Auto-ShuDBoF Valves

AD_ward9 · 2nd September 2005, 18:33

The combined Auto ShutOff, DIL, Bail-out and Flush valve thread is here:

http://www.rebreatherworld.com/t1153-.html

3D pictures of it are in the Gallery, including see-through so construction is apparent.

Issues to improve/refine:

1. Main issue/weakness is how to make the ADV part so it cannot freeflow.

The design does this presently uses four cams, such that two cams from opposite sides must lift, for the valve to open. The diaphram is a condom, which presses on 4 paddles, each of which is connected to a cam. It does work, but concern about paddles sticking when they go through the wall. We are now trying paddles that clip directly to the cam and have no other bearing surface.

Presentation on this is attached (sorry, commercial at end, it is a company presentation).

2. Secondary Issues. During testing it failed the porridge test. Put dilute Readybreak through the valve and dry out. It should not stick. It does. Porridge equates to cave silt, and to bio-grundge that ends up on the mechanism. Thinking about how to fix this one. The valve itself clogs up.
A paddle like on the Jetstream second stage may be an answer.

3. If it is connected to the scrubber, and located on the back, it is not possible to reach the buttons for manual DIL inject that are on the valve. Do we add a second chord, or just put in a normal manual DIL button?

All suggestions or constructive criticism of the valve is welcome. Any other weaknesses?

Cheers,
Alex

Faceless · 10th October 2006, 19:21

Regarding mug/valve being clogged up.
I've come to interesting conclusion ( sorry in advance if it does loook stupid).
Ok so the problem appears when loop is being fllooded somehow with polluted water (for example huge amount of silt floating around).
IMHO the most obvous option here would be to fit a plunger operated with extended stroke/push of manual dulent addition button.

Or (maybe) you've already solved this issue with some purge mechanism ?

AD_ward9 · 11th October 2006, 02:30

Quote: (Originally Posted by Faceless)

Regarding mug/valve being clogged up.
I've come to interesting conclusion ( sorry in advance if it does loook stupid).
Ok so the problem appears when loop is being fllooded somehow with polluted water (for example huge amount of silt floating around).
IMHO the most obvous option here would be to fit a plunger operated with extended stroke/push of manual dulent addition button.

Or (maybe) you've already solved this issue with some purge mechanism ?

The flood is detected before it gets to the inhale bag, by detecting the increase in breathing resistance across the scrubber. This then shuts the shutoff valve before water can get into the inhale counterlung.

Cheers

Alex

Faceless · 11th October 2006, 07:14

Heh, that tryly elegant solution: instead of trying to withstand contamination, let's detect flood at very early stage. Thanks for explanations.

10th October 2006, 19:21	#2 (permalink)
Faceless New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: May 2006 Location: France, Montpellier Posts: 88	Re: Auto-ShuDBoF Valves Regarding mug/valve being clogged up. I've come to interesting conclusion ( sorry in advance if it does loook stupid). Ok so the problem appears when loop is being fllooded somehow with polluted water (for example huge amount of silt floating around). IMHO the most obvous option here would be to fit a plunger operated with extended stroke/push of manual dulent addition button. Or (maybe) you've already solved this issue with some purge mechanism ?
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11th October 2006, 02:30	#3 (permalink)
AD_ward9 So much more to learn Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 1,605	Re: Auto-ShuDBoF Valves Quote: (Originally Posted by Faceless) Regarding mug/valve being clogged up. I've come to interesting conclusion ( sorry in advance if it does loook stupid). Ok so the problem appears when loop is being fllooded somehow with polluted water (for example huge amount of silt floating around). IMHO the most obvous option here would be to fit a plunger operated with extended stroke/push of manual dulent addition button. Or (maybe) you've already solved this issue with some purge mechanism ? The flood is detected before it gets to the inhale bag, by detecting the increase in breathing resistance across the scrubber. This then shuts the shutoff valve before water can get into the inhale counterlung. Cheers Alex
(Offline)

11th October 2006, 07:14	#4 (permalink)
Faceless New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: May 2006 Location: France, Montpellier Posts: 88	Re: Auto-ShuDBoF Valves Heh, that tryly elegant solution: instead of trying to withstand contamination, let's detect flood at very early stage. Thanks for explanations.
(Offline)

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