Refilling 1lb propane bottle

[bangerjim]

bangerjim,

Because of the leaking relief valve, I never actuate it. Freezing the small tank allows it to be filled mostly full, >50%, and attaching the torch or other appliance seals off the main valve to prevent leaking.

That could be, but most people do not have 5-6 "things" to attach to filled tanks and the gas can and does leak out the main valve connection also....usually slowly....but within 36 hours the tanks are empty. They fill them and store them for later use with NOTHING attached.

I just think refilling those tanks is rather a waste of time. The are not that expensive at Sam's or Costco. I buy 6 of them every 2 years. And throw the empties away like they are intended to be. I would have gone thru MUCH more wasted gas trying to refill the stupid little things!

Not trying to be a Debbie Downer.................just stating the facts I have personally experienced trying this! Many times it is just wise to spend the little extra money and move on!

[fcvan]

I have refilled before and never had a problem with has leaking out, but I do check them with soapy water. Once they do leak I cut them down for a forge to melt aluminum or old brass. I trimmed a lot of brass to make 300 BO cases, and melt down the berdan primed brass. I have a buddy who pounds the brass into making strips for medieval battle armor. You don't get many uses out of the 'crucible' but they are never on short supply.

[CastingFool]

I bought my adapter through amazon. I refill my 1lb tanks by weight. I will have to check my refilled bottles to see if they have leaked out. In my space heater, a 1lb bottle lasts about 8 hrs on "low". That's the main reason for refilling the bottles

[Hossfly]

I’ve been filling those 1# bottles for last several years, can fill 4 with 1 gallon of propane @ $1.47 per gallon cost, that’s approximately.37 per fill. Kinda like reloading, recycling etc. so what if a few leak just throw em in the burn barrel and exit the area. Don’t take much to entertain us out in the country.

[monadnock#5]

I just use a hose to attach my stove to a 20 gallon bottle.

No messing with small bottles for any purpose unless I go hunting and need a small easily portable source of gas.

Years ago I was gifted a plumbers pot with a hose that was checked and cracked. I took the hose to a business front for industrial and home gas supplies. After some muttering and poking the counter man found what I needed. They're out there.

[454PB]

I've never had one leak after refilling, and some of mine have been refilled 4 or 5 times. I always weigh the empty before and after refilling, all hold 1 pound of propane after refilling. I don't mess with the relief valve.....just put the empties in the deep freeze overnight. I use a shop-mate folding work bench to hold the 20 pound tank upside down, after hook up, it takes maybe 30 seconds to refill the empty.

[dverna]

I was going to get one of the fill adapters but my research showed many issues. Even if 90% of the reviews are positive, I figure I will be one of the 10% who will have a problem. May not matter if buying a flashlight, but these can be a danger.

I did get the adapter to use a standard 20 lb tank on the devices that use the 1 lb’ers.

[Ozark mike]

I figure for 6 dineros i would try it. You have to be careful with those rubber hose adapters heres why

[monadnock#5]

My plumbers pot was designed to use a hose and a 20lb tank. It never even occurred to me to try and use it indoors.

[Three44s]

For burning brush and weeds I got tired of packing around a 20# bottle so I eyed a smaller regular cylinder at a neighbor’s places and talked him out of it. It is likely a 5 or 8 pounder. You can pack it for long stretches without getting worn out and it fuels a regular weed burner touch just as well as the so called 5 gallon model.

My point is I trust that tank on an accessory FAR more than those throw away cylinders and trying to refill them.

Ozark Mikes video is a wake up call about melting the adapter hose between a burner and a regular refillable tank such as I favor. The guy that did the video makes a salient point that one needs a solid metal line off the portable burner to dissipate heat before going to a soft flexible line.

What the video does not cover however is that he was very careless about running that stove and sleeping in there. Never the less it is a good wake up call about those soft hoses coming right off the appliance.

The small hand torches would be an exception in my mind though because or the typical short runs and the fact you are hanging onto it. I would not favor a long run with a stand because you could get to a melt down because your hand is not on the mini torch.

Best regards

Three44s

[smithnframe]

I've been using one of those for about 10 years now!

[fivegunner]

I have tryed refilling coleman propane bottles , some leaked , so I baught the FlameKing refillible bottels and filler kit. works great , and is safe . a littel more money but it is safe.

[GregLaROCHE]

How do you know how much liquid propane to put in? You can’t fill them full. Refillable bottles have a tube going down from the vent so liquid comes out before it’s full. Do the small bottles have the same feature or do you have to fill them on a scale?

[Petrol & Powder]

You can use one of those adaptors to transfer SOME propane from a larger tank to a smaller tank but you cannot FILL the smaller tank with just one tank.
454PB has the right idea of lowering the temperature of the smaller tank prior to the transfer in an effort to increase the amount you can transfer in one equalization, but even then you are only going to equal the pressures in the two tanks.

With a cascade system you could significantly improve the amount of propane you could get in the smaller bottle but even then you're going to reach a point of diminishing returns for your effort.

So if your goal is to simply put SOME propane into the smaller bottle, the adaptor will work just fine but you're not going to be able to FILL that smaller bottle with a single larger tank.
I have one of those adaptors and I use it to put propane in the smaller bottles for convenience. I don't need them to be full and it does save some money. And there's no need to play with the relief valve on the small tank while adding propane; there's no air (or very little air) in the small tank that needs to be purged.

[Ozark mike]

One of the mills i worked at i ran a propane forklift to fill it up we just drove em over to a 100 gallon tank hooked a hose up and turned on the valves. No chilling no burping though that might of got em fuller. Thats about the only time i ever messed with filling small tanks from a bigger one.

