Duncan's New Add System

DanDunfee · 7th June 2007, 01:24

Quote: (Originally Posted by Tom Rose)

I completed the changes in the system. First I again modified the o2 side as planned above. Then I assembled the rig. The pics below speak for them selves.

Tom: It's looking cleaner and better all the time ....now if it just had two loop hoses ;-)

Duncan: Do I remember correctly that one of those little push-button Clippard valves sstuck open on you...maybe inside a wreck ?? If so, what's the corrective action ??

Dan

Tom Rose · 7th June 2007, 01:37

Quote: (Originally Posted by DanDunfee)

Tom: It's looking cleaner and better all the time ....now if it just had two loop hoses ;-)

Dan

Thanks Dan,

I think thats about it. The only mods now will be a bigger (13 cf) diluent tank for deeper diving as it is also the bailout.

You feeling better yet?

Tom

DanDunfee · 7th June 2007, 01:40

Tom

I' thought I understood your gas routing, but am now less sure.
I assume that the green-hosed route is the oxy, and blue is air / nitrox.
and that the second, blue, branch line (kinked slightly) is a whip for a bailout reg.
If that's not correct, please straighten ne out.

Dan

DanDunfee · 7th June 2007, 02:37

For My phase I initial testing, I'll use the original little 0.8 l bottle & RGU valve and, like you, a 2 l diluent bottle for BC, and to provide a minimal, shallow- water bailout capability.

For Phase II I'll use a 2 l O2 bottle and a CMF systen similar to what y'all are working up now, and about a 5 l diluent bottle, for several reasons, including:

* Those bottle sizes will provide for 2 dives, of my kind of recreational boat
diving , without having to change or refill bottles,.. only changing out the
smaller pre-filled scrubbers, so each dive begins with a fresh scrubber.

* Also the larger dil tank will provide adequate BC, ullage, bailout, ...and the limited deco
obligation that can occurr with that sized scrubber, even near the end of
a 2 nd repetitive dive.

* Also, I'll have an SCR variant of the rig, .... just for the hell of it. ;-).....
and because its hard to wean ole EOD Frogs from the kind of rigs they
suckeled on ;-)

Dan

Tom Rose · 7th June 2007, 03:13

Quote: (Originally Posted by DanDunfee)

Tom

I' thought I understood your gas routing, but am now less sure.
I assume that the green-hosed route is the oxy, and blue is air / nitrox.
and that the second, blue, branch line (kinked slightly) is a whip for a bailout reg.
If that's not correct, please straighten ne out.

Dan

You got it right. I just rerouted the system Dave set up for Duncan on the O2 side. All the parts are there...the orifice...the valve...and of course a filter. Just rotated a few parts to get them off the tank. I am in the process of designing a BOV for the pend.

Tom

Duncan Price · 7th June 2007, 07:34

Quote: (Originally Posted by DanDunfee)

Duncan: Do I remember correctly that one of those little push-button Clippard valves stuck open on you...maybe inside a wreck ??

I caught the diluent injector on the frame of an access hole in the floor of the helecopter at Stoney Cove. I was going head first through it witnessed by John Routley (Narked@90). The gas just vented out of the o.p. valve in the base of the scrubber.

Quote: (Originally Posted by DanDunfee)

If so, what's the corrective action ??

Fit a shrouded cover over the button: sump4.com/rebreather/d5_construction

You'll notice the the O2 feed has an isolater, so can be switched off withought depressurising the feed, both O2 and diluent lines can be disconnected.

I consider the Clippard valves no more unreliable than any other push button add (e.g. a drysuit inflator). Mind you, even though they had 25 in stock, the UK distributor still hasn't sent me the two I ordered 2 weeks ago - so I may be going elsewhere.

Tom Rose · 7th June 2007, 12:12

Quote: (Originally Posted by Duncan Price)

I caught the diluent injector on the frame of an access hole in the floor of the helecopter at Stoney Cove. I was going head first through it witnessed by John Routley (Narked@90). The gas just vented out of the o.p. valve in the base of the scrubber.

Fit a shrouded cover over the button: sump4.com/rebreather/d5_construction

You'll notice the the O2 feed has an isolater, so can be switched off withought depressurising the feed, both O2 and diluent lines can be disconnected.

I consider the Clippard valves no more unreliable than any other push button add (e.g. a drysuit inflator). Mind you, even though they had 25 in stock, the UK distributor still hasn't sent me the two I ordered 2 weeks ago - so I may be going elsewhere.

Duncan, I have 8 in stock myself,

I can send you one.

Tom

DanDunfee · 7th June 2007, 12:34

[quote=Duncan Price;119095].
sump4.com/rebreather/d5_construction quote]

Nice writeup on a novel, and well-thought-thru concept for a specialized application....caving. Have a greenie.
Good gas routing plan, but wish fewer joints / FMECA Failure Sites... esp with tubing.
Specifically what factor(s) prompted you to a 2nd (inh.) CL ??

