Using Nitrox after Air?

[BluewaterSail]

I just bought my first set of regs!

I have Scubapro MK25/G250V with S600 for the octopus.

I was reading the manual, and it said that if I use regular compressed air the regulators need to be serviced by an autorized Scubapro technician before using Nitrox. I understand why cleaning would be needed for tanks, but do people really do this for regulators?

Seems a bit inconvenient. There are small shops that don't offer Nitrox, so this would put them off limits!

 

[Insta-Gator]

Not every time you switch. If you plan to use Nitrox, tell your service provider you will be using Nitrox and they will use different o-rings, etc. Higher oxygen level means higher oxidation on the cheaper internal replacement parts.

 

[halocline]

The regulator is fine for anything up to 40% O2. It's not the titanium first stage, is it? Unless it is, don't worry about it.

It's really simple; recreational nitrox up to 40%, any regulator (except titanium) will work fine and be safe. Why does this issue get confused over and over? I wonder if it has anything to do with selling "nitrox" regs and kits?

 

[blkirk91]

If you wanted a reg to dive nitrox with this may not have been the best choice. Looking over the Data from ScubaPro this is not a nitrox compatable regulator. As the post above says you will need to get the O rings changed and they will probably apply silicon protectant to the internal metal parts. All metal regulator, lots of parts to oxidize

 

[Fishpie]

Nonsense from Hawaii.

 

[ECpirates96]

If you wanted a reg to dive nitrox with this may not have been the best choice. Looking over the Data from ScubaPro this is not a nitrox compatable regulator. As the post above says you will need to get the O rings changed and they will probably apply silicon protectant to the internal metal parts. All metal regulator, lots of parts to oxidize

Are you confused blkirk91? You can use a MK25 up to 100% O2. The only MK25 that doesn't need to be used with high O2 is the titanium model which few people buy due to the cost.

You are fine up to 40% Nitrox with a MK25 and either of the 2nds. 2nds are not as much an issue than 1st with high O2 levels.

 

[BluewaterSail]

I would like to clarify, because some of the answers did not answer the concern.

I understand that I can use it up to 40% oxygen. What the manual said is:

Warning!
If SCUBAPRO regulators have been used with standard compressed air it will be
necessary to perform a new maintenance and cleaning procedure specifically
designed for the use of nitrox mixes and carried out by a SCUBAPRO authorized
technician, before using them again with Nitrox​

It's this cleaning that I was asking about; like why would they write this and is it for real?

I probably will want to use Nitrox about half the time.

Another question: In the manual it says that these regulators are manufactured with materials, assembly procedures and lubricants that ensure compatibility with gas mixtures containing up to 40% oxygen.

Since I just bought this new, I am sure that it has the factory installed parts.

Are some of you saying that what is in the manual isn't accurate, and that I should take it back to the store and ask them to install different parts?

So now I have 2 things from the manual that are not true? Now I am really confused!

 

[BluewaterSail]

btw, what it says in the manual is that the "Nitrox" models can be used with up to 100% O2. That is not of interest to me. 40% is fine.

 

[blkirk91]

So reviewing the information from the Scubapro web site about this reg, thinking I had made an error, it happened once. The first stage does not say anything about nitrox compatabiliy and the second stage show

Titanium components: No
Nitrox compatible up to 100% oxygen concentration: No
Divers adjustable inhalation effort: Yes

If the reg is good for 40% cool. The availalbe information i got from their website doesnt say anything about that.


LMB

 

[adelman]

Scubapro is confused, covering their ass, or both.

In order to use Nitrox mixes richer than EAN40, a first-stage regulator needs to be oxygen-clean and built with oxygen-compatible parts (and lubricants). The second stage just doesn't matter, because it isn't exposed to HIGH-PRESSURE/high-oxygen gas.

The Scubapro regulator out of the box is oxygen-clean, and what they're trying to tell you is that if you use it with non-oxygen-clean gas, it won't be oxygen-clean anymore (true). It is false that you need an oxygen-clean regulator for any Nitrox, you only need oxygen-clean if the first stage is exposed to mixes richer than 40%. So you can ignore what Scubapro has to say about gases and arbitrarily switch between Air and Nitrox (up to 40% O2 content) without any special servicing of the regulator.

If you want to go with Oxygen contents GREATER than 40%, then the regulator needs to be used and maintained in an oxygen-clean state. It needs to be assembled with O2 clean and compatible parts, with O2 compatible lubes, and not allowed to come into contact with non-O2 clean gas. That isn't to say that it can no longer be used with air, provided the air has undergone the extra filtration to further minimize the hydrocarbons in it and is blessed as "oxygen clean air". It also isn't to say that all Nitrox is oxygen-clean either; for example, Nitrox made by a continuous flow or membrane system that feeds the EAN32 into a regulator scuba compressor isn't oxygen-clean unless it also undergoes the extra filtration (and it doesn't have to). Many fill stations only deliver oxygen-clean gasses (mine is set up that way), and many don't; you need to ask if you care.

As far as oxygen-compatible parts, a few years ago Scubapro started selling (for extra cost) an Oxygen-compatible overhaul kit for the Mk25. Prior to that, a lot of technical divers (myself included) used the regular overhaul kit with the Mk25s with pure oxygen no ill effects, but today I would have to recommend you use the Oxygen-compatible kit if you're planning on mixes over 40% O2.

Another commenter mentioned the use of silicon to prevent corrosion inside an oxygen regulator. I wouldn't recommend it. In a high-pressure oxygen environment we have another name for silicon -- FUEL.