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>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 OK - then lets change it to a broken regulator or some other gas loss problem. My only point was that it goes quickly and time is of essence. Regards. Joe ----- Original Message ----- From: David Pearson <djpearson@sy*.ca*> To: <techdiver@aquanaut.com> Sent: Thursday, June 21, 2001 9:18 PM Subject: RE: Left Post Knob - Reverse Thread ? > > 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'. > -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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