what is the difference beetween a stako and a normail fibre wrap bottle?
are they more dangerous to fill?
are they more dangerous to fill?
Stako - norm?
- Thread starter head_-_shot
- Start date
Standard fibre wraps are a thin aluminium tank wraped iin fibre for strength.
Stakos do not have this aluminium core and instead have what could be described as an innertube, like on a bike only mush heavier duty.
Stakos do not have this aluminium core and instead have what could be described as an innertube, like on a bike only mush heavier duty.
I spy with my little eye an oxymoron!
OK, the differences are:
Normal fibre wrap bottles have a 2 part construction, a rigid aluminium inner that extends to the neck where the reg screws in wrapped in a glass fibre outer shell for additional strength, this composite of the two gives the whole more strength than either material on its own for the same overall thicknes/weight.
Stako bottles are made of three components, an aluminium neck piece, a flexible plastic bladder and a carbon fibre outer wrap, this makes them lighter but there is the ability for the bladder to contract when emptied, allowing air to escape through the outer carbon shell when refilled.
As for flash filling, no bottle, steel, aluminium, conventional fibre wrap or Stako should be flash filled! Go to a dive shop and see the care and time they take over filling a tank.
With Stakos that have 'exploded' in the various incidents it is normally the reg that has been ripped out at the threads, basically blown out of the top of the bottle. To keep weight down regs often have a high magnesium content in their alloy, magnesium is highly flammable in its raw state and alloys with a high magnesium content are more prone to igniting. During flash the friction created by forcing a large volume of compressed air into a small space causes a build up of heat, if there is the presence of any containments, especially mineral oils, this can cause ignition (like a diesel engine) and lead to a fire in the bottle. If the material the reg is made from then ignites and melts you don't want to be there when it does.
All high-pressure vessels are susceptible to failure under flash filling, in the case of Stakos, the liner, being made of thermoplastic, is more likely to ignite, given the right circumstances to do so.
As with any high pressure air system you treat it with the utmost respect and treat it properly. Do this and it is as safe as they can be.
i assumed they had an inner tube but recently, down at fat bobs a couple of weeks ago we had a damaged stako bottle that needed to be destroyed so out of interest we cut through the carbon firbre outta shell (which by the way is pretty thick) to have a look at the rubber innertube and what we found was that there was no rubber inner tuber but a thick plastic casing
are there different types of stako bottles???
i assumed they had an inner tube but recently, down at fat bobs a couple of weeks ago we had a damaged stako bottle that needed to be destroyed so out of interest we cut through the carbon firbre outta shell (which by the way is pretty thick) to have a look at the rubber innertube and what we found was that there was no rubber inner tuber but a thick plastic casing
are there different types of stako bottles???
No, they all have that plastic, he's just saying it behaves "like" a rubber inner tube.
Any bottle, should be filled as SLOWLY AS IS POSSIBLE.
Screw the people behind you in the queue. The slower you fill it, the safer it will be, the less it will heat up and the more air you will have in the bottle.
If you fill quickly, the bottle/air heats up and when it cools, you will have a lower pressure.
I open the fill valve on fill stations, very gingerly. Also, I grab the fill whip, hold it, and give it a quick quirt (fill handle) to blow out any crap that might be sitting in it, before I put it on my fill nipple.
Decent fill rigs have a non flash fill setup, so you cant fill too quickly, especially on an emptyish bottle.
