Quote: (Originally Posted by
mempilot)
First, it doesn't roll on and off, it slides. There is a big difference between rolling and sliding off. I wouldn't use a shutoff that can roll off. As for sliding off. BS. Otherwise, you need to replace yours. It's worn out.
of course it slides
i used the term rolls beause in diving we talk about 'rolling off' tank valves when they rub against things. In the same way a sliding shut off valve is easy to slide shut/open by rubbing (in my case rubbing against my stage tank) Do I detect your starting to be rude? Just sharing my experiences and trying to help make sure you have a safe bail out method. you did invite crituque by putting details up no?
Quote:
I've been diving with a shut off on my ADV and all stage 2nd stages for more than your 20 dives and never had one turn off. That is either silliness or you have one really f'd up shutoff. You may want to consider replacing it with a new one.
ah, I was right, turning rude, 'silliness' now is it? OK Ignoring the tone, so you havent experienced sliding of shut off valve so it cant happen and me and matt have experienced difficulty on qc reconnection so...that also cant happen - got it.
all of 20 dives huh? wow. Ive been using the shut off valve since my 1st Rebreather dive- so what? still doesnt change that it CAN slide shut.
This isnt about personal experience - (or at least it shouldnt be) its about what
COULD happen.
Do you believe a QC can
never be difficult to connect? (then you must beliebe I and Matt are a) insane, or b) liars
Do you believe a shut off valve
could never be slid shut by rubbing? (then you must believe that I am a) insane or b) a liar.
Look before you turn what was a ok thread into something silly and snipping;
My position is you should consider all possibilities and experiences, you should (if your going to put pics of your rig on the net and invite crituque, be open to that critique) - seams to me your only considering YOUR experiences and not availing yourself of others. Well thats ok its your choice - just dont get all upity and rude cos itll just piss me off. Ive just tried to share and help
Quote:
Dynamic pressure comes from breathing through the reg. That is a function of the 2nd. The first is supplying expected static pressure all the way through what you are calling restrictions. They aren't restrictions, and therefore dynamic pressure should be as expected without the QC or shutoff. ISC uses this same shutoff on the ADV, and it gives one hell of a lot of gas off a LP hose. There is no difference on the LP reg hose I'm talking about.
No thats not the way it works. The 1st stage outlet pressure (and therefore flow) is regulated yes - but the flow at the 2nd stage depends on the losses between the 1st stage outlet and the 2nd stage. Total flow depends all all losses incl 1st stage valve. Any change in dia, every bend every step and fitting is a pressure loss (which will relate a flow restriction for constant pressure). Im sorry thats physics. Please dont get mad at me.
ADDED: By way of an example, try breathing out naturaly through a small straw (high loss) then compare to breathing out naturally through a bigger straw (low loss) which straw will take the longest to breathe out of? ie which has the biggest flow restriction (losses) ?
The average pressure in both straws are the same yet the flow rates are different
Quote:
OK. Checking that tomorrow. But, since static pressure wasn't affected at 1 ATA, I doubt it will be affected other than expected through the 2nd at depth. Again, there is no restriction.
if theres no restriction then its a valve less QC.....which I doubt as you would be flooding your stages everytime.... The available flow rate into your lungs is whats critical. That flow rate is a function of the losses in the system and the pressure set at 1st stage. Increase losses (through fittings, gas density etc) and you will see less flow for const P. So depth, gas choice and fittings will all effect. We all have regs that seam to beathe great at surface but dogs at depth with high rmv and gas density. You will see that CE ratings for regs specify wob at 40m, this is because the deeper you go (increased gas density) the higher the losses and the higher the wob will be - so yes depth is important (which is why i said a pool test wont tell you much)
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Mike, if you can't deal with 10 seconds without gas, you shouldn't be technical diving. Go back to deco procedures 101 and practice you skills. Actually, go back to Open Water and practice a lost reg skill. Please don't sensationalize this to try and make your point. It sounds rediculous.
I think your starting to sound a bit childish here and frankly starting to get on my tits. Ive ONLY made the point (as has others) that QCs can stick and can be hard/impossible to reconnect. I have made the point that when stressed and unable to breathe 10 secs can feel like a lifetime underwater and I have shared with you my experience that I had a mare when I had my kit configured just as yours is and my QC failed in just the way Im describing.
But you dont want to hear that and start calling me a sensationalist well fine - just trying to offer you some advice seeing as Id tried it your way and it sucked. If you dont want to hear peoples critique and experiences dont put pics and discriptions of your set up up on the net and invite them!!
I guess Im an asshole now because I didnt say how lovely your set up was and how cool you are and clever at making it. Guess Im the assholle now for simply trying to warn you about my experiences with the exact same set up!
Nice
ok silly time over. Im an ass - got it. i wont be posting anymore in this thread so feel free to confrm im an ass then you can move on.