Here is a ....WHY NOT ?? ...question..

[wreckchick]

but since I've just had a wee freeflow incident I've thought a lot about this kind of stuff. I actually don't know if my octo freeflowed or not, but it seems probable that it did. Anyway, I know my octo is detuned to keep it from freeflowing during normal diving so if my primary is tuned more open (which mine is) then when the first stage lets go than the air has a place to go that follows the path of least resistance. Consider this: if you had a faucet with a hose attatched and that hose was split into 2 and you have a stopper on the end of one of the hoses, when you turn on the water it will come out the open hose unless the water pressure was such that there was a pressure build up in the corked hose sufficient to pop out the stopper. With a regulator the cracking pressure of the 2nd stages is different but not to the degree in the example above so it seems likely that in some freeflow incidents it would only be the more tuned 2nd that would be susceptible while in a major freeflow both of them would be going.

Like I said, I could be wrong.

Rachel

 

[RICHinNC]

hi rachel....well i guess we could all be wrong...it sure wouldnt be the first...or the last...time for me!!

now that is just my point. i can not remember reading about or talking with someone about (although i am sure it has happened) their first stage going doo doo on them.

it has 99.999999999999999999999% of the time been a poorly "tuned" secondary....icing problem with secondary....and so on...with the secondary. therefore, if it had some kind of quick disconnect the problem could be resolved quickly. And, if it is the 1st stage....and the octo does not start to free flow....it could happen...work with me here...you would at least not be areating the whole ocean. and, have an air source till ...your always closeby buddy....came up and helped.

i guess if you could have a quick disconnect the question would be raised.....do you carry a spare 2nd stage....hummmm...
yet i carry a knife every dive and have yet to use it. When the day comes i get all wrapped up in mono like is common here in NC i will be dang glad i carry it....would probably feel the same about a quick disconnect too.....but i understand it isnt for everyone.

 

[pescador775]

A quick disconnect on the reg hose is about as useful as a quick disconnect on your vest strap. You don't want it to quick disconnect when it is needed for survival.

Listen to Bob. If you disconnect or shut off your reg LP hose due to free flow there is a possibility that the hose will blow up close by your head. Might be the last thing you hear. If anyone is determined to make such a contraption add an OMS or DiveRight pressure relief valve to the first stage.

 

[Bob3]

Most of the freeflows I've seen have been from 1st stages freezing up. Next to that, mischief in the HP seat allows the IP to creep up. (eyelash in the 1st stage, happens to folks that bring their regs in to get serviced just before going on that "big trip").
Only once in over 35 years have I seen a 2nd stage ice up while underwater, and that was in heavy surge in 28 degree water (slush, actually).
2nd stages ice up very easily on the surface if the wind chill is much below freezing. I don't count those because that remains an operator malfunction, not the reg's fault. Keep the things out of your mouth 'till you're under water.
If you just HAVE to add a QD, just be aware it probably won't help anything. Be sure to add that popoff OPV like pescador775 says.

Here's a little read on regulator freeze: http://www.scubadiving.com/members/divetips.php?s=153