Just saw a video weirded me out.

Garth

Tunnel Vision
I'm trying to figure out what the heck this video of UTD MX Series mCCR rebreather of a meg is talking about. Do they have the loop reversed? He keeps saying the exhale side is on the left and diluent side is on the right.


Sent from my Shearwater Predator...
 
I'm trying to figure out what the heck this video of UTD MX Series mCCR rebreather of a meg is talking about. Do they have the loop reversed? He keeps saying the exhale side is on the left and diluent side is on the right.


Sent from my Shearwater Predator...


UTD, Garth, Dude don't drink that kool aid.
 
Yes if I remember corectly. There is no leaky valve on the unit so O2 injection is all manual through the MAV.
Gabe
 
Yes if I remember corectly. There is no leaky valve on the unit so O2 injection is all manual through the MAV.
Gabe

I may live to regret stepping in here, but oh well :)

The UTD unit does have the exhale on the left, and inhale on the right
O2 is injected on the left side manually on the "MX" and manually/leaky valve on the "MC"

MX is the "current" version, but some MC's might still be around.

The O2 is on a slung/stage bottle with a QC connector, and the diluent is from a set of doubles, with the primary diluent added on the right-side (manual add only on the Meg but I think there may be an ADV on the KISS version)

BOV is connected to the left-post regulator on the doubles.

Also a 7-foot long hose on the right side (can only supply diluent)

Also a spare plugin on the right-side for a stage, intermediate gas, or if the left-side were to fail.
 
I may live to regret stepping in here, but oh well :)

The UTD unit does have the exhale on the left, and inhale on the right
O2 is injected on the left side manually on the "MX" and manually/leaky valve on the "MC"

MX is the "current" version, but some MC's might still be around.

The O2 is on a slung/stage bottle with a QC connector, and the diluent is from a set of doubles, with the primary diluent added on the right-side (manual add only on the Meg but I think there may be an ADV on the KISS version)

BOV is connected to the left-post regulator on the doubles.

Also a 7-foot long hose on the right side (can only supply diluent)

Also a spare plugin on the right-side for a stage, intermediate gas, or if the left-side were to fail.

Interesting. Kinda the what if system... However it has a lot more bits than mine. Also I expect it is a little top heavy.

I have tried a few different tank sizes. I really feel a diference as they get larger.

I just replaced my orfice with a needle valve, so I am in no position to dis the no orfice bunch.

I think less is more. Each to his own.

Peter
 
Diluent add on right to be consistent with their philosophy I presume is the reasoning. Just odd they would totally switch the normal pattern of a rebreather to do this.


Sent from my Shearwater Predator...
 
Diluent add on right to be consistent with their philosophy I presume is the reasoning. Just odd they would totally switch the normal pattern of a rebreather to do this.


Sent from my Shearwater Predator...

I guess I dont know enough about it to make any judgements.
Not having used any other CCR I guess i never had any other "instincts" to unlearn from that perspective.

If anyone is interested, there are plenty of videos and documents on the UTD site that go into far more detail about the reasoning than I'd ever have any hope of doing!
 
Interesting. Kinda the what if system... However it has a lot more bits than mine. Also I expect it is a little top heavy.

I have tried a few different tank sizes. I really feel a diference as they get larger.

I've not noticed any particular head-heaviness, maybe the extra gas in the lungs up front helps.

People use it from Steel LP45s, through 85s, AL80s and even up to LP120s (sorry for all my imperial units, I know many people here use metric)

It's a pretty simple system without a lot of doo-hickies overall.
 
I'm trying to figure out what the heck this video of UTD MX Series mCCR rebreather of a meg is talking about. Do they have the loop reversed? He keeps saying the exhale side is on the left and diluent side is on the right.


Sent from my Shearwater Predator...


The megas an American unit and they even drive on the wrong side of the road so you cant expect them to get a gas path corect.:thumbsup:


Set from my full sized qwuerty key board and Packard Bell desk top


ATB

Mark
 
The megas an American unit and they even drive on the wrong side of the road so you cant expect them to get a gas path corect.:thumbsup:


Set from my full sized qwuerty key board and Packard Bell desk top


ATB

Mark

Haha!
I just wanted to see what the rest of the rebreather community thought about making such a change to the flow of gas. One would have to be very careful when diving a system like this if they had any training with conventional configuration because of the fact that the oxygen MAV and diluent MAV are switched.
Muscle memory may get you in trouble if things start to get weird. ;-)


Sent from my Shearwater Predator...
 
