UKC

Google was no help.

Thanks

What does the nipple do? (I'm not familiar with a jetboil).  MSR Dragonflys have a filter on the bottle end of the fuelpipe to stop nasties getting to the burner and clogging it.

Not sure if the nipple refers to the jet/atomiser, but fairly common on oil burners to stop erosion of the jet. Dunno about gas jets.

Edit 

This sort of thing?

https://www.google.co.uk/search?q=oilburner+jet&ie=UTF-8&oe=UTF-8&a...

All nipples have filters, don't they?

Wierd, I was wondering the same thing yesterday, but Google didnt help...

Like a small piece of fluff inside the brass jet? That's what I found anyway.

I wasn't sure if it was a blockage, or meant to be there, so I pulled it out anyway.

My guess is it could be to spread any debris that gets in there around a larger area, rather than it collecting in and blocking the small hole of the jet.

Mine had seemed to slow down, which is why I pulled it all apart. Possibly due to the dust trapped in this strange filter? Seems better without. 

There is the possibility of some gung in the liquid gas, easier to clean / replace the filter than clean out a blocked nipple hole.

After failing with the correct size wire, I have cleaned out blocked nipples by boiling them in water for a few minutes. Needs a spare stove obviously.

Thanks everyone.

Yes, the nipple is the nozzle to others.

I've had a ton of liquid fuel stoves in the past, and none have had a filter based on a cotton wool like material, as my jetboil has. As liquid fuel stoves pass liquid not gas through the nipple during priming, this make sense as it would turn into a soggy mess.

I was wondering what it is trying to keep out? I don't think my old camping gaz stove had this. Is it because something might be in the fuel, or just dirt and sand? And is it that important? Does it also play a role in flow limitation, as the nipple does? Can it just be removed if needs be?

This all started because my jetboil started playing up. Running slow (not even getting water to boiling), then normal, then cutting out randomly. I don't think I have ever had to strip a gas stove down, as there isn't much to go wrong. If that happened on a portaledge, or other places the consequences might be less than ideal. Interestingly, the base of the burner has a neat hexagonal spanner cutout that fits the nipple - so jetboil must be expecting people to have to remove the nipple in the field, which as I said, I've never even thought of having to do with a gas stove. 

I removed the nipple, then the filter from the nipple. I examined the nipple hole with a magnifying glass. It looked unobstructed. The filter had some grey discolouring. I just fluffed it around a bit. Then rebuilt. All seems good now.

To get the filter out one needs either very fine tweezers (I used the ones for removing ticks), or something fine and pointy, like a pin. Hence a pin might be worth carrying when using a jetboil in extreme settings.

It would be good to others with similar experiences, as a working stove can be important.

I am not a petrochemical expert but I think butane and propane are a by product of crude oil distillation and nothing is  100% pure product.

Some gunk or even oil sludge is possible, or contamination from the cartridge filling process.

LPG liquid petroleum gas.

I had a gas stove give up on me a few times, more likely with liquid feed (inverted canister for winter) or dubious knock-off canisters. The inverted canister stove once blocked up especially badly (fortunately we had a backup, it wouldn't be nice melting snow without and I wasn't keen on rebuilding it right there). But it could happen with bad canisters even with a normal gas stove - a filter might be some help there? There could be all sorts of gunk in the canisters, especially the dubious ones. Or even just rust on the canister valve, even the brand ones rust very easily. Fluffy filter would catch rust particles quite well I guess.