Nitrox ??Dedicated Regulator, HP hose and gauges, etc???

[TropiGal]

I am reading my NAUI Nitrox Guide in prep for the class. I have come to the chapter regarding the equipment list and recommendations for cleaning, etc....

Now I'm wondering.....???? Is it necessary to have a separate regulator, HP hoses and gauges specifically to be used with Nitrox? Obviously....ideally, that would be the route to go...but I will not be able to buy a new regulator just to be used maybe one week out of a year.

I just had my equipment (regulator, bcd and alt air source) serviced last month. Do I have to have this done again and it refitted with "nitrox" parts?

For the most part, I will not be diving Nitrox locally. I am taking the class so that I can dive multiple dives per day over a week period in Roatan. So, having said that....can I dive part of the time with Nitrox and part of the time without - and use my one and only regulator and other equipment.

Please excuse these questions if they have already been asked and answered many times....and if so, please direct me to the particular threads to give me the info I need.

Thanks for all the help and advice everybody so readily and cheerfully gives.

 

[Green_Manelishi]

All things being equal If the EAN <= 40% O2 you can use the regs, etc. without 'dedicating' them.

The two major reasons that manufacturers suggest
dedication is:

1) it sells more gear

2) it keeps the lawyers happy.

 

[kelpmermaid]

if you are diving a mix that is less than 40% O2, you should not need a second regulator, etc.

Re: mixing nitrox dives with air dives...what is your purpose for using nitrox? Are you looking to extend bottom time or are you seeking to lessen nitrogen intake? If it is the latter, it should not be a problem.

 

[MikeFerrara]

Most agree that nothing special is needed for mixes under 40%. The tank and valve need some attention if PP blending is to be done in it. When in doubt follow the manufacturers recomendations. Some manufacturers like Aqualung make that very hard. In that case I recomend keeping the nitrox and dumping Aqualung.

 

[O-ring]

Kidding...we just had a similar discussion and you may get something out of it...

Here's the link.. apeks nitrox thread

 

[grouchyturtle]

Why only up to 40%?
Why would you have to clean it?
What effect do difference gases have on a regulator that would make any regulator not suited for a certain type of gas?
After a dive you purge the gas out of the regulator anyway. How much is really still left in it?
What effect does this tiny little bit have, if you are now diving with a different gas?

Is this just a bunch of Put Another Dollar In propaganda from the agencies and manufaturers?
Or possibly the fact that when stupid people f-up with something and die, it's always someone else's fault, and there's law suits, etc, so they're covering their asses?

 

[mddolson]

The answer two fold, one is historical data.
The US navy and industry has used nitrox in concentrations up to 40% without incident since the 1950's.

We know that hydocarbons (greases and oils inluding silicone grease) will spontainiously combust when exposed to pure oxygen at pressure. In high concentrations 40+ % the heat of compression, ie cracking the valve on your tank to charge the regulator can also cause conbustion.

To prevent this we remove the fuel(hydrocarbons) from the fuel, oxidzer, heat combution trangle to prevent an accident.
Dedicating the equipment, prevents re-contaminating the gear, with normal (non-nitrox quality air) from an oil lubricated compressor.

While you purge your regulator of the gas after a dive, contaminates (hydrocarbons) precipitate out at high pressures and collect on the inside of the regulator and in the hose.

This information is covered in your Nitrox diver certification course by all agencies, PADI, NAUI, TDI etc.

Mike D
:blfish:

 

[Zept]

MikeFerrara said...
When in doubt follow the manufacturers recomendations. Some manufacturers like Aqualung make that very hard.

Aqualung has recently (12 Aug) published a document about nitrox compatibility. Some of its new regs are okay up to 40%. Existing Cousteau, Titan, or Calypso first stages can be overhauled for use with nitrox -- there's a new service kit.

If you have an Aqualung reg, check the document for details. You can look up the serial number and find out what the deal is for your particular model.

Tech library (look under regulators):
http://www.aqualung.com/AL_comm_techlib/techlib_ALC.html

I came across the document by accident and was quite surprised by the change. Thought I'd share the details in case anyone else was cursing the old 'not above 23%' policy.

Zept

 

[padiscubapro]

Zept once bubbled...


Aqualung has recently (12 Aug) published a document about nitrox compatibility. Some of its new regs are okay up to 40%. Existing Cousteau, Titan, or Calypso first stages can be overhauled for use with nitrox -- there's a new service kit.

If you have an Aqualung reg, check the document for details. You can look up the serial number and find out what the deal is for your particular model.

Tech library (look under regulators):
http://www.aqualung.com/AL_comm_techlib/techlib_ALC.html

I came across the document by accident and was quite surprised by the change. Thought I'd share the details in case anyone else was cursing the old 'not above 23%' policy.

Zept

Zept if you read their tech letter you would see the new regs and overhauled regs are now using o2 compatible materials.. and its states its the users responsiblity to maintain cleanliness, if it is used with grade "E" air it should be recleaned before using with nitrox again..

I don't know what type of o rings they are using, but they are listed as compatible.. for regs that use burna-nitril o rings which is most regs that aren't sold as EANx ready (unless they were overhauled with viton).
With the increasing acceptance of Nitrox many manufactures are switching to oxygen comptible materials and procedures as standard. This prevents cross contamination during assembly and eliminates inadvertant mixing of component materials.
Burna-nitril becomes brittle in the presence of oxygen.. The risk of combustion is very low with less than 40% but thats not my big concern.. I have seen many regs useing b-n with nitrox sure they work but they require much more frequent servicing and the likelyhood for failure is much greater.. All my regs are cleaned and have o2 compatible materials, even my 1 reg setup that I use when I don't know the gas quality since Viton is a much more durable material..

I tell my students get their gear cleaned and converted and just make sure you get gas from a known hydrocarbon free source(it doesn't habe to be nitrox)..
Personally I don't use any gas that the fill station doesn't have periodic testing reports.
Getting a reg recleaned in not a big deal, most regs can be cleaned without changing any of the expensive parts and add a few bucks for some o rings (I'll call it an underhaul)is no big deal.. Some regs like poseidons (which I personally prefer) this is not the case, poseidon HP seats should not be reused.

 

[Zept]

padiscubapro said...
Zept if you read their tech letter you would see the new regs and overhauled regs are now using o2 compatible materials.. and its states its the users responsiblity to maintain cleanliness.

Absolutely. I hoped that putting 'check the document for details' in bold would encourage people to actually read it, rather than do X or Y based on something they heard from someone on the Net.

As you say, the new regs are using different parts, and these parts can be retrofitted to existing regs. AFAIK this is a new development... certainly my manual doesn't mention this option, it just says the reg shouldn't be used with enriched air.

But anyone who actually has an Aqualung reg should RTFM (or tech document, in this case) rather than rely on my summary.

Zept