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Why do regs leak?

Discussion in 'Regulators' started by Juris Diver, Jun 11, 2002.

  1. Juris Diver

    Juris Diver Angel Fish

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    So I bought a set of Apeks regs (ATX50/40 DS4) and jumped in the pool (hehe) to test em out. I'm lying on my back on the bottom (just relaxing) and, cough, my new second stage is leaking. She breathes perfect in all other positions though (deep at the bottom of that 7' pool).

    Now I confess, I don't know jack about the inner-workings of those things, so somebody tell me what makes a reg leak? Will ANY reg leak in that position?

    TY

    :confused:
     
  2. Scubaroo

    Scubaroo Great White

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    Leak? Leak from where? The hose, or out of the mouthpiece?

    Almost all Apeks regs have a venturi adjustment lever on them to prevent freeflow - just twist the lever to the minus (-) position, and it should fix the problem. When you need to use it, after the initial bedlam of being out of air and averted drowning, adjust it back to the plus (+) position for easier breathing.

    That's what it sounds like from your description of leaking while on your back. If it's the hose that's leaking, take the second stage off the hose, and check the o-ring is not deformed or something.
     
  3. WreckWriter

    WreckWriter Instructor, Scuba

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    Most regulator leaks are caused by simply not holding your mouth right. Also, by laying on your back, you put the regulator in it's absolutely "least favored" position. Poor performance is generally the result, not leakage.

    I'm guessing it doesn't leak at all when you're in proper position?

    Tom
     
  4. redacted

    redacted Guest

    Somr regs are a bit wet breathing particuliarly in the upside down position. I believe this is due to a very small delay in the sealing of the exhaust diaphram which allows a little water in. In most positions, the water is not in the breathing path and is just expelled with the next exhale - and the cycle continues. In the inverted position, that water is in the breathing path and you experience wet breathing. If it is a lot of water, it might be a good idea to get a tech to look at it.

    If you are talking an air leak then I don't understand. The inverted position should be the least likely position to experience free flow.
     
  5. Rick Murchison

    Rick Murchison Trusty Shellback Staff Member ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
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    Barring any defect like a cracked housing or pinched mouthpiece, and assuming you're not letting water in around your mouth, the exhaust valve is the only place water can get into your regulator. These valves are nothing more than little silicone "flappers" on a plastic or metal seat. A grain of sand, a piece of leaf, most anything can cause a minor leak. If the flapper gets sucked or tucked into the exhaust port you'll have a major leak. All these can usually be cured with a quick purge of the reg.
    Rick
     
  6. pt40fathoms

    pt40fathoms PADI Pro

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    When you are in the "normal" chest down and swimming position, your reg is also in a "normal" position. You see, the exhast valve opens when you exhale, and while open, a little water (a few droplets) may enter at just the moment when you stop exhaling and the pressure is neutral inside the reg. But because you are in the "normal" orientation of swimming, this little water is expelled the next time you begin to exhale.

    But when you are on your back, or inverted, the tiny droplets are not expelled, they accumulate, and soon you feel "wet air" when you inhale. The droplets accumulate, because gravity is no longer pooling the water around the exhast valve after it enters your regulator, it is pooling it at some point away from the valve, and is allowed to build.

    So their you have it, blame it on gravity!
     
  7. Juris Diver

    Juris Diver Angel Fish

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    That makes sense. Gravity holding the diapham open a bit and hence the trickle of water <cough>.

    Ben: I tried switching the ventri to "-" and increasing the cracking pressure too. I also switched to and breathed from my octo (ATX 40) and had the same trickle of water.

    Wreck: Yep, it breathes just fine when in a "normal" position.

    Awap: The water began to leak into my mouth as soon as I laid on my back (happened with both primary and octo). I made sure water wasn't leaking from my mouthpiece. Also, there was a trickle flow of water - more than a wet breathe.

    It seems that if this trickle of water is caused by gravity holding the diaphram open, then all regs will "leak" when in this "inverted" position.

    Thanks.
     
  8. redacted

    redacted Guest

    It allow exhaled gas to exit the reg and then seals to block water from coming in when you inhale. Gravity would be working to close it when you are inverted. Sounds like you have an abnormal leak through the diaphram. Small enough that the water is expelled without problem when you are in a normal position - but leaking none the less. It could be dirt stuck in the sealing surface that is not clearing with a good purging or a defect in the diaphram. Sounds like a job for a tech.
     
  9. pt40fathoms

    pt40fathoms PADI Pro

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    I guess I'll have to go into a little more detail. First of all, the diaphram will close normally regardless of the position of the reg. What gravity has to do with it is this.

    - When you exhale, the diaphram opens because the pressure in the regulator is greater than the pressure of the water, allowing the air to excape.

    - At the point when your exhalation stops the diaphram is under equal pressure on both the inside and ourside of the regulator. It is during this time that a very small amount of water may leak into the regulator.

    - In the normal, exhaust valve down diver swimming happily position, this water will remain on the rim of, or next to the exhaust diaphram. This is normal. When you exhale once again, this little amount of water will be expelled with your breath, and you never know it was ever there.

    - In the abnormal position, as is the case of being on your back, or in a head down position, the small droplets of water that normally enter your regulator, patiently waiting to be expelled with your next breath. Are no longer where they are supposed to be, because gravity has pulled those droplets to a point away from the exhaust valve. Over several breaths this small amount of water will build to a point that they will either fall into your mouth (gravity again) or be pulled into your mouth with the rush of air when you inhale (wet air symptom).

    This is completely normal, and will happen to every regulator when operated in an abnormal orientation. Some regulators may seal themselves faster than other, and may take a little longer to show symptoms, but over a short time they will. Oddly enough it is the "cheap" harder to breath regulators that will have a tendancy to be dryer when used in other than normal orientations.

    Whew,,,hope I made this a little clearer. Anything more would require the explanation of low pressures around the exhaust valve rim, caused by the turmoil of air excaping, and why this in fact has a pulling effect on the water surrounding the valve,,, but I digress. :geek:
     
  10. Juris Diver

    Juris Diver Angel Fish

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    PT, thanks for the expanded coverage. I'm still a bit unclear about why so much water was trickling in. In your explainations you describe droplets that form and that, when inhaled, cause the wet breathe phenomenon. What's happening with my regs (both primary and octo) is that as soon as I lay on my back, a trickle of water runs into my mouth. I literally have to spit the water out as I exhale. These are brand new Apeks regs. This leads me to believe that every reg is going to perform the same (or worse) in that position. But I'm surprized that nobody else has said they've experienced the same thing or that this is "normal."

    ;-0 :mgun:
     

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