Mixing regs / pony regs

David Walker <wbsdavenews@hotmail.com> writes:

>If I can't get an Oceanic 1st stage, I was looking at the Apeks DS4 - I
>thought i'd get the 4 port rather than the 1 port so that I can upgrade in
>future. Question is, how well do reg types like to be mixed, and will it
>cause me any problems? Will an Oceanic reg on an Apeks first stage be OK?

If you are going to buy an Apeks first stage, don't buy the DS1. The
HP and LP hose are at something like 160 degrees to one another which
makes it very difficult to get an acceptable hose routing for a conventional
pony and impossible if you intend to use the reg on a stage or twinset
later on in its life. The DS4 is a good choice.

The combination you suggest will work, but you will probably also run
into difficulties getting it serviced. By mixing manufacturers, some
shops will argue that you have invalidated the CE markings and will
refuse to service the gear: or at least the will service the component
parts and you will get back a collection of bits to assemble yourself.

>Any thoughts? What can I mix and what can't I? Will I benefit from having
>main reg and pony reg matching to be worth the extra?

In practise you can mix and match just about everything except some
of the more eccentric old Poseidon stuff that runs high interstage
pressures - I gather that their more modern regs run lower.

Yes, because you will have better options for interchanging stuff.
And no, because if one reg fails, you might avoid a situation where the
other one fails because you don't have an identical device. In
practise most of us seem to opt for interchangeabilitiy. So Yes.

The other thing to bear in mind is that cheap != good for a pony reg.
You are only going to need this thing when you are really in the shit,
and you will have no idea whether the reg is going to work until you
take a breath off it. My advice is to try and get at least a good
a reg for the pony as you use for your main reg, and put the
better reg on the pony if you don't have that option.

Pete

--
__________________________________________________ __________________
Pete Young pete@antipope.org Remove dot. to reply
"Just another crouton, floating on the bouillabaisse of life"

David Walker wrote:
> I suppose if there was something that would make both fail at the
> same time, it would be pretty extreme and should be known about
> already if it was a particular and consistent manufacturing / design
> fault. That, or it would happen to any reg (ie someone chops through
> all your hoses with a big knife!)

I think the problem with a pony reg is it doesn't get much of
an outing and is more likely to have furred up unnoticed so
it can deliver a couple of breaths at surface flow rates on a
predive check but still give you trouble at depth just when
you don't need it.

I bought a DS1 on my first pony and consider it a mistake. I
only saved a couple of quid and had something that was stuck
in one job while I rotated everything else. Admittedly it now
gets plenty of use on a suit inflation bottle but I bought
others for the stages.

<sigh> Live and learn.

nigelH

> I think the problem with a pony reg is it doesn't get much of
> an outing and is more likely to have furred up unnoticed so
> it can deliver a couple of breaths at surface flow rates on a
> predive check but still give you trouble at depth just when
> you don't need it.
>
> I bought a DS1 on my first pony and consider it a mistake. I
> only saved a couple of quid and had something that was stuck
> in one job while I rotated everything else. Admittedly it now
> gets plenty of use on a suit inflation bottle but I bought
> others for the stages.

Ahhh - thats a good idea! More reason to get the same make as my main reg I
suppose. Anyway, if I do get one now, it will be one of the Oceanic ones -
depending on money though, I might end up waiting til early next year. I
hate being poor! :o(

David

In article <sPAmb.1028$sP5.8955@newsfep4-glfd.server.ntli.net>,
Iain Smith <iainmsmith@btinternet.com> wrote:
>> > Oxygen Compatible means that the parts are suitable for use
>> > with oxygen (and are not going to explode/burst into
>> >flames/give off toxic fumes or similar nasties)
>> >
>> > Oxygen Clean means that the item has had contaminants
>> > removed (eg hydrocarbon residue, grit, metal filings) so
>> > that they cannot react with oxygen. This usually involves
>> > some sort of solvent.
>>
>> Sounds a bit silly really - surely if you're going to clean
>> something with the idea of putting oxygen in (ie oxygen
>> clean), you should make sure the rest of the cylinder is OK
>> to take oxygen (ie oxygen compatible) otherwise
>> theres no point in doing it.
>
>Yes, of course. The point is that something that is compatible may not be
>suitable for oxygen service until it is clean. While you could O2 clean
>something, as you say, it would be rather futile if it were not already
>compatible!

