O2 addition methods

seeboth · 18th April 2008, 16:49

Quote: (Originally Posted by Dave Sutton)

I have not: That is 180 degrees out of my suggestions.

I use blocked first stages for everything I build. I DO NOT suggest or support the use of non blocked first stages for mCCR "leaky valve" systems of any sort, orifice or needle valve. I'm not a needle valve fan either, and a search will come up with the posts that articulate my reasons.

And, not for nothing: You are making this WAY too complex. Just grab any small orifice, hook it up to a first stage, adjust the intermediate pressure to give you somewhere about 0.7 LPM and block off the first stage. Add 02 using a manual add valve as needed. Go diving. If I spent as much time thinking about this as some of you, I would never have built a thing.

Theory is only valid insofar as it reflect reality.

The reality is that this is butt-simple stuff to build.

Best,

Dave

.

I didnt mean to miss-quote you, and you have made your opinion on needle valves clear.
I was reading an older thread where I got the idea, (http://www.rebreatherworld.com/home-...tml#post107524)
see if I set the flow to be what I want at my bottom depth, taking the depth compensating regulator into mind, and them lock the needle valve into place, it is essentially and orifice that I can either close all the way (the unit is no longer a hybrid) or I could adjusted it for just over what my max depth would be, all done pre-dive. The entire set up would be in one block with the manual add button (bypass valve) so the whole thing could be added to the stock unit with out much in the way of drilling and tapping.

I go to college full time and work at a dive shop the rest of the time, so this is all about experimenting. At school I have a full machine shop and can get parts and raw material really easy and cheap, normally next day from McMaster-Carr, and as far as adjusting the needle valve to the right flow, I need to do something while I am filling everybody else's doubles on our small 2-whip fill station.

This might not be the best solution out there, but its an experiment, and I am positive there are more to come. The whole point of the way I am doing this is to only change one thing on the unit at a time. That way when I go on a trip or am doing a bigger dive I wouldn't have to use the needle valve if I am still working on it's performance.

As for the hybrid part of this, I plan on flying the unit manually and leaving the controller set to a set point of .4, and then keeping an eye on everything to manually keep a set point around 1 to .7 or whatever is needed for the dive.

no matter what, If the needle valve is set right to produce the correct flow at depth (ie not more than .7lpm), than this should be easier than flying the stock unit manually (by just adding manually to maintain the right set point), correct? The user would just get the most benefit if they are at that max depth, the rest of the time you would just need to add more often.

Thanks,
Alex

OceanOpportunity · 19th April 2008, 01:42

Quote: (Originally Posted by seeboth)

I go to college full time and work at a dive shop the rest of the time, so this is all about experimenting. At school I have a full machine shop and can get parts and raw material really easy and cheap, normally next day from McMaster-Carr, and as far as adjusting the needle valve to the right flow, I need to do something while I am filling everybody else's doubles on our small 2-whip fill station.

As for the hybrid part of this, I plan on flying the unit manually and leaving the controller set to a set point of .4, and then keeping an eye on everything to manually keep a set point around 1 to .7 or whatever is needed for the dive.

no matter what, If the needle valve is set right to produce the correct flow at depth (ie not more than .7lpm), than this should be easier than flying the stock unit manually (by just adding manually to maintain the right set point), correct? The user would just get the most benefit if they are at that max depth, the rest of the time you would just need to add more often.

