Aqualung Legend LX First Stage Failure at depth

[Couv]

I would love to see AL offer to retro fit anyone's first stage who decided the "Automatic Cause of Death" feature was not acceptable.

 

[lexvil]

I would love to see AL offer to retro fit anyone's first stage who decided the "Automatic Cause of Death" feature was not acceptable.

To be fair it should be “chance”

 

[rsingler]

I would love to see AL offer to retro fit anyone's first stage who decided the "Automatic Cause of Death" feature was not acceptable.

Well, if we come up with the right parts swap from @JackD342 's comments, I'll offer to have folks just send their stuff to me. I'll come up with some sort of Waiver of Liability.
Should be a very easy parts swap plus postage. Aqualung will probably revoke my Technician's Certificate, but WTH, ScubaBoard is family!
Stand by, the parts are on order...

 

[Doctor Rig]

I hope this information is useful to someone. 25 dives after a complete rebuild service for my Aqualung Legend LX I had my first stage fail shut at 60 feet 40 minutes into the dive. Fortunately my buddy recognized the international signal for out of air - eyes as wide as saucers - and he had his reg in my mouth ASAP. I had 1500 lbs left in the tank (although the gauge fell to zero until we got back to the boat). Took the regulator to a different Aqualung authorized service dive shop for analysis/repair and the issue was determined to be the ACD. From the dive shop - "We found that the ACD inner post valve and yoke nut had come loose." The regulator was rebuilt as listed on the intake documents and theses parts have been torqued to their proper specifications". So, holy cow - a bad service can result in a failed shut condition on the first stage with no prior indication that things are going south. Caveat Emptor.

@databob
Thanks for sharing your experience. I just found this thread but didn’t have the time to read all 21 pages. Wonder if you could give us SBers a recap with what AL ultimate response was, if they ever did and if you have confidence in your AL regulators anymore. By the way, have you started replacing any of them yet?

I’m wondering if anyone knows what other brands/regulators have a ACD and could potentially fail as your regulator did. (Repost if that info was already discussed.... please.)

P.S. If you haven’t you should send your report experience to the dive industry publication “Undercurrent” as this is typical of what they like to report on.

 

[JackD342]

I don't now if they still produce them or not, but AUP had Oceanic and Aeris (Hollis too?) models with DVT, Dry Valve Technology. They had one recall a few years ago due to one run of plastic parts that weren't hard enough and could extrude.
Mares recently added an optional AST Auto Sealing Technology kit to their catalog. Haven't seen one yet, don't know it's design, says "activated by gas."
Never saw anything similar in Sherwood or Cressi.
Any other brands are out of my scope of knowledge.

 

[JackD342]

Well, if we come up with the right parts swap from @JackD342 's comments, I'll offer to have folks just send their stuff to me. I'll come up with some sort of Waiver of Liability.
Should be a very easy parts swap plus postage. Aqualung will probably revoke my Technician's Certificate, but WTH, ScubaBoard is family!
Stand by, the parts are on order...

Regardless of any possible next steps that are or are not taken, here are a couple of summary points you can quickly check on your own.

1. Picture A shows a properly seated ACD valve assembly. You can't tell from visually inspecting it if the valve is torqued to spec, but you can tell if it has started to loosen up to look like Picture B. So, if yours looks like B then do NOT dive with it, bring it in for correction.
2. In the unlikely but still real possibility of the shutter valve loosening up as seen in B above, be most concerned if using a convertible tank valve with a 6mm hex yoke insert. If the insert has an 8mm hex, my expectation is reduced performance in this scenario, but not a total block. So if you have a choice of cylinders to use today, may as well choose the 8mm hex insert.

 

[Diving Dubai]

I'm not sure you can define a "safe insert" from the hex size.

I have nueriouls inserts, and lots require different hex sizes (most annoying are the imperial ones) Having done a quick survey of my stock with a vernier the only dimension that differs amongst mine it the hex size

 

[rsingler]

I think the point is, that a 6mm insert can be completely covered by the hat of the shutter valve.

An 8mm, not so much. The insert I pictured above was a 6mm. I'll try to photo an 8mm with the shutter valve and post it later.

 

[inka]

FWIW, the 8 mm allen key insert, is the new norm since 01/16 (Norme 12209:2013)
For a same 8 mm insert, there are 2 options with differents O´ring
Ref O´ring : if same O´ring front & rear = AN10
Ref O´ring: if different front & rear: front = R10 ; rear = R9 (Norme 12209:2000)

 

[JackD342]

Here is some actual new information to add!
Inspecting my store stock, I find that my most recently shipped Mikron with ACD has a small modification to the shutter valve. There is now a small raised ridge down the center on the top of the valve, not even 1mm high. My assumption is that this prevents the top of the valve from forming a metal to metal seal with the face of a tank valve, since there is no longer an unbroken, perfectly round edge on the top.

I also just received an order with that individual part, and the loose part is also the new version. So it looks like it is a running replacement using the same part number. (Can't guarantee the next parts order might not have the old version; depends on how diligent they are at rotating stock for first-in first-out.)

So at the very least, there is now an option to retrofit the ACD with an updated version of a $14 part, without completely removing the ACD and swapping it with a "standard" yoke retainer.

No, I have no idea if there are any manufacturer plans or discussions to make these a free replacement for a period of time or not.
I can say that I did my best this past week to make sure that Aqualung USA is aware of this thread - so time will tell.
Between all the resources that are probably currently focused on the DEMA show in two weeks, and the fact that Aqualung ultimate authority is in France and not the US, I would expect other updates (if any) to take some time. (Unless there is already something in the pipeline.)

But I will definitely post back if I hear anything new.