ADV Placement

diverrob · 31st May 2005, 14:17

I currently have a CCR Dolphin and will be integrating a HS Explorer into it to help with decompression. I am concidering removing the relief valve in the exhale counterlung and replacing it with the ADV and then adding a third fuel cell in place of the ADV in the inhal counterlung. At present the only down side I can see is the lack of a relief valve which may be a problem if the O2 is left on after a dive or the valve gets bumped during transport. I would like to get some feed back on this. Thanks

Rob

narked at 90 · 31st May 2005, 19:26

hi rob this mod works very well but i would advise keeping the opv in the loop as i've left my o2 on a few times after the dive and im shoure i would have done some damage if i had removed the opv
i removed mine from the exhale and placed it on the back of the inhale so it sits between the scrubber ports and fitted an extra p-port so i have one for my displays and 1 for my vr3
you should be able to see some picys at http://www.yorkshire-divers.co.uk/gallery/rebreathers
also check out Tubby's site on the links page
hope this helps
kind regards john routley

Quote: (Originally Posted by diverrob)

I currently have a CCR Dolphin and will be integrating a HS Explorer into it to help with decompression. I am concidering removing the relief valve in the exhale counterlung and replacing it with the ADV and then adding a third fuel cell in place of the ADV in the inhal counterlung. At present the only down side I can see is the lack of a relief valve which may be a problem if the O2 is left on after a dive or the valve gets bumped during transport. I would like to get some feed back on this. Thanks

Rob

Scuba_Vixen · 31st May 2005, 20:29

Quote: (Originally Posted by diverrob)

I currently have a CCR Dolphin and will be integrating a HS Explorer into it to help with decompression. I am concidering removing the relief valve in the exhale counterlung and replacing it with the ADV and then adding a third fuel cell in place of the ADV in the inhal counterlung. At present the only down side I can see is the lack of a relief valve which may be a problem if the O2 is left on after a dive or the valve gets bumped during transport. I would like to get some feed back on this. Thanks

Rob

Timely Question, as I'm involved with a pair of Dolphin ccr conversions myself.

I also have an Explorer to use with it, and I'll be using the HSE PO2 monitor on a second cell.

Tubby has been moving the ADV to the OPV position for some time now on conversions that he's done. Just put a new P-Port in the hole you remove the opv from.

The reasoning was to increase the PO2 stability in the loop by giving the O2 a chance to more completely blend before reaching the O2 sensors.

He left the OPV out for a while but ended up relocating it to a position in the inhale bag slightly right of the original ADV location.

Here's a link to his website with a pic: (close to the bottom)

http://www.vk4tub.org/tubby/FinDolph.html

And another showing the ADV on top of the shell:

http://www.vk4tub.org/tubby/gasinjection.html

It would seem that the P-Ports and the OPV assembly use the same diameter hole.

I like the idea of adding the O2 well upstream of the sensors, but I'm not all that keen on placing the ADV in an exposed external location. I'm a bit more hesitant about placing the OPV in a more confined area.

My plan is to inject the O2 at the inlet to the scrubber, keeping the opv in it's original location. I will add another P-Port on the inhale bag, at the same location where Tubby's opv is, for redundant PO2 monitoring.

Tecme has a really nice adapter that uses a BC fitting to add O2 at the scrubber inlet.

Personally, I wouldn't move the ADV and do away with the OPV, for the sole purpose of freeing up a p-port. You could just add another one without disturbing anything that's already sealed and working. You have to buy one anyway to put the ADV in the opv's location. If you add O2 at the ADV, I'd consider changing that. With the add point so close to multiple sensors, I'd imagine you'll get very little agreement between readouts.

From Tubby's write ups, his conversions seem to work wonderfully, but as he says, they have very little over about 30m in depth. I can't predict if greater depths would add any complications with the relocated ADv or not.

Darlene

jdz · 31st May 2005, 20:43

Quote: (Originally Posted by Scuba_Vixen)

Timely Question, as I'm involved with a pair of Dolphin ccr conversions myself.

I also have an Explorer to use with it, and I'll be using the HSE PO2 monitor on a second cell.

Tubby has been moving the ADV to the OPV position for some time now on conversions that he's done. Just put a new P-Port in the hole you remove the opv from.

The reasoning was to increase the PO2 stability in the loop by giving the O2 a chance to more completely blend before reaching the O2 sensors.

He left the OPV out for a while but ended up relocating it to a position in the inhale bag slightly right of the original ADV location.

