100% Propane Inverted Canister Use in Warmer Weather

[Bailey Gin]

I have an adapter that allows 100% propane tanks to be used with standard lindal value stoves…use is only done at temps below 40*F. Using a remote canister stove with a pre-heat tube and inverting the propane tank, inducing liquid feed mode, could I use it in warmer/hot conditions? Guess what I'm asking is at warmer temps, is the greater internal vapor pressure forcing the liquid feed out at a greater rate?

b.gin

[Roger Caffin]

Hi Bailey

Yes, the internal pressure will be significantly higher. The following is not official BPL stuff, just my private opinion.

You can use it at higher temperatures, but the stove may roar a bit (that's the propane) and adjustment is going to be more difficult because of the higher pressure due to the propane. It would be considerably safer to let the propane bottle sit upright if that will give it a gas feed.

However, there is a danger, in that the hose will now be subject to a pressure several times higher than from a butane/propane canister. If there are any weaknesses there … BIG problem. Like fireball. Trust me, that is MAJOR fear country. A BLEVE can be fatal.

You might be able to handle this by using the valve on the propane tank – IF there is one, as a primary pressure reducer. Use the tank upright in gas feed mode and only open the primary valve a tiny whisker. Then fine tune the flow with the valve on the stove. This is how the standard pressure-reducer on a propane tank normally works. This will not work in liquid feed mode as the liquid flow rate is too slow.

All in all – dangerous stuff, and not advised.

Cheers

[Stuart R]

A few points to consider:

1) With 100% propane (or 100% butane) there is no need and NO POINT in inverting the canister. With a single gas, it cannot boil off faster than the 'other' gas as there is no other, unlike propane/butane mixes.

2) With 100% propane, the pressure is considerably higher than the stove components are designed for. Where is the flame control valve on your remote stove? If it's at the stove end of the hose, there is a serious risk that the hose could leak or burst – instant flame thrower! You might get away with it if the flame control valve is at the canister end of the hose.

3) Coleman make a stove designed for use with 100% propane. It would be a lot safer to use that, and just as effective at low temps – see point 1)

[Stuart R]

touche

[Hikin’ Jim]

Hi, Bailey,

Is there a particular reason that you want to invert the propane canister? In warm weather, you should have all the gas pressure you could ever want, yes?

Inverting is usually for cold weather. For cold weather, I can see inverting the tank even with 100% propane. In that way, I think you would get less chilling of the fuel due to vaporization since the majority of vaporization would happen at the burner. I would think some chilling would still occur since when liquid is withdrawn from the canister, the volume will increase, the pressure will decrease, and additional vaporization will occur within the tank.

Roger, am I on track here regarding less chilling?

HJ

[Rick Dreher]

Agree with the above-straight propane has vastly different characteristics.

n-Butane: 2.05 atmospheres, 31F boiling point

Isobutane: 3.1 atm, 11F B.P.

Propane: 8.4 atm, -44F B.P.

(1 atmosphere is 14.7 psi at STP.)

Unless the adapter has a pressure reducing function I can't imagine a standard Lindal-valve camping stove would be safe using it.

Rick

[Bailey Gin]

This is the setup I have in mind,

So it should be in liquid feed mode. Will the higher warm weather vapor pressure cause the liquid flow rate to overwhelm the hose and the control valve?

Please correct me if I am using this chart wrong,

At 40F a propane tank vapor pressure is almost equal to 70(butane)/30(propane)'s vapor pressure is at 90F. I tend to read this as if I use this stove with an upright propane tank at temps under 40F I should have a safety margin. Above 40F the vapor pressure is too great to chance.

Bailey

[Bailey Gin]

Hi Jim. In warm weather a propane tanks will generate way too much vapor pressure to be safe. I'm thinking/hoping that inverted the vapor pressure in warm weather will not affect the liquid feed rate as much. Does that make sense?

Bailey

[Jerry Adams]

Where'de you get the propane to Lindl converter?

I don't know why I'm asking, I enjoy life.

[Rick Dreher]

Hi Bailey,

My concern is what happens to liquid propane in the generator tube at the burner, when it is heated directly by flame? The little brass tube isn't designed to contain what might suddenly become a couple hundred psi. (I'm presuming the Xtreme setup would deliver liquid fuel to the burner.)

With a standard Max cartridge some vaporization seems to happen at the valve, which can get frosty, but it always appeared to me that liquid was making it to the burner itself, hence the generator tube.

What comes out of the burner head when you open the valve?

Rick

[Hikin’ Jim]

Hi, Bailey,

Is that the Kovea Propane to standard threaded Lindal valve adapter? If it is the Kovea, the Kovea adapter does have a set screw sort of an arrangement on the side that functions as something of a valve. I don't have one, so I'm not intimately familiar with the Kovea adapter.