THis is getting too complicated for me to read, let alone figure out what would be going on underwater.

a few more of my thoughts, as I dive a needle valve: 1. it takes seconds to set it....do it right before you get in the water, not at the dive shop. One advantage to the needle valve is its an easy on/off without messing with the cylinder valve. 2. Pick one primary O2 add method and stick with it. The parachute concept scares me a bit. If using a solenoid, to rely on it, I'd want to make sure it was firing regularly during the whole dive. To depend on electronics that arent being regularly used the whole dive as a backup seems bass-ackwards to me. Use the electronics first, backup with a manual add system (if you are using 2 systems, which I dont necessarily agree with). 3. just a tip...I've found the best practive for diving a needle valve is on pure O2 in a pool. sit still, swim easy, swim fast, and find the sweet spots on the needle valve to keep up with your metabolism. THis way when you dive, you are making minimal adjustments. I respect the fact that many folks elect to use a non-compensated first stage, and understand that rationale. I use a compensated first stage for my own reasons. One, no mods necessary to the first stage and you can use a piston reg (which is my preference for all diving). Two, A graph of gas flow through an orifice over varying depths/IP's shows some variability, but not so much that its particulalry difficult to manage. Set the orifice or needle for the flow needed at depth, and add manually more in the shallows. I'm diving with 100% O2 to 20fsw anyway, and generally speaking there is little time spent futzing with descent and ascent...during deco you should be paying more attention to manually injecting anyway. Naturally, all is up for debate but thats a subject for a different time/place.

Short story is that I just dont see why its important to have this hybrid concept in place.

**Dave Sutton** · 19th April 2008, 12:02

Quote: (Originally Posted by seeboth)

I didnt mean to miss-quote you, and you have made your opinion on needle valves clear.

No worries, as you say it's all about learning and experimenting.

With that said, I suggest that you proceed in your own learning by starting at the bottom (technically) and working up. Add a layer at a time as each lower layer is mastered.

First, I would use a non-leaky mCCR for a while. Use simple manual injection of 02. Get a handle on that and put all of your attention to the task at hand: Staying alive. The experience you will gain in 10-15 hours of this will be irreplacable for you. Do it on pure 02 in the shallows if you like. You'll find yourself learning a LOT about 02 metabolism at different workloads. You can read about it all you like, but there's nothing like doing it.

Second, use a basic leaky-MCCR for a while. Add an orifice or needle valve and experiment. I would, once again, start at the lowest level of technology (orifice) and see how that works for a while. No need to use a sealed first stage in reasonable depths, say to 40-50 feet. Just go and play and see how that system works in relationship to the basic MCCR you played with before.

Third, if you want to proceed further, try a needle valve setup. All that does is allow you to select a different orifice pre-dive. Personally I don't see the value to this, other than to say the following: You need to tune either and orifice/regulator system or a eedle valve/regulator system somehow for flow. What my friend and colleague in Providence does with a piston (non adjustable intermediate pressure) first stage regulator is to adjust the *orifice* (using a needle valve). What I do is to use a diaphrgm first stage (easy to adjust intermediate pressure) and a fixed orifice. What he does with a knob on the needle valve, I do with a hex-key at the first stage. We are both doing the exact same work, just he at the back end of the system and myself at the front end. He likes piston first stages, I like Poseidons and Apeks (Diaphragms) so we each have adapted our method to the hardware we have. Each of us has ONE 'tuning point'. The learning point ought to be that neither of us adjusts anything in the water... it's all predive.

I would not even dream of starting out with any sort of parachute system until you have totally internalizd and experimented with the simpler options. DO NOT skip the learning steps. Go about this deliberately. If/when you do use a combined orifice bleed and solenoid system, use the electronics to hold setpoint and the orifice to back that up, not the other way around. You want the least reliable system (eectronics) to be the primary so you can monitor it's work... the orfice ought to be there just to buffer out the time to detect and correct malfunction of the 'lekkies. Personally... I would dive either one or the other, mCCR or eCCR, but not both at once. (naturally I'll be doing the opposite of what I reccomend with the hybrid rEvo, but that's just because setting up my rig that way will let me teach it either as a mCCR or an eCCR without needing to fool with it).

I'd read what Mike says in the post just above with care, as what he writes is dead-on. He and I are telling you virtually the same exact thing.

Dave

.

divelermentov · 20th April 2008, 23:58

Quote: (Originally Posted by Dave Sutton)

No worries, as you say it's all about learning and experimenting.

