• Welcome to ScubaBoard


  1. Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

    Benefits of registering include

    • Ability to post and comment on topics and discussions.
    • A Free photo gallery to share your dive photos with the world.
    • You can make this box go away

    Joining is quick and easy. Login or Register now by clicking on the button

New rEvo BOV

Discussion in 'Rebreather Diving' started by stuartv, Oct 2, 2019.

  1. Heat Miser

    Heat Miser DIR Practitioner

    # of Dives: 100 - 199
    Location: Perth
    61
    46
    18
    I have never heard of it

    But I have attached a product description and the below quote scares me a bit.

    "Molykote 111 Compound is not to be used with liquid oxygen and should not be used in applications requiring LOX compatibility." Granted its not liquid O2
     

    Attached Files:

  2. rjack321

    rjack321 ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Port Orchard, WA
    10,658
    5,172
    113
    QC4 is smaller and doesnt support full flow aka heavy breathing. QC6 is larger and can support full OC flow
     
    Heat Miser likes this.
  3. stuartv

    stuartv Seeking the Light ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Manassas, VA
    9,458
    5,254
    113
    No, I used Tribolube.
     
  4. stuartv

    stuartv Seeking the Light ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Manassas, VA
    9,458
    5,254
    113
    It also basically don't get it in your eyes and it does not say anything about being safe to breathe.

    And it's made from silicon, which is not really safe for O2 service.

    I will pass on using that on my CCR.
     
  5. kensuf

    kensuf Cave Instructor

    2,309
    3,239
    113
    The SF2 used to use QC4's for offboard DIL and O2, but not for a BOV. They've moved to QD's.
     
  6. stuartv

    stuartv Seeking the Light ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Manassas, VA
    9,458
    5,254
    113
    I guess I should add a real update to this thread.

    I got the rEvo BOV last September. Since then, I have right around 50 dives on it.

    As received, it turns out that it had 2 issues. One was an assembly issue from the factory and the other was a design flaw.

    The assembly issue was that the diaphragm in the OC 2nd stage portion of the BOV was not installed properly. It had a small portion of the diaphragm dislodged from its retention groove, thus allowing water to come in from outside. The design of the reg body makes this really easy to do and can be hard to see that it's dislodged. The gap was small and on the bottom of the diaphragm, so diving it just seemed like it breathed a little wet - which was hard to notice considering that I don't normally do more than take a couple of breaths off the OC part, to make sure it is working.

    The design issue is the size of the O-ring that fits into a groove on the inner barrel and separates the OC and CC sides of the BOV. That O-ring needs to be longer (not thicker). It stretches to fit into its groove which, of course, makes it somewhat thinner. Thanks to another rEvo diver (Aaron Moser) who figure this problem out and worked out the solution, I was saved a lot of research on my own. He told me the correct O-ring dimensions, material, and durometer, and I replaced mine without problem.

    The problem with the O-ring is that it seals okay at first. But, eventually it gets worn and then starts to allow some leaking between the OC and CC sides. Aaron worked this out because he was getting dil leaking into his loop. Aaron reckons it takes about 20 dives on the original O-ring before it becomes worn enough to start leaking. IIRC, the original O-ring is 55mm x 3. He (and I, now) replaced that with one that is 58mm x 3 (same material and duro). The longer one stretches less to fit into its groove and seems to last indefinitely.

    In Aaron's case, the problem he experienced was dil leaking from the OC BOV into the loop. In my case, eventually I had both of the aforementioned problems at the same time. My OC diaphragm was not fully seated in its retention groove. It had developed a somewhat sizable gap. That was letting water come into the OC portion of the BOV. Then the worn O-ring was letting it leak into my loop. When I finally had this perfect storm of issues, I was doing some practice diving in my local lake and I discovered that 3 minutes into a dive, I had enough water in my loop that I had audible gurgling on every exhale.

    Since then, I disassembled and reassembled the diaphragm correctly. And I have verified that once it is assembled correctly, I cannot get it to dislodge, no matter how hard I try. At this point, I am convinced that it will not dislodge when assembled correctly. The problems I have had with that are because of incorrect assembly from the factory and then subsequent times of incorrect assembly by myself and then by a service tech. It is EASY to get wrong! And can be almost impossible to see that it's wrong if you don't really know what to look for.

    And I replaced the O-ring with the one spec'ed by Aaron.

    Since I took these 2 steps, my loop has been DRY. Well, slobber only. I have done 10 dives with it since I fixed those 2 issues, including 8 ocean/wreck dives. 6 below 100 feet. All to NDL limits. No salt water in the loop at all after any of those.

    I have been in communication with rEvo HQ about the O-ring issue, as had Aaron Moser before me. They have not been dismissive, per se. But, I do not have any information that would tell me that they have acknowledged there is a problem with the O-ring or made a production change.

    Nevertheless, I am very happy with the rEvo BOV. Now, it is very good (in my very inexperienced opinion - I have no other BOV experience to compare it to). And even better that it seems to be less expensive than other BOV options. And even if they have not fixed the O-ring issue, the fix only costs a few cents. Maybe a couple of bucks with shipping. And it is easy to swap out during a normal service disassembly of the barrel (very similar to servicing the original DSV).

    If anyone wants pictures of any of these things or firm specs on the O-ring, let me know.
     
    Heat Miser and cathal like this.
  7. cathal

    cathal Barracuda

    # of Dives: 500 - 999
    Location: Ireland
    270
    133
    43
    Great real world feedback on the rEvo BOV, glad you got it sorted in the end.
     
    stuartv likes this.
  8. Heat Miser

    Heat Miser DIR Practitioner

    # of Dives: 100 - 199
    Location: Perth
    61
    46
    18
    I would like pictures / firm apec of O-ring ciao
     
  9. stuartv

    stuartv Seeking the Light ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Manassas, VA
    9,458
    5,254
    113
    The correct O-ring spec is 55x3mm (70 durometer).

    Metric EPDM 70 Orings 55 x 3mm Minimum 2 pcs

    Sorry, I don't have a picture of that. I have pictures of the diaphragm and the way it can end up dislodged from its retention groove. The O-ring is the one that goes into a groove on the barrel that is inside the BOV that separates the OC and CC sides. If you take that barrel out, it's pretty obvious which one it is.
     
    Heat Miser likes this.

Share This Page