That would be very interesting to know. Anyone on here have that capability?

"We provide you with a special high altitude stove and fuel canisters. Our stoves are of the "hanging" type, designed to be used inside the tent (well ventilated of course). We have found these to be the best possible stoves for high altitude use, as it is essential to cook inside the tent during stormy weather. Our stoves are suspended above the floor so you have room to sit comfortably and warmly in your sleeping bag while cooking.

Our high altitude fuel is of two types. Above 7000 metres/23,000 feet we use imported propane/butane 250 gramme canisters. Below 7000 metres/23,000 feet we refill the canisters with propane gas. Liquid fuel does not work above 6000 metres/19,700 feet so we don't use liquid fuel above basecamp or advanced basecamp."


This info is from the Summitclimb.com website. Sounds like standard practice for these folks. They cook in the tent with cylinders that have been refilled with propane. Perhaps the device was for propane after all.

Our high altitude fuel is of two types. Above 7000 metres/23,000 feet we use imported propane/butane 250 gramme canisters. Below 7000 metres/23,000 feet we refill the canisters with propane gas.

Liquid fuel does not work above 6000 metres/19,700 feet so we don't use liquid fuel above basecamp or advanced basecamp."

> Nick and I would like to know the burt rate of canisters.
Specify the temperature first.
Below 50 C it is meant to be zero. Yes, there is regular testing.

> canisters were designed to withstand the pressures of gas many time over than what
> was going to be introduced into them
and
> What pressure exists inside of a clear plastic hose filled with liquid propane?

For more info on this general area, read our articles on
Cold Canisters and
Canister Overheating

The info is mostly there. Otherwise, check the DoT regulations.

Cheers

Edited by rcaffin on 03/29/2012 22:35:41 MDT.

> it only leaked when the flame was out and I was unscrewing it.
> It would flame up, I blew it out, screwed it on tighter and then it worked.
If I read this correctly, it says that the canister started to leak while you were connecting or unscrewing the stove? In that case, keep (un)screwing the stove fast.

What is happening (when unscrewing) is that the O-ring seal is being broken BEFORE the actuating pin has retreated enough that it no longer depresses the valve. This does happen sometimes, as the exact dimensions between the Lindal valve and the stove pin are NOT defined. Some stove/canister combos can do this.

The secret here is to always screw the stove down and unscrew the stove fairly quickly. That way you pass through any possible leaking stage very quickly.
Yes, it is annoying.
Yes, it could be dangerous if done right next to a running stove.
No, we probably have no chance of getting all players to agree on a single standard. No-one will be willing to accept that they have to change.

> I'm still waiting for someone that overflows their boiling pot onto the canister,
> which raises temperature of canister, which could produce a much bigger flame.
Be very careful about what you wish for. There have been accidents with over-heated tanks, resulting in burst tanks and people getting 3rd degree burns over a significant part of their body. I have photos, but they can stay unpublished.

Cheers

> Maybe someone could pressure test some empty containers to get an idea of the pressure where they fail

Been there, done that.
See Canister Overheating
for the details.
Yeah, very loud bangs!

Cheers

Edited by rcaffin on 03/29/2012 22:55:28 MDT.

"Our high altitude fuel is of two types. Above 7000 metres/23,000 feet we use imported propane/butane 250 gramme canisters. Below 7000 metres/23,000 feet we refill the canisters with propane gas. Liquid fuel does not work above 6000 metres/19,700 feet so we don't use liquid fuel above basecamp or advanced basecamp."


Next question is what kind of stove and canisters are they? Perhaps the Coleman style 16oz propane canisters? Those are heavy and thick. Plus these folks are not UL hiking, they are doing serious high altitude work.

> Our high altitude fuel is of two types. Above 7000 metres/23,000 feet we use imported
> propane/butane 250 gramme canisters. Below 7000 metres/23,000 feet we refill the
> canisters with propane gas.
ALL canisters are imported - mostly from China.
Above 7,000 m it is going to be very cold. That's where I would use Propane.
Below 7,000 m it will be warmer: that's where I would use propane/butane.
Not sure about these guys. They worry me. Do they have any idea of what they are talking about?

> Liquid fuel does not work above 6000 metres/19,700 feet so we don't use liquid fuel
> above basecamp or advanced basecamp."
That is total rubbish.
Nope, they have no idea at all. Turkeys.
(Mind you, I am not sure I want to be refilling a white gas stove at high altitude: my concentration might not be quite as good as I would like.)

cheers

>Been there, done that.
See Canister Overheating
for the details.
Yeah, very loud bangs!


At what pressure do they burst.

"The secret here is to always screw the stove down and unscrew the stove fairly quickly. That way you pass through any possible leaking stage very quickly."

