Bad design of boris'sloop?

Marc T

I prefer to open a new thread, for this tittle-question not to disappear to fast or without answer even if I am completely Wrong.
Im very surprised when reading th thread boris-flood that nobody find its abnormal that water can come from the exhale CL-water trap directly in the scrubber.
I guess its due to the special design of the boris so I think a better way could be to eliminate the exhale CL and to place the OPV on the inhale CL.

Hum I certainly dont get any friend or green on this one

Mdemon

I don't think it's a bad thing criticising a unit if you are trying to find a solution - I don't quite understand the benefits of your solution though? More info?

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www.southwestmafia.com

It's as easy as abc;

a) "Carry adequate bailout"

b) "If in doubt, bail out"

c) "Always know your PO2"

If you find that hard, stick to crochet.

"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"

Drmike

Hang on, hang on So can every other rebreather.

Exhale is into the exhale lung (That is your water trap) then from there into the scrubber

Just like a YBOD, PRISM,, Meg etc etc etc. No different

The OPV should be on the exhale side as thats where you need to be able to clear water - BEFORE it fills the water trap (that is the CL) and gets into the scrubber.

Perhaps you should get more familar with Rebreather design before going on a rant?

I agree its not yet perfect - but thats the OPV fault not a fault with the loop design. One of the issues with teh MK15 series design was no opv to clear water out the exhale side. Its not much good having the ability to clear water out the inhale side (like a MK15 series) if theres no way to clear it out the exhale/scrubber.

The only thing that I think needs sorting on the Boris loop is a more muck tolerant OPV.

Thats not rocket science and Im sure it will be sorted soon. in the meantime keeping crap out the CL would prevent problems happening.


I think its important to keep things factual assuming the agenda is to improve system design and not just to flame

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Marc T

If you get water in the exhale OTS CL its stay in the CL you see and feel it and can dump it.
In the boris the water can obviously too easily come from exhale CL into the Scruber and create caustic cocktail.
Its as dangerous as if the OPV was directly fited in the scrubber.
MK15 is one of my prefered Rebreather ( nether own it and nether will because its a too old and difficult to maintain ) Boris is one of my theorically prefered RB but flooding a loop is one of the greatest prob you can have on a RB, preventin flood is much important to me thank the possibility of recovering the loop.
Was'nt the MK15 OPV in the (unique) inhale counterlung?

Drmike

I do love it when people who have never owned or dived them tell me how both of my rebreathers work.

Boris = in prone position you would have water coming from the flooded exhale lung down the exhale hose and giving you warning that the lung was flooding before the water level rises enough to enter the scrubber. Scrubber outlet is at the top when prone.

In upright position (who spends much time like that) you would have to fill half the CL to get water in the scrubber. I dont know why (unless your teaching as has happened to one owner, but not thru a opv leak) you would spend that long upright (it would take a while to fill a CL)



I own a MK15.5 I bought a Boris in part because it has far better flood recovery ability. And it does. When my MK15.5 flooded in a cave It was a nasty caustic cocktail and no chance of recovery, when my Boris flooded I had no cocktail and was able to recover it.

To recover a loop you need an OPV. Yes sure Im the first to admit the boris OPV needs work. Focus on the actual problem.

Not with the hydrophobic membrane. Some like me have used o-rings to seal them in, some and the factory use silicon, but a sealed membrane will/does stop cocktails.

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Mark Chase

I agree I have had a significant flood on the YBOD (maby 2ltrs of water following the mouthpiece falling off) and all the water staid in the counter lung there was little more than a few drops in the bottom of the scrubber.

I dumped most of it through the OPV and finished the dive on loop

Even if the leek was perpetual you have clear indication in the loop and counterlung and emptying the loop is simple enough. With a bit of fafing you can do it without using up dill as well.

It seems obvious that with rear mounted lungs this is going to be a lot harder to achieve. but I am not failure with loop recovery on a Boris so it may have a trick up its sleeve. However from the posts of Iani and Dr Mike its not a very good one.

ATB

Mark Chase

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CCR900

If you get water into an Inspiration exhale CL for example it too will migrate to the base of the scrubber and eventually into the sofnolime. In that case there is a semi hydrophobic membrane that keeps a portion of the water out, though the scrim's primary function is to stop the sofnolime falling through the spider. There is no option for that particular diver other than to expel water by lying on his stomach and massage water out via the OP valve which happens also to be on the exhale side (this process is not easy).

In the case of the Ouroborus water that collects in the exhale CL is met by a far more effective hydrohobic membrane (there is an issue of water by passing this membrane but I understand that this is being resolved), expelling water requires to diver to go into a +/- vertical position and over pressurising the loop, gravity does the rest. As DrMike said the OPV needs to be 'bettered'.

If you are for an OPV on the inhale side then it would be best to give us a few pro's but I think you will be hard pressed.

F

CCR900

Your OPV is on your exhale lung right? The water will stay in the lung as long as you mainatin an upright position it would migrate quickly if your body position were to change i.e. in a wreck or cave. Dumping water from a YBOD lung can be tricky and I note is not taught as standard practise...

F

Drmike

Clearing the Boris loop is really hard...it involves staying horizontal and pressing the dil button

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Marc T

I just suggest to to do some tests with a boris with only a inhale CL with the OPV on it just like MK15.
The other modification is to increase the ability of the exhale CL to maintain more water in it before going in the scrubber (perhaps changing the place of the OPV ).
The solution of the unique inahle CL as the interest of lowering the leak risk in the exhale part of your Rebreather that you cant easily and quickly detect.
Thats a technical choice that has been done after long reflexion either on the Joki Rebreather and the Decorider (side monted RB ).
Nothing is perfect in the Rebreather world, I neither flame for pleasure, just reflexion.
The "tonality" of some responses make me feel that I was right to open a new thread when the subject is "disturbing