Mailing List Archive Mailing List Archive
You'd never be able to breath a tank down much below the IP, anyway. I've sucked my O2 bottle dry numerous times, and there is always some gas left in it. --------------------------------------- Kevin Connell <kevin@nw*.co*> Northwest Labor Systems http://www.nwls.com --------------------------------------- On Thu, 21 Jan 1999, David Reinhard wrote: > >>>I will admit it, on two occasions I have needed to use my pony bottle. Both > >>>times were in no-deco situations, and I didn't have enough gas in my tank > >>>to complete my safety stop without draining my main tank below 500 psi. > > > >Or maybe everything would've come out okay -- I wouldn't've been bent and > >my tanks would have passed inspection for another year, and > > > >From the above comments it would seem you are concerned about "damaging" > your tanks if they should happen to go below 500psi. If you completely > drain your tanks there is a chance that water may enter the tank, which > clearly is not desirable. You do not however need 500psi for this purpose. > As long as the tank pressure is slightly higher than the ambient water > pressure water will not enter the tank. For a shallow stop you won't need > much pressure at all, probably 50psi would be plenty. In fact if you are > still able to take unrestricted breaths off the tank (even if it is very > low) then the pressure inside must be higher than the pressure outside and > water will not enter. So in fact 500 psi was probably more than enough to > complete a safety stop without using your pony. > If fact some people argue that there is little point in getting back in > the boat with 500psi still in your tank when you could have used that gas > to extend your safety stop and therefore decrease your risk of bends. (This > of course would only be advisable in "uncomplicated" circumstances where > you are unlikely to need the 500psi to extract yourself from some other > situation) > > PS - I otherwise agree with your comments on ponies! I use one regularly > and can see no point whatsoever in lugging around twin tanks on > recreational dives where a twin tank and a pony will provide you with all > the redundancy you could ever want. > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > Ocean Internet - "The Quality ISP" > http://www.ocean.com.au/info.html > > -- > Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. > -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
Navigate by Author:
[Previous]
[Next]
[Author Search Index]
Navigate by Subject:
[Previous]
[Next]
[Subject Search Index]
[Send Reply] [Send Message with New Topic]
[Search Selection] [Mailing List Home] [Home]