Options for onboard gas access.

Dave Sutton

To make it easy, I copied this from the rEvo page where it was hidden.



Blue hose to valve is onboard diluent coming FROM the cylinder to the manifold, able to be shut off with the valve.

Blue hose in middle returns diluent to the rig.

Black hose on left feeds BOV feed line (has CEJN on other end at BOV).

Inlet thru Swagelok non-return valve accepts any CEJN input (offboard gas bottle). Means that offboard gas can be fed from any bottle with the same hose that is used on a Viking Suit or Unisuit. Note that my drysuit inflator hose lays about 6 inches away from this inlet, and could be connected to it, or the offboard feed connected to my drysuit if needed.

Whatever diluent is selected as rig gas also feeds the BOV.

Onboard gas always feeds the drysuit (normal use).

Green 02 line feeds the wings / breathing inflator (wing inflate hose is on right side)

In abnormal conditions, either the diluent feed line or the 02 feed line can feed either BOV or the inflator... (redundant open circuit access to the gas)

Drysuit line can also feed the BOV or the inflator..... BOV has an articulating swivel that can feed at a 90 degree angle down, so the drysuit hose can be led directly to it, as can the feed hose from the offboard cylinder.

*Lots* of flexibility, but in normal use VERY simple. Leave the black valve closed. Internal bottle feeds drysuit. Offboard feeds BOV and ADV. Onboard 02 feeds wings (never inflated unless drysuit fails). Shut off (or disconnect) the offboard bottle, open the black valve, and onboard diluent feeds BOV and ADV. VERY simple and EVERYTHING can feed ANYTHING in an emergency. Offboard cylinder also has second stage (naturally).


The manifold with the QD and valve hangs trapped under my chest-strap on my harness. Makes it easy to access, simple to work with, and can be "unstuffed" and held out towards a buddy if needed. Actually, to be precise, the manifold is tie-wrapped to the left handset of the rEvo. The cross-chest strap goes over the *handset* cable/hose, and the manifold lays *on top* of the cross chest strap. I'll shoot photos of that later. It's a small detail.


Comments?


Dave


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Attached Images

	block.JPG (35.1 KB, 769 views)
	block2.JPG (37.0 KB, 767 views)
	bov.JPG (32.1 KB, 768 views)
	02[1].JPG (40.5 KB, 765 views)

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Professional Small Boy: Never Successfully Cubicled.

sadave

Convert your stage bottles to DIN?

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Hanssing

Dave, what happens if the block is switched off or you run out of dill without any offboard connected?

Will the block loose pressure, and get water-ingress through the checkvalve for the offboard? And fill the tubing?

I've been thinking a lot about your setup, since my rEvo is now on order.
And I really like the idea for OC-access to O2, via inflator/octo on right side. Its the best application for a low performing POS i've seen. I think I'll adapt the O2-idea right away, but I'll perhaps further discourage any buddys and myself from breathing this reg at depth by covering it with:
Mouthpiece octopus holder BEST DIVERS Accessories Regulators Denmark Dive Scuba store .com
If I can find it in green.

Bailout from dil, will have to be a necklaced reg to start with.

I find your system very well thought out, and is looking for any single point of failures - but I dont see any, because you can disconnect the offboard completely, and go oc directly from this supply. Though not very likely, as that would mean a leak after the block. And you can still move connector to your BOV.

Only thing: Doesn't the BOV get very heavy, with QD, swivel and all?

Nicolai - Newbie

Dave Sutton

Yup, well.... I just happened to have that old 30 hanging around. It's the last yoke clamp bottle on the boat, usually consigned to use for trailer tire inflation.


Dave

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"All animals are equal, but some animals are more equal than others"


Professional Small Boy: Never Successfully Cubicled.

Dave Sutton

Hi Nicolai,

With the diluent turned off and the stage bottle unplugged, it would take a lot to get water thru the checkvalve. In any event, it would be a REALLY unusual day for that to happen. Frankly, in the time I've used these sorts of systems (Have had this same thing on my IDA-71 for years now), I've *never* unplugged the offboard underwater. And if a few CC's of water did get past the checkvalve... so what? As DrMike said in an earlier post, clean your second stage after you clean your underwear, 'cause you had a really bad day.....

I suppose you could also add one more valve to the system, at the base of the non-return valve. I have considered it many times, but have decided not to do it. If I did add a valve, it would be a globe valve, IE: "turn on by opening a few turns" as opposed to the ball valve "turn by 90 degree reposition of the handle" so there would be NO doubt about what valve was under the hand in bad vis.

One thing not shown: A dummy female CEJN that I stick on the thing when intentionally diving with no offboard connected. It's a plugged CEJN that just acts as a blind plug. Keeps crap from entering the NRV.

