Dedicated Nitrox equipment

[MonkSeal]

Every mix with <= 40% O2 can be used with standard equipment (regs, tanks).

 

[Canadian_Diver]

Every mix with <= 40% O2 can be used with standard equipment (regs, tanks).

MonkSeal, agreed except for the tank part.

 

[StSomewhere]

I agree with what you're saying to a certain extent. However, if you're running a higher blend of EAN (say EAN36 or higher), your MOD quickly becomes restricted and an increased chance of CNS oxygen toxicity can occur.

Diving on EAN36 @ 94ft gives you a PO2 of 1.39 ATA -- almost over the threshold of what the human body can stand

:06: 1.4 is a perfectly safe PO2. If my max depth was going to be 95 feet I would use EAN36 every time if it was available.

The NOAA limits are actually 1.6 for 45 minutes.

I use Nitrox for larger margin of safety, not to increase my bottom time.

The advantage to Nitrox isn't so much longer bottom time for one dive as it is longer bottom times for repetitive dives.

 

[chrisch]

You need a dedicated tank for EAN up to 40% and nothing else. If the dive shop uses partial pressure blending it should be O2 clean. Pre-mix EAN 40 or less does not need any O2 cleaning of the tank (its just the labelling). Titanium and EAN are not considered compatible.

Using standard air through the regulator is fine you can use EAN or air at any time no cleaning is required. Viton O rings are a waste of money.

European regulations for commercial divers require O2 clean at 23% - but this doesn't apply to pleasure diving - its just one of many stupid rules that politicians think up when they have too much time on their hands and too little knowledge of the subject.

All the rest is industry BS to get more money out of gullible divers.

Chris

 

[MonkSeal]

If the dive shop uses partial pressure blending it should be O2 clean.

Strictly speaking in this case you'll have mix with > 40% O2 (100% O2) in contact with parts of tank during blending. I don't know how often this way of blending is used. We use nitrox mixers, so nothing more than 40% O2 is ever in contact with tank.

 

[MonkSeal]

European regulations for commercial divers require O2 clean at 23% - but this doesn't apply to pleasure diving - its just one of many stupid rules that politicians think up when they have too much time on their hands and too little knowledge of the subject.

Have you heard about the initiative for different valves and regs for nitrox? That's even more stupid.

 

[padiscubapro]

You need a dedicated tank for EAN up to 40% and nothing else. If the dive shop uses partial pressure blending it should be O2 clean. Pre-mix EAN 40 or less does not need any O2 cleaning of the tank (its just the labelling). Titanium and EAN are not considered compatible.

Using standard air through the regulator is fine you can use EAN or air at any time no cleaning is required. Viton O rings are a waste of money.

European regulations for commercial divers require O2 clean at 23% - but this doesn't apply to pleasure diving - its just one of many stupid rules that politicians think up when they have too much time on their hands and too little knowledge of the subject.

All the rest is industry BS to get more money out of gullible divers.

Chris

Actually under the recently adopted EU rules ( I don't remember the mandatory adoption date off hand), nitrox will require special valves and regs with a different attachment.. The valves are already available in Germany.. The sizes chosen will make it difficult to make adapters to use regs on the wrong types.

 

[Canadian_Diver]

:06: 1.4 is a perfectly safe PO2. If my max depth was going to be 95 feet I would use EAN36 every time if it was available.

The NOAA limits are actually 1.6 for 45 minutes.

The advantage to Nitrox isn't so much longer bottom time for one dive as it is longer bottom times for repetitive dives.

The threshold for oxygen toxicity symptomst starts at a PO2 level of 1.10 ATA

A PO2 level of 1.40 ATA is the level at which oxygen presents a moderate risk to divers. This is the maximum recommended limit for normal recreational divers. MODERATE risk does not equal perfectly safe in my books. This is from the SSI EAN Nitrox specialty manual.

Our physiology wasn't designed to cope with PO2 levels much past 1.0 ATA. Beyond 1.0 ATA, a risk starts to build, albeit small to start with, but it's still a risk. Why push the envelope?

I do agree with your last comment, there are a number of benefits to using Nitrox.

The benefit that I enjoy the most, is the extra added margin of safety it provides against DCS .... treating it like an air dive with regards to maximum bottom time, thus adding in an additional margin of safety.

 

[randy54]

Won't get into the dedicated system, that's been beat already. as to question 2, I dive off a boat that only pumps air. I start with whatever nitrox mix I want, and then for the next refill or two, the mix gets closer to air. At the end of the day, I've absorbed less nitrogen, and feel much less fatigued on my 3 hour drive home. If I got a second tank, I'd do the last dive on nitrox. And before you ask, yes you can change the nixtrox computer for each new mix. as a matter of fact, you need to, or they defult to 50%, and that realy cuts down your depth.

 

[DA Aquamaster]

Won't get into the dedicated system, that's been beat already. as to question 2, I dive off a boat that only pumps air. I start with whatever nitrox mix I want, and then for the next refill or two, the mix gets closer to air. At the end of the day, I've absorbed less nitrogen, and feel much less fatigued on my 3 hour drive home. If I got a second tank, I'd do the last dive on nitrox. And before you ask, yes you can change the nixtrox computer for each new mix. as a matter of fact, you need to, or they defult to 50%, and that realy cuts down your depth.

I do something similar. On any given day I'll have about 10 tanks on the boat and some will have Nitrox 25% and others will have 36%. This works pretty well as with a 1/3rd reserve remaining on the 36% tanks, it takes very little adjustment to top them off to obtain 25% for the next day's deep dives. It gets double duty out of a single nitrox fill.