What happened on one canister is that even if totally unscrewed, it still leaked.

Low rate. Faint smell. Faint hiss.

I screwed it back on and off. Banged it...

I think this is rare based on my experience.

I just left stove screwed onto canister until canister was used up.

"We use imported propane/butane 250 gramme canisters. Below 7000 metres/23,000 feet we refill the canisters with propane gas."

Next question is what kind of stove and canisters are they? Perhaps the Coleman style 16oz propane canisters? Those are heavy and thick. Plus these folks are not UL hiking, they are doing serious high altitude work.

See what you can decipher from this:

<center>




</center>

One bar = 14.5038 psi

Edited by zelph on 03/30/2012 09:15:26 MDT.

What Code is that from and what is the scope of that code?

It is very dangerous to apply design practice or rules from one code to the jurisdiction of another code.

To find out what the design basis for these canisters is you need to determine the code they are built to and check only that code.

In piping code generally the stress limit is 2/3rds yeild so theoretically something can handle 1.5 times design pressure. However that safety factor is there for a reason. The codes don't take into account all possible load cases, the metal you are using might not quite be up to standard. It might be used improperly by the operator, the upset condition you designed for my not take into account all possible scenarios, you may be designing for static conditions and dynamic effects may produce pressure transients above the calculated values, poor assumptions, accelerated corrosion, etc etc. I could go on and on of things that aren't neccessarily accounted for by design codes as they are not a cookbook they are minimum standards.

So even if you find out what the maximum burst pressure is for the canister it is stupid and against code to exceed the design pressure of the canister. Generally manufacturers will build to the maximum design pressure and no more.

> So what would happen with a canister gas leak?

first thing that would happen, I guess, is you would notice. It's hard to ignore the sound and the smell.

Not a nice thing to happen, I know, and potentially dangerous but not necessarily a catastrophic event.

Greg, The code is for Aerosol Dispensers filled with compressed or dissolved gas and Containers used for filling with liquefied gas.

It doesn't say REI stove gas dispensers. I have not found the code for those. You seem to know a lot about codes, can you determine where to find the code for the canisters we are concerned with? I'm trying, that's all I can do to answer my own questions. Roger pointed us in a direction of a resource only available to donating member of which I am not. My subscription ran out. If anyone has access to that info please let us know what the bursting pressure is.

The info is out there, only a matter of time to find it. Wish Jim could find that for us. Even you Greg, maybe you can find it, at least try.

>So even if you find out what the maximum burst pressure is for the canister it is stupid and against code to exceed the design pressure of the canister. Generally manufacturers will build to the maximum design pressure and no more.

Even though I'm not going to fill a canister with propane, I want to know what the maximum psi gas canisters are rated for. And I'm talking about the small canisters we use for our back packing stoves.

Tha manufacturer may go well beyond the code just to cover their backsides. Especially when they know that end users are wrapping windscreens around their stove.

Greg, the canisters might be rated far beyond what is produced by LPG.

but the generation, curation, formatting, annotating and publication of information still costs money.

Hi Dan

> At what pressure do they burst.
Subscribe, and all will be revealed.

Cheers

EN 417 is the standard the canisters are generally designed to. I dont have access to that standard so that is as far as i can go. Also even if i did get acess to it I am very weary about interpeting a standard which i dont have expertise in over the internet where i have no control over how that information is used.

Hence my perfered default response would be dont do it.

Actually, while all the stove and canister mfrs say they conform to EN417, that really means NOTHING. I'm serious. I have asked some of the stove 'mfrs' in USA for a copy of the relevant part of EN417, and I was told they don't even have a copy.

All EN417 does is to specify safety limits, in a general manner. And they have a special exemption for small camping gas canisters anyhow.

The crucial thing is for the canister mfrs to get a DoT approval for their canister. That's about it.

For further reading, see
http://www.bushwalking.org.au/FAQ/FAQ_GasStoves.htm#EN417

Cheers

I think you are all being unnecessarily cautious. I have being refilling canisters for years. However, it is important to consider how best to mitigate the potential risks. I mitigate by getting one of my hiking partners to carry them. They can't tell what's in the canister and it's so much safer for me.

On one hike the heat and elevation got to the canister. So it went off with a bang... pretty exciting. But what made it even better was the explosive decompression ejected every thing out the top of his pack like so much UL confetti. Cool. His sleeping bag came shooting out the top like one of those trick spring/snakes in can... except bigger. Just as I was thinking it couldn't get any better I noticed the canister bottom had come out the bottom of his fancy pack and clipped his left cheek as it went by.

So.. if he should happen to tell you this story and wants to show off the scar to prove it, just say no.

Please note that this is all complete BS. I don't really have any hiking partners. Not since the flare gun incident anyway.