Barnaby'sDad
Contributor
See the section on partial-pressure mixing. Below is what’s in my NAUI book. See the last sentence.
Is nitrox worth it for deeper rec dives?
- Thread starter Marie13
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
See the section on partial-pressure mixing. Below is what’s in my NAUI book. See the last sentence.
I don’t think anyone has mentioned this but, if a shop offers partial pressure blending, chances are it’s also possible to rent Nitrox tanks on-site.
All, I have had a private discussion with Marie13. She has not interest in further participation in this thread/discussion.
During my discussion with her she sent me a screenshot of DRIS' gas mixing policy. There is a statement in their policy that partial pressure fills require a O2 cleaned cylinder and valve.
I explained to her that partial pressure fills usually means 100 % O2 is added and then other gas is added to dilute the mix to the desired percent. I explained that from safety standppoint that is different from starting with a partially filled tank with say 32% EANx and adding "air" to dilute the mix down to 28% or whatever
She responded that she did not know if DRIS would do a custom mix this way or not. I did not directly state that she should investigate this as I believe it was implied by the nature of the discussion.
Regardless, the responsibility to investigate this further with DRIS is on the shoulders of the person who wants the gas fill. I believe Marie13 knows this and if she desires will discuss it with DRIS, which is her local dive shop.
I am sure she will figure this out from the standpoint of doing what she believes to be in her best interest.
While she stated she has no intent of further participation in this thread, I do not know whether or not she is monitoring the thread or not..
I think we may have reached the point where we are beating a dead horse even though there is a lot of good discussion on the use of Nitrox. and gas blending. I just don't think the posts that are offering advice to the OP is adding anything productive, so perhaps this discussion on Nitrox use, gas blending, etc can be split off under a different header where discussion about the topics can be further fostered.
-Z
During my discussion with her she sent me a screenshot of DRIS' gas mixing policy. There is a statement in their policy that partial pressure fills require a O2 cleaned cylinder and valve.
I explained to her that partial pressure fills usually means 100 % O2 is added and then other gas is added to dilute the mix to the desired percent. I explained that from safety standppoint that is different from starting with a partially filled tank with say 32% EANx and adding "air" to dilute the mix down to 28% or whatever
She responded that she did not know if DRIS would do a custom mix this way or not. I did not directly state that she should investigate this as I believe it was implied by the nature of the discussion.
Regardless, the responsibility to investigate this further with DRIS is on the shoulders of the person who wants the gas fill. I believe Marie13 knows this and if she desires will discuss it with DRIS, which is her local dive shop.
I am sure she will figure this out from the standpoint of doing what she believes to be in her best interest.
While she stated she has no intent of further participation in this thread, I do not know whether or not she is monitoring the thread or not..
I think we may have reached the point where we are beating a dead horse even though there is a lot of good discussion on the use of Nitrox. and gas blending. I just don't think the posts that are offering advice to the OP is adding anything productive, so perhaps this discussion on Nitrox use, gas blending, etc can be split off under a different header where discussion about the topics can be further fostered.
-Z
Most threads repeat content already posted countless times in other threads before that.
The title of this thread is relevant to many divers, not just her. Just because she doesn’t care anymore doesn’t mean the thread needs to die.
The title of this thread is relevant to many divers, not just her. Just because she doesn’t care anymore doesn’t mean the thread needs to die.
That doesn't explain the potential banked EAN32 has for blending, without requiring oxygen clean equipment.
I am curious, don't shops in the US CFM blend nitrox that much? Everybody is only talking about (ocygen) partial pressure fills or banked nitrox.
I would dive nitrox in OP's situation. I would also get deco trained immediately instead of doing 120+ft bounces.
admikar
Contributor
I don't know how thing works on your side of the pond, but from this thread it seems to you have only two options: partial blending and banked EAN.
What about continuous blending? That's how my club is doing it. Hook up O2 bottle to mixer, set desired mix,up to 40% and feed it to compressor. Voila, you get whatever mix you want, without need for O2 clean tanks or banks.
Alan Browne
Contributor
Doh. My misinterpretation and mixing another poster's suggestion. My sense of it was getting a full 32% tank (prefilled), blowing off some of the gas, replacing it with "regular" 21% to achieve a desired percentage. That's what's "not" mentioned in the PADI manual.
Barnaby'sDad
Contributor
I thought it was implied. I guess my issue is that given the detail my instructor went into for Nitrox (he's a tech diver)...I read the section that I included above and filled in the blank that you can start with any higher number O2 blend (ex. 32%) and work your way down from there by way of topping the tank off with air.
I can't say that I've run into it or read about it being offered at any of the shops that I've looked into diving with. Most shops either say "we have banked 3x % Nitrox" or "your tank must be O2 clean."
I've read about it, but I can't say that I've run into it.
See issue above. Other than high traffic dive sites that are filling off a banked Nitrox tank...I have yet to see a CONUS reference to not requiring an O2 clean tank to get a Nitrox fill.
Why can't the shop blend the 32% banked with air to make 28%? If they would be willing to do that you wouldn't need O2 clean tanks.
EDIT: I posted this question after reading the initial post. Then I read the next 12 pages of the thread and found that the same question had already been asked a few dozen times.
Alan Browne
Contributor
I for one am quite happy that Marie13 brought things up as the ensuing discussion taught me a lot following my study of the PADI manual and the course that I'll take in Feb. Hopefully wet in March if plans don't go awry.
From various posters I'm beginning to grok how different O2 percentages can be tailored to fit a particular plan. That is cool (if juggling a lot of variables). Next trip won't see a lot of deep dives (most 1st-dive-of-the-day to 60 - 80'), but there are 2 sites that get down to about 100 - 115'. I've been studying the tables (EAN32/36) with these in mind. (I don't know what flexibility the DC have on mix, however), but it's clear that I'll be either requesting a lower O2 mix or diving regular air at those sites.
A fellow I met last winter is going to sell me his backup computer (the one he lent me last year). He's off to Cozumel next week so I guess I'll get it on his return - just in time for my course.
Similar threads