Here's a link to his website with a pic: (close to the bottom)

http://www.vk4tub.org/tubby/FinDolph.html

And another showing the ADV on top of the shell:

http://www.vk4tub.org/tubby/gasinjection.html

It would seem that the P-Ports and the OPV assembly use the same diameter hole.

I like the idea of adding the O2 well upstream of the sensors, but I'm not all that keen on placing the ADV in an exposed external location. I'm a bit more hesitant about placing the OPV in a more confined area.

My plan is to inject the O2 at the inlet to the scrubber, keeping the opv in it's original location. I will add another P-Port on the inhale bag, at the same location where Tubby's opv is, for redundant PO2 monitoring.

Tecme has a really nice adapter that uses a BC fitting to add O2 at the scrubber inlet.

Personally, I wouldn't move the ADV and do away with the OPV, for the sole purpose of freeing up a p-port. You could just add another one without disturbing anything that's already sealed and working. You have to buy one anyway to put the ADV in the opv's location. If you add O2 at the ADV, I'd consider changing that. With the add point so close to multiple sensors, I'd imagine you'll get very little agreement between readouts.

From Tubby's write ups, his conversions seem to work wonderfully, but as he says, they have very little over about 30m in depth. I can't predict if greater depths would add any complications with the relocated ADv or not.

Darlene

Hi Darlene,
I have used Tubby's mod for quite some dives now including regular dips to 80m+ (see on Tubbys site http://www.vk4tub.org/tubby/Bayonet/bayonet.html

The O2 add is in my adv and it is placed in the Exhale bag. However, I have not put my clungs under the knife to add an OPV.

I admit that leaving the O2 on can cause an overinflation situation, but its like launching a boat without the bungs, you only do it once!!

I have an on/off valve added inline at the needlevalve and I use it as soon as I surface and remove the mouthpiece.

However, if you insist to add the OPV, it is relatively easy. Use the smallest one you can find (from an old BC) and tuck it away, making sure you crank up the crack pressure..

Cheers, JDZ

Scuba_Vixen · 31st May 2005, 21:37

Quote: (Originally Posted by jdz)

Hi Darlene,
I have used Tubby's mod for quite some dives now including regular dips to 80m+ (see on Tubbys site http://www.vk4tub.org/tubby/Bayonet/bayonet.html

The O2 add is in my adv and it is placed in the Exhale bag. However, I have not put my clungs under the knife to add an OPV.

I admit that leaving the O2 on can cause an overinflation situation, but its like launching a boat without the bungs, you only do it once!!

I have an on/off valve added inline at the needlevalve and I use it as soon as I surface and remove the mouthpiece.

However, if you insist to add the OPV, it is relatively easy. Use the smallest one you can find (from an old BC) and tuck it away, making sure you crank up the crack pressure..

Cheers, JDZ

Why not use the original OPV, and just relocate it as in the photo onTubbies website?

What were you guys using for diluent on that trip to the Bayonet?

Nice looking conversions there,

Darlene

jdz · 31st May 2005, 22:50

Quote: (Originally Posted by Scuba_Vixen)

Why not use the original OPV, and just relocate it as in the photo onTubbies website?

What were you guys using for diluent on that trip to the Bayonet?

Nice looking conversions there,

Darlene

Thanks,

a) The Dolphin OPV in the casing takes up too much room.

Side rave. One of the main problems of the CCR dolphin IMO is that the clungs are too small for CCR. Especially under workload, it is easy to bottom out the lungs with an inhale and fill up with an exhale and this adds to the WOB. Sure, you can increase the offset of your backplate brkt and take care in how tight you close the flaps with the velco, but at the end of the day, buoyancy and comfort of unit on the back without too much roll adds to the fine tuning..

b) 80m 20 mins...

Dil 14/45 END 37m Vplanner 73min RT setpoint 1.2
Bailout 10lt 16/35 bottom mix + 10lt Nx40 Travel/deco runtime = 77mins

c) Thanks, I have now moved the cyls from the side and added them to the base of the casing as it allows me a narrower profile. I usually use 2 x 7lt sidemounts (instead of stages) for my bailouts upto ~60m. see http://www.smartgroups.com/pictures/openalbum.cfm?GID=257650&AlbumID=4198425

Cheers, JDZ

**wedivebc** · 31st May 2005, 22:59

Rob my big concern with doing away with the OPV is in the case of OC bailout. Where does that gas go as I ascend? Will I have the presence of mind to vent it after the shit hits the fan?

jdz · 31st May 2005, 23:58

Quote: (Originally Posted by wedivebc)

Rob my big concern with doing away with the OPV is in the case of OC bailout. Where does that gas go as I ascend? Will I have the presence of mind to vent it after the shit hits the fan?

