Wanted: Info on nitrox blending sticks. Any good? Advantages/disadvantages? Dangerous? Where to get one? Blah blah blah

In article <4j4bh01a0vklgoqv8fof201g60in1ns6b7@4ax.com>, kiwitwat
<kiwitwat@furby.co.nz> wrote:


"Nitrox Blending Sticks" is a clever marketing term for continuous flow
(CF) blending, where you pre-mix the gasses into the proper ratio
before compressing them.

NAUI sells an overpriced, kinda cheap mixer called the "Nitrox Stick",
but a much higher quality, low volume mixer is made by one of our own
and is sold here:

<http://www.selchie.com/gas_mixing.htm>

Major advantages of CF blending include:

Easy mix customization
Mixtures can be analyzed before filling
Complete (or nearly complete) utilization of He and O2 cylinders

Major disadvantages include:

Potential for compressor damage if using high PPO2 mixtures and
improper lubicants (and even with proper lubricants, high PPO2 mixtures
are hard on compressors)
Potential for gas wastage while adjusting flow rates (not the most
efficient method for filling a single tank, but very good for filling
banks)

Jammer or Scott - anything else?

Alan

High F(He) mixtures tend to cause compressor overheating. This becomes a
real issue when you start wanting to mix up something other than 30/30.
Solveable with additional cooling fan(s) in most cases.

High F(O2) mixtures can cause detonation without warning, usually in the
cooling tubes due to them collecting oil vapor drop-out, which causes severe
damage to the compressor. The same incident in the dryer/purifier can cause
catastrophic failure, much like a tank explosion. The other possibility is
silent combustion which makes a nice dollop of CO to go into your tank.
This is not a common risk, but it is a possible risk and one you need to
understand.

More common is the increased wear on cylinder bores and rings, along with
valves, that enriched FO2s cause. That is inescapable. Expect to cut
overhaul intervals to half or less of that if you are running straight
air with 32% FO2, and very likely completely unacceptable service life if
you want to make 36%.

Most important is the absolute requirement that a compressor used with
a stick have a magnetic starter fitted so that in the event of a power
failure while the stick is in use so it does NOT restart when power
returns. Lacking this it is likely that the compressor will ingest
a bolus of near-100% O2 when the juice comes back on. That is quite
likely to result in an immediate explosion.

Sticks can be safely used, but they're not a panacea and the issues need
to be understood and dealt with.

For my money, I prefer to PP mix for Nitrox.

I can't use a stick to make 50% Nitrox anyway (FO2 is too high), which I
need for ocean deco bottles, so since I already have to PP mix for those,
I may as well PP mix for the rest.

I might think differently if I was making up normoxic or hypoxic trimix,
where the O2-related risks are a non-issue and the only issue to be dealt
with was that of possible overheating. That one I can handle easily enough
with a nice big fan pointing at the compressor to augment its already-present
flywheel fan. Indeed, once the Oriskany goes down here normoxic trimix is
going to be rather common in my tanks, and I will almost certainly use a
stick to make it for that reason.

If you choose to use a stick with elevated FO2s, make sure your compressor
is very clean internally (including the cooling tubes), keep it that way,
attend to the cooling requirements if you intend to pump Helium through it,
and use synthetic oil (or use a Rix which requires no oil at all.)

-
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net My home on the net
http://scubaforum.org Your UNCENSORED place to talk about DIVING!
http://boaterforum.com Talk about Boating online - any topic, any time!
http://www.spamcuda.net SPAM FREE mailboxes - FREE FOR A LIMITED TIME!

In article <070820042140405240%agstreet@nonono_san.rr.com>,
Alan Street <agstreet@nonono_san.rr.com> wrote:
>
>
>In article <4j4bh01a0vklgoqv8fof201g60in1ns6b7@4ax.com>, kiwitwat
><kiwitwat@furby.co.nz> wrote:
>
>
>"Nitrox Blending Sticks" is a clever marketing term for continuous flow
>(CF) blending, where you pre-mix the gasses into the proper ratio
>before compressing them.
>
>NAUI sells an overpriced, kinda cheap mixer called the "Nitrox Stick",
>but a much higher quality, low volume mixer is made by one of our own
>and is sold here:
>
><http://www.selchie.com/gas_mixing.htm>
>
>Major advantages of CF blending include:
>
>Easy mix customization
>Mixtures can be analyzed before filling
>Complete (or nearly complete) utilization of He and O2 cylinders
>
>Major disadvantages include:
>
>Potential for compressor damage if using high PPO2 mixtures and
>improper lubicants (and even with proper lubricants, high PPO2 mixtures
>are hard on compressors)
>Potential for gas wastage while adjusting flow rates (not the most
>efficient method for filling a single tank, but very good for filling
>banks)
>
>Jammer or Scott - anything else?
>
>Alan

In article <nBiRc.15885$Jp6.14176@newsread3.news.atl.earthlin k.net>,
Karl Denninger <karl@FS.Denninger.Net> wrote:


Excellent synopsis - Thanks, Karl.



