Introduction: 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.)
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.
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.