Yes; but the idea of oxygen cleaning something that is not
going near oxygen is not so outragous. If you fill O2-compatible
air anyway you may just as well clean everything. That way you can
move regulators etc. around at will. Also, clean is good for
wear and tear. If you are a stickler for pure air and clean
equipment your tanks will still be in mint condition when they
are 10 years old; and your regulators will last a LOT longer
between service.

>> However, going on that I just want oxygen compatible for the
>> moment, and then get it oxygen cleaned later.
>
>Correct. Or, at least, ensure that it is possible to make the item O2
>compatible at a later date.

You'll have to O2-clean it again yearly anyway.

-- mrr

In article <bnebvb$8i2$1@wisteria.csv.warwick.ac.uk>,
David Walker <wbsdavenews@hotmail.com> wrote:
>> There's no real reason that you shouldn't use an Apeks 1st stage and an
>> Oceanic octo, except that it'll probably void the warranty on both.
>> IIRC they both work on the same interstage pressure.
>
>Oh - I quite like the Oceanic warranty because you get free parts for the
>service as long as you do it every year.
>
>> > Would the best idea be to just buy a nitrox pony now, use it with air
>(which
>> > unfortunately isn't "clean" air from our club compressor), and then when
>I
>> > get round to doing nitrox if I still want to use it I just need to have
>it
>> > O2 cleaned? That sound about right?

For O2 service you need three factors :

[1] It must be designed for oxygen service ( the materials and construction)
[2] It must have been serviced for O2 (O-rings, seats etc)
[3] It must be O2 clean.

>> Nope. If you're going to use the kit on dirty air, there's no point
>> paying over the top for O2 clean stuff. Get a non-O2 clean tank and
>> normal reg. When you're ready to switch to nitrox, have the tank O2
>> cleaned and the reg put thru O2 service. If you were to buy O2 clean
>> stuff and then use it on dirty air it'd need cleaning just the same.
>
>Ah - this was the bit I wasn't sure about. I seem to remember reading
>something not long ago about oxygen compatible and oxygen clean not being
>the same thing. If it is to be used for nitrox, am I right in assuming it
>needs different o-rings and things to a normal cylinder? I was under the
>impression that an O2 clean was effectively just "rinse it out with O2"?

Oxygen under pressure will start a fire when in contact with some
materials. Bystanders to such fires are normally reluctant to use
this word, preferring "explosion" or "fireball" or similar
words. (This is one of those parts of the English language we
foreigners must just learn, even if they are not completly logical)

Rubbers, Oils, fats and some metals like Titanium and Magnesium are
the main problems. Titanium has a self-ignition temperature of 72
degrees C in pure oxygen. Magnesium is similar. Oils vary; the very
worst offender is Margarine butter and some cheap silicone products.
Hodrogenization of cleap unsaturated oils make fats that are
EXTREMELY O2-reactive.

O2 will also break down rubber and plastic products rapidly, leading
to failures, or fires from the breakdown products.

So, step 1 is to see to it that the tank, valve, reg and hoses are
actually designed for O2 use. The manufacturer will state this.
Then, when you take it in for service you ask for O2-service; and
the bottle, valve, If they are in good condition they will be cleaned,
O-rings, seats etc will be changed, and then they will be cleaned again.

You can now use the set with pure O2. But add some compressor oil
from one unclean fill, and you can forget the whole thing.

>I'll go and do some reading up of that, but I do vaguely remember some
>confusion about the terms used (I think it was someone bought a cylinder for
>nitrox, which was o2 clean, but couldn't be filled because it wasn't o2
>serviced or something... i'll have to dig it out).

