Nitrox with titanium or aluminium regulators

kiwitwat wrote:
> Hi all. I have been told you cannot use titanium or aluminium
> regulators for nitrox (enrichd air in PADI speak). Is this true.? If
> so, does the oxygen % have a limit or is it for all mixes above
> ordianr air? TIA

I hope it's not true, because I've been diving EAN with my titaniom regs
for years. I certainly don't want anybody to think I'm some sort of
terrorist because I'm not doing things their way. On second thought,
never mind, let 'em think what they want, I don't care.

--
jer email reply - I am not a 'ten'
"All that we do is touched with ocean, yet we remain on the shore of
what we know." -- Richard Wilbur

"kiwitwat" <kiwitwat@furby.co.nz> wrote in message
news:kd3eg05lc44dskee2hrk04coudta30hru3@4ax.com...

> Hi all. I have been told you cannot use titanium or aluminium
> regulators for nitrox (enrichd air in PADI speak). Is this true.? If
> so, does the oxygen % have a limit or is it for all mixes above
> ordianr air? TIA

No more than 40% is wise for a number of good reasons.

Why do you want an aluminum or titanium reg?

There were some aluminum regs that were put on O2 kits for medical emergency
use that had a few fires, and then were recalled.

Titanium or aluminum, if ground into fine enough particles, will ignite upon
exposure to air alone.

"kiwitwat" <kiwitwat@furby.co.nz> wrote in message
news:kd3eg05lc44dskee2hrk04coudta30hru3@4ax.com...
> Hi all. I have been told you cannot use titanium or aluminium
> regulators for nitrox (enrichd air in PADI speak). Is this true.? If
> so, does the oxygen % have a limit or is it for all mixes above
> ordianr air? TIA

http://www.cyberdiver.net/gear/gearr...ecall_dan.html

http://www.fda.gov/cdrh/oxyreg.html

In article <kd3eg05lc44dskee2hrk04coudta30hru3@4ax.com>, kiwitwat
<kiwitwat@furby.co.nz> wrote:

€ Hi all. I have been told you cannot use titanium or aluminium
€ regulators for nitrox (enrichd air in PADI speak). Is this true.?

Yes.

You can't use either of those regs for anything that involves water.

--
"We're going to rush the hijackers."
-Jeremy Glick, aboard United Airlines flight 93, September 11, 2001

Jammer Six wrote:

> In article <kd3eg05lc44dskee2hrk04coudta30hru3@4ax.com>, kiwitwat
> <kiwitwat@furby.co.nz> wrote:
>
> € Hi all. I have been told you cannot use titanium or aluminium
> € regulators for nitrox (enrichd air in PADI speak). Is this true.?
>
> Yes.
>
> You can't use either of those regs for anything that involves water.
>

What happens when you do?

"Jon C" <news@jonnythan.com> wrote in message
news:6CHNc.67129$yd5.57550@twister.nyroc.rr.com...
> Jammer Six wrote:
>
> > In article <kd3eg05lc44dskee2hrk04coudta30hru3@4ax.com>, kiwitwat
> > <kiwitwat@furby.co.nz> wrote:
> >
> > € Hi all. I have been told you cannot use titanium or aluminium
> > € regulators for nitrox (enrichd air in PADI speak). Is this true.?
> >
> > Yes.
> >
> > You can't use either of those regs for anything that involves water.
> >
>
> What happens when you do?

You don't have enough money left to dive.

Both Aluminium and Titanium can oxidise (combust) under certain conditions;
in fact Aluminium is highly reactive, with similar properties to magnesium,
however because it creates a hard, non-porous oxide layer almost immediately
when in contact with oxygen (such as in air), most people assume that it is
a non-reactive metal.

As a comparison, Iron, which is far less reactive than Aluminium, (as
commonly used in mild steel such as car bodywork & chassis) will rust,
however, rust (Iron Oxide) is porous, so even after a surface coating of
rust is present, oxygen can still reach underneath to virgin metal, so the
rusting process (oxidisation) continues. That is one of the reasons why
many car manufacturer's are now making many new cars with aluminium chassis
& body parts, and for many years the mild steel of cars have been Zinc
coated to stop rusting (as is the external surface of SCUBA cylinders before
they are painted).

