What happens if you use a regular regulator with 100% oxygen?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

So instead of anecdotal evidence, how about some peer reviewed research: https://books.google.com/books?id=ZkyA6XU-zp8C&lpg=PA358&ots=XoZtQZtB19&dq=pure%20oxygen%20high%20pressure%20hydrocarbons&pg=PA365#v=onepage&q&f=false

My biggest concern with oxygen cleaning is generally hydrocarbon contamination from dirty air - diving a lot in dodgy places makes this more likely, and certain ones can accumulate in the reg. Luck and probability has something to do with it as well, but by and large if I've been breathing dodgy gas I tear everything down and clean it well before using it on anything richer than 50%.

The rule of thumb for chemists & engineers is to treat anything above 50% as pure O2, and having seen a few oxygen fires, I'm more than happy to indulge in some extra cleaning and TLC.

Material selection also has something to do with it - most metals are actually extremely reactive and will happily autoignite in pure oxygen under certain pressures. Magnesium is a fun one that's used sometimes for strength (not in scuba gear but elsewhere) which is extremely energetic. more here: http://www.hq.nasa.gov/office/codeq/doctree/canceled/1740151.pdf
 
Is titanium considered pretty inert in these cases?

By my reading of this, [edit] NO (caveat: they're looking at freshly formed faces, such as drawn or more importantly for us abraded - think debris in the regulator):
REACTIONS IN GASEOUS AND OXYGEN CONTAINING
MIXTURES
The Stanford Research Institute investigated the reactions
of titanium and oxygen-containing atmospheres (ref. 10). A freshly
formed titanium surface reacted rapidly with oxygen, and the energy
released by this reaction resulted in ignition of the titanium sample,
which then continued to burn until either the metal was consumed or
the supply of oxygen was exhausted. Under static conditions at room
temperature, at least 350 psi of 100 percent oxygen was necessary to
initiate the reaction, whereas, with 45 percent by volume of oxygen,
a pressure of 2000 psi was required. Under dynamic conditions,
as in the case of a ruptured pressure disc, much less stringent
conditions were needed. With pure oxygen, 50 psi pressure would
initiate the reaction. Once the reaction began, it would propagate
at high pressures with as little as 2 percent oxygen in steam. About
10 percent oxygen was required for propagation at atmosphere
pressure.

Battelle Memorial Institute investigated the effect of low
temperature on the ignition of titanium in gaseous oxygen (ref. 11).
At room temperature, titanium 75A alloy required 75 psi of oxygen
to initiate reaction upon the freshly formed metal surface (by tensile
testing). With the same alloy and test conditions, but at -123. 3°C
(-190°F), 100 psi of oxygen were necessary for reaction. Similar
tests with the Ti-6A1-4V alloy showed 100 psi necessary at room
temperature and 125 psi at -123. 3°C (-190°F).
 
Last edited:
My biggest concern with oxygen cleaning is generally hydrocarbon contamination from dirty air - diving a lot in dodgy places makes this more likely, and certain ones can accumulate in the reg. Luck and probability has something to do with it as well, but by and large if I've been breathing dodgy gas I tear everything down and clean it well before using it on anything richer than 50%.
My tec gears are for tec dive ONLY. And I have yet to come across any tec operator who do not look after its own gas.
Unfortunately my recreational regs had experienced dodgy gas on several occasions before. And everytime I had to strip down everything and clean it.
 
My tec gears are for tec dive ONLY. And I have yet to come across any tec operator who do not look after its own gas.
Unfortunately my recreational regs had experienced dodgy gas on several occasions before. And everytime I had to strip down everything and clean it.

I'm about at that point as well but for a while I was traveling a lot and doing rec instruction with some fun tec on the side - so I got very good at cleaning!
 
Any reg will do, aside from maybe a titanium reg. No extra set of regs needed, one for tech, one for rec. Don't buy (literally) into the hype. As long as your not pumping oil or silicone into your reg, you're fine.
 
Any reg will do, aside from maybe a titanium reg. No extra set of regs needed, one for tech, one for rec. Don't buy (literally) into the hype. As long as your not pumping oil or silicone into your reg, you're fine.
Happened THREE times over last couple of yrs. Those operators will never get my business again but that is different story.
My recreational reg is my tec reg back up so it has anything to do with "hype".
 
https://www.shearwater.com/products/swift/

Back
Top Bottom