Hi Dave,

I know we have discussed this before but if your sensors are in the inhale bag and you have to bail out and assuming you are ascending somewhat, then I can't see you needing the OPV, as I have said before, just spit the mouthpiece and don't shut it off and it will vent!

In all my bailout training and muck around towards the end of my dives, I haven't totally flooded the inhale bag, scrubber yes, but not knocked out my sensors..

Cheers, JDZ

**wedivebc** · 1st June 2005, 05:07

Quote: (Originally Posted by jdz)

Hi Dave,

I know we have discussed this before but if your sensors are in the inhale bag and you have to bail out and assuming you are ascending somewhat, then I can't see you needing the OPV, as I have said before, just spit the mouthpiece and don't shut it off and it will vent!

In all my bailout training and muck around towards the end of my dives, I haven't totally flooded the inhale bag, scrubber yes, but not knocked out my sensors..

Cheers, JDZ

So you're saying you just bail with the DSV open? I would then be concerned about buoyancy as well. Has that been an issue? I am interested in tubby's latest mod with an OPV where the ADV lives usually. Although I don't have a problem with cl volume since I am using Ron's backplate and I have moved it far enough away from the shell to allow plenty of volume, I don't like all the hardware flopping around inside the shell.

buggeriamold · 1st June 2005, 05:18

As a non dolphiner i am just wondering what the size total of the counterlungs is, the inhale looked largish to me.

Mark

31st May 2005, 14:17	#1 (permalink)
diverrob The Evolution of Diving Current Rebreather/s: Evolution Other SCR Other Rebreather/s: Not Bought Yet Other SCR Join Date: May 2005 Location: Victoria BC Canada Posts: 336	ADV Placement I currently have a CCR Dolphin and will be integrating a HS Explorer into it to help with decompression. I am concidering removing the relief valve in the exhale counterlung and replacing it with the ADV and then adding a third fuel cell in place of the ADV in the inhal counterlung. At present the only down side I can see is the lack of a relief valve which may be a problem if the O2 is left on after a dive or the valve gets bumped during transport. I would like to get some feed back on this. Thanks Rob
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31st May 2005, 19:26	#2 (permalink)
narked at 90 John Routley Current Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Other Rebreather/s: Other CCR Dolphin Home Build Join Date: Feb 2005 Location: middlands uk Posts: 1,035	hi rob this mod works very well but i would advise keeping the opv in the loop as i've left my o2 on a few times after the dive and im shoure i would have done some damage if i had removed the opv i removed mine from the exhale and placed it on the back of the inhale so it sits between the scrubber ports and fitted an extra p-port so i have one for my displays and 1 for my vr3 you should be able to see some picys at http://www.yorkshire-divers.co.uk/gallery/rebreathers also check out Tubby's site on the links page hope this helps kind regards john routley Quote: (Originally Posted by diverrob) I currently have a CCR Dolphin and will be integrating a HS Explorer into it to help with decompression. I am concidering removing the relief valve in the exhale counterlung and replacing it with the ADV and then adding a third fuel cell in place of the ADV in the inhal counterlung. At present the only down side I can see is the lack of a relief valve which may be a problem if the O2 is left on after a dive or the valve gets bumped during transport. I would like to get some feed back on this. Thanks Rob
(Online)

