Options for onboard gas access.

Mdemon · 7th September 2007, 17:14

For normal diving, Quick Connect all round. Very deep, from second stage of cylinder.

silent running · 8th September 2007, 09:32

Quote: (Originally Posted by Drmike)

Why not get rid off all that hardware and utilize the LP port areas inside the onboard 1st stages as manifolds.

All you need is 2 QCs.

Onboard feed everything incl BOV.

If you are in danger of exhausting the onboard dil when youve bailed you close off the dil valve (if you want) and connect the QC hose to the off board dil. Now your running BOV, adv, and inflation off off board dil.

This the way I was taught to rig my BO in tmix class-using the 1st stage lp ports as a manifold. Except my off board gas is connected with the QC lp whips to the dil 1st stage all the time, with valve closed until needed. It is a very flexible and simple system and with a BOV, access to BO gas is just a valve and lever turn and away.

MarcLaukien · 10th September 2007, 13:11

Quote: (Originally Posted by Drmike)

Why not get rid off all that hardware and utilize the LP port areas inside the onboard 1st stages as manifolds.

I like the simplicity of this solution. However, I have two comments/questions:

Even if the QD has a check valve, a small amount of salt water will get into the LP port area of the 1st stage, if the offboard is connected in the water (or even above, if the QD is still wet from a prior dive). Do you consider this a problem?
I'm not a regulator expert, but can this be done with all common regulators, such as the DiveRite regulators? Are there regulators that won't tolerate the LP section being pressurized externally without the HP section being under pressure?

lizardland · 10th September 2007, 14:58

Quote: (Originally Posted by Drmike)

Why not get rid off all that hardware and utilize the LP port areas inside the onboard 1st stages as manifolds.

I'm waiting on some parts to do something similar. Instead of hooking offboard to the inboard 1st stage I thought of using my wing inflator. Basically it's an adaptor made from 2 nipples back to back on a 3/8"-UNF double-ender.

If you need it, disconnect the wing, plug the adaptor into an inflator on the offboard bottle, hook it into the wing inflator and now you've got gas to the manifold.

With the KISS there is no real way of adding an offboard connection without adding another failure point in the gas plumbing so I figured if I could use existing connections then there is less chance of it going wrong. It's a last ditch effort, really meant for SCR'ing out of caves so I don't care about getting water inside (better in the Rebreather's pipework than in mine).

I've no idea if it'll work but it's only cost me a couple of quid for parts.

Cheers,

Stuart

Drmike · 10th September 2007, 15:22

Quote: (Originally Posted by MarcLaukien)

I like the simplicity of this solution. However, I have two comments/questions:

Even if the QD has a check valve, a small amount of salt water will get into the LP port area of the 1st stage, if the offboard is connected in the water (or even above, if the QD is still wet from a prior dive). Do you consider this a problem?

the swageloks I use are self clearing with only a tiny amount of water being allowed in if connected undereater. the LP port area is just a hole - nothing to get damaged by salt water - my bail gas 2nd/1st stages are flooded on most dives - just need to service 2nds from time to time. but yes use a qc underwater and you will get a bit of water in.

Quote:

I'm not a regulator expert, but can this be done with all common regulators, such as the DiveRite regulators? Are there regulators that won't tolerate the LP section being pressurized externally without the HP section being under pressure?

its just a cavity in the 1st stage you can connect there or into a inline manifold.

Gilles · 12th September 2007, 13:09

Here comes another stab following the above feedback, and using available hardware.

Pic 1: Revised schematic.

Pic 2: Note the QD male with checkvalve installed on the t near the wing inflator. Offboard bailout or Oxygen are connecyed here.

Pic 3: Close up showing the t and BOV hose with a shut-off on both the BOV and ADV.

Pic 4: Onboard O2 connected to system for OC access (this hose normally connected to left CL man-ad).

Much lighter and simpler

.

More comment/critique invited before further small refinements and cleaning.

OceanOpportunity · 12th September 2007, 13:33

I've arrived at a this system:

onboard O2 and offboard O2 meet at a block on my right shoulder. The offboard is connected via a QD. A switch 'on' draws from onboard. Swith 'off' draws from offboard. From the block, O2 travels to solonoid or orifice and manual add. The offboard O2 can be unplugged and plugged directly to my BOV for O/C O2 at shallow deco if necessary

onboard dil (air) and offboard dil (air or gas) feeds a block on my left shoulder. Offboard is via a QD. Switch 'on' for onboard. Switch 'off' for offboard. From the block, dil feeds my ADV, manual add, and BOV via a QD. The dil can be unplugged from the BOV to directly plug in O2, or another offboard dil cylinder.

