Rebreather World - View Single Post - Why not redundant one-way valves?

***jradomski*** · 4th January 2006, 19:52

Quote: (Originally Posted by Sutty)

Just a thought which has been nagging at me since before I bought a Rebreather....

Why do we not have redundant one-way valves, ie 4 rather than 2? You could have 1 inhale next to the mouthpiece and one at the scrubber head, same on exhale side.

I find it hard to believe it would increase WOB significantly, and I understand there has been at least 1 death from deformed valves.

I suspect if my kiss inhale valve was stuck open a significant part of each exhale would go back to the inhale counterlung (especially if I was tilted right side down) and get re-breathed, potentially leading to hypoxia/hypercapnia. Same applies to other makes of Rebreather.

Any thoughts anyone?...

Neil

Hi neil,

If you have ever seen testing of the WOB on rebreathers, you wouldn't even have to ask this question.. Its something that many divers are not aware of..

On many designs the greatest contribution to WOB IS the DSV, and the flapper/mushroom valves are a significant part of this..

Most people do not realize how much changing the DSV can alter the characteristics of the breathing loop.

4th January 2006, 19:52	#7 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,000	Re: Why not redundant one-way valves? Quote: (Originally Posted by Sutty) Just a thought which has been nagging at me since before I bought a Rebreather.... Why do we not have redundant one-way valves, ie 4 rather than 2? You could have 1 inhale next to the mouthpiece and one at the scrubber head, same on exhale side. I find it hard to believe it would increase WOB significantly, and I understand there has been at least 1 death from deformed valves. I suspect if my kiss inhale valve was stuck open a significant part of each exhale would go back to the inhale counterlung (especially if I was tilted right side down) and get re-breathed, potentially leading to hypoxia/hypercapnia. Same applies to other makes of Rebreather. Any thoughts anyone?... Neil Hi neil, If you have ever seen testing of the WOB on rebreathers, you wouldn't even have to ask this question.. Its something that many divers are not aware of.. On many designs the greatest contribution to WOB IS the DSV, and the flapper/mushroom valves are a significant part of this.. Most people do not realize how much changing the DSV can alter the characteristics of the breathing loop. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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