With that said, I suggest that you proceed in your own learning by starting at the bottom (technically) and working up. Add a layer at a time as each lower layer is mastered.

First, I would use a non-leaky mCCR for a while. Use simple manual injection of 02. Get a handle on that and put all of your attention to the task at hand: Staying alive. The experience you will gain in 10-15 hours of this will be irreplacable for you. Do it on pure 02 in the shallows if you like. You'll find yourself learning a LOT about 02 metabolism at different workloads. You can read about it all you like, but there's nothing like doing it.

Second, use a basic leaky-MCCR for a while. Add an orifice or needle valve and experiment. I would, once again, start at the lowest level of technology (orifice) and see how that works for a while. No need to use a sealed first stage in reasonable depths, say to 40-50 feet. Just go and play and see how that system works in relationship to the basic MCCR you played with before.

Third, if you want to proceed further, try a needle valve setup. All that does is allow you to select a different orifice pre-dive. Personally I don't see the value to this, other than to say the following: You need to tune either and orifice/regulator system or a eedle valve/regulator system somehow for flow. What my friend and colleague in Providence does with a piston (non adjustable intermediate pressure) first stage regulator is to adjust the *orifice* (using a needle valve). What I do is to use a diaphrgm first stage (easy to adjust intermediate pressure) and a fixed orifice. What he does with a knob on the needle valve, I do with a hex-key at the first stage. We are both doing the exact same work, just he at the back end of the system and myself at the front end. He likes piston first stages, I like Poseidons and Apeks (Diaphragms) so we each have adapted our method to the hardware we have. Each of us has ONE 'tuning point'. The learning point ought to be that neither of us adjusts anything in the water... it's all predive.

I would not even dream of starting out with any sort of parachute system until you have totally internalizd and experimented with the simpler options. DO NOT skip the learning steps. Go about this deliberately. If/when you do use a combined orifice bleed and solenoid system, use the electronics to hold setpoint and the orifice to back that up, not the other way around. You want the least reliable system (eectronics) to be the primary so you can monitor it's work... the orfice ought to be there just to buffer out the time to detect and correct malfunction of the 'lekkies. Personally... I would dive either one or the other, mCCR or eCCR, but not both at once. (naturally I'll be doing the opposite of what I reccomend with the hybrid rEvo, but that's just because setting up my rig that way will let me teach it either as a mCCR or an eCCR without needing to fool with it).

I'd read what Mike says in the post just above with care, as what he writes is dead-on. He and I are telling you virtually the same exact thing.

Dave

.

absolutely right Dave,

I wouldn't think of building an eCCR as my first homebuilding project.

I just wanted to make him aware of the problem with non-depth and depth compensating first stages in his project.

I personally think that the hybrid idea is more born out of the fact that many divers on eCCR start to get worried of being dependent on the electronics, but do not want to buy a second rebreather.

I for example had a recent incidence where my inspo suddenly decided to run both handsets as masters, got me a bit worried. It was easily rectified, however didn;'t quite trust the damn thing for the rest of the dive, so i was very glad to have a redundand HUD on the unit.

but these are only my .02

JADIVER · 26th May 2008, 15:43

hi, i had come across an posting about how to built an o2 injector valve from a bc power inflater .now i cant find it can anyone help me or does anyone have the link

