Alleged illegal tanks sold by Add Helium-Heads up to any that may have purchased

[MarkFlory]

FYSA, I'm fairly certain Paul the maker of rEvo after trying other luxfer tanks ended up using these tanks himself and he is a safety freak.

 

[Rick Sanders]

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A ScubaBoard Staff Message...

I will try. Threads like this are very, very hard to moderate. Post after post is close to the limit. We try very hard not to interfere unless posts go over the line because we sincerely want to keep communication flowing on an important topic. If a post is close to being over the line but is decided to be within limits, and then a response to it is clearly over the line (and the post I deleted was clearly over the line), then it may seem like we re playing favorites, but it is really a matter of a fallible human doing his best to be fair.

Right now, there is growing moderator sentiment to close the thread and nuke the entire discussion. Is that what you folks want? Then keep posting personal attacks that are near or over the line, and that will be that. We will all be done with that and everyone will be at peace. Of course, there will be no discussion on an important topic, but, hey, if that's what you prefer....

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Has the board considered requiring everyone to be in True Name rather than a callsign to be anonymous? People tend to insight rather than be constructive when they can hide behind a false identity.. They promote a personal agenda for their benefit. People will tend to be more constructive when their comments are directly associated with them personally. Much of this tread is calling Peter and AH names when he is not here to explain or defend himself. Its clear some (mostly anonymous) people have a personal agenda to public destroy him rather than use fact, wait for facts or allow him to have a side. You removed a post calling a Bully out (it was not bad at all); yet if you go back, there are still several of the Bully's posts calling people names and using much harsher language, etc.. None of those recipients ask you to remove them, nor did you did it on your own???? When one of the Bullies complains there action??? Kind of a double standard; just something to consider.. Respectfully Rick

 

[Rick Sanders]

hope you are not referring to me .......my sfa chapter guys at 1-18 (life member ) might take offense at that (by the way my name is the same on THEIR blog as well,,, oh but I forgot you cant see it if your not a member

I am truly surprised he didn't ask to have this post removed.. Dish it out but Shawn can't take it.. He anonymous, so I am sure he will come back with some tough commit.. Just ignore him, everyone has his number now.. Elite Keyboard Ranger!

 

[cerich]

Ah. So the water is the reason they are not commonly used for scuba tanks, and yet are used commonly in non-underwater applications?

Being a volunteer firefighter at two different departments for about a year at each, carbon fiber wrapped tanks seem almost universal for the firefighter's SCBA units. At the time, I had no experience with scuba and I guess just assumed the CF wrapped tanks were so they were lighter, which I still think is why. Going into a fire with an SCBA, full bunker gear, axes/sledges/chainsaws/firehose and rescuing people, you want your tank to be lightweight. An AL80 wouldn't be fun at all. My first department had 3000 PSI carbon fiber tanks, the second department had smaller 4500 PSI tanks (probably the "30 minute tanks" as they are called, holding 45 cu ft of air at 4500 PSI). My first department later switched out to the smaller 4500 PSI tanks, again size and weight are concerns. Unlike going underwater, a tank doesn't become (almost) weightless, you have to carry it the entire time while simultaneously working your ass off, so lightweight is a priority.[/QUOT

View attachment 389428 FYSA, I'm fairly certain Paul the maker of rEvo after trying other luxfer tanks ended up using these tanks himself and he is a safety freak.

You're being misleading, he specifically is discussing Luxfer wrapped cylinders,not Chinese with allegedly false markings on them.

 

[cerich]

anyhow,Luxfer is pretty clear on using their wrapped cylinders for diving..don't. Except the one cylinder that has been approved

Underwater use of Luxfer full-wrap Type 3 carbon composite cylinders

L6X® Hoop-wrap SCUBA cylinder

Hmm..wonder why they would do that? Oh,I have a idea,maybe they know something about the science

 

[iain/hsm]

View attachment 389428 FYSA, I'm fairly certain Paul the maker of rEvo after trying other luxfer tanks ended up using these tanks himself and he is a safety freak.

Again Mark.

The devil is in the detail or in this case the heading Luxfer
Using Luxfer Carbon Fibre tanks on rebreathers.

I am more than happy to submit the QA and documented CE Certification and independant verification for Luxfer cylinders but not in this post. Your detracting us all from the point.

These are Add Helium supplied cylinders supplied from a chap out of Sweden selling Muslim Women's wear from an outfit out of China using his own QA, No certification, no verification, no certification.

Thats the point of this whole mess. Iain

I should add regarding Paul and his product I recall it didnt make the required CE EN 14143:2003 certification standard at the time so as he was a member of the CE committee he and others revised the original standard to a lower bar in order for some of these so called recreational products to make muster by removing the original requirement for rebreather to include "Functional Safety as required in the original EN 14143: 2003 standard under the IEC 61508 functional safety requrement. Again happy to discuss this in detail if you wish. Iain

 

[St John the Diver]

Just because cave fills don't bug you doesn't mean that they are safe, It just means you have something in common with all the people that own carbon fiber tanks that don't get bugged by them being filled.
Just because Add Helium , in your opinion, hasn't offered any proof that they are safe , you haven't offered any proof that they are dangerous so all I can go by is their track record and I've never heard of one single problem, that is probably the reason you're not bugged by Cave fills because you haven't seen a problem with that either.
So far I don't proof of a problem so I don't see why everybody is so worked up over what could happen.
I think we would be better focusing our energy on keeping our caves open, after the death in Eaglesnest today you know people are going to try to shut it down again and probably with the argument you're using "what could happen "

So to cave fills:

****... This is going to be a long post so bear with it.

"Back in the 20's" the old ICC wanted to make sure that high pressure cylinders were safe. So they came up with a way to determine when steel cylinders ended working within the elastic range of steel and began entering the plastic range. To make that simple, steel will return to its original size after deformation within limits and after those limits are exceeded will become plastic, i.e. no longer returning to size. Think "pulling apart taffy". That's plasticity.

