matt
Well-Known Member
They've got a bit of a cult status in the UK at least, and they used to be expensive but the Euro's not so strong now
Matt.
Safety of radial vs axial scrubber
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They've got a bit of a cult status in the UK at least, and they used to be expensive but the Euro's not so strong now
Matt.
gianaameri
gian @ gian.ameri.name
That is the benefits of "CE."
You can have rebreathers with a massive WOB relative to the NEDU limits, but you cannot have a BOV.
That is because the "CE" Committee has been unable to agree that a BOV should be part of the CE standard (which in any event is applied differently by different Notified Bodies in different EU countries).
Absolute madness!
You are in the U.S..
Buy a Meg with an 8 lbs. ISC Radial (HSL Tested) and APECS Primary and Secondary (NEDU Tested, and none of the complexity of the Shearwater) and you have a reliable product which will not let you down (although it can kill you)... and add a Golem Shrimp BOV to it!
Personally, I would not dive it without adding an entirely separate and redundant pPO2 Monitoring system (I do not use a Secondary connected to the same O2 Cells as the Primary), but then again according to the manufacturer and NEDU it is fine as it is.
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Excellent although why not add an ISC BOV to it? Is it less efficient than the Shrimp?
Envoy***233; depuis mon GT-I9100 avec Tapatalk
gianaameri
gian @ gian.ameri.name
Golem has published an independent test report from ANSTI for its Shrimp BOV.
I would not dream to use untested equipment or tested equipment with undisclosed test results or tested equipment with poor test results. It would be way too risky.
Do you have a test report for the ISC BOV to compare?
It all boils down to WOB numbers (and dependability of course).
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PeterN
Active Member
I have the 5.5 lb. Meg radial. I do not find any big deal about the fill, tapa tapa fill, tapa tapa fill, tapa tapa proccess. I have never found any settling even after very long car and boat rides.
I have never found any settling after a dive. I am carefull to pack it tight. I place a weight on the lid when I am finishing it off.
I am certain the axial is faster and easier, not sure I greatly miss the ten minuets lost from my day though.
Peter
matt
Well-Known Member
Thanks for the info Peter. I rather suspect you are right - no big difference between them on all scores.
Matt.
paulraymaekers
Active Member
this whole tread starts to read like a joke!
first, people are bragging about the need for the lowest WOB scrubber, must be this, must be that, radial better then axial,... all for 'safety'
then the next post.. advice to modify the unit against manufacturers recommendation, and so that it dramatically increases the WOB of the whole unit???
first, people are bragging about the need for the lowest WOB scrubber, must be this, must be that, radial better then axial,... all for 'safety'
then the next post.. advice to modify the unit against manufacturers recommendation, and so that it dramatically increases the WOB of the whole unit???
gianaameri
gian @ gian.ameri.name
This is an interesting point.
Is modifying a rebreather a bad thing to do?
Hell NO, it is the thing to do, if you increase dependability and safety.
I would not dive any rebreather including the Meg, despite being one of the best and most tested rebreather, without modification to make it ALARP conformant.
I would never modify any electronics though (add electronics and O2 cells, YES, but not modify).
MeRodent
New Member
Starts?
paulraymaekers
Active Member
modifiing a rebreather, without understanding the consequences, is only done by ... not so smart people
some examples:
replacing a good working DSV by a BOV: the WOB on the unit increases
replacing a wide bore bite piece by a small bore bite piece; the WOB sky-rockets
adding/exchanging the backplate on a unit with BMCL; hydrostatic imbalance goes outside the CE limits
using non-appoved sorb, non approved sensors...
gianaameri
gian @ gian.ameri.name
Building a rebreather with a WOB of 2.75 j/l at 100 meters is not a good thing.
Building a rebreather with back-mounted counterlung and not meeting the NEDU standard for Hydrostatic Imbalance is not a good thing.
Everybody can do the wrong things without understanding the consequences.
That is why it is important to use the best sorb, the best sensors, the best scrubber, the best DSV or BOV, the best... but to determine what is the "best" the user needs numbers from independent test houses.
No numbers, and no smart person can know right from wrong.
What is the Hydrostatic Imbalance of the rEVO and the JJ, for example?
No numbers, and we do not know if the design is right or wrong.