Duncan Price · 7th June 2007, 15:49

Quote: (Originally Posted by Tom Rose)

Duncan, I have 8 in stock myself,

I can send you one.

Tom

Two? I could do with a couple of shrouded push button covers as well. We have buckets full of Swagelok ones here but they have tilt levers.

Duncan Price · 7th June 2007, 15:53

[quote=DanDunfee;119139]

Quote: (Originally Posted by Duncan Price)

.
sump4.com/rebreather/d5_construction quote]

Nice writeup on a novel, and well-thought-thru concept for a specialized application....caving. Have a greenie.
Good gas routing plan, but wish fewer joints / FMECA Failure Sites... esp with tubing.
Specifically what factor(s) prompted you to a 2nd (inh.) CL ??

Am trending towards completely manual diluent and O2 adds to reduce complexity - simple to drive, simple to dive (tm??!). All the tubing is now stainless steel braided PTFE.

The current unit only has one CL (inhale side). Dual CL's too complex. In due course I'll update the information presented.

7th June 2007, 01:24	#61 (permalink)
DanDunfee Custom Title Allowed! Current Rebreather/s: Other CCR Other SCR Home Build Other Rebreather/s: Not Bought Yet Other CCR Other SCR Home Build Join Date: Sep 2005 Location: Virginia, USA Posts: 204	Re: Duncan's New Add System Quote: (Originally Posted by Tom Rose) I completed the changes in the system. First I again modified the o2 side as planned above. Then I assembled the rig. The pics below speak for them selves. Tom: It's looking cleaner and better all the time ....now if it just had two loop hoses ;-) Duncan: Do I remember correctly that one of those little push-button Clippard valves sstuck open on you...maybe inside a wreck ?? If so, what's the corrective action ?? Dan __________________ There are 'Bold' divers and old divers, but NO old, ' Bold ' divers
(Offline)

7th June 2007, 01:37	#62 (permalink)
Tom Rose Still Learning Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Prism Topaz Other CCR Home Build Join Date: Oct 2005 Location: USA,North Carolina Posts: 331	Re: Duncan's New Add System Quote: (Originally Posted by DanDunfee) Tom: It's looking cleaner and better all the time ....now if it just had two loop hoses ;-) Dan Thanks Dan, I think thats about it. The only mods now will be a bigger (13 cf) diluent tank for deeper diving as it is also the bailout. You feeling better yet? Tom __________________ The 50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong the first time. www.atlimp.com
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7th June 2007, 01:40	#63 (permalink)
DanDunfee Custom Title Allowed! Current Rebreather/s: Other CCR Other SCR Home Build Other Rebreather/s: Not Bought Yet Other CCR Other SCR Home Build Join Date: Sep 2005 Location: Virginia, USA Posts: 204	Re: Duncan's New Add System Tom I' thought I understood your gas routing, but am now less sure. I assume that the green-hosed route is the oxy, and blue is air / nitrox. and that the second, blue, branch line (kinked slightly) is a whip for a bailout reg. If that's not correct, please straighten ne out. Dan __________________ There are 'Bold' divers and old divers, but NO old, ' Bold ' divers Last edited by DanDunfee : 7th June 2007 at 01:44.
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7th June 2007, 02:37	#64 (permalink)
DanDunfee Custom Title Allowed! Current Rebreather/s: Other CCR Other SCR Home Build Other Rebreather/s: Not Bought Yet Other CCR Other SCR Home Build Join Date: Sep 2005 Location: Virginia, USA Posts: 204	Re: Duncan's New Add System For My phase I initial testing, I'll use the original little 0.8 l bottle & RGU valve and, like you, a 2 l diluent bottle for BC, and to provide a minimal, shallow- water bailout capability. For Phase II I'll use a 2 l O2 bottle and a CMF systen similar to what y'all are working up now, and about a 5 l diluent bottle, for several reasons, including: * Those bottle sizes will provide for 2 dives, of my kind of recreational boat diving , without having to change or refill bottles,.. only changing out the smaller pre-filled scrubbers, so each dive begins with a fresh scrubber. * Also the larger dil tank will provide adequate BC, ullage, bailout, ...and the limited deco obligation that can occurr with that sized scrubber, even near the end of a 2 nd repetitive dive. * Also, I'll have an SCR variant of the rig, .... just for the hell of it. ;-)..... and because its hard to wean ole EOD Frogs from the kind of rigs they suckeled on ;-) Dan __________________ There are 'Bold' divers and old divers, but NO old, ' Bold ' divers Last edited by DanDunfee : 7th June 2007 at 12:12.
(Offline)