31st May 2005, 20:29	#3 (permalink)
Scuba_Vixen e/mCCR Dolphin Pilot Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: May 2005 Location: St. Croix USVI Posts: 557	Quote: (Originally Posted by diverrob) I currently have a CCR Dolphin and will be integrating a HS Explorer into it to help with decompression. I am concidering removing the relief valve in the exhale counterlung and replacing it with the ADV and then adding a third fuel cell in place of the ADV in the inhal counterlung. At present the only down side I can see is the lack of a relief valve which may be a problem if the O2 is left on after a dive or the valve gets bumped during transport. I would like to get some feed back on this. Thanks Rob Timely Question, as I'm involved with a pair of Dolphin ccr conversions myself. I also have an Explorer to use with it, and I'll be using the HSE PO2 monitor on a second cell. Tubby has been moving the ADV to the OPV position for some time now on conversions that he's done. Just put a new P-Port in the hole you remove the opv from. The reasoning was to increase the PO2 stability in the loop by giving the O2 a chance to more completely blend before reaching the O2 sensors. He left the OPV out for a while but ended up relocating it to a position in the inhale bag slightly right of the original ADV location. Here's a link to his website with a pic: (close to the bottom) http://www.vk4tub.org/tubby/FinDolph.html And another showing the ADV on top of the shell: http://www.vk4tub.org/tubby/gasinjection.html It would seem that the P-Ports and the OPV assembly use the same diameter hole. I like the idea of adding the O2 well upstream of the sensors, but I'm not all that keen on placing the ADV in an exposed external location. I'm a bit more hesitant about placing the OPV in a more confined area. My plan is to inject the O2 at the inlet to the scrubber, keeping the opv in it's original location. I will add another P-Port on the inhale bag, at the same location where Tubby's opv is, for redundant PO2 monitoring. Tecme has a really nice adapter that uses a BC fitting to add O2 at the scrubber inlet. Personally, I wouldn't move the ADV and do away with the OPV, for the sole purpose of freeing up a p-port. You could just add another one without disturbing anything that's already sealed and working. You have to buy one anyway to put the ADV in the opv's location. If you add O2 at the ADV, I'd consider changing that. With the add point so close to multiple sensors, I'd imagine you'll get very little agreement between readouts. From Tubby's write ups, his conversions seem to work wonderfully, but as he says, they have very little over about 30m in depth. I can't predict if greater depths would add any complications with the relocated ADv or not. Darlene
(Offline)

31st May 2005, 20:43	#4 (permalink)
jdz Prism Cave Diver Current Rebreather/s: Prism Topaz Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Feb 2005 Location: Melbourne Australia Posts: 219	Quote: (Originally Posted by Scuba_Vixen) Timely Question, as I'm involved with a pair of Dolphin ccr conversions myself. I also have an Explorer to use with it, and I'll be using the HSE PO2 monitor on a second cell. Tubby has been moving the ADV to the OPV position for some time now on conversions that he's done. Just put a new P-Port in the hole you remove the opv from. The reasoning was to increase the PO2 stability in the loop by giving the O2 a chance to more completely blend before reaching the O2 sensors. He left the OPV out for a while but ended up relocating it to a position in the inhale bag slightly right of the original ADV location. Here's a link to his website with a pic: (close to the bottom) http://www.vk4tub.org/tubby/FinDolph.html And another showing the ADV on top of the shell: http://www.vk4tub.org/tubby/gasinjection.html It would seem that the P-Ports and the OPV assembly use the same diameter hole. I like the idea of adding the O2 well upstream of the sensors, but I'm not all that keen on placing the ADV in an exposed external location. I'm a bit more hesitant about placing the OPV in a more confined area. My plan is to inject the O2 at the inlet to the scrubber, keeping the opv in it's original location. I will add another P-Port on the inhale bag, at the same location where Tubby's opv is, for redundant PO2 monitoring. Tecme has a really nice adapter that uses a BC fitting to add O2 at the scrubber inlet. Personally, I wouldn't move the ADV and do away with the OPV, for the sole purpose of freeing up a p-port. You could just add another one without disturbing anything that's already sealed and working. You have to buy one anyway to put the ADV in the opv's location. If you add O2 at the ADV, I'd consider changing that. With the add point so close to multiple sensors, I'd imagine you'll get very little agreement between readouts. From Tubby's write ups, his conversions seem to work wonderfully, but as he says, they have very little over about 30m in depth. I can't predict if greater depths would add any complications with the relocated ADv or not. Darlene Hi Darlene, I have used Tubby's mod for quite some dives now including regular dips to 80m+ (see on Tubbys site http://www.vk4tub.org/tubby/Bayonet/bayonet.html The O2 add is in my adv and it is placed in the Exhale bag. However, I have not put my clungs under the knife to add an OPV. I admit that leaving the O2 on can cause an overinflation situation, but its like launching a boat without the bungs, you only do it once!! I have an on/off valve added inline at the needlevalve and I use it as soon as I surface and remove the mouthpiece. However, if you insist to add the OPV, it is relatively easy. Use the smallest one you can find (from an old BC) and tuck it away, making sure you crank up the crack pressure.. Cheers, JDZ
(Online)