PeterN
Active Member
The major mod to my Meg has been to add a rEvo cast off gag strap. :wavey:
Thanks Paul,
Peter
matt
Well-Known Member
Does also poking wires into the loop (a la mode Beanie holder for Inspo) and other loop touching mods also affect WOB - Paul? I always thought it should. I've also heard others say about the mouth piece (common mod). I dive a totally unmodified Inspo with DSV (not for WOB specifically - just because it works).
Thanks
Matt.
gianaameri
gian @ gian.ameri.name
I suspect the gag strap is made by Draeger and not by rEVO.
I have one as well as one of my Meg mods (the Draeger one).
anarchista
New Member
Do you remember Paul, stream continuity equation?
You know where there is a chemical reaction, of CO2 binding.
Ca (OH) 2 + CO2 -> CaCO3 + H2O
The canister component wanes, comes another. Even in serious cases you talking about fairy tales.
greet rc
paulraymaekers
Active Member
rc: what do you want to say? please get a translator polish-english
JacobT
New Member
I'm not tooting any particular team here, but I have to ask. Are all those "upgrades" tested on the unit you are applying it to?
Saying one BOV is better because it has lower WOB is surely only applicable if it has been tested in your specific unit. Again I have to refer to my lack of CCR experience but from what I have read this seems to be a rather complicated area and just because XYZ reduces WOB on unit X doesn't automatically mean it reduces WOB on unit Y?
-Jacob
PS. personally, I find it strange when someone asks for numbers to compare with his/hers without providing ones him/her self (it might have been provided earlier in the thread and I missed it, in which case ignore this comment)
MeRodent
New Member
Paul my point is that this thread started to read like a joke a considerable time ago.
And Gian, I think everyone on this thread understands your desire to dive nothing but numbers in isolation, that only NEDU testing is good enough, CE is a total waste of time (doesn't affect me in Australia anyway) and all CCR deaths are related to WOB.
I received a Dilbert calendar for Christmas and there is a cartoon that I think applies here. Alice (one of the characters) asks "If I can get sworn statements from everyone here that we understand your point, will you stop talking?"
I generally find that packing a radial scrubber is a little more time consuming than packing an axial scrubber. That said, I do not find it overly complicated, and would not make my decision of which unit to purchase based on the ease of packing the scrubber. I am much more concerned about the performance of the scrubber.
By the way, I would also add that the axial vs. radial scrubber argument is a little bit of a red herring. There is much more that goes into the performance of a scrubber than just whether it is radial or axial. Things such as gas flow, size, environmental protection (insulation) and so on and so forth have a huge impact on the overall performance and duration of the scrubber. IMHO, simply stating that radial or axial is a preferred design, is not possible without taking into consideration other design elements which highly impact the performance of the scrubber.
Warm regards,
Randy
JONT
New Member
Randys statements are accurate you must consider the design of the unit and its various attributes in order to paint an accurate picture because other factors affect WOB and scrubber performance i.e.:
I've put 9 hours on my revo in Ginnie on one very long day with standard axials.....BUT you need to consider other factors like the following that swing duration BIG TIME.
1) Water temp...Ginnie 72 degrees
2) Work load...the super majority of that was at low to no work
The point being that if this was 39 degree water and was working the smart money would say I'd be dead.
As far as speed and ease of packing scrubbers properly pre packed and cartridge units go into the idiot proof category, that would be followed by the revo and meg axial (less the 4 minutes to pack properly), the radials with springs would be next but they are substantially more time consuming and more care must be taken (20 minutes or less), then you have the pain in the ass category (cis lunar, radials without springs, and a few others) these take time and a vibrator becomes very handy but if you dont really know what they are or understand the need don't worry because you have years of RB diving before you will be ready to even look down that road.
There are a lot of RB divers that develop these overly complex units with isolation slides, various gas flow paths and bla, bla, bla, truth be told its nonsense, there are even some instructors out there that promote these rigs and thats just a money grab.
Most that have these mega rigs have never seen the end of the gold at Ginnie, couldn't tell you where Big or Little Sister is and have never seen the end of cow or done the grand traverse and reverse traverse in one day.
truth be told they are safer on LP 104's.
RB diving is great but make a good, informed decision and try before you buy, the scrubber is a factor not a reason.
Today I did a two plus hour dive with a friend from NJ at Ginnie and was more then happy and I have scrubber left over for tomorrow, to quote JOEL from LIGHT MONKEY "If you can dive here on Christmas Day you're doing something right"
Take it slow and be smart, you are asking the right questions.
Jon
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