O2 Clean

[DwayneJ]

OK - Simple discussion on the Equipment Regulator list -

I asked the question what type of regs do you use on your back gas and stage/deco bottles and the one response listed regs that were only rated to EANx 40%. The comment was made that any regulator can be O2 cleaned for higher concentrations of O2.

Since there are good choices for 100% O2 - eg OMS Workhorse, 80% O2 eg Atomics M1, do you only use 100% O2 rated regs for your stage/deco and 40% O2 rated regs for your backgas?

Do you subscribe to the belief that any reg including regs rated to EANx 40% can be O2 Cleaned for use in 100% O2 environments?

I was planning to purchase and use regs rated for their appropriate O2 use.


Thanks!

 

[Rainer]

I (had) cleaned a "rated EANx 40%" for my deco reg. Surprise, I haven't blown up.

 

[DA Aquamaster]

The DIR answer will be that the deco/stage regs are one and the same and obviously should be interchangeable. Many divers extend that to all the regs being interchangeable.

I interpret that to mean that all my regs run at the same IP so that all the second stages are interchangeable between all my regs. I do not like using diaphragm regs on stage or deco bottles, but prefer Mk 17's for my back gas regs so I have two types of first stages but all my second stages are G250's or G250V's. It cuts down on parts in the save a dive kit.

In my opinion some designs are more ammenable to O2 use than others. The Mk 2 for example is a flow by piston design that is dirt simple and has only 2 dynamic o-rings none of which are exposed to high pressure gas. In the Mk 2 the only areas exposed to high pressure gas are upstream of the seat making them very O2 friendly. That is true of virtually all flow by piston designs.

Most regs can be converted to use EPDM o-rings and many companies already use them anyway. But a diaphragm first stage in my opinion is a poor choice for an O2 reg as the diaphragm, regardless of what it is made out of, is one really large potential fuel source and in most the flow path is a bit tortured with more turns than a flow by or flow thru piston design.

Titanium regs are also a poor choice as Ti is not ammenable to O2 cleaning.

The big issue with scuba valves and regs is that they were never really designed for O2 use. Scuba valves turn on and pressurize quickly and may have flow paths that can cause issues with entrained particles and heating due to rapid compression or flow restrictions. Same with some first stage designs. So even if it is "perfectly" O2 clean and O2 compatible, be prudent when pressurizing it. Open the valve slowly with the purge depressed to minimize any potential heating due to rapid compression.

 

[rainman_02]

There's no such thing as a scuba valve or regulator for O2 service. They're all poorly designed such as DA mentions.

I use O2 cleaned ATX50s for all my stage regs. They work just fine, but I still take precautions--opening the valve as slowly as I can etc etc.

 

[Jimmer]

Well the point I was getting at in the other thread is that there is no real difference internally between the so called oxygen regs and a non O2 equivalent. Case in point with the Atomic M1. Internally it's the exact same as all the other Atomics, aside from the material, which is low on the list of potential problems, when you're talking about Monel/Brass/Stainless Steel.

Another thing to mention, is that the M1 is "rated" for 80%. So does that mean you would never use it for O2?