31st May 2005, 21:37	#5 (permalink)
Scuba_Vixen e/mCCR Dolphin Pilot Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: May 2005 Location: St. Croix USVI Posts: 557	Quote: (Originally Posted by jdz) Hi Darlene, I have used Tubby's mod for quite some dives now including regular dips to 80m+ (see on Tubbys site http://www.vk4tub.org/tubby/Bayonet/bayonet.html The O2 add is in my adv and it is placed in the Exhale bag. However, I have not put my clungs under the knife to add an OPV. I admit that leaving the O2 on can cause an overinflation situation, but its like launching a boat without the bungs, you only do it once!! I have an on/off valve added inline at the needlevalve and I use it as soon as I surface and remove the mouthpiece. However, if you insist to add the OPV, it is relatively easy. Use the smallest one you can find (from an old BC) and tuck it away, making sure you crank up the crack pressure.. Cheers, JDZ Why not use the original OPV, and just relocate it as in the photo onTubbies website? What were you guys using for diluent on that trip to the Bayonet? Nice looking conversions there, Darlene
(Offline)

31st May 2005, 22:50	#6 (permalink)
jdz Prism Cave Diver Current Rebreather/s: Prism Topaz Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Feb 2005 Location: Melbourne Australia Posts: 219	Quote: (Originally Posted by Scuba_Vixen) Why not use the original OPV, and just relocate it as in the photo onTubbies website? What were you guys using for diluent on that trip to the Bayonet? Nice looking conversions there, Darlene Thanks, a) The Dolphin OPV in the casing takes up too much room. Side rave. One of the main problems of the CCR dolphin IMO is that the clungs are too small for CCR. Especially under workload, it is easy to bottom out the lungs with an inhale and fill up with an exhale and this adds to the WOB. Sure, you can increase the offset of your backplate brkt and take care in how tight you close the flaps with the velco, but at the end of the day, buoyancy and comfort of unit on the back without too much roll adds to the fine tuning.. b) 80m 20 mins... Dil 14/45 END 37m Vplanner 73min RT setpoint 1.2 Bailout 10lt 16/35 bottom mix + 10lt Nx40 Travel/deco runtime = 77mins c) Thanks, I have now moved the cyls from the side and added them to the base of the casing as it allows me a narrower profile. I usually use 2 x 7lt sidemounts (instead of stages) for my bailouts upto ~60m. see http://www.smartgroups.com/pictures/openalbum.cfm?GID=257650&AlbumID=4198425 Cheers, JDZ
(Online)

31st May 2005, 22:59	#7 (permalink)
wedivebc Dave Tomblin Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,447	Rob my big concern with doing away with the OPV is in the case of OC bailout. Where does that gas go as I ascend? Will I have the presence of mind to vent it after the shit hits the fan? __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
(Offline)

31st May 2005, 23:58	#8 (permalink)
jdz Prism Cave Diver Current Rebreather/s: Prism Topaz Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Feb 2005 Location: Melbourne Australia Posts: 219	Quote: (Originally Posted by wedivebc) Rob my big concern with doing away with the OPV is in the case of OC bailout. Where does that gas go as I ascend? Will I have the presence of mind to vent it after the shit hits the fan? Hi Dave, I know we have discussed this before but if your sensors are in the inhale bag and you have to bail out and assuming you are ascending somewhat, then I can't see you needing the OPV, as I have said before, just spit the mouthpiece and don't shut it off and it will vent! In all my bailout training and muck around towards the end of my dives, I haven't totally flooded the inhale bag, scrubber yes, but not knocked out my sensors.. Cheers, JDZ
(Online)

1st June 2005, 05:07	#9 (permalink)
wedivebc Dave Tomblin Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,447	Quote: (Originally Posted by jdz) Hi Dave, I know we have discussed this before but if your sensors are in the inhale bag and you have to bail out and assuming you are ascending somewhat, then I can't see you needing the OPV, as I have said before, just spit the mouthpiece and don't shut it off and it will vent! In all my bailout training and muck around towards the end of my dives, I haven't totally flooded the inhale bag, scrubber yes, but not knocked out my sensors.. Cheers, JDZ So you're saying you just bail with the DSV open? I would then be concerned about buoyancy as well. Has that been an issue? I am interested in tubby's latest mod with an OPV where the ADV lives usually. Although I don't have a problem with cl volume since I am using Ron's backplate and I have moved it far enough away from the shell to allow plenty of volume, I don't like all the hardware flopping around inside the shell. __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
(Offline)

1st June 2005, 05:18	#10 (permalink)
buggeriamold Custom Title Allowed! Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Feb 2005 Location: australia Posts: 100	As a non dolphiner i am just wondering what the size total of the counterlungs is, the inhale looked largish to me. Mark __________________ Well, it is cheap stuff and it comes almost from the local gardening store, but it works fine and it's very solid. We tried to destroy one by hitting it with a hammer... we succeeded but we really had to hit it hard.
(Online)

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