So: when a cylinder is filled it expands. And when the pressure is taken off it contracts. BUT it doesn't contract completely. There's a small permanent expansion. And if you continue to cycle the cylinder you "one day" will have begun to leave the region of elasticity and enter the region of plasticity. And this is what a hydrotest is set up to test.

A hydrotest measures the PERMANENT expansion of the cylinder and compares it to the transient expansion. A steel cylinder for diving will expand about 70 cc's when filled. It'll maintain about a 1 cc permanent expansion. Testing allows up to a 10% permanent expansion. If you fill a cylinder and it expands 70 cc's and only returns to a permanent expansion of 50 cc's the cylinder is getting towards plastic, meaning it's reached its total cycle life. NOTHING else other than number of cycles (inflation/deflation cycles) impacts this. Not corrosion, not abuse. Just cycles.


So what about working pressures?

The STATED working pressure is selected by the manufacturer to offer usable volume while retaining the ability for a cylinder to (a): be at its maximum acceptable expdnsion at a hydrotest and then ALSO (b): still be filled for another FIVE YEARS before a second test will reject the cylinder.

The actual YIELD point (burst of a new cylinder) is so high above stated fill pressure that it's not approachable. Think in the 10,000 PSI range.

So: Working pressures are selected based on the manufacturers estimations of the maximum number of fill cycles that are available before a cylinder reaches its plastic limit. Fill it to a higher pressure? You'll reduce the total NUMBER of cycles it'll be ok for. But that's about it.

Here's the thing: industrial cylinders used, for example, as hydraulic accumulators, can be cycles hundreds of times a DAY. The same specifications are used for scuba cylinders. The thing to realize is that even the most dedicated diver will NEVER approach the number of cycles needed to "fatigue-out" a cylinder. Our scuba cylinders lead a pretty babied existence, cycle-number wise.

Cave fills? Well if a bottle is designed for a million fills at 2400, it'll be ok at 3600 for 990,000 fills. I'm making that up, but it's pretty close. The takeaway is that cave fills are well within safe limits both from an engineering standpoint and an empirical observation one. You ever hear of a steel cylinder blowing up when cave filled?

Hydrotests are NOT designed to detect flaws that will result in a cylinder bursting. If that occurs it's "nice to have found out" but it's not really what the test is designed to find. The problem with aluminum cylinders is neck cracking. You find that by non-destructive testing. If you actually blow apart an aluminum cylinder in the hydrotest machine you're WAY past when it should have been removed from service based on NDT.


BTW, the reason that wrapped cylinders are discarded after five years is that you CAN NOT hydrotest them. The fiber wrapping prevents the interior (thin) metal liner from expanding at all. You can't measure permanent expansion if temporary expansion is inhibited by wrapping. And that's one reason we don't use them.

 

[MarkFlory]

You're being misleading, he specifically is discussing Luxfer wrapped cylinders,not Chinese with allegedly false markings on them.

I'm not being misleading I said " AFTER trying luxfer I'm fairly certain Paul ENDED UP using these tanks.

 

[MarkFlory]

So to cave fills:

****... This is going to be a long post so bear with it.

"Back in the 20's" the old ICC wanted to make sure that high pressure cylinders were safe. So they came up with a way to determine when steel cylinders ended working within the elastic range of steel and began entering the plastic range. To make that simple, steel will return to its original size after deformation within limits and after those limits are exceeded will become plastic, i.e. no longer returning to size. Think "pulling apart taffy". That's plasticity.

So: when a cylinder is filled it expands. And when the pressure is taken off it contracts. BUT it doesn't contract completely. There's a small permanent expansion. And if you continue to cycle the cylinder you "one day" will have begun to leave the region of elasticity and enter the region of plasticity. And this is what a hydrotest is set up to test.

A hydrotest measures the PERMANENT expansion of the cylinder and compares it to the transient expansion. A steel cylinder for diving will expand about 70 cc's when filled. It'll maintain about a 1 cc permanent expansion. Testing allows up to a 10% permanent expansion. If you fill a cylinder and it expands 70 cc's and only returns to a permanent expansion of 50 cc's the cylinder is getting towards plastic.. meaning it's reached its total cycle life. NOTHING else other than number of cycles (inflation/deflation cycles) impacts this.

The STATED working pressure is selected by the manufacturer to offer usable volume while retaining the ability for a cylinder to (a): be at its maximum acceptable expdnsion at a hydrotest and then ALSO (b): still be filled for another FIVE YEARS before a second test will reject the cylinder.

The actual YIELD point (burst of a new cylinder) is so high above stated fill pressure that it's not approachable. Working pressures are selected based on the manufacturers estimations of the maximum number of fill cycles that are available before a cylinder reaches its plastic limit. Fill it to a higher pressure? You'll reduce the total NUMBER of cycles it'll be ok

BTW, the reason that wrapped cylinders are discarded after five years is that you CAN NOT hydrotest them. The fiber wrapping prevents the interior (thin) metal liner from expanding at all. You can't measure permanent expansion if temporary expansion is inhibited by wrapping. And that's one reason we don't use them.

I'm fairly certain the industry standard is 15 years for the lifespan of these cylinders . Five years was my comfort point.

 

[cerich]

I'm not being misleading I said " AFTER trying luxfer I'm fairly certain Paul ENDED UP using these tanks.

the tanks being discussed are the Chinese ones. So when you say "these tanks" well...

However,if you want to discuss the Luxfer..what particular knowledge does a CCR manuf have with regards to Luxfers testing and recommendations that lead him to believe that Luxfers recommendations should be ignored? Do you even know?