Refilling gas bottles.

[Graham_Wright]

I have some serious concerns that my other half may be unable to hold aloft the 70kg gas bottle while it drains into the 3.9kg bottles.
Any tips on how to upend it and support it during the transfer please?

 

[wonkywinch]

deleted as it appears though this is a done thing!

 

[Daverw]

If you cannot handle the 70kg bottle inverted I would use a smaller bottle that you can manage, we use 15kg and sit it upside down on a bench, only needs to be just above the top of the receiver bottle

 

[Sandy]

Get a stronger other half, or build a frame with a few lengths of timber and square lashings.

 

[B27]

Or you can use the warm source, cold collector method, the butane transfers as gas and condenses in the receiving bottle. I've heard of people using a lot of ice packs to cool the receiving bottle.
This malarkey makes it hard to monitor the weight of the bottle.
The latent heat of the gas evaporating/condensing is significant.
It's probably a GCE question to work out the mass of melting ice you'd need to condense the right amount of gas.

go careful.

Latent heat of Butane 386kJ/kg
Latent heat of Ice 334KJ/kg

But bear in mind those figures are probably not exactly valid under the conditions of the experiment....

I know of people who used to do similar with nitrous oxide....

 

[Graham_Wright]

I had a fire (two now!) and discharged a CO2 extinguisher tackling it. The local fire appliance outfit, advised they could refill it but their pump was out of action. I was baffled for a while but realised that their fixed reservoir bottles would not empty by gravity.
My gas is propane. I wonder how much residue there is after running out of gravity.

 

[BobnLesley]

If you're on the boat just hoist your donor bottle on the main halyard, that's what we did. Contrary to an earlier post, we did find a longer drop increased transfer speed, as did bottle temperature; hoisting up the mast a few feet gets the donor bottle in the sunshine, with the recipient bottle shaded in the cockpit.

 

[snowbird30ds]

A bit of webbing strap from any framework, leave donor bottle in the sun and recipient bottle in freezer before filling and it's much quicker, ring around valve has empty weight in lb oz, fill till appox. 4kg over empty weight to give an error margin.


That luggage scale is actually surprisingly accurate and won't time out halfway through the job like electronic scales, temp difference makes the first 3kg quick then slows down quite a lot.

 

[Graham_Wright]

If you're on the boat just hoist your donor bottle on the main halyard, that's what we did. Contrary to an earlier post, we did find a longer drop increased transfer speed, as did bottle temperature; hoisting up the mast a few feet gets the donor bottle in the sunshine, with the recipient bottle shaded in the cockpit.

I love the word "just"!
70kg swinging on the end of a halyard would make a good video!
We have a few trees in the garden but that is up a slope.
I have a pit (two actually) in the garage that would serve but I fear filling it with escaped propane.
I have just given away a load of scaffolding (you never find a use for something until the day after it goes) that would make a tripod stand.
Until I shut down the factory, I can use the fork lift.
Step ladders might do the trick.

 

[BobnLesley]

I love the word "just"!
70kg swinging on the end of a halyard would make a good video!
...

Even a 30kg bottle would make a good video; you choose a calm day/sheltered anchorage and keep a look out for passing power boats. Security/safety can be improved by tying down to a side-deck cleat too - hoist until the two lines are taut, with the cylinder held away from the mast and other breakable items. We used the spring balance approach that Snowbird shows above to avoid over/under filling; each succesive bottle will fill more slowly than the last and you won't get all the gas to decant out of your donor bottle. Forklift should work a treat... I'll remember to ship one on our next boat.

 

[Plum]

I had a fire (two now!) and discharged a CO2 extinguisher tackling it. The local fire appliance outfit, advised they could refill it but their pump was out of action. I was baffled for a while but realised that their fixed reservoir bottles would not empty by gravity.
My gas is propane. I wonder how much residue there is after running out of gravity.

CO2 is stored as pressurised gas so can't transfer by gravity. Propane and Butane, as in a Calor bottle, are stored as a liquid which can be transferred by gravity. Not sure what you mean by "I wonder how much residue there is after running out of gravity"

 

[fisherman]

Play a blowtorch on the donor bottle, as well as the hose to stop any tendency to freeze. Oh, no, that's stupid........you probably don't have another bottle to supply it.

 

[ProDave]

I stand the 45Kg bottle on it's head on a step in an internal corner so it can't roll or slide anywhere. It's not difficult single handed.

I assume when you talk of 70Kg you are talking of the gross weight?

 

[B27]

Play a blowtorch on the donor bottle, as well as the hose to stop any tendency to freeze. Oh, no, that's stupid........you probably don't have another bottle to supply it.

Would it be safer to blast the recipient bottle with escaping gas to cool it?








Do not try this at home!


If you need to take advice from us buggers, you probably should not be playing with gas.

 

[MontyMariner]

Plant pot stand. Table, Chair. FFS it's not beyond the wit of man!

 

[Graham_Wright]

Plant pot stand. Table, Chair. FFS it's not beyond the wit of man!

I can lift 70kg with a strop around my shoulders (ok, I'm a wimp). But no way could I hug the cylinder and drop it inot such a device.
However, at 0300 this morning (my best inspirational time), I remembered that I had drilled a 1"n diameter hole through the garage wall for reasons I can't remember and a matching one through another wall a couple of feet away.
They are at sufficient height to enable a a bar to be inserted and a mini turfer or the like to hoist the bottle to a sufficient height for the valve to clear the valve gear. Need three hooks and a bit of chain.

 

[Graham_Wright]

I assume when you talk of 70Kg you are talking of the gross weight?

Correct.

 

[Graham_Wright]

CO2 is stored as pressurised gas so can't transfer by gravity. Propane and Butane, as in a Calor bottle, are stored as a liquid which can be transferred by gravity. Not sure what you mean by "I wonder how much residue there is after running out of gravity"

I thought CO2 existed only as a gas or a solid but checking it seems I am wrong.
I meant when the donor bottle pressure equals the recipient bottle pressure, presumably the transfer will stop.
What remains in the donor bottle would be wasted (unless it can be used as a gas - torch heater & etc). See #10.

 

[shanemax]

I have some serious concerns that my other half may be unable to hold aloft the 70kg gas bottle while it drains into the 3.9kg bottles.
Any tips on how to upend it and support it during the transfer please?

Where did you buy the fittings from and perhaps you could supply a list of names and sizes. thankyou

 

[BobnLesley]

Where did you buy the fittings from and perhaps you could supply a list of names and sizes. thankyou

You need a length of suitable hose, a couple of jubilee clips and a free-flow fitting - preferably incorporating a stop-valve - with matching hose barbs to suit each bottle; I've seen more than one person trying (and failing) to decant through regulator valves. However, if such free-flow connection is not readily available, get a preferably old regulator for that bottle type and a power drill with some small bits; drill into the regulator from either end and it'll wreck the guts of the regulator, blow out the swarf and you've got yourself a suitable free-flow fitting.
The only bottles we consistently failed to decant from were those from the USA; they apparantly contain some sort of internal flap/tilt valve, which closes when you invert the bottle