> High F(He) mixtures tend to cause compressor overheating. This becomes a
> real issue when you start wanting to mix up something other than 30/30.
> Solveable with additional cooling fan(s) in most cases.
>
> High F(O2) mixtures can cause detonation without warning, usually in the
> cooling tubes due to them collecting oil vapor drop-out, which causes severe
> damage to the compressor. The same incident in the dryer/purifier can cause
> catastrophic failure, much like a tank explosion. The other possibility is
> silent combustion which makes a nice dollop of CO to go into your tank.
> This is not a common risk, but it is a possible risk and one you need to
> understand.
>
> More common is the increased wear on cylinder bores and rings, along with
> valves, that enriched FO2s cause. That is inescapable. Expect to cut
> overhaul intervals to half or less of that if you are running straight
> air with 32% FO2, and very likely completely unacceptable service life if
> you want to make 36%.
>
> Most important is the absolute requirement that a compressor used with
> a stick have a magnetic starter fitted so that in the event of a power
> failure while the stick is in use so it does NOT restart when power
> returns. Lacking this it is likely that the compressor will ingest
> a bolus of near-100% O2 when the juice comes back on. That is quite
> likely to result in an immediate explosion.
>
> Sticks can be safely used, but they're not a panacea and the issues need
> to be understood and dealt with.
>
> For my money, I prefer to PP mix for Nitrox.
>
> I can't use a stick to make 50% Nitrox anyway (FO2 is too high), which I
> need for ocean deco bottles, so since I already have to PP mix for those,
> I may as well PP mix for the rest.
>
> I might think differently if I was making up normoxic or hypoxic trimix,
> where the O2-related risks are a non-issue and the only issue to be dealt
> with was that of possible overheating. That one I can handle easily enough
> with a nice big fan pointing at the compressor to augment its already-present
> flywheel fan. Indeed, once the Oriskany goes down here normoxic trimix is
> going to be rather common in my tanks, and I will almost certainly use a
> stick to make it for that reason.
>
> If you choose to use a stick with elevated FO2s, make sure your compressor
> is very clean internally (including the cooling tubes), keep it that way,
> attend to the cooling requirements if you intend to pump Helium through it,
> and use synthetic oil (or use a Rix which requires no oil at all.)
>
> -

In article <080820042200063470%agstreet@nonono_san.rr.com>,
Alan Street <agstreet@nonono_san.rr.com> wrote:
>
>
>In article <nBiRc.15885$Jp6.14176@newsread3.news.atl.earthlin k.net>,
>Karl Denninger <karl@FS.Denninger.Net> wrote:
>
>
>Excellent synopsis - Thanks, Karl.

'Yer welcome :)

Going boom is a real bummer.

Destroying a perfectly good compressor is as well.

Sticks are often sold or made without the intended user understanding the
issues, and thinking they can use them and pump the gas "just like air."

It ain't so.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net My home on the net
http://scubaforum.org Your UNCENSORED place to talk about DIVING!
http://boaterforum.com Talk about Boating online - any topic, any time!
http://www.spamcuda.net SPAM FREE mailboxes - FREE FOR A LIMITED TIME!

On Tue, 10 Aug 2004 16:55:01 GMT, karl@FS.Denninger.Net (Karl
Denninger) wrote:

>
>In article <080820042200063470%agstreet@nonono_san.rr.com>,
>Alan Street <agstreet@nonono_san.rr.com> wrote:
>>
>>
>>In article <nBiRc.15885$Jp6.14176@newsread3.news.atl.earthlin k.net>,
>>Karl Denninger <karl@FS.Denninger.Net> wrote:
>>
>>
>>Excellent synopsis - Thanks, Karl.
>
>'Yer welcome :)
>
>Going boom is a real bummer.
>
>Destroying a perfectly good compressor is as well.
>
>Sticks are often sold or made without the intended user understanding the
>issues, and thinking they can use them and pump the gas "just like air."
>
>It ain't so.
>
>--


Thanks for the help. I think I may give the 'stick' a miss. The
dangers arn'e so much of a factor as the wear and tear on the
compressor.

