My Reg Fails Closed, sort of, huh?

[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?

 

[chrispete]

I'll hazard a WAG. IP way too low?

 

[paulwlee]

I'm not a reg tech but I can take a wild guess..
Is the regulator sealed? If so, is it packed full of Christolube? I'd think that if there isn't enough Christolube inside the ambient chamber, then since the ambient chamber trim ring doesn't allow free water exchange it might be a problem as the air in the ambient chamber results in a "squeeze". The trim ring is not water-tight but most of the pressure transmission seems to occur from the water pressing on the very supple trim ring surface which in turn exerts pressure on the lube/air/water beneath it. If there is enough negative pressure inside the ambient chamber due to excess air that gets compressed, I could possibly see the trim ring membrane getting sucked onto the ambient chamber holes and then fail to adequately transfer the ambient pressure to the inside of the ambient chamber.

One way to find out would be to get a syringe and try pumping in some Christolube through the ambient chamber holes (yes some will squirt out, but be thorough).
Or if you are going to send it in for service anyway try diving without the trim ring, with the ambient chamber holes exposed. If it was the above issue, it will go away without the trim ring.

Whatever it is, I'd be very curious to know what the problem turns out to be. I have several Atomics myself (although none are sealed) and the knowledge might come in handy some day.

 

[paulwlee]

The IP is one of the things the tech would actively adjust for when servicing the regulator, so I have a hard time believing it's the IP. And although a low IP might result in some difficulty getting enough gas deeper, I doubt the symptoms would vary so dramatically with depth. But to eliminate that possibililty, measure the IP to make sure it's in the right range. If you don't have an IP gauge, get one, it is very very useful, and it's $20 or less.

 

[Rick Inman]

I'll check the IP tonight at my LDS, and maybe squeeze some more Christolube in. I can't imagion that ScubaToys didn't totally fill it with fresh Christolube, though, and not adjust the IP, but hey, I'll have a looksy.

 

[do it easy]

Here is my grassy knoll theory- there is a bent or sticky part that is preventing the piston from travelling properly.

 

[paulwlee]

I'll check the IP tonight at my LDS, and maybe squeeze some more Christolube in. I can't imagion that ScubaToys didn't totally fill it with fresh Christolube, though, and not adjust the IP, but hey, I'll have a looksy.

I'm sure that they put in fresh Christolube, but it's possible that there were large air spaces left in the chamber, I can see someone stopping before the ambient chamber was adequately filled.

 

[SteveAD]

I am a reg tech, but I am not familiar with the specs for an atomic, what it sounds like to me is that the first stage is not responding to ambient pressure. this is most likely a result of improper assembly by the tech either a spring in the wrong place or something blocking the ambient chamber. but when taking into account the fact that it had similar problems to a lesser extent pre-service it could be a manufacturing problem. get it to an authorized atomic tech.

 

[ScubaMilo]

Here is my grassy knoll theory- there is a bent or sticky part that is preventing the piston from travelling properly.

I'm going to have to agree with do it easy on this one it sounds like a bent or sticky part.
Maybe even the piston itself.

Milo

 

[scubatoys]

It would be hard to say without looking at it but sounds to me like Paulwlee hit it on the head… The best way would be send it back and I will take a look at it and get it back to you in just a couple days! But if you have time constraints and need to have it looked at there just send me the invoice and I will refund the cost of the repair!

Sorry!


Thanks


Joe