There's a million ways to do this, what I show is just what I do. BOV's are essential kit, and should access as miuch gas as you plan to use for at least the first 5 minutes on OC, in my opinion. You may need that much time. Forget that regulator on a necklace. Order a BOV and never dive without it.

One permutation you might consider before your BOV comes: Simply connect the "BOV supply hose" (for lack of a better term) to the breathing inflator, and leave the green 02 line paralled to it, but not connected. It then requires an intentional "disconnect of diluent and connection of 02" to make that reg have 02 available. Surprisingly, the Zeagle verson of that inflator breathes very well (it's an Apeks product), and was originally also sold as a primary regulator. Jay Harding, for example, uses the primary regulator version as his OC regulator. It's not a bad reg. Also note that I added a LONG corrugated hose to it, so it's actually long enough to breathe out of properly. I would not likely hand it off, that's what the Poseidon on the stage bottle is for. Note also that the Zeagle "whatever it is" is bolt-snapped to the chest harness D-Ring. It's not likely that anyone is going to grab it and breathe out of it without my knowlage.

BOV balances just fine, remember that the hoses are bouyant. In fact, it's more comfortable than ever.


Few more photos attached, as these things sometimes defy words; The side of the rig, showing the diluent from the first stage taken to a brass manifold on the side of the rig, then split to two hoses: One for drysuit, and the other to the offboard/onboard block. Next photo shows the chest area of the diver (in fuzzy drysuit undies at the dock, BTW). Next shows the 02 line disconnected from the Zeagle inflator and connected to the BOV. Last shows the offboard cylinder supply line connected directly to the BOV.


The beauty of this system is that it requires NO management underwater for normal use, BOV and rig see the same gas, only management in a bailout is to go to the BOV, start ascent, breathe as long as you want to deco on mix, when mix exhausted shut off stage and open the ball valve (onboard air or nitrox now feeds both rig and BOV), continue deco on nitrox, and then for final deco grab the Zeagle and breathe your pure 02.

In the event of an "Oh SHIT" scenario, anything can be connected to anything. Even my drysuit feed line can feed both open circuit regs (BOV and Zeagle) and could be connected to the offboard gas QD on the chest block. Similarly, the offboard gas line can go t the drysuit.... nice to decon sometimes on a cooler gas when the surface water is warm.



Once again, the photos are actually wrong: In them I show the block and the handset trapped under the chest strap. In practice, the handset is trapped under the chest strap, the block hangs ovder it, and both are tie-wrapped togethetr so that that block hangs "right where you want it" all the time. I can see it with my mask on for visual ID and interaction.



Hinmt: If you WANT to be able to discnnect easially, with gloves, use a GENUINE Unisuit inflator hose. They have the large diameter "grip" on the coupling. If you DO NOT want it to be easy to disconnect, use the other versions of the supply hoses. They require a bit more work to disconnect. Like they say in the parachute loft at the squadron: "No detail too small to save a human life".



Dave

Attached Images

	chest.JPG (34.2 KB, 727 views)
	revoside.JPG (33.0 KB, 733 views)
	bovdil.JPG (33.3 KB, 727 views)
	revo02.JPG (31.9 KB, 727 views)

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Professional Small Boy: Never Successfully Cubicled.

divetheworld

Very Kirby Morgan. I can smell a commie a mile away!

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UWSojourner

I've had a few CO2 hits, not as severe as others have described on this forum. I was able to get to my bailout reg, but I can see how a more critical event would make it much more difficult if not impossible. BOV on order.

Thanks for the pics Dave.

Dave Sutton

"Commie" being slang for "Commercial Diver" I presume and not one who flies Commie Jet Fighters or dives Commie IDA-71's? .... ?

The block is functionally identical to the one on a Superlite 17 or any of the band masks, less the freeflow valve, so good eye.



Dave

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"All animals are equal, but some animals are more equal than others"


Professional Small Boy: Never Successfully Cubicled.

Hanssing

Ahh, ok, that sounds like a good idea.


Advice taken, but I didn't think I would thinking about modifying my first Rebreather before I had even recieved it... I must be



Again a good idea,
Tough if used on a very shallow dive, with only onboard dil/o2, I would be without OC while changing over, not so good.
Thats where I find your system really shines. For shallow change nothing, just dont bring all the stages, you have access to all gas as OC. For deep stuff, bring all the stages you want, and current dil is allways available OC.
And if you feel creative, you can reroute everything.

Noted now - did not see that before, thnx.

Great with the ekstra pics.

Nicolai

Gilles

I found it a peice of cake. Handing off to an OC buddy, trying to make things difficult for me (at my request) by pulling on the hose before dis-connecting. Needed two hands for that. Otherwise, the Golem QD I use can disconnect with a single hand if I get a good grip on it.


I felt your efforts at uploading your photos and furhter explanation warranted another green blob. On behalf of those benefitting from the efforts you make at teaching others what you know, thank you .

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Gilles
http://www.dirrebreather.com