Haha!
I just wanted to see what the rest of the rebreather community thought about making such a change to the flow of gas. One would have to be very careful when diving a system like this if they had any training with conventional configuration because of the fact that the oxygen MAV and diluent MAV are switched.
Muscle memory may get you in trouble if things start to get weird. ;-)


Sent from my Shearwater Predator...

Well, here is my view.

If I understand correctly, the flow of gas is

1. O2 manual add in the exhale counterlung
2. Diluent manual add in the inhale counterlung

Personally, I agree with 1. above because it places the the O2 manual injection upstream of the O2 Cell. Under no circumstance in a eCCR or mCCR you want the O2 injection downstream of the O2 Cells and upstream of the mouth, as this would breach the 1st Rule of Rebreather Diving: "Always Know your pPO2." You cannot know the pPO2 you are breathing if the O2 injection (manual or solenoid) is downstream of the O2 Cells.

Instead, I disagree with 2., for the same reasons as in point 1. above. Not a good idea to have the Diluent injection downstream of the O2 Cells and upstream of the mouth especially if you use hypoxic diluent.

So, for me (personal choice), O2 and Diluent manual injection in the exhale counterlung on the left side. Diluent on the ADV and O2 on a manual add button (two different locations and tactile feel and operation modes... so no risk to make a mistake... and everything is operated with one hand only, including dry-suit and BCD inflator), leaving the right hand free for the Cave Line or Scootering or checking instruments or holding the reel...

I am obviously neither DIR nor UTF nor ISC compliant (so I must be "wrong")... but better S t r o k e all the way than something else somewhere else.
 
Last edited:
Well, here is my view.

If I understand correctly, the flow of gas is

1. O2 manual add in the exhale counterlung
2. Diluent manual add in the inhale counterlung

Personally, I agree with 1. above because it places the the O2 manual injection upstream of the O2 Cell. Under no circumstance in a eCCR or mCCR you want the O2 injection downstream of the O2 Cells and upstream of the mouth, as this would breach the 1st Rule of Rebreather Diving: "Always Know your pPO2." You cannot know the pPO2 you are breathing if the O2 injection (manual or solenoid) is downstream of the O2 Cells.

Instead, I disagree with 2., for the same reasons as in point 1. above. Not a good idea to have the Diluent injection downstream of the O2 Cells and upstream of the mouth especially if you use hypoxic diluent.

So, for me (personal choice), O2 and Diluent manual injection in the exhale counterlung on the left side. Diluent on the ADV and O2 on a manual add button (two different locations and tactile feel and operation modes... so no risk to make a mistake... and everything is operated with one hand only, including dry-suit and BCD inflator), leaving the right hand free for the Cave Line or Scootering or checking instruments or holding the reel...

I am obviously neither DIR nor UTF nor ISC compliant (so I must be "wrong")... but better ****** all the way than something else somewhere else.

Do you have a photo? How far apart are they? Do you have the dil above the o2 or vice versa?


Sent from my Shearwater Predator...
 
Do you have a photo? How far apart are they? Do you have the dil above the o2 or vice versa?


Sent from my Shearwater Predator...

You can see the history of all my mods. beginning with the ridiculous and ending with the current one here:



When I have time I will take some of the latest pics. form the above link and post them here as well (later, not now).

The Diluent is connected to the Meg exhale counterlung ADV. If you know what it looks likes, no change except that I have added a hi-flo Omniswivel QD (can put any gas I want and in a no electronics emergency I can exit cave scootering in semi-closed rebreather bail-out mode... plus I sidemount my dil. so it is a convenient way to hook on since I place first my sidemount tanks in the water, and then walk in and hook them up).

The O2 is connected to the standard Meg (Sitech) manual add valve below the ADV (exhale counterlung). This was before I modified further the configuration (I now use the same connection, but it is modified to free-flow without pushing the button, has an Omniswivel QC with one-way valve, and connected to it there is a Pelagian Needle Valve connected to a dedicated O2 bottle... which makes the rebreather an hCCR).

If you look at the pics. of the Mods in my forum you will understand better what I mean.

I still can use the standard Meg connector on the inhale side and feed there O2 from the 2nd O2 bottle feeding the eCCR side (I have 3 O2 Cells in the inhale counterlung so can do this safely), but I leave this free with nothing connected (if the solenoid fails, I disconnect the O2 feed from the solenoid end and connect the QC to the inhale counterlung connection... so I can manual feed O2 from any one of the O2 bottles on inhale or exhale... but this will only be done if eCCR fails and Pelagian Needle Valve fails as well... there is a shut-off valve to isolate the solenoid if I disconnect the QC)

It is for the purpose of redundancy and survival allowing me to have several options without over-complicating the configuration, but again pics. will explain better.
 
