Atomic B2 - cold water sealed, supposedly

[RIdiverMike]

Had a good reminder today. Only my third dive with my new Atomic B2, sealed. I'm using my old Aqua Lung Titan, which I've logged 300 dives with, on my new pony bottle. Since I've been diving all winter in RI in mid 30's, thought it would be wise to get a sealed reg and I read a lot of good things about this Atomic. My Titan isn't sealed and would free flow sometimes, and I've certainly had free flows with rental regs, but all of those were tame compared to today's free flow with the B2. Since I was only in 30fsw, I used it as a training thing and kept diving, though heading back to shore. Even closing the adjustment knob, I went from 1800 to 200psi in 7 minutes! Pretty good flow rate I thought. So loud my mask was vibrating on my face - lol.

Certainly glad I wasn't at 100+ when this happened - safety stop might have been an issue if my buddy wasn't there.

Good reminder to test your critical new equipment in shallow water first if you can. If you get into trouble in deeper water, does it really matter that your failing equipment has a good reputation? And my buddy's scubapro mk17 just had a similar issue when he went ice diving last w/e - so I don't think the problem is limited to Atomic.

 

[HIGHwing]

Did you pre breathe it on the surface?

 

[BKP]

I also have an Atomic B2, and never, in the six years I've owned it, experienced a free-flow. However, I don't do sub-freezing diving, in fact I haven't been below 46 degrees with it (my 1st stage is not sealed, either).

That being said, and while I know that you can get a sealed 1st stage with any Atomic reg, I always thought their monel 1st stage, coupled with the M1 2nd stage was specifically designed for cold water (or extreme conditions in general), which would lead me to believe the others are not ideal for sub-freezing (even with a sealed 1st stage).

Just speculation and my $.02...

 

[Eric Sedletzky]

I heard form the guys at North East Scuba Supply that all the serious ice divers like those Sherwood Ice regulators.
Besides that, believe it or not one of the most freeze up proof regs of all time are the old USD DA Aquamasters and Royal Aquamasters. But being a vintage reg they are probably not suitable for todays diver.
...Just saying.

 

[RIdiverMike]

Never pre-breath on the surface. I believe it's true that the M-1 model is their premier cold water model but the B-2 has gotten many rave reviews, including with ice divers. Also, today's temps ranged from 37 to 39, compared with 35 to 37 earlier this month - warmer today. I guess what's annoying me is that my 10 year old Titan, unsealed and much less a cold water reg than the Atomic, never had anything like today's free-flow. Avoiding today is why I bought the Atomic in the first place. Should have simply left well enough alone eh? Grrrr. OK, whining over. LDS tomorrow - he's a stand-up guy and he'll straighten it out. Cheers!

 

[Fishpie]

The AquaLung is a diaphragm 1st stage which is inherently better in the cold than a piston.
If it is the LX it also has a heat sink sleeve on the 2nd.

 

[Bubbletrubble]

Is it possible that Atomic's second stage Automatic Flow Control feature, which doesn't allow user selectable Venturi vane position, contributed somewhat to the free-flow incident?

For cold water diving with other reg brands, is it recommended that the Venturi lever be set in the "-"/pre-dive position?

 

[fnfalman]

Is the B2's first stage sealed or not? And by whom?

The B2 does not come from the factory with a sealed first stage.

 

[BKP]

Is the B2's first stage sealed or not? And by whom?

The B2 does not come from the factory with a sealed first stage.

You actually *can* buy the 1st stage optionally sealed from Atomic...
From the B2 reg page:


First Stage:

First stage materials are chrome-plated Brass and 316 Stainless Steel
Atomic Jet Seat high-flow piston first stage
Optional factory-sealed first stage to prevent outside contamination such as silt and sand and prevent freezing
Nitrox ready for mixtures up to 40%
First stage ports: 2 HP fixed / 5 LP on swivel cap

 

[RIdiverMike]

Yes, it came sealed from Atomic.