Mailing List Archive Mailing List Archive
I can't help but comment on some of the data here. I am questioning your comment about dealing with a "catastrophic gas leak at depth (Like 300 fsw with a blown HP hose.)". I would refute catastrophic nature of this event. The HP hose end that screws into the regulator has such a small hole that it would take a very long time to drain a set of large LP tanks. It is best not to take my word on this because I am a weenie diver with no technical experience to speak of. However, I happen to have a lot of SCUBA equipment, including a couple of questionable SPG's. I pulled the SPG off the hose one day and turned on the tank to see what would happen. At a starting pressure of 3000PSI on an AL63 I left the valve full open for 1 minute. When I checked the pressure after, it had only dropped 400PSI. Next, I did the same thing with one of the low pressure hoses on a medium performance reg. (SP MK10+), only this time the air came out so fast that I only left it on for 15 seconds. The pressure had dropped close to 1000LB. At 300 fsw, the intermediate pressure would be even higher, and I suspect an LP hose failure would drain air even faster. A higher performance reg. would help speed up the process. I have practiced working the valves of my manifold and find that I can turn them on or off very quickly without having to think about which way to turn the valve. I vote for leaving them alone. Once again, I do no diving of consequence and I do not know anything. But I do want to learn. So if I am missing something please let me know. David Pearson Ottawa, Ontario djpearson@sy*.ca* > -----Original Message----- > From: Joe [mailto:joe@po*.co*] > Sent: June 21, 2001 11:01 PM > To: Porter, Greg; techdiver@aquanaut.com; FlTechDiver@mikey.net > Subject: Re: Left Post Knob - Reverse Thread ? > > > Some people can't seem to remember to turn left when using the left turn > signal in their car. Can you imagine the mayhem if they had to > decide which > way a particular valve turns? > > A key to survival is to have the behavior ingrained so that when under > stress it is done by rote. Choices use up time. Usually, in any > underwater > event, time is the most critical factor. Using it to turn a knob in error > can be deadly. > > The emphasis has been on roll offs where you can go to your back up while > sorting things out, but what about a catastrophic gas leak at > depth? (Like > 300 fsw with a blown HP hose.) While you are pondering left or right the > gas is draining - and very rapidly I might add. > > Standardization of component function is critical, especially for life > support equipment. Given the PADI mentality of the dive industry, I could > foresee some manufacturers deciding that lefthanders should have knobs > designed for them. Can you imagine the chaos then? Lets see, if > he's lefty > I turn it this way, if he's righty I turn the other way. Uh oh, he's > ambidextrous.... > > jc > > > > ----- Original Message ----- > From: Porter, Greg <Gregory.Porter@AR*.Bo*.co*> > To: <techdiver@aquanaut.com>; <FlTechDiver@mikey.net> > Sent: Thursday, June 21, 2001 1:29 PM > Subject: Left Post Knob - Reverse Thread ? > > > > The other night in a Scott Bonis decompression class he > explained why the > > long hose is now moved to the right post - because it fixes the > problem of > > my OOA buddy in front being the victim of my left post being > shut down via > > rolling the knob along the ceiling - and the fact that rolling along the > > ceiling now shuts down the SPG instead. > > > > Given the machining abilities today's manufacturers possess, why do we > > continue to deal with this potential of the left post being shut down > during > > a roll along the ceiling ? > > > > > Why not build the manifold so that the left post knob is reverse > threaded > > > ? This eliminates the rolling off problem and it may also simplify > > > shutting down either valve because divers would no longer have to > remember > > > righty-tighty and how to apply it to opposing posts. Shutting down > either > > > cylinder would be done by rolling the top of the knob > forward... either > > > knob. > > > > > Are there significant reasons preventing this change ? > > > > Cheers, > > Greg > > > > > > ============================================================ > > To contact the list administrator, email > > Mike Rodriguez at mikey@mi*.ne* > > To UNSUBSCRIBE from this list, send a message to: > > listserv@mi*.ne* > > and in the *BODY* of the message type: > > unsubscribe FLTechDiver > > > > -- > 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]