Your cylinder complies with [1] and [2] above.

>Since its likely to be after christmas when I do nitrox (depending on course
>availability) I don't have a particular problem with paying for an o2 clean
>/ o2 service in 3 or 6 months, as long as it doesn't require a whole new
>valve and things put in.

The valve and first stage are the main problems with pure oxygen.
>
>> If you back mount it, you're not going to be able to remove it if you do
>> want to squeeze thru a tight spot. With it slung as a stage, you can
>> just unclip it.If you want to get into a rib you can remove it in water
>> and hand it over too. Plus you can bungee the hose to the pony, so
>> you don't have 3 hoses coming over on your right. That means that you're
>> less likely to breath from the wrong reg by mistake.
>
>I'm still not convinced - sorry! I just don't think i'd like something
>hanging there all the time, and like I say i'd just end up not using it.
>I'll be using it a lot when i'm teaching in Stoney, so having it hanging
>isn't really ideal under those circumstances. On other dives I do it might
>be OK hanging, but then i'd already have a clips and things so would
>probably just leave it on my back.

With students I'd just use a smallish twinset; a 2x8 or similar.
A twinset has primary/backup just the way the student's own equipment
is configured, and there are very few extra complexities.

>For reg positioning, I have main reg on my right, and octopus on the left so
>that its oriented better for my buddy. I'd put the pony reg on the right
>too, clipped to a d-ring or tied on somewhere so its out of the way but
>still easy to get to and get out quickly. Even though i'm wanting to get
>the same sort of reg for the pony, I will be trying to get one which looks
>physically different - at the minute I have a small black main reg, and a
>larger yellow octopus - i'd probably end up getting the larger black reg for
>the pony. However, it depends where I get it from. There are two i'm
>looking at at the minute which are cheap, but I wouldn't get the choice of
>colours - I can have it as it is, or not at all.

No. Breathe the long hose. Prepare to give it away. Have the pony
or backup reg in a bungee/surgical loop around your neck. The backup
reg is for YOU. If your buddy is OOA you give away the main reg; and
YOU take the pony/backup reg. You are probably a lot less stressed out.
Also, after doing this with a long hose once you will never want
to go back. You will probably want to migrate towards a twinset though.

>> Plus it'll mean that by the time you really do want to do accelerated
>> deco, you'll be used to it and going from a 3L to a 7L won't be a
>> problem.
>
>Can't see me doing that really - not with anything clever like side-slung
>things anyway. A twinset is something I would use if I got one, and may do
>in a few years, but at the minute the type of diving I mostly do doesn't
>justify a twinset, and it really is overkill - I just don't need that volume
>of gas. Even if I did have one, no one else in my main club uses twins
>except in Egypt or the odd UK dive, so me having one doesn't really help.
>I really can't see me having it mounted anything other than on the main tank
>on my back. I understand some of the things in favour of doing so, but it
>wouldn't be best for the diving i'm mostly doing.

Someone has to start. I do almost all my diving with twinsets now.
Twinsets doesn't have to be 2x18 232's all of them. I get enough gas
for all non-deco dives with a 2x8 200; surfacing with 100 bar even
with a low fill.

I sometimes bring a lot more gas than is needed. Just think of it as
diving thirds. Or fourths. This is sensible when you bring students.
It only takes a little incident for you to rack up 15 minutes of deco.
Then you will be glad you brought the gas.


-- mrr

Morten Reistad wrote:

> Oxygen under pressure will start a fire when in contact with some
> materials.

There's a good example of the effects of high
O2 concentrations on combustible material at:

http://ep.llnl.gov/msds/Chem120/lox-oxidation.html

- Keith

Keith S. wrote:

> Morten Reistad wrote:
>
>> Oxygen under pressure will start a fire when in contact with some
>> materials.
>
> There's a good example of the effects of high
> O2 concentrations on combustible material at:
>
> http://ep.llnl.gov/msds/Chem120/lox-oxidation.html
>
> - Keith

Hmmm... Having read that one bit struck me, "One briquette presoaked in
Liquid Oxygen is approx equivalent to 1 stick of dynamite".

