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Apeks 1st stage diaphragm clamp leaks

Discussion in 'Regulators' started by taimen, May 12, 2021.

  1. couv

    couv Instructor, Scuba

    # of Dives: 1,000 - 2,499
    Location: 13th floor of the Ivory Tower
    Hi @stepfen ,

    I probably should not be butting into a "diaphragm first stage thread," but (here is where I butt in anyway) ensure the kit you install is a MK11 kit as the MK17 uses a different diaphragm (thinner) and 2 diaphragm washers as opposed to 1 found in the MK11.
    lexvil and rsingler like this.
  2. stepfen

    stepfen Contributor

    # of Dives: 200 - 499
    Location: Greece
    Thanks for the detailed explanation Rob. As always to the point. I was guessing that the diaphragm would withstand the force as the pin/disk moves just a tiny bit (less than maybe 1mm if I remember correctly). I forgot though that air is in there pressing the diaphragm too. I might (carefully) give it a try when I will be disassembling it out of curiosity.

    I did try once long tools as levels, weights at appropriate distances etc to get the required torque but things kept moving around so gave up.

    Thanks for the warning. At least I didn't try to deep the whole thing in super glue to seal it and call it a day :)

    Back in 2018 when I first serviced that same reg I was puzzled by this 1 vs 2 washers. I did ask and things were made clear by you and Rob back then:
    Newbie repairing a Scubapro Mk11, R395, R295 regulator set. Progress report and questions

    Thanks for all the info.

    BTW service kit hasn't been posted yet! Grrrr
    rsingler and couv like this.
  3. happy-diver

    happy-diver Skindiver Just feelin it

    # of Dives: 2,500 - 4,999
    Location: Same ocean as you!
    No weights stepfen it's just the feel
    bigger tools give you bigger control
    of course with a reg box, and a vice
    and torque valve parts in their tank
  4. marsh9077

    marsh9077 Contributor

    # of Dives: I just don't log dives
    Location: Australia
    This is interesting, I own about a dozen Apeks regs between DST's, DS4's and US4's as well and have never experienced this. Just wondering are you using Apeks diaphragm's or generic? Also what mixes are you using the regs on? reason I ask about mixes is I have noticed with my deep bailout regs high He mixes 70%+ the clear environmental seal will bulge out over time, I think this is from the He seeping through the diaphragm. But not leaks or Champaign bubbles just a puffy environmental seal and only seems to happen with high He mixes.

    To answer your questions I dont know if this is very common, I have seen it once on a friends with Champaign bubbles but that was a 4 year old neglected DST. My recommendations are maybe make sure your tightening the cap enough, Also once its on do not remove it and if you do replace with new diaphragm. For torque as happy-diver mentioned TAF seems to be the going torque for the cap. I tighten mine with a full "man grunt" or two :)
  5. Scuba Client

    Scuba Client Banned

    # of Dives: 500 - 999
    Location: Australia
    You would think JJCCRs would have gone with the Poseidon XStream first.
  6. Centrals

    Centrals Barangay Pasaway

    # of Dives:
    Location: Hong Kong
    I believe AP valve has been using Apeks for quite a while.
  7. marsh9077

    marsh9077 Contributor

    # of Dives: I just don't log dives
    Location: Australia
    Apeks regs might be the most used regs on rebreathers than any other brand. Nothing wrong with them I think this diaphragm issue that the OP is discussing might be an isolated issue. If it was common then I highly doubt Apeks regs would hold the reputation they do for so many years.

    off the top of my head in addition to JJ some other units that use Apeks regs are Kiss, Liberty, Revo, ISC, Triton, XCCR, Fathom all very well know units.
  8. Scuba Client

    Scuba Client Banned

    # of Dives: 500 - 999
    Location: Australia
    I'm sure you're right. A one off incidence shouldn't induce panic. I'm considering buying Apeks DST/ATX50s to replace my Hollis DC1/212s when diving extreme depths. When lockdown subsides.
  9. rsingler

    rsingler Scuba Instructor, Tinkerer in Brass Staff Member ScubaBoard Sponsor

    # of Dives: 500 - 999
    Location: Napa, California
    The observation was just a good excuse for me to shift to Poseidon XStream firsts. :D I think they are far and away the best designed diaphragm reg on the planet. Their cup seat and ruby ball are unique, as is their flexible Kevlar diaphragm. Some folks diss the integrated OPV, but I've never had any trouble.

    But this Apeks diaphragm issue isn't the only complaint that's out there. HP seat failure in high O2 environments has also been noted. Their design is widely imitated to a greater or lesser extent, but this metal to metal clamp has traded prevention of technician torquing error for possible manufacturing variance, infrequent tho it may be. And three or four first or second hand reports in this thread alone is not a one-off problem.
    Me, I've never quite understood the level of enthusiasm. Solid design; good manufacturing, but unexciting. The second stage seats indent quickly.
    I'm not a hater, but not much of a fan. I've got old ATX100's and all the variants up thru Sapphire, but mostly just for show.
    Rant over. :)

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