I understand what you mean about vapor pressure vs. liquid feed. Still, that liquid will be under a great deal of pressure because of the vapor pressure in the tank. It's as if you had taken pressure stove (like say an Optimus 00 or 111) and pumped the no-tomorrow, ever living heck out of it. That liquid is going to be super pressurized — if you do it on a warm day.

Your temperature-pressure chart is interesting though. If you did it in cold weather, you might be able to get away with it.

I guess the ultimate question is: why?

Powermax canisters are still being made, and even if you couldn't find a Powermax canister, you already have an adapter for standard threaded canisters. The big green tanks are cheap, but Powermax canisters aren't that expensive. With the big green 100% propane tanks, you've got a lot of weight and bulk. If you're going car camping, just take a stove that is meant to work with the big green tanks. If you're going bike camping or backpacking, take your Xtreme but use Powermax. Why screw around with something that might blow up in your face? Even if you could get the 100% propane set up to work, I doubt it would be any better than just using Powermax.

If you're short Powermax canisters, I just picked up a whole slew of them. They're plentiful here locally. Happy to send you some.

HJ

[Bailey Gin]

Hey Jim. The adapter was made by Chickenthief (a mutual acquaintance of Jim and me from another forum).

"why?" Since propane freezes at -390F, it gives me a lot of latitude in cold weather use…provided the stove doesn't "freeze up" LOL. Actually its "my economics", if I can get away with something cheaper and its safe to do, why not, plus it will have 3 different fuel cells options.

Powermax are easily purchased around here also.

Bailey

[Hikin’ Jim]

Ah, yes, "Chickenthief." He's a character. I haven't heard anything from him in a long time. I hope he's OK.

Well, it's certainly an interesting idea. I guess for me if I were going out in anything warmer than -10F, I'd just use PowerMax. Where you headed bro that you're going to need to go below -10F? :)

Just keep the valve down low on the Xtreme. I think the fact that the valve is at the connection to the tank works to your advantage. The full force of the liquid propane won't hit the fuel line if you're careful. If the valve was at the burner, I think you'd have a real problem on your hands.

I think the pre-heat loop should be able to handle the expansion of the propane. At the temperatures present in the pre-heat loop, the standard 60-40 butane-propane blend is going to be exerting some pretty terrific pressure. That pre-heat loop has to be able to stand that. I think. Still not 100% convinced this is a good idea, but like I say if you keep that valve turned low, I think you'll be OK.

HJ

[Roger Caffin]

Hi HJ

> Roger, am I on track here regarding less chilling?
Roughly speaking, yes.

> I would think some chilling would still occur since when liquid is withdrawn from the canister
True, but microscopic. You would be justified in ignoring the chilling from this.

Cheers

[Roger Caffin]

Hi Bailey

I see.

You could tip the tank over on its side of course. That might give you liquid some of the time and gas some of the time. Interesting mess.

What scares me most about that arrangement is that the propane tank can and will get radiant heat from the stove unless you have a good aluminium windscreen between the two. And that radiation heating could be … exciting.

What also scares me on top of the above is the potential for the propane tank to be knocked over, send the stove flying, and all sorts of mayhem following.

Possible, but I have to say it scares me.

Cheers

[Roger Caffin]

Hi Rick

> My concern is what happens to liquid propane in the generator tube at the burner, when it
> is heated directly by flame? The little brass tube isn't designed to contain what might
> suddenly become a couple hundred psi. (I'm presuming the Xtreme setup would deliver liquid
> fuel to the burner.)

I don't think it would work that way. The pressure all along the hose and preheat tube would be very close to being all the same. The big problem will be throttling the flow of liquid propane – very tricky to do. Bear in mind that the expansion ratio between propane liquid and gas is of the order of 250:1.

Actually, the little brass tube will be a lot stronger than the flexible hose. For ultra-high pressure applications they use small-bore COPPER tube!

Cheers

[Roger Caffin]

Hi Bailey

> Since propane freezes at -390F, it gives me a lot of latitude in cold weather use.
Actually, hardly relevant imho!
You should be mainly concerned about the boiling point, not the freezing point.

Cheers

[Hikin’ Jim]

Roger,

Thanks for a lot of good information.

> Since propane freezes at -390F, it gives me a lot of latitude in cold weather use.
Actually, hardly relevant imho!
You should be mainly concerned about the boiling point, not the freezing point.

Bailey,

If the propane gets below boiling point, then you won't have any pressure in the tank, and your set up will cease to function well. You might get some feed just due to gravity but I'm not sure it would be sufficient. You'd have to experiment — in an environment that's about -45F or colder. Good luck on that. :)

HJ

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