7th June 2007, 03:13	#65 (permalink)
Tom Rose Still Learning Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Prism Topaz Other CCR Home Build Join Date: Oct 2005 Location: USA,North Carolina Posts: 331	Re: Duncan's New Add System Quote: (Originally Posted by DanDunfee) Tom I' thought I understood your gas routing, but am now less sure. I assume that the green-hosed route is the oxy, and blue is air / nitrox. and that the second, blue, branch line (kinked slightly) is a whip for a bailout reg. If that's not correct, please straighten ne out. Dan You got it right. I just rerouted the system Dave set up for Duncan on the O2 side. All the parts are there...the orifice...the valve...and of course a filter. Just rotated a few parts to get them off the tank. I am in the process of designing a BOV for the pend. Tom __________________ The 50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong the first time. www.atlimp.com
(Offline)

7th June 2007, 07:34	#66 (permalink)
Duncan Price Sump Monster Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Feb 2005 Location: Wells, Somerset, UK Posts: 335	Re: Duncan's New Add System Quote: (Originally Posted by DanDunfee) Duncan: Do I remember correctly that one of those little push-button Clippard valves stuck open on you...maybe inside a wreck ?? I caught the diluent injector on the frame of an access hole in the floor of the helecopter at Stoney Cove. I was going head first through it witnessed by John Routley (Narked@90). The gas just vented out of the o.p. valve in the base of the scrubber. Quote: (Originally Posted by DanDunfee) If so, what's the corrective action ?? Fit a shrouded cover over the button: sump4.com/rebreather/d5_construction You'll notice the the O2 feed has an isolater, so can be switched off withought depressurising the feed, both O2 and diluent lines can be disconnected. I consider the Clippard valves no more unreliable than any other push button add (e.g. a drysuit inflator). Mind you, even though they had 25 in stock, the UK distributor still hasn't sent me the two I ordered 2 weeks ago - so I may be going elsewhere.
(Offline)

7th June 2007, 12:12	#67 (permalink)
Tom Rose Still Learning Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Prism Topaz Other CCR Home Build Join Date: Oct 2005 Location: USA,North Carolina Posts: 331	Re: Duncan's New Add System Quote: (Originally Posted by Duncan Price) I caught the diluent injector on the frame of an access hole in the floor of the helecopter at Stoney Cove. I was going head first through it witnessed by John Routley (Narked@90). The gas just vented out of the o.p. valve in the base of the scrubber. Fit a shrouded cover over the button: sump4.com/rebreather/d5_construction You'll notice the the O2 feed has an isolater, so can be switched off withought depressurising the feed, both O2 and diluent lines can be disconnected. I consider the Clippard valves no more unreliable than any other push button add (e.g. a drysuit inflator). Mind you, even though they had 25 in stock, the UK distributor still hasn't sent me the two I ordered 2 weeks ago - so I may be going elsewhere. Duncan, I have 8 in stock myself, I can send you one. Tom __________________ The 50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong the first time. www.atlimp.com
(Offline)

7th June 2007, 12:34	#68 (permalink)
DanDunfee Custom Title Allowed! Current Rebreather/s: Other CCR Other SCR Home Build Other Rebreather/s: Not Bought Yet Other CCR Other SCR Home Build Join Date: Sep 2005 Location: Virginia, USA Posts: 204	Re: Duncan's New Add System [quote=Duncan Price;119095]. sump4.com/rebreather/d5_construction quote] Nice writeup on a novel, and well-thought-thru concept for a specialized application....caving. Have a greenie. Good gas routing plan, but wish fewer joints / FMECA Failure Sites... esp with tubing. Specifically what factor(s) prompted you to a 2nd (inh.) CL ?? __________________ There are 'Bold' divers and old divers, but NO old, ' Bold ' divers Last edited by DanDunfee : 7th June 2007 at 12:44.
(Offline)

7th June 2007, 15:49	#69 (permalink)
Duncan Price Sump Monster Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Feb 2005 Location: Wells, Somerset, UK Posts: 335	Re: Duncan's New Add System Quote: (Originally Posted by Tom Rose) Duncan, I have 8 in stock myself, I can send you one. Tom Two? I could do with a couple of shrouded push button covers as well. We have buckets full of Swagelok ones here but they have tilt levers.
(Offline)

7th June 2007, 15:53	#70 (permalink)
Duncan Price Sump Monster Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Feb 2005 Location: Wells, Somerset, UK Posts: 335	Re: Duncan's New Add System [quote=DanDunfee;119139] Quote: (Originally Posted by Duncan Price) . sump4.com/rebreather/d5_construction quote] Nice writeup on a novel, and well-thought-thru concept for a specialized application....caving. Have a greenie. Good gas routing plan, but wish fewer joints / FMECA Failure Sites... esp with tubing. Specifically what factor(s) prompted you to a 2nd (inh.) CL ?? Am trending towards completely manual diluent and O2 adds to reduce complexity - simple to drive, simple to dive (tm??!). All the tubing is now stainless steel braided PTFE. The current unit only has one CL (inhale side). Dual CL's too complex. In due course I'll update the information presented.
(Offline)

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