thank you

jadiver @aol.com

ChristianM · 16th June 2008, 13:49

Hi Jadiver,

to you mean this Post http://www.rebreatherworld.com/semi-...tml#post152294

Cheers!
Christian

ChristianM · 16th June 2008, 20:38

Here some pics of my setup.
You can also add more gases to the loop

Cheers!
Christian

18th April 2008, 16:49	#41 (permalink)
seeboth New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jan 2008 Location: Wisconsin, United States Posts: 45	Re: O2 addition methods Quote: (Originally Posted by Dave Sutton) I have not: That is 180 degrees out of my suggestions. I use blocked first stages for everything I build. I DO NOT suggest or support the use of non blocked first stages for mCCR "leaky valve" systems of any sort, orifice or needle valve. I'm not a needle valve fan either, and a search will come up with the posts that articulate my reasons. And, not for nothing: You are making this WAY too complex. Just grab any small orifice, hook it up to a first stage, adjust the intermediate pressure to give you somewhere about 0.7 LPM and block off the first stage. Add 02 using a manual add valve as needed. Go diving. If I spent as much time thinking about this as some of you, I would never have built a thing. Theory is only valid insofar as it reflect reality. The reality is that this is butt-simple stuff to build. Best, Dave . I didnt mean to miss-quote you, and you have made your opinion on needle valves clear. I was reading an older thread where I got the idea, (http://www.rebreatherworld.com/home-...tml#post107524) see if I set the flow to be what I want at my bottom depth, taking the depth compensating regulator into mind, and them lock the needle valve into place, it is essentially and orifice that I can either close all the way (the unit is no longer a hybrid) or I could adjusted it for just over what my max depth would be, all done pre-dive. The entire set up would be in one block with the manual add button (bypass valve) so the whole thing could be added to the stock unit with out much in the way of drilling and tapping. I go to college full time and work at a dive shop the rest of the time, so this is all about experimenting. At school I have a full machine shop and can get parts and raw material really easy and cheap, normally next day from McMaster-Carr, and as far as adjusting the needle valve to the right flow, I need to do something while I am filling everybody else's doubles on our small 2-whip fill station. This might not be the best solution out there, but its an experiment, and I am positive there are more to come. The whole point of the way I am doing this is to only change one thing on the unit at a time. That way when I go on a trip or am doing a bigger dive I wouldn't have to use the needle valve if I am still working on it's performance. As for the hybrid part of this, I plan on flying the unit manually and leaving the controller set to a set point of .4, and then keeping an eye on everything to manually keep a set point around 1 to .7 or whatever is needed for the dive. no matter what, If the needle valve is set right to produce the correct flow at depth (ie not more than .7lpm), than this should be easier than flying the stock unit manually (by just adding manually to maintain the right set point), correct? The user would just get the most benefit if they are at that max depth, the rest of the time you would just need to add more often. Thanks, Alex __________________ yes those are double lp steel 121's on my back yes those are the main reason i want a rebreather
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19th April 2008, 01:42	#42 (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: 543	Re: O2 addition methods Quote: (Originally Posted by seeboth) I go to college full time and work at a dive shop the rest of the time, so this is all about experimenting. At school I have a full machine shop and can get parts and raw material really easy and cheap, normally next day from McMaster-Carr, and as far as adjusting the needle valve to the right flow, I need to do something while I am filling everybody else's doubles on our small 2-whip fill station. As for the hybrid part of this, I plan on flying the unit manually and leaving the controller set to a set point of .4, and then keeping an eye on everything to manually keep a set point around 1 to .7 or whatever is needed for the dive. no matter what, If the needle valve is set right to produce the correct flow at depth (ie not more than .7lpm), than this should be easier than flying the stock unit manually (by just adding manually to maintain the right set point), correct? The user would just get the most benefit if they are at that max depth, the rest of the time you would just need to add more often. THis is getting too complicated for me to read, let alone figure out what would be going on underwater. a few more of my thoughts, as I dive a needle valve: 1. it takes seconds to set it....do it right before you get in the water, not at the dive shop. One advantage to the needle valve is its an easy on/off without messing with the cylinder valve. 