The only compressors (to my knowledge) that are less affected by pumping EAN
greater than 21% are the RIX range of oil-free compressors that use PTFE
(Teflon) bearings & seals.

However they are BLOODY expensive compared to a normal compressor.


"kiwitwat" <kiwitwat@furby.co.nz> wrote in message
news:eieih0ho46pun3bfpqr10tnog3i7ldgmqb@4ax.com...
> On Tue, 10 Aug 2004 16:55:01 GMT, karl@FS.Denninger.Net (Karl
> Denninger) wrote:
>
> >
> >In article <080820042200063470%agstreet@nonono_san.rr.com>,
> >Alan Street <agstreet@nonono_san.rr.com> wrote:
> >>
> >>
> >>In article <nBiRc.15885$Jp6.14176@newsread3.news.atl.earthlin k.net>,
> >>Karl Denninger <karl@FS.Denninger.Net> wrote:
> >>
> >>
> >>Excellent synopsis - Thanks, Karl.
> >
> >'Yer welcome :)
> >
> >Going boom is a real bummer.
> >
> >Destroying a perfectly good compressor is as well.
> >
> >Sticks are often sold or made without the intended user understanding the
> >issues, and thinking they can use them and pump the gas "just like air."
> >
> >It ain't so.
> >
> >--
>
>
> Thanks for the help. I think I may give the 'stick' a miss. The
> dangers arn'e so much of a factor as the wear and tear on the
> compressor.

In article <4j4bh01a0vklgoqv8fof201g60in1ns6b7@4ax.com>, kiwitwat
<kiwitwat@furby.co.nz> wrote:


"Nitrox Blending Sticks" is a clever marketing term for continuous flow
(CF) blending, where you pre-mix the gasses into the proper ratio
before compressing them.

NAUI sells an overpriced, kinda cheap mixer called the "Nitrox Stick",
but a much higher quality, low volume mixer is made by one of our own
and is sold here:

<http://www.selchie.com/gas_mixing.htm>

Major advantages of CF blending include:

Easy mix customization
Mixtures can be analyzed before filling
Complete (or nearly complete) utilization of He and O2 cylinders

Major disadvantages include:

Potential for compressor damage if using high PPO2 mixtures and
improper lubicants (and even with proper lubricants, high PPO2 mixtures
are hard on compressors)
Potential for gas wastage while adjusting flow rates (not the most
efficient method for filling a single tank, but very good for filling
banks)

Jammer or Scott - anything else?

Alan

High F(He) mixtures tend to cause compressor overheating. This becomes a
real issue when you start wanting to mix up something other than 30/30.
Solveable with additional cooling fan(s) in most cases.

High F(O2) mixtures can cause detonation without warning, usually in the
cooling tubes due to them collecting oil vapor drop-out, which causes severe
damage to the compressor. The same incident in the dryer/purifier can cause
catastrophic failure, much like a tank explosion. The other possibility is
silent combustion which makes a nice dollop of CO to go into your tank.
This is not a common risk, but it is a possible risk and one you need to
understand.

More common is the increased wear on cylinder bores and rings, along with
valves, that enriched FO2s cause. That is inescapable. Expect to cut
overhaul intervals to half or less of that if you are running straight
air with 32% FO2, and very likely completely unacceptable service life if
you want to make 36%.

Most important is the absolute requirement that a compressor used with
a stick have a magnetic starter fitted so that in the event of a power
failure while the stick is in use so it does NOT restart when power
returns. Lacking this it is likely that the compressor will ingest
a bolus of near-100% O2 when the juice comes back on. That is quite
likely to result in an immediate explosion.

Sticks can be safely used, but they're not a panacea and the issues need
to be understood and dealt with.

For my money, I prefer to PP mix for Nitrox.

I can't use a stick to make 50% Nitrox anyway (FO2 is too high), which I
need for ocean deco bottles, so since I already have to PP mix for those,
I may as well PP mix for the rest.

I might think differently if I was making up normoxic or hypoxic trimix,
where the O2-related risks are a non-issue and the only issue to be dealt
with was that of possible overheating. That one I can handle easily enough
with a nice big fan pointing at the compressor to augment its already-present
flywheel fan. Indeed, once the Oriskany goes down here normoxic trimix is
going to be rather common in my tanks, and I will almost certainly use a
stick to make it for that reason.

