

Attach the 1lb Cylinder to the valve and then open the quarter turn valve. You should here propane rushing in to the bottle. Due to the fact that we have the 5 gallon tank inverted, we are pushing liquid in to the 1lb cylinder. Insert the tire valve tool into the relief valve, unscrew the valve until you hear propane escaping past the valve. I have found the most efficient method is to crack the valve open for  a few seconds and then close it. every time you do this, you will hear more liquid propane rushing in to the cylinder.

Step 6: Completely Fill the Cylinder!

Continue Venting the gas from the bottle in this manor until you get a small liquid spray out the vent. Once this happens, the cylinder is completely full.  Screw the relief valve closed until you hear it click. Turn off the quarter turn valve, and remove your completely refilled Cylinder! a full 5 gallon propane bottle will fill about 20 1 lb cylinders.

When I am done, I cover the top of the 1lb cylinder  with a bit of foil or plastic wrap to keep the connector clean and to mark the cylinder as full. If you save the plastic connector cap that came with the bottle, that is even better. IF you need more bottles, check the dumpster at the camp ground, there is always a plethera of them discarded by people who do not reuse...

You can now save money, and keep the cylinders out of the land fill.  Keep your cylinders dry and clean. replace the cylinder if it gets rusty or starts to leak. When in doubt, error on the side of caution.

Comments

[a1pskgg]

Flammable gas can be more than dangerous..can be deadly..obviously..but some people don't grasp HOW it could be so dangerous if "everyone else is doing it"and have no issues..if this method safely works for this guy..great..I would rather him be giving DIY instructions (that work)to the masses that may otherwise just guess at it and in fact get hurt without some instruction..because it is those who do it blindly and get hurt..are exactly the reason this is such a bad idea..its not the refilling of the cylinders that's the problem...it's the lack of research and verification and cross-reference of the subject before refilling these little cans. I been doing it before I even knew about refill adaptors ..30 yrs..maybe more..I don't know much about flammable gas other than pressure makes it burn hotter..(my experience)..and that ..yeah..flamable gas is...flamable...just apply these 4 things before you do anything dangerous..1)common sense 2)research the subject 3)cross reference the findings of your research 4) verify what you determine to be best from your cross-referenced research.
In the end..if you still unsure..repeat those 4 steps.. Thanx to all the people who are willing to share their success with their DIY projects with those of us who aren't able or aren't willing to do so. To the rest of us that need to watch these videos..you know yourself..if you are a moron. Don't do dangerous things.if you are accident prone..buy your propane cylinders from the store. If you are in a hurry..don't do these.
These things that can hurt you...Murphys law and all. Think about it..widen your view,make your view huge..what do you see?..this whole world is dangerous..
Just use common sense.

[ksunken]

Number 1- It is ILLEGAL and very DANGEROUS to refill a 1# bottle, they are not designed for reuse. (Check your DOT regulations!)
Number 2- You should only fill a bottle to 80% capacity!
Number 3- Buy a reusable bottle with an adapter hose which is LEGAL and a lot safer! (Saves time by changing bottles less often!) or buy REUSABLE bottles!
Propane handling and plumbing takes a licensed professional, not a DIY situation!

[None0722]

Dude,
1. It is not illegal. There is a difference between should and shall.
2. Bleeders are on all tanks, generally located near the valve which is at the top of the tank... being almost 100%.
3. You don't have to be a licensed plumber for this project.
4. I have a masters in safety and retired from osha.

[CaesarO]

I would recommend getting the Flame King refillable 1 lb propane cylinder instead of scouring campsites for these used disposable propane cylinders. These can rupture from repeated refills, it's happened before. Not to mention also illegal to transport after refill.

https://minnesota.cbslocal.com/2012/02/06/1-dead-1-injured-in-polk-county-garage-explosion/
https://www.phmsa.dot.gov/training/hazmat/phmsa-cautions-against-refilling-dot-39-cylinders

[rpjn59]

I find that Minnisota article a wee bit hard to believe. A 77 year old woman is refilling 1 lb bottles in her garage using what a 20 lb. inverted bottle. The 20 lb. when full is almost 37 lb. I'd be looking at how much $ that 'husband' got in insurance money. This seems fishy to me. Who's the cop from Fargo? She needs to look into this...