The surface of Aluminium can be made less porous and toughened by the
anodising process, which creates a deeper shell of oxidation (and comes in
several lovely colours), however the metal underneath is still reactive.

Titanium is also reactive, but not as aggressively as Aluminium.

The most common metals for use in high levels of Oxygen (O2) are Stainless
Steel and Brass, both are alloys of two or more metals and relatively inert;
the Chromium plating on brass is mainly for cosmetic reasons and is also
relatively unreactive (inert) with Oxygen.

Neither Aluminium or Titanium are approved for use with Nitrox, and
certainly not any Nitrox higher than 40%, however most of the Compressed gas
agencies such as the HSE in the UK state that any EAN greater than 25%
requires equipment in Oxygen Service, I.E made of compatible materials, with
all seals & lubricants made of hydrocarbon free compounds, this usually
means Brass or Stainless Steel (only specified steel alloys).

It does not require the metal to be in powder form for any oxidation or
ignition to occur (although it does assist, due to the greater surface area
for combustion of particulate matter), as there is localised heating created
where high pressure gas at high velocities is passed over an obstruction,
such as when you open the cylinder valve and the gases are released into the
1st stage of the regulator. This is especially important where the gases
are restricted as in the pressure valve assembly) and where they have to
change direction or pass over a sharp edge, such as a corner.

Ignition may not be obvious, however, you would not want to be breathing the
by-products oxidation, especially if ant hydrocarbons are present (O rings,
lubricants etc.) as they may have formed poisonous or corrosive gases.

Obviously Aluminium per-se is not banned from use with even 100% O2, as I &
many divers use Aluminium cylinders for 100% O2 as a decompression gas, but
it is that the 1st stage of a regulator is forcing the high pressure gas
through restrictions & therefore creating localised heating that is the
issue.

Anyway, why pay for expensive Aluminium or Titanium 1st stages, as any
weight saving will only require to be offset with extra weights elsewhere
such as on your weightbelt.


"kiwitwat" <kiwitwat@furby.co.nz> wrote in message
news:kd3eg05lc44dskee2hrk04coudta30hru3@4ax.com...
> Hi all. I have been told you cannot use titanium or aluminium
> regulators for nitrox (enrichd air in PADI speak). Is this true.? If
> so, does the oxygen % have a limit or is it for all mixes above
> ordianr air? TIA

On 27 Jul 2004 21:24:08 -0500, kiwitwat <kiwitwat@furby.co.nz> wrote:

>Hi all. I have been told you cannot use titanium or aluminium
>regulators for nitrox (enrichd air in PADI speak). Is this true.? If
>so, does the oxygen % have a limit or is it for all mixes above
>ordianr air? TIA

40% and below can be treated as air.


--- Rich
http://richlockyer.tripod.com/

On Tue, 27 Jul 2004 19:42:02 -0700, "Scott" <scottk@localaxes.com>
wrote:

>Titanium or aluminum, if ground into fine enough particles, will ignite upon
>exposure to air alone.

Especially in the presence of a 480vac arc.

Ouch.

I think I can still see the purple trails from that one, and it was 20
years ago.



--- Rich
http://richlockyer.tripod.com/

In article <6CHNc.67129$yd5.57550@twister.nyroc.rr.com>, Jon C
<news@jonnythan.com> wrote:

€ Jammer Six wrote:
€
€ > In article <kd3eg05lc44dskee2hrk04coudta30hru3@4ax.com>, kiwitwat
€ > <kiwitwat@furby.co.nz> wrote:
€ >
€ > € Hi all. I have been told you cannot use titanium or aluminium
€ > € regulators for nitrox (enrichd air in PADI speak). Is this true.?
€ >
€ > Yes.
€ >
€ > You can't use either of those regs for anything that involves water.
€ >
€
€ What happens when you do?

Bad, bad things.

--
"We're going to rush the hijackers."
-Jeremy Glick, aboard United Airlines flight 93, September 11, 2001