If you choose to use a stick with elevated FO2s, make sure your compressor
is very clean internally (including the cooling tubes), keep it that way,
attend to the cooling requirements if you intend to pump Helium through it,
and use synthetic oil (or use a Rix which requires no oil at all.)

-
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net My home on the net
http://scubaforum.org Your UNCENSORED place to talk about DIVING!
http://boaterforum.com Talk about Boating online - any topic, any time!
http://www.spamcuda.net SPAM FREE mailboxes - FREE FOR A LIMITED TIME!

In article <070820042140405240%agstreet@nonono_san.rr.com>,
Alan Street <agstreet@nonono_san.rr.com> wrote:
>
>
>In article <4j4bh01a0vklgoqv8fof201g60in1ns6b7@4ax.com>, kiwitwat
><kiwitwat@furby.co.nz> wrote:
>
>
>"Nitrox Blending Sticks" is a clever marketing term for continuous flow
>(CF) blending, where you pre-mix the gasses into the proper ratio
>before compressing them.
>
>NAUI sells an overpriced, kinda cheap mixer called the "Nitrox Stick",
>but a much higher quality, low volume mixer is made by one of our own
>and is sold here:
>
><http://www.selchie.com/gas_mixing.htm>
>
>Major advantages of CF blending include:
>
>Easy mix customization
>Mixtures can be analyzed before filling
>Complete (or nearly complete) utilization of He and O2 cylinders
>
>Major disadvantages include:
>
>Potential for compressor damage if using high PPO2 mixtures and
>improper lubicants (and even with proper lubricants, high PPO2 mixtures
>are hard on compressors)
>Potential for gas wastage while adjusting flow rates (not the most
>efficient method for filling a single tank, but very good for filling
>banks)
>
>Jammer or Scott - anything else?
>
>Alan

In article <nBiRc.15885$Jp6.14176@newsread3.news.atl.earthlin k.net>,
Karl Denninger <karl@FS.Denninger.Net> wrote:


Excellent synopsis - Thanks, Karl.



> High F(He) mixtures tend to cause compressor overheating. This becomes a
> real issue when you start wanting to mix up something other than 30/30.
> Solveable with additional cooling fan(s) in most cases.
>
> High F(O2) mixtures can cause detonation without warning, usually in the
> cooling tubes due to them collecting oil vapor drop-out, which causes severe
> damage to the compressor. The same incident in the dryer/purifier can cause
> catastrophic failure, much like a tank explosion. The other possibility is
> silent combustion which makes a nice dollop of CO to go into your tank.
> This is not a common risk, but it is a possible risk and one you need to
> understand.
>
> More common is the increased wear on cylinder bores and rings, along with
> valves, that enriched FO2s cause. That is inescapable. Expect to cut
> overhaul intervals to half or less of that if you are running straight
> air with 32% FO2, and very likely completely unacceptable service life if
> you want to make 36%.
>
> Most important is the absolute requirement that a compressor used with
> a stick have a magnetic starter fitted so that in the event of a power
> failure while the stick is in use so it does NOT restart when power
> returns. Lacking this it is likely that the compressor will ingest
> a bolus of near-100% O2 when the juice comes back on. That is quite
> likely to result in an immediate explosion.
>
> Sticks can be safely used, but they're not a panacea and the issues need
> to be understood and dealt with.
>
> For my money, I prefer to PP mix for Nitrox.
>
> I can't use a stick to make 50% Nitrox anyway (FO2 is too high), which I
> need for ocean deco bottles, so since I already have to PP mix for those,
> I may as well PP mix for the rest.
>
> I might think differently if I was making up normoxic or hypoxic trimix,
> where the O2-related risks are a non-issue and the only issue to be dealt
> with was that of possible overheating. That one I can handle easily enough
> with a nice big fan pointing at the compressor to augment its already-present
> flywheel fan. Indeed, once the Oriskany goes down here normoxic trimix is
> going to be rather common in my tanks, and I will almost certainly use a
> stick to make it for that reason.
>
> If you choose to use a stick with elevated FO2s, make sure your compressor
> is very clean internally (including the cooling tubes), keep it that way,
> attend to the cooling requirements if you intend to pump Helium through it,
> and use synthetic oil (or use a Rix which requires no oil at all.)
>
> -