View Full Version : O2 cleaning
Just a quick question regarding O2 cleaning. Hoping to do EAN course in Feb. A buddy and I got talking the other day. He said he was gonna get one of his tanks O2 cleaned and use Nitrox for a couple of dives. He then planned refilling clyinder with compressed air and was under the impression he could get another Nitrox fill without having to get it cleaned again.
As I said I haven't done my Nitrox course yet but was under the Impression that once you refilled it with compressed air that you would need to get it O2 cleaned again if you wanted to use Nitrox. I think a friend of mine used to use a filter to get his O2 cleaned clyinder filled if it was just air he was getting.
So the question is: If after getting clyinder O2 cleaned and then using compressed air do you need to get it O2 cleaned again before you can get a Nitrox fill?
Nope, makes no difference, just because you have used Air ie EANx21 instead of say EANx22, 23, 24, 25, 26 or so on. You don't even need to get them O2 Serviced to use Nitrox, just slap some Nitrox Stickers on them and take them to a LDS like EDC who use a Membrane System for Nitrox fills.
The Membrane System does not require your equipment to be O2 Serviced.
Yogi Diver
04-01-09, 15:39
As long as you are sure of the cleanliness of the air source, there is no need to get tanks re-cleaned. Most LDSs that supply Nitrox by partial pressure blending will use the same lines to fill air as they do to blend Nitrox so you can be fairly sure their air is clean. If in doubt, on a dive boat for instance, invest in an in-line filter to use when filling with air.
However some LDS won't fill your cylinders with Nitrox unless they have done the O2 Service.
Yep, as Yogi said. So long as the air you get is hydrocarbon free (aka "clean") air you are cool to get a nitrox fill afterwards.
All dive shops should have their air tested at a regular interval for cleanliness so you should be OK to get an air fill from any dive shop.
Be carefull of things like portable compressors where the filtration system won't be as beefy and possibly not as well maintained. A personal in line filter is needed here. In saying that no shop can tell if you have been using one so you will still get a fill so long as you are within you O2 clean period. And as IFairly says, some LDS's will only put Nitrox in cylinders that they have cleaned due to partial pressure blending (i.e. blowing pure O2 into the tank then topping off with air)
Thanks lads.
Any thoughts on which agency is best to do EAN course with? Padi or Iantd?
Thanks lads.
Any thoughts on which agency is best to do EAN course with? Padi or Iantd?
Is it the basic nitrox course or Adv. Nitrox?
Basic, I don't think there is much difference, get one that allows you any mix up to 40% rather than one that qualifies you for 32% or 36% only. Not sure which do what but worth checking.
Advanced and it more down to the intructor. I'm currently doing mine with Northern Technical (on here). Recomended http://www.congeralley.com/forum/images/icons/icon14.gif
:confused:
Confused you may be, but the basic nitrox course is just that, basic!
The main information imparted is the difference in using enriched air with an oxygen content of either 32% or 36% compared to air. You'll find out how to work out maximum operating depths for these gases, and a couple of other arithmetical formulae. The main selling points of nitrox are increased no decompression times and / or greater safety at relatively shallow depths compared to air.
There are other aspects to nitrox use i.e. as a decompression gass which are part of an advanced course.
In the main it's not a taxing course and the course content at the basic level is very similar across the training agencies.
As ever the trainer is more important than the training agency. Get some personal recommendations. There are more than a few of our forum members who are instructors.
I think its much of muchness regarding the "basic course" No diving involved with the PADI course now, all theory!
Nitrox and o2 cleaning thought, the theory discussed above is only relevant when using a membrane filling system and a dive shop that is content to fill your cylinders! I notice EDC was mention, I regularly use them for both tyre gas and Nitrox in the same cylinders and as they use a membrane they fill them no problemo!
tyre gas
something your not telling us??:D
i hear that some 'dive gods' actually breathe that stuff when not diving..:eek:
I think its much of muchness regarding the "basic course" No diving involved with the PADI course now, all theory!
Nitrox and o2 cleaning thought, the theory discussed above is only relevant when using a membrane filling system and a dive shop that is content to fill your cylinders!
How is nitrox diving theory only relevant when the gas comes from a membrane system :confused:
Membrane systems blow the desired % straight into the cylinder (upto 40%). It is believed that O2 levels below 40% will not cause combustion on contact with hydrocarbons (along with the heat created by compressing gas)
Partial pressure filling involves drainging the tank, calculating the amount of pure O2 required based in tank size and desired mix, blowing the amount of 100% O2 required into the cylinder.