[Petrol & Powder]

I'm sure there are some firefighters on this forum that are familiar with a cascade system for filling air tanks.

When connecting one tank to another tank, the pressure between the two tanks will equalize. If the larger tank has an initial higher pressure than the smaller and lower pressure tank (we'll label that smaller tank as empty even though it isn't truly empty) the the net result after the two tanks equalize will be a slightly lower pressure in the larger tank before the two tanks equalized and a higher pressure in the small tank than it started with (because it now has more gas in it than before we started).
Now, if we repeat the process using the same small, but now partially filled tank, and a new completely full large tank, the two tanks will again equalize but the smaller tank will now have a higher pressure than it had before the second cycle. If we have multiple large tanks we can repeat this cycle and get the small tank almost full (because the two tanks equalize with each cycle, we can never get the small tank to the same initial pressure as the large tank but we can get pretty close)

Here's the formula shamelessly stolen directly from Wikipedia:

"When gas contained in a cylinder at high pressure is allowed to flow to another cylinder containing gas at a lower pressure, the pressures will equalize to a value somewhere between the two initial pressures. The equilibrium pressure is affected by transfer rate as it will be influenced by temperature, but at constant temperature the equilibrium pressure is described by Dalton's law of partial pressures and Boyle's law for ideal gases.

The formula for the equilibrium pressure is:

P3 = (P1×V1+P2×V2)/(V1+V2)
where P1 and V1 are the initial pressure and volume of one cylinder
P2 and V2 the initial pressure and volume of the other cylinder
and P3 is the equilibrium pressure."

SO -in theory, if we had several full 20lb propane tanks and and adaptor, we could probably get a lot more propane in that little 1lb bottle than if we just had a single 20 lb. tank. However, there are some problems with that.

1. As any HVAC technician knows, when you compress a gas it gets hotter and when you reduce the pressure of a gas, it gets colder (thank Mr. Willis Carrier for inventing modern refrigeration and air conditioning). So the smaller tank will gain heat as we compress propane into that small confined space.
2. Because propane boils at roughly -44F (at 1 atmosphere), when the propane moves from the large high pressure tank to the smaller, much lower pressure, "empty" tank - it will either immediately boil and transition to a gas OR simply remain a gas. If you can get enough pressure in the smaller tank to raise the boiling point above the temperature of the tank, you might be able to store some of that propane in the smaller tank in the form of liquid, but that would likely take several cycles of a cascade system OR a compressor. Plus you will need to cool the receiving tank as you fill it.

Bottom line - Yes, you can transfer SOME propane from a large high pressure tank to a small low pressure tank. That is exactly what Ozark Mike referred to in post # 35 when he added propane to fork lift tanks. And even though the smaller tank is never actually filled to capacity, Who Cares? You can put enough in it to make it work.

[Ozark mike]

With the exception of when ya send a compressed gas through an orifice it cools
High pressure-orifice-lower pressure
Room temp-temp drops-room temp as pressure builds back

[Mal Paso]

I have tryed refilling coleman propane bottles , some leaked , so I baught the FlameKing refillible bottels and filler kit. works great , and is safe . a littel more money but it is safe.

Thanks for that, I didn't know about FlameKing.

The cheap adapters work, freeze the empties first, the supply bottle needs to be upside down and you can fill the 1 pounders to a safe level without touching the safety valve. 80% full is all you want for safety. Don't let the supply bottle get too cold or you will get short fills. Warm water works.

Just watch out for valve failures on those cheap tanks.

[mazo kid]

Here is my 2 cents worth, please correct me if I have something wrong. I put my 20# tank upside down on my deck, in the sun. This increases pressure, right? I take my 1# tank from the freezer, attach it to the tank adapter and time the filling process. This process fills my small tank very nearly full with liquid petroleum as weighed on a postal scale. I have not had any of the Coleman tanks leak. I think the reason for the statement on the small tank (about not refilling) is partly a CYA for not being legally responsible. Also, DOT does not want those re-filled tanks transported.

[44magLeo]

Filling the one lb. bottles is done exactly like mazo kid describes. You don't need a sun shiny day to warm the 20 lb. bottle.
I have been filling my 1 lb. bottles that way for years. When I started I weighed them before and after. I gave that up because they always got a 1 lb. fill. I have a mall spring scale that reads in ounces. The lightest I ever got was 14 oz.
I have a hose adapter to hook the devices that use the 1 lb. bottles to a 20 lb. bottle. I use it on my BBQ grill. It's a small table top BBQ. I also took it to a torch head. I only use these out side.
I have a weed burner that hooks to a 20 lb. bottle. I have a small hand dolly I set the tank on. A bungie cord holds it in place. This lets me wheel the tank along instead of carrying the tank.
Ozark mike. If you have a good solid stand, why not get a burner that hooks to a 20 lb. tank? I have an old fish fryer that is supposed to have a 50k burner but it never worked very well. I replaced the burner with a larger unit. the new burner is 6" diameter with feet on the bottom so it can set on a flat surface, or it can be bolted into a frame.
I paid either $25 or $29 for it. It came with a regulator and hose to hook it to the 20 lb. tank. I'll post a pic if I can find one.
They make these burners in a 4, 6 or 12 inch size. The 4" ones are round 50k BTU, the 6 around 100k BTU, the 12 is 200K BTU.
The smallest can be found for around $15-$20, the 6 " for $25-$35, the 12 is $89 and up.
These don't have any stand, just a burner.
The small one doesn't have feet but can be bolted to a piece of steel for a base.
I can't seem to find any pics. I'll post them after I find them.
Leo