paulwlee:
The IP remains constant at 120-150 PSI and is set at the first stage, depth does not change it. The step down from IP to ambient is done in the airspace of the second stage.
My Reg Fails Closed, sort of, huh?
- Thread starter Rick Inman
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The IP remains constant at 120-150 PSI and is set at the first stage, depth does not change it. The step down from IP to ambient is done in the airspace of the second stage.
Charlie99
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Depends whether you measure IP as gauge pressure with local ambient vs. absolute pressure (or with a fixed 1ata reference gauge pressure). The IP as described in absolute pressure must go up with depth if you want to keep it a constant psi above ambient. Specifically, at 100'/3atm a 135psia IP will only be about 90psi above ambient.chrispete:
The point paulwlee is making is that if airspaces in the christolube let the trim ring outside the ambient chamber seal off the openings and develop pressure across it, the IP will not increase in absolute pressure as it should. Or from your point of view, IP won't remain constant.
Richard Pyle the rebreather-using fish nerd of Bishop Museum has posted an interesting story about the failure of multiple regulators nearly simultaneously down around 300' depth. The problem was simliar to Paulwlee's suppositiion. IIRC, the problem was a sealed chamber where either fluid or grease had leaked out, and then the rubber seal got pressed into place, sealing off the ambient chamber. By the time he got down to 300', he wasn't getting any replacement gas into his rebreather.
chrispete:
What Charlie99 said. IP is maintained constant relative to ambient. Otherwise there would be no need for those ambient chambers nor would any moving parts need to be exposed to the water, and thus no need for 'environmental seals'!
BTW, some regulators such as the dry sealed Apeks and Aqualung balanced diaphragms are overbalanced, meaning that even the relative IP goes up with increasing depth, although only by a small degree.
scubafanatic
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Rick Inman:My Atomic M1 did not seem to be itself, and it was due for service, so I sent it in the the dealer I bought it from (ScubaToys) for service.
As usual, ScubaToys was timely and professional, and I got the reg back about 2 weeks ago.
I use this reg as a stage reg, cause it's so great in cold water and breaths like a dream - or at least it used to.
It still breaths perfectly on the surface. But is is having problems at depth and the deeper you breathe it, the worse it gets. Here is what it does:
Last night I deployed it at 100', and it immediately began to spit and sputter as I inhaled, and the reg made clicking and clacking noises. At the end of the inhale, it free-flowed. During the inhale, the reg would fail closed, giving nothing. If I sucked hard enough, there would be a loud "clack" and then it would open and deliver too much air and free flow. Then it would spit and sputter again, forcing very hard pulls on it to get enough air, then fail closed again, then "break" back open, and then free-flow.
What a noisy mess.
At 30' feet the symptoms lessen to the point that it is breathable. At 20' it seems just fine, maybe a little hard breathing, and the clicking noises are very quiet.
I know the problem is with the first stage, because I changed the second stage as a test and it does the same thing.
Obviously it is going back for service. But, any idea what could cause such a calamity - right after being serviced?? Remember, it was doing this same stuff, to a much milder extent, before the service. Now that it's been serviced, it's about 100 times worse.
Thoughts?
....well dang, now you've got me all worried...... I just had my B1 serviced and upgraded with the 'new' piston upgrade, and it's got that environ-seal kit on it too....it was performing great prior to service, but since the new dive season is beginning, and it's a couple years, maybe 125 dives , since last service, I thought I'd get it all taken care of during 'slow season' at my LDS...... I've hooked it up to a tank and it seems fine, but I doubt I'll actually get to test dive it until my next trip.....so now I'll have to keep a sharp eye out for the phenomenon you described.
Karl
P.S. ...please keep us posted on the outcome/findings...OK ?
OP
Naw... no reason to worry. On a board of tens of thousands of members, there has to be the occasional failure - but it is so rare that I wouldn't worry about it.scubafanatic:
Rick Inman:
Your probability calculations are flawed. LOL The probability that this was going to happen to you was 100%.
Come on and fess up- I bet you put your car keys in the second stage so that you wouldn't loose them.Rick Inman:
WARNING; Kids, don't try this at home or underwater. Rick is a trained professional.
OP
do it easy:Come on and fess up- I bet you put your car keys in the second stage so that you wouldn't loose them.
Ha, ha. Thanks to the Smothers Brothers for their input.MikeFerrara:Your probability calculations are flawed. LOL The probability that this was going to happen to you was 100%.
Actually, there is no reason this reg should have failed. After I took it apart, I actually had extra parts left over. The guy I bought it from on ebay also has a father in Nigeria that is going to transfer million of dollars into my bank account, as soon as I send them a small account fee, and then I'll be rich!
We'll see whose laughing then...
scubafanatic:
I wouldn't really worry about it too much. Seems like this is a rare occurence.
BUT..
Any time a regulator that's working fine is opened up and put back together, there's some probability, however small, for something to go wrong. Stories of regulators going berserk on the first dive after service are pretty common on dive forums. A good service tech will make the chances of this happening very very small, but it can still happen.
This is why it's a good idea to not use a regulator on a big dive right after a service, and if you use multiple regulators (doubles, pony, etc.) stagger the services so you know at least one is going to work on a dive.
sambolino44
Contributor
I tell you what. I bet them ScubaToys fellas was a lookin' at them funny pitchers they got on their website while they was fixin' your reg, and they got confused an' put somethin' in there backwards! Either that or you got a bubble in your goopage.
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