This is the dangerous bit. If there is enough hydrocarbons present the cylinder can go pop. The amount of hydrocarbons needed to do this is open for debate and could result in quite a large thread :rolleyes:
The cylinder is then filed with air to max pressure and this should give you your desired mix.
Some dive shops have a different views on the risks involved in blowing pure O2 into a cylinder and some prefer to only fill cylinders that they have cleaned. Again this can result in a long thread...... You know who they are. Make your own mind up to use them or not :rolleyes:
Thanks lads.
Any thoughts on which agency is best to do EAN course with? Padi or Iantd?
Hi Dave.
I'm doing Nitrox with C-divers in Feb.
They have been recommended to me although I haven't used them before myself.
They are based in central Scotland and the course costs £45 which is cheap compared to most others I have seen.
Cheers , JohnB :)
stafforddiver
05-01-09, 10:32
This is all making it sound far more complicated than it already is.
Nitrox is easy and straightforward as long as you follow a few rules.
Get a basic course done if your going to use it with a single cylinder and pony, get an advanced course done if you have a twinset and want to start going deeper for longer and are happy to do decompression stops.
Make sure the course allows you to use any nitrox mix between say 22 and 36%.
At a basic level its far less important to have a good instructor, but still a good idea :)
If you intend to have your cylinders nitrox filled at Aquatron, get them 02 cleaned there.
Cheers,
gareth.
How is nitrox diving theory only relevant when the gas comes from a membrane system :confused:
The quote from me was not in the context of the Nitrox training theory, but more what was being discussed in the original threads, with regard to o2 cleaning and cylinder filling. Maybe I should not have used the word Theory!
Hi Dave.
I'm doing Nitrox with C-divers in Feb.
They have been recommended to me although I haven't used them before myself.
They are based in central Scotland and the course costs £45 which is cheap compared to most others I have seen.
Cheers , JohnB :)
Hi ... have "signed" up for same course. Just waiting on Confirmation and dates etc
i dont go to the shops for nitrox anymore, not since i bought N2 termites.
i just pop six of them in a cylinder, wait for them to eat the nitrogen, then charge the cylinder.
i find, using six of them in twin 10's gives me a nice 32% mix by the time they have finished.
the only down side is the vacume thats left, generally causes the pressure to drop, so a good 232 bar fill is more of a 200 bar fill.
still, you get what you pay for..:rolleyes:
Yogi Diver
06-01-09, 21:29
I want these N2 termites.:D
I still prefer Peter's self filling garage! Leave the tanks in there for a couple of weeks and they are filled. I am pretty sure they are breeding in there too, he has about 8 cylinders in there now!
Hopefully see you there then :)
Hi ... have "signed" up for same course. Just waiting on Confirmation and dates etc
i dont go to the shops for nitrox anymore, not since i bought N2 termites.
i just pop six of them in a cylinder, wait for them to eat the nitrogen, then charge the cylinder.
i find, using six of them in twin 10's gives me a nice 32% mix by the time they have finished.
the only down side is the vacume thats left, generally causes the pressure to drop, so a good 232 bar fill is more of a 200 bar fill.
still, you get what you pay for..:rolleyes:
At times I hate this website - I started reading this thinking oooh N2 termites, wonder how they work? how do you pop them in a cylinder? wh........... :rolleyes:
At times I hate this website - I started reading this thinking oooh N2 termites, wonder how they work? how do you pop them in a cylinder? wh........... :rolleyes:
sorry mate, just a moment of madness on my part.:o
but i generally pop them in when the cylinders are empty, try doing it when they are pressurised sends them flying across the garden never to be found again.:rolleyes::D
Yogi Diver
08-01-09, 14:14
Do the termites migrate via the manifold in a twin set or is there a possibility of differing mixes in each tank? :confused::o:p
Also, if you leave them in, do they not eat the N2 from the top up air? This would surely result in a mix getting higher all the time?
Do the termites migrate via the manifold in a twin set or is there a possibility of differing mixes in each tank? :confused::o:p
Also, if you leave them in, do they not eat the N2 from the top up air? This would surely result in a mix getting higher all the time?
Q1. it makes no odds which tank they are in, gas will mix itself, same way as in the shops;)
Q2. not quite, they stop feeding once they are full and only start again when they have off gassed. if you need a higher mix, you need more termites..
its basic science..:rolleyes:
can we have an artists rengering of these lil fellas :D
can we have an artists rengering of these lil fellas :D
Have you seen Stew's Photoshop skills before :eek:
can we have an artists rengering of these lil fellas :D
if you insist, as best i can with this forum software...:)
they look like these > . . . . . .