Plain and simple, no it isn't. Dynamite is a high explosive, ie it
detonates, charcoal in liquid oxygen would deflagrate, a much lower grade
of explosion.

I would be amazed if one briquette of charcoal soaked in liqiud oxygen even
burns as fast as the same amount of gunpowder, a low order explosive which
has charcoal as its fuel.

It strikes me as media hype, same as most of the info on O2 cleaning.
Someone did the calcs as to how much oil it would take to cause a problem
under 200 bar of O2, it was a lot, a hell of a lot, enough that you would
be dead from breathing it.

The page also says to get the effect that they are demonstrating you need an
ignition source, the example they use is a lit ciggarette, I personally
don't have one of them in my cylinders. An interesting thing to show O2
burning is to get your nearest smoker (If I'm around I'll do it) to take a
breath of O2 and exhale it through a lit ciggarette. Lovely little blow
lamp effect.

Anyway enough rambling

Danny
--
The box said windows 98 or better, so I installed Linux

Header is false, correct is Danny at danshome dot org

"Danny Burchett" <me@privacy.net> wrote in message
news:booc11$1fgg96$1@ID-188750.news.uni-berlin.de...
>
> The page also says to get the effect that they are demonstrating you need
an
> ignition source, the example they use is a lit ciggarette, I personally
> don't have one of them in my cylinders. An interesting thing to show O2
> burning is to get your nearest smoker (If I'm around I'll do it) to take a
> breath of O2 and exhale it through a lit ciggarette. Lovely little blow
> lamp effect.

It is not always necessary to have an ignition source. A flammable material
and oxygen in the right proportions can spontaneously ignite.

Cliff.

Cliff Coggin wrote:

>
> "Danny Burchett" <me@privacy.net> wrote in message
> news:booc11$1fgg96$1@ID-188750.news.uni-berlin.de...
>>
>> The page also says to get the effect that they are demonstrating you need
> an
>> ignition source, the example they use is a lit ciggarette, I personally
>> don't have one of them in my cylinders. An interesting thing to show O2
>> burning is to get your nearest smoker (If I'm around I'll do it) to take
>> a breath of O2 and exhale it through a lit ciggarette. Lovely little blow
>> lamp effect.
>
> It is not always necessary to have an ignition source. A flammable
> material and oxygen in the right proportions can spontaneously ignite.
>
> Cliff.

I concur, however other than titanium I suspect not very many of these
materials are in scuba equipment. On any that are I suspect the ignition
temperature is fairly high.

Danny
--
The box said windows 98 or better, so I installed Linux

Header is false, correct is Danny at danshome dot org

> Yes; but the idea of oxygen cleaning something that is not
> going near oxygen is not so outragous. If you fill O2
> -compatible air anyway you may just as well clean everything.
> That way you can move regulators etc. around at will.

Yes...but I really can't be bothered shelling out to get my back gas regs or
my argon reg O2 cleaned just in case I might like to use them on my O2
bottle. Then again, I didn't O2 clean my "straight out of the box" 50% or O2
regs either. I'll probably get the O2 reg cleaned when it finally needs
servicing.

> Also, clean is good for wear and tear. If you are a stickler
> for pure air and clean equipment your tanks will still be in
> mint condition when they are 10 years old; and your
> regulators will last a LOT longer between service.

As opposed to lasting several years between services anyway?

> >> However, going on that I just want oxygen compatible for the
> >> moment, and then get it oxygen cleaned later.
> >
> >Correct. Or, at least, ensure that it is possible to make the item O2
> >compatible at a later date.
>
> You'll have to O2-clean it again yearly anyway.

Allegedly. Tanks probably do need to get done, because it's difficult to get
fills without the requisite stickers. That there is no real need for annual
cleaning is a different matter.

Iain