In this case, all ccr systems are fed by the gas that is switched either 'on' for onboard, or 'off' for offboard. I can also bypass all of the plumbing on the ccr and plug gas directly into my BOV for an OC bailout scenario.

jdicediver · 13th September 2007, 19:37

Quote: (Originally Posted by Gilles)

Here comes another stab following the above feedback, and using available hardware.

Pic 3: Close up showing the t and BOV hose with a shut-off on both the BOV and ADV.

Where did you purchase the cool tees from?

Gilles · 13th September 2007, 23:15

Quote: (Originally Posted by jdicediver)

Where did you purchase the cool tees from?

Golem Gear, Inc. - Hose Fittings and Adapters

Drmike · 16th September 2007, 13:33

Quote: (Originally Posted by Gilles)

Here comes another stab following the above feedback, and using available hardware.

Pic 1: Revised schematic.

Pic 2: Note the QD male with checkvalve installed on the t near the wing inflator. Offboard bailout or Oxygen are connecyed here.

Pic 3: Close up showing the t and BOV hose with a shut-off on both the BOV and ADV.

Pic 4: Onboard O2 connected to system for OC access (this hose normally connected to left CL man-ad).

Much lighter and simpler

.

More comment/critique invited before further small refinements and cleaning.

how does the check valve effect the wob?

View Poll Results: Which BOV plumbing concept (to include onboard gas) is preferred?
All QD's using no switchblocks	14	38.89%
1 Switch for off to onboard dil. QD at BOV for O2	5	13.89%
Like option2 but QD's at switchblock	2	5.56%
Two switchblocks.	1	2.78%
Use 2nd stages on each tank	17	47.22%
Multiple Choice Poll. Voters: 36. You may not vote on this poll

7th September 2007, 17:14	#41 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,866	Re: Options for onboard gas access. For normal diving, Quick Connect all round. Very deep, from second stage of cylinder. __________________ www.southwestmafia.com
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8th September 2007, 09:32	#42 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,743	Re: Options for onboard gas access. Quote: (Originally Posted by Drmike) Why not get rid off all that hardware and utilize the LP port areas inside the onboard 1st stages as manifolds. All you need is 2 QCs. Onboard feed everything incl BOV. If you are in danger of exhausting the onboard dil when youve bailed you close off the dil valve (if you want) and connect the QC hose to the off board dil. Now your running BOV, adv, and inflation off off board dil. This the way I was taught to rig my BO in tmix class-using the 1st stage lp ports as a manifold. Except my off board gas is connected with the QC lp whips to the dil 1st stage all the time, with valve closed until needed. It is a very flexible and simple system and with a BOV, access to BO gas is just a valve and lever turn and away.
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10th September 2007, 13:11	#43 (permalink)
MarcLaukien Custom Title Allowed! Current Rebreather/s: Other CCR Other Rebreather/s: Optima Other CCR Join Date: Dec 2006 Location: South East Florida Posts: 169	Re: Options for onboard gas access. Quote: (Originally Posted by Drmike) Why not get rid off all that hardware and utilize the LP port areas inside the onboard 1st stages as manifolds. I like the simplicity of this solution. However, I have two comments/questions: Even if the QD has a check valve, a small amount of salt water will get into the LP port area of the 1st stage, if the offboard is connected in the water (or even above, if the QD is still wet from a prior dive). Do you consider this a problem? I'm not a regulator expert, but can this be done with all common regulators, such as the DiveRite regulators? Are there regulators that won't tolerate the LP section being pressurized externally without the HP section being under pressure?
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10th September 2007, 14:58	#44 (permalink)
lizardland Yak Current Rebreather/s: Classic Kiss Ray Home Build Other Rebreather/s: Ray Home Build Join Date: Mar 2005 Location: North... Posts: 1,138	Re: Options for onboard gas access. Quote: (Originally Posted by Drmike) Why not get rid off all that hardware and utilize the LP port areas inside the onboard 1st stages as manifolds. I'm waiting on some parts to do something similar. Instead of hooking offboard to the inboard 1st stage I thought of using my wing inflator. Basically it's an adaptor made from 2 nipples back to back on a 3/8"-UNF double-ender. If you need it, disconnect the wing, plug the adaptor into an inflator on the offboard bottle, hook it into the wing inflator and now you've got gas to the manifold. With the KISS there is no real way of adding an offboard connection without adding another failure point in the gas plumbing so I figured if I could use existing connections then there is less chance of it going wrong. It's a last ditch effort, really meant for SCR'ing out of caves so I don't care about getting water inside (better in the Rebreather's pipework than in mine). I've no idea if it'll work but it's only cost me a couple of quid for parts. Cheers, Stuart __________________ Can you imagine drifting along in the sea with your mouth open and a load of f***ing plankton going in? You'd like it, would you? www.westons-cider.co.uk Azerbaijani Association of Technical Divers Publicity Officer and Goat Wrangler
(Online)