[Deadhead024]

Not sure why but I have filled hundreds of 1lb tank without a glitch
freeze small tank - connect - turn upside down fill for one minute little tank between 26 to 30 then one day I can’t get a tank past 21 even bought a new adapter and new one won’t get it past 18 tried leaving go for 2 minutes same result I’ve tried over 20 different 1 lb bottles some I’ve filled before some being refilled for the first time
I tried using a different 20 lb tank still won’t fill it’s driving me crazy

[rpjn59]

Thd fact that this perplexes you is one good reason why this is dangerous. You may not understand the basics here. If your 20 lb bottle can not fill 20 1 lb small tanks. There's only a few options.
1. You didn't have 20 lbs. to start with.
2. You over filled some or all of the first 15.
3. You're losing a fair amount of gas while swapping out bottles.

Having a scale and knowing the tare and refill weight of both the 20 lb tank and the 1 lb tank. Will tell you pretty much all you need to know.

Not knowing this is pretty scary. It also shows the freakin limitations of amateurs posting how to diy videos and articles on the internet. The smart thing is to go thru maybe 100 f'in resources before one messes with explosive gases. Especially when the manufacturer and the government are saying dont do it.

Case in point I haven't seen one dyi reference even say 'visually inspect' the 1 lb. bottle for heaven's sake.

[andersonalan82]

I have filled 20lb off of 100lb cylinders in cold weather by heating the 100lb cylinder. In cold weather its easy to increase the pressure enough to condense without exceeding safety guidelines on equipment.. no need to purge the tank and no fuel release into the atmosphere.. freeze one tank and heat the other.. i just set my tank on an electric hotplate and taped a thermostat to it.. caution dont exceed 120 f is labeled on every tank usually I recommend following that rule.. dont use old rusty tanks. Be safe.

[cnorris6]

Found this on the tank is it illegal to refill??

[pblanton]

It's illegal to refill them and sell them. There is nothing to prevent you from refilling them for your own use.

[ksunken]

Yes it is!

[CaesarO]

Illegal to transport after refill. The government can't stop you from filling your water bed with gasoline, but they can make it illegal for you to carry gasoline in a water bed strapped on top of your vehicle on public roads. These disposable cylinders are DOT 39 cylinders which are not designed to withstand the repeated stresses of rapid change in pressure and temperature (via refilling) on the cylinder. It's inherently dangerous to refill these cylinders even though accidents have been rare. An explosion caused by the rupture of a DOT 39 cylinder due to refilling was reported in Polk County, FL in 2012, killing the individual and injuring her husband.

https://minnesota.cbslocal.com/2012/02/06/1-dead-1-injured-in-polk-county-garage-explosion/
https://www.phmsa.dot.gov/training/hazmat/phmsa-cautions-against-refilling-dot-39-cylinders

[drock402]

Sooo... If this is so illegal how come its so easy to get a refill adapter from Amazon? I mean, it was very easy, no warning anywhere... And came with this card as well. Don't get me wrong, i absolutely understand there are major dangers when handling combustible gases but my question is really trying to fig out why its so damn easy to get one if so damn dangerous..? There are MANY things that can be very dangerous if not approached properly, & i at first was wondering if this was an old ass post that was possibly obsolete cuz of new regulations in maybe 1# propane tanks or something similar... But nope! There are def comments dating just a few months back. I actually have refilled several in the past few days since i ordered the adapter & have done so with zero fear/concern. After reading this I'm THE MOST timid and quite worried lol! Crazy

[pblanton]

It's illegal to refill them and sell them. There is nothing to prevent you from refilling them for your own use.

[tonyswhirl]

I think this is a bad idea - http://www.gizmology.net/dot39.htm

[marcbachman]

I'm with you. Another post says use the refillable kind. I'm going to treat myself with the ones that somebody else makes. Of course I don't use a whole big lot of them anyway.

[JaneSpangler2007]

This looks like a great way to save money so you have it to spend at the hospital after this thing blows up in your face. You pay to play. Walmart has best prices

[pcooper2]

Your comment is not helpful.

I have been refilling disposable cylinders for over 30 years for personal use without so much as an incident, much less an accident.

[MulishaMaiden666]

I'm a journeyman welder and journeyman plumber/HVAC. Ppl blow them selves up because they dont know what they are doing or use improper equipment. Refilling cylinders is perfectly fine doing it the correct way. All though refilling a store cylinder I would not do more than once or twice. They are not made to withstand repetitive pressure .you can buy 1lbs cylinders specifically made for refillable next to nothing. 5$/$10$. Air gas used to carry them. I deal with argon, helium, acetylene, LP GAS, OXYpropane, OXY ACETYLENE on a DAILY BASIS AS A PROFESSIONALM

[drew.k.frye]

In the US this is a crime. $500,000 fine and/or 5 years in prison.
https://www.youtube.com/watch?v=g2_GhyAw3vM