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From: James Dibbs <JDibbs@ma*.co*.au*>
To: "'William Gearman'" <gearman_1@ya*.co*>, Salty32321@ao*.co*,
     techdiver@aquanaut.com
Subject: RE: Breathing off the inflator/Air II
Date: Thu, 10 Feb 2000 16:45:57 +1100
I don't use an Air 2 and neither am I considering using one but I think you may
have misinterpreted "salty's" post.

I think (correct me if I am wrong) he is suggesting that you have an AIR 2 on
your inflator IN ADDITION to the primary and backup 2nd stages on your DIR
setup. His reasoning being that it is easier to use the AIR 2 as a third option
reg than depressing both buttons on the BCD inflator.

I also had some comments about the points in your post (see below).

>1. Assuming a redundant dual outlet manifold, if the Air II begins to free
flow, what exactly would your management procedure be?
(No arguments there and I expect that a free flow in an air 2 is more likely
than an standard BDC inflator free flow. )

>a. How would you make subsequent buoyancy adjustments? 
(The oral inflator mechanism is separate to the reg mechanism. When you orally
inflate with the unit you shut off the flow  from the reg part. You could still
use the oral inflator if you had to disconnect the LP hose or shut down the
post - not a great option though)

>b. Do you sacrifice your breathing devise if the auto inflator malfunctions?
(not sure what an auto inflator is. I assume you mean power inflator. Refer to
point (a). reg mechanism/flow path is separate to power inflator path. You
would be in the same boat with a standard inflator.)

>2. Is the Air II second interchangeable at the LP hose connection with the
long hose primary 2nd of your rig and your other team >member's rigs?
(I agree with your point in that you cannot connect your BCD hose to another
team member's BCD inflator if they are using a standard unit. However if the
AIR 2 is your 3rd option reg then you can swap your first two 2nd stages if
required and you cannot connect a bcd inflator to a reg hose regardless of what
type of inflator you use)

>3. Most modern high performance first stages have multiple LP ports usually
split equally between i.e. 2 for high volume second >stage delivery, and 2 for
lower volume accessory inflation devices.
(A good example of this is the Apex and Poseidon 1st stages. In the case of the
Poseidon (and I expect the Apex) it is academic as ALL the LP ports have a flow
rate far in excess of the flow capabilities of the second stage anyway. The
flowrates they give you in the brochures are performed under test conditions
using a test unit, not while attached to a SCUBA tank.)  

>a. Recognizing such, which port would you choose to connect the Air II/BC
inflator to?
(see point above. Doesn't matter)

>b. The HV ports, which are usually about 2400 liters per minute flow rate,
resulting in possible too rapid an inflation rate? 
(would maybe have slightly higher flow rate but again, ultimate flow rate is
restricted by the 2nd stage/inflator)

>c. The LV ports, which are usually about 1700 liters per minute resulting in
diminished flow rate to the backup Air II?
(Again, no way 1700 litres/min can go through an AIR 2/2nd stage)

>4. Is the cover plate of the Air II easily removable to facilitate clearing
the exhaust valve or inspecting the interior-breathing
>chamber?
(Can be unscrewed in the water provided you remove the retaining pin the same
as with the G250)

>5. What exactly would be your choice of hose configurations at the first
stages [note, plural] if you employed the Air II?
(I expect that it would be the same as a standard DIR config)

>6. How well does your Air II breathe at say 200+fsw as compared to a
conventional 2nd stage choice and higher gas densities?
(It would suck big time (in fact they suck in the shop) but this would be your
3rd reg and I expect that BCD inflators don't breathe too good at 200+FSW
either)

7.Where would you recommend parking the Air II to minimize entanglement and
impact hazards while providing efficient streamlining?
(Same place your normal inflator goes, on the left side under a piece of bungee
coming from the D-ring)

In a nutshell I would avoid using an AIR 2 for reasons 1. and 1a. but I don't
think the other reasons are valid.

James Dibbs
Sydney, Australia
jdibbs@ma*.co*.au*


--- Salty32321@ao*.co* wrote:
> I dont know I use the Air II and think its
> better than a standard inflator. 
> For one thing how many people get their
> inflators serviced every year..maybe 
> that's why we keep hearing about all these
> inflator breakdowns. Also it 
> eliminates a hose, that can't be a bad thing. I
> will admit it is larger than 
> an inflator but that's nice when your wearing
> three finger mitts and after a 
> little practice using it becomes second nature.
> You should be comfortable 
> using all your equipment at any time no matter
> what any way.
> --
> Send mail for the `techdiver' mailing list to
> `techdiver@aquanaut.com'.
> Send subscribe/unsubscribe requests to
> `techdiver-request@aquanaut.com'.
> 
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