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Hyperbaric Chamber Question.

Discussion in 'Basic Scuba Discussions' started by Jim Ernst, Apr 22, 2010.

  1. Dirty-Dog

    Dirty-Dog Frequently Censored ScubaBoard Supporter

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    And if you don't call ahead, just surface real fast. Then you'll get the tour for sure.
     
  2. Aquatic Eagle

    Aquatic Eagle Instructor, Scuba

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    Byford Dolphin

    Yeah...that's pretty disgusting but very interesting.
     
  3. DCBC

    DCBC Banned

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    It shouldn't happen. Most chambers exert internal pressure on a locking mechanism (fail-safe hatch) that will not release until the pressure has equalized.
     
  4. Superlyte27

    Superlyte27 Cave Instructor

    # of Dives: 5,000 - ∞
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    agree completely
    I too am a chamber operator. You can't open the door with even a little bit of depth. Imagine you are at 20'. What's the pressure per square inch at 20'? 20 x .445 = ?

    Now, the size of the hatch on the chambers I used were probably 24" - 30" in diameter. So, what's the area of a 30" circle? So Area = Pie x R(squared)

    3.14 x 15 x 15 = Radius

    706 square inches, x pressure at 20'
    706 x 8.9 = 6283.4lbs of pressure to pull that door open at 20'

    Even with the ball valves full open, you'd still survive, if you didn't get bent. Not that it was bright or encouraged, but when I first started, I watched as the "seasoned professionals" would take people down absolutely as fast as they could clear their ears, and bring them up as fast as we could vent the ball valves. Never saw any blood spatter.
     
  5. ben_wilson3301

    ben_wilson3301 Public Safety Diver

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    Kinda similar story involving pressure at depth and blood everywhere. On the show Mythbusters they did a myth that a Navy diver using SNUBA (a long hose that pumps air down to the diver) was down at around 300 feet when the hose came off the compressor and the one way valve was missing. He was literally sucked through the hose, they did the experiment and sure enough, there was so much pressure it almost instantly sucked a pig through a one inch hose.
    Crazy stuff!
     
  6. DCBC

    DCBC Banned

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    An experience of the past (even before my time). :wink:
     
  7. Superlyte27

    Superlyte27 Cave Instructor

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    That doesn't make sense to me. Please explain. So basically a Navy diver is surface supplied, and his umbilical breaks from the compressor. Where did the suction occur? Am I missing something?

    Ok, I just watched the Mythbusters. The video is completely bs. For a multitude of reasons. YouTube - Mythbusters - Compresed Diver *Gory*
     
  8. Aquatic Eagle

    Aquatic Eagle Instructor, Scuba

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    I think the idea is that the pressure of about 300 feet is being forced through the air hose since there is no compressor on the surface to feed it air.
     
  9. Thalassamania

    Thalassamania Diving Polymath ScubaBoard Supporter

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    But it doesn't actually happen because of the non-return valve that is always mounted on the hat.
     
  10. Superlyte27

    Superlyte27 Cave Instructor

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    See, the hose supplying that hat is 3/8" inner diameter. So 300' is roughly 150psi. Well 150psi x 3/8" is less than 75psi. And quite honestly, we hold up to more than 75psi. Hehe. So even if the check valve was bad or non-existant, it's still not enough pressure to suck a person through it. Ever hold your hand over a turned on water hose? Did the water hose blow a hole through your hand?

    The other thing is, the drysuit was filled with water. In life, it wouldn't be. And if you notice the 3 ball valves in the boat, they have changed the direction of the pressure. They are not just bleeding the air, they are actually sucking the air out.
     

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