2. Pick one primary O2 add method and stick with it. The parachute concept scares me a bit. If using a solenoid, to rely on it, I'd want to make sure it was firing regularly during the whole dive. To depend on electronics that arent being regularly used the whole dive as a backup seems bass-ackwards to me. Use the electronics first, backup with a manual add system (if you are using 2 systems, which I dont necessarily agree with). 3. just a tip...I've found the best practive for diving a needle valve is on pure O2 in a pool. sit still, swim easy, swim fast, and find the sweet spots on the needle valve to keep up with your metabolism. THis way when you dive, you are making minimal adjustments. I respect the fact that many folks elect to use a non-compensated first stage, and understand that rationale. I use a compensated first stage for my own reasons. One, no mods necessary to the first stage and you can use a piston reg (which is my preference for all diving). Two, A graph of gas flow through an orifice over varying depths/IP's shows some variability, but not so much that its particulalry difficult to manage. Set the orifice or needle for the flow needed at depth, and add manually more in the shallows. I'm diving with 100% O2 to 20fsw anyway, and generally speaking there is little time spent futzing with descent and ascent...during deco you should be paying more attention to manually injecting anyway. Naturally, all is up for debate but thats a subject for a different time/place. Short story is that I just dont see why its important to have this hybrid concept in place. __________________ 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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19th April 2008, 12:02	#43 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Classic Kiss rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,671	Re: O2 addition methods Quote: (Originally Posted by seeboth) I didnt mean to miss-quote you, and you have made your opinion on needle valves clear. No worries, as you say it's all about learning and experimenting. With that said, I suggest that you proceed in your own learning by starting at the bottom (technically) and working up. Add a layer at a time as each lower layer is mastered. First, I would use a non-leaky mCCR for a while. Use simple manual injection of 02. Get a handle on that and put all of your attention to the task at hand: Staying alive. The experience you will gain in 10-15 hours of this will be irreplacable for you. Do it on pure 02 in the shallows if you like. You'll find yourself learning a LOT about 02 metabolism at different workloads. You can read about it all you like, but there's nothing like doing it. Second, use a basic leaky-MCCR for a while. Add an orifice or needle valve and experiment. I would, once again, start at the lowest level of technology (orifice) and see how that works for a while. No need to use a sealed first stage in reasonable depths, say to 40-50 feet. Just go and play and see how that system works in relationship to the basic MCCR you played with before. Third, if you want to proceed further, try a needle valve setup. All that does is allow you to select a different orifice pre-dive. Personally I don't see the value to this, other than to say the following: You need to tune either and orifice/regulator system or a eedle valve/regulator system somehow for flow. What my friend and colleague in Providence does with a piston (non adjustable intermediate pressure) first stage regulator is to adjust the orifice (using a needle valve). What I do is to use a diaphrgm first stage (easy to adjust intermediate pressure) and a fixed orifice. What he does with a knob on the needle valve, I do with a hex-key at the first stage. We are both doing the exact same work, just he at the back end of the system and myself at the front end. He likes piston first stages, I like Poseidons and Apeks (Diaphragms) so we each have adapted our method to the hardware we have. Each of us has ONE 'tuning point'. The learning point ought to be that neither of us adjusts anything in the water... it's all predive. I would not even dream of starting out with any sort of parachute system until you have totally internalizd and experimented with the simpler options. DO NOT skip the learning steps. Go about this deliberately. If/when you do use a combined orifice bleed and solenoid system, use the electronics to hold setpoint and the orifice to back that up, not the other way around. You want the least reliable system (eectronics) to be the primary so you can monitor it's work... the orfice ought to be there just to buffer out the time to detect and correct malfunction of the 'lekkies. Personally... I would dive either one or the other, mCCR or eCCR, but not both at once. (naturally I'll be doing the opposite of what I reccomend with the hybrid rEvo, but that's just because setting up my rig that way will let me teach it either as a mCCR or an eCCR without needing to fool with it). I'd read what Mike says in the post just above with care, as what he writes is dead-on. He and I are telling you virtually the same exact thing. Dave . __________________ "Changes in Lattitudes, Changes in Attitudes, Nothing remains quite the same".... www.nobubblediving.com Last edited by Dave Sutton : 19th April 2008 at 12:06.
