Re: [PSUBS-MAILIST] For Bill A., recharging battery pods, Vacuums and unknown gas loss.

[Phil Nuytten <pnuytten@compuserve.com>]

Dear Bill:
        Regarding battery pod vacuum: We ( Nuytco) don't use Hydro-caps on
our current sub battery pods. We did use them for many years on several
early subs such as Sea-Otter, Sea-Urchin,  and various stand-alone
manip/jet-pump/ cutting systems/etc., with their own,independant, power
supply. As Vance says, we most often had a  vacuum on surfacing. So, if you
must use caps, plan on a vacuum..
        Of far greater concern, safety-wise and IMHO, is your proposed use
of a scuba reg for pod compensation. No matter how you cut it, by
definition, at some point in the system you have nothing between the
interior of your pod and the water but 1/32nd of an inch of rubber. If you
forget to turn on your comp air and descend, or comp airline is blocked, or
comp air is exhausted and you dont realize it and go deeper - the pods will
flood and you will go deeper mucho rapido or,and, when you hit bottom, you
will be stuck there like a limpet! Don't use a standard scuba reg with with
an unmodified diaphragm and/or diaphragm retainer - or a mushroom or
flutter-valve exhaust. Do use a positive pressure reg and
positive-over-ambient pressure exhaust, so that any leaks are gas out, not
water in. Do also provide pod water alarms and the usual pod sensors,
ground-fault indicators, breakers, etc. Overkill? Think about flooded pods
or flooded significant volumer external housings dragging you down . . .
not a pleasant thought!     
Regards
Phil Nuytten  




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