10th September 2007, 15:22	#45 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,062	Re: Options for onboard gas access. Quote: (Originally Posted by MarcLaukien) I like the simplicity of this solution. However, I have two comments/questions: Even if the QD has a check valve, a small amount of salt water will get into the LP port area of the 1st stage, if the offboard is connected in the water (or even above, if the QD is still wet from a prior dive). Do you consider this a problem? the swageloks I use are self clearing with only a tiny amount of water being allowed in if connected undereater. the LP port area is just a hole - nothing to get damaged by salt water - my bail gas 2nd/1st stages are flooded on most dives - just need to service 2nds from time to time. but yes use a qc underwater and you will get a bit of water in. Quote: I'm not a regulator expert, but can this be done with all common regulators, such as the DiveRite regulators? Are there regulators that won't tolerate the LP section being pressurized externally without the HP section being under pressure? its just a cavity in the 1st stage you can connect there or into a inline manifold. __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you
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12th September 2007, 13:33	#47 (permalink)
OceanOpportunity for a world of water Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Other CCR Dolphin Home Build Join Date: Nov 2006 Location: Providence, RI USA Posts: 465	Re: Options for onboard gas access. I've arrived at a this system: onboard O2 and offboard O2 meet at a block on my right shoulder. The offboard is connected via a QD. A switch 'on' draws from onboard. Swith 'off' draws from offboard. From the block, O2 travels to solonoid or orifice and manual add. The offboard O2 can be unplugged and plugged directly to my BOV for O/C O2 at shallow deco if necessary onboard dil (air) and offboard dil (air or gas) feeds a block on my left shoulder. Offboard is via a QD. Switch 'on' for onboard. Switch 'off' for offboard. From the block, dil feeds my ADV, manual add, and BOV via a QD. The dil can be unplugged from the BOV to directly plug in O2, or another offboard dil cylinder. In this case, all ccr systems are fed by the gas that is switched either 'on' for onboard, or 'off' for offboard. I can also bypass all of the plumbing on the ccr and plug gas directly into my BOV for an OC bailout scenario. __________________ Michael Lombardi Oceans of Opportunity www.oceanopportunity.com Elected Director, Society for Human Performance in Extreme Environments MN'07, The Explorers Club Project Manager, Diving a Dream
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13th September 2007, 19:37	#48 (permalink)
jdicediver Single/burdened with cash Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jun 2006 Location: Calgary, Alberta Posts: 253	Re: Options for onboard gas access. Quote: (Originally Posted by Gilles) Here comes another stab following the above feedback, and using available hardware. Pic 3: Close up showing the t and BOV hose with a shut-off on both the BOV and ADV. Where did you purchase the cool tees from? __________________ Regards; "Alterations performed under controlled conditions, on a closed course by a qualified Closed Circuit Diver" "Some people shouldn't dive...others shouldn't even get wet".
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13th September 2007, 23:15	#49 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 761	Re: Options for onboard gas access. Quote: (Originally Posted by jdicediver) Where did you purchase the cool tees from? Golem Gear, Inc. - Hose Fittings and Adapters __________________ Gilles http://www.dirrebreather.com
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16th September 2007, 13:33	#50 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,062	Re: Options for onboard gas access. Quote: (Originally Posted by Gilles) Here comes another stab following the above feedback, and using available hardware. Pic 1: Revised schematic. Pic 2: Note the QD male with checkvalve installed on the t near the wing inflator. Offboard bailout or Oxygen are connecyed here. Pic 3: Close up showing the t and BOV hose with a shut-off on both the BOV and ADV. Pic 4: Onboard O2 connected to system for OC access (this hose normally connected to left CL man-ad). Much lighter and simpler . More comment/critique invited before further small refinements and cleaning. how does the check valve effect the wob? __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you Last edited by Drmike : 16th September 2007 at 13:36. Reason: took another look at pics
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