Last edited by a moderator:
You can see the history of all my mods. beginning with the ridiculous and ending with the current one here:

Login

When I have time I will take some of the latest pics. form the above link and post them here as well (later, not now).

The Diluent is connected to the Meg exhale counterlung ADV. If you know what it looks likes, no change except that I have added a hi-flo Omniswivel QD (can put any gas I want and in a no electronics emergency I can exit cave scootering in semi-closed rebreather bail-out mode... plus I sidemount my dil. so it is a convenient way to hook on since I place first my sidemount tanks in the water, and then walk in and hook them up).

The O2 is connected to the standard Meg (Sitech) manual add valve below the ADV (exhale counterlung). This was before I modified further the configuration (I now use the same connection, but it is modified to free-flow without pushing the button, has an Omniswivel QC with one-way valve, and connected to it there is a Pelagian Needle Valve connected to a dedicated O2 bottle... which makes the rebreather an hCCR).

If you look at the pics. of the Mods in my forum you will understand better what I mean.

I still can use the standard Meg connector on the inhale side and feed there O2 from the 2nd O2 bottle feeding the eCCR side (I have 3 O2 Cells in the inhale counterlung so can do this safely), but I leave this free with nothing connected (if the solenoid fails, I disconnect the O2 feed from the solenoid end and connect the QC to the inhale counterlung connection... so I can manual feed O2 from any one of the O2 bottles on inhale or exhale... but this will only be done if eCCR fails and Pelagian Needle Valve fails as well... there is a shut-off valve to isolate the solenoid if I disconnect the QC)

It is for the purpose of redundancy and survival allowing me to have several options without over-complicating the configuration, but again pics. will explain better.

Sorry, but I am overquota and the forum here does not allow me to add any more attachments (maybe the Admin or a Mod can release more storage space and increase my quota).
 
O.K., with the help of Clare managed to figure out how to upload images donating some of the rebreathermallorca.com bandwith to CCRX.

Be aware that nothing is what it seems insofar the Sitech manual add valve and Omnsiwivel QC one-way valves have modifications (5 in total)... so DO NOT try to replicate anything from any picture as it may kill you. This is just to show what I do (i.e. "show and tell" like at school) and as it is contrary to original manufacturer design and configuration it is "wrong" (but that is the way I like it :chuckle: as it increases dependability and gives me "options" in accordance to my Homebuilder rebreather standard).

...also these are oldish pics. which give a good idea of the overall concept (but if you want to see details of the current configuration which is from time to time updated check regularly here: Login )

IMG_20110630_095103.jpg


IMG_20120413_110406.jpg
 
You do know that Leon (ISC) makes a part that would replace your gutted-out drysuit inflator valve to do the same thing (add a place to inject gas). They are basically the body of the ADV but as a simple add-port without any internal valve, etc. They were the gas injection points for the Manta Lungs, where the add valves were remotely mounted. They thread into the CL's just like an ADV, using the same backing plate. Just might clean it up a bit and reduce points of possibility for failing.


Dave

.
 
You do know that Leon (ISC) makes a part that would replace your gutted-out drysuit inflator valve to do the same thing (add a place to inject gas). They are basically the body of the ADV but as a simple add-port without any internal valve, etc. They were the gas injection points for the Manta Lungs, where the add valves were remotely mounted. They thread into the CL's just like an ADV, using the same backing plate. Just might clean it up a bit and reduce points of possibility for failing.


Dave

.

The standard ADV and ADV exhale counterlung port I need it as is from the ISC factory because I use it as an ADV for diluent (or any other gas I want to QC into it).

I needed some place to inject the Needle Valve output (or CMF output for those who prefer the CMF), and it is easy enough to QC it into the standard MAV (modified to leak) in the exhale counterlung.

Of course, once you modify it to leak gas... you need to stop it leaking water in when you disconnect the QC :thumbsup:

I had a different contraption made by N@90 to go on top of the head to connect the Needle Valve (or CMF), but it kept on getting loose and leak (not nice because I could not reach it behind the head to fix it while diving)... so found the solution described above which requires very little modification (and reliable and cheap).
 
Last edited:
Back
Top