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20th April 2008, 23:58	#44 (permalink)
divelermentov Nutty dentist - uwdriller Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Home Build Join Date: May 2006 Location: Auckland Posts: 645	Re: O2 addition methods Quote: (Originally Posted by Dave Sutton) No worries, as you say it's all about learning and experimenting. With that said, I suggest that you proceed in your own learning by starting at the bottom (technically) and working up. Add a layer at a time as each lower layer is mastered. First, I would use a non-leaky mCCR for a while. Use simple manual injection of 02. Get a handle on that and put all of your attention to the task at hand: Staying alive. The experience you will gain in 10-15 hours of this will be irreplacable for you. Do it on pure 02 in the shallows if you like. You'll find yourself learning a LOT about 02 metabolism at different workloads. You can read about it all you like, but there's nothing like doing it. Second, use a basic leaky-MCCR for a while. Add an orifice or needle valve and experiment. I would, once again, start at the lowest level of technology (orifice) and see how that works for a while. No need to use a sealed first stage in reasonable depths, say to 40-50 feet. Just go and play and see how that system works in relationship to the basic MCCR you played with before. Third, if you want to proceed further, try a needle valve setup. All that does is allow you to select a different orifice pre-dive. Personally I don't see the value to this, other than to say the following: You need to tune either and orifice/regulator system or a eedle valve/regulator system somehow for flow. What my friend and colleague in Providence does with a piston (non adjustable intermediate pressure) first stage regulator is to adjust the orifice (using a needle valve). What I do is to use a diaphrgm first stage (easy to adjust intermediate pressure) and a fixed orifice. What he does with a knob on the needle valve, I do with a hex-key at the first stage. We are both doing the exact same work, just he at the back end of the system and myself at the front end. He likes piston first stages, I like Poseidons and Apeks (Diaphragms) so we each have adapted our method to the hardware we have. Each of us has ONE 'tuning point'. The learning point ought to be that neither of us adjusts anything in the water... it's all predive. I would not even dream of starting out with any sort of parachute system until you have totally internalizd and experimented with the simpler options. DO NOT skip the learning steps. Go about this deliberately. If/when you do use a combined orifice bleed and solenoid system, use the electronics to hold setpoint and the orifice to back that up, not the other way around. You want the least reliable system (eectronics) to be the primary so you can monitor it's work... the orfice ought to be there just to buffer out the time to detect and correct malfunction of the 'lekkies. Personally... I would dive either one or the other, mCCR or eCCR, but not both at once. (naturally I'll be doing the opposite of what I reccomend with the hybrid rEvo, but that's just because setting up my rig that way will let me teach it either as a mCCR or an eCCR without needing to fool with it). I'd read what Mike says in the post just above with care, as what he writes is dead-on. He and I are telling you virtually the same exact thing. Dave . absolutely right Dave, I wouldn't think of building an eCCR as my first homebuilding project. I just wanted to make him aware of the problem with non-depth and depth compensating first stages in his project. I personally think that the hybrid idea is more born out of the fact that many divers on eCCR start to get worried of being dependent on the electronics, but do not want to buy a second rebreather. I for example had a recent incidence where my inspo suddenly decided to run both handsets as masters, got me a bit worried. It was easily rectified, however didn;'t quite trust the damn thing for the rest of the dive, so i was very glad to have a redundand HUD on the unit. but these are only my .02 __________________ May The Sorb Be With You
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26th May 2008, 15:43	#45 (permalink)
JADIVER New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Dec 2006 Location: N.Y. USA Posts: 2	Re: O2 addition methods hi, i had come across an posting about how to built an o2 injector valve from a bc power inflater .now i cant find it can anyone help me or does anyone have the link thank you jadiver @aol.com Last edited by JADIVER : 26th May 2008 at 15:47. Reason: address
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16th June 2008, 13:49	#46 (permalink)
ChristianM New Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Sep 2005 Location: Germany Posts: 46	Re: O2 addition methods Hi Jadiver, to you mean this Post http://www.rebreatherworld.com/semi-...tml#post152294 Cheers! Christian
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