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Decompression Chamber-homemade

Discussion in 'Do It Yourself - DIY' started by Lawman, Jan 21, 2005.

  1. Lawman

    Lawman Senior Member

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    Here in Central Michigan we don't have a decompression chamber. Our dive club would like to build our own. We have a 2000 gal fiberglass septic tank and an 8 hp aircompresser. We thought with a few fittings and a larger hatch we could adapt our tank and save a ton of $$$$. Does anyone have any ideas that might help?
     
  2. roakey

    roakey Old, not bold diver ScubaBoard Supporter

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    Does anyone know where the link is to the homemade decompression chamber that blew up that killed someone?
     
  3. String

    String Master Instructor

    # of Dives: I just don't log dives
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  4. jbd

    jbd Dive Shop

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    I remember that thread, but IIRC the explosion was linked to the use of 100% O2.
     
  5. jbd

    jbd Dive Shop

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    I took the post as being serious. Conceptually a deco chamber is quite a simple appartaus. The only thing I wonder is how long will it take them to pressurized a tank that size with the compressor they have? Curious also if they intend on using O2?
     
  6. Gary D.

    Gary D. ScubaBoard Supporter ScubaBoard Supporter

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    Check the NASA web site. They are always looking for more efficient ways to get items into orbit.

    Go buy a used one. They're affordable.

    Gary D.
     
  7. miketsp

    miketsp Solo Diver

    # of Dives: 500 - 999
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  8. simbrooks

    simbrooks Snr LayZboy Meteorologist ScubaBoard Supporter

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    There was one on ebay recently, although i cant find the thread, but i know there was one on here! ;)
     
  9. fdog

    fdog ScubaBoard Supporter ScubaBoard Supporter

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    It would be cheaper to buy used, than build from scratch and meet the ASME pressure vessel (for human use) specs, have the redundant gas supplies, paint off-gas requirements, keep OSHA happy...windows...

    Not to mention installing a medical director (M.D.) and a training program so you can actually use the thing. Since putting someone in is "medical treatment" under order of a physician.

    IIRC, test pressure has to be around 2.5 times working pressure. To run a Table 2A that'd be 185 psig. So the septic tank would have to pass this (questionable), and I'm not sure fiberglass is even a permisable material under ASME.

    All the best, James

    PS Besides there's just something wrong about it...."Here ya go, we'll fix you up in this sh*! tank"
     
  10. rmediver2002

    rmediver2002 Instructor, Scuba

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    Are you planning on using this chamber for treatment or some type of familiarization dives?

    It is doubtful the tank will have enough integrity to hold the pressure required for treatments (around 100 psi for TT-6A) and 26.7 psi for standard treatment tables (TT-5 and TT-6)

    Your compressor (8 HP) is more than likely only going to provide between 6 and 8 cubic feet a minute so your decent time is going to be very slow and the compressor is going to be running at 100% duty cylcle so the air is going to be extremely hot (this temperature is going to be a big issue with your compressor especially if it is oil free / teflon rings)

    Once the chamber is at depth your flow from the compressor is not going to be enough to allow venting of the chamber, this is going to cause a build up of CO2 from the exhaled air from the divers inside. Another more serious issue would be a build up of O2 if you are having the patients breath O2 during the treatment.

    If you do decide you want to try and see if the vessel will hold pressure, first fill it with water. You can increase the internal pressure slowly using a pressure washer, having the container filled with water will greatly decrease the amount of energy released in the event of a rupture but you really need to be careful...

    Before considering putting any human being inside of any pressure vessel make sure you consider all of the possible hazards (rapid depressurization, O2 toxicity, CO2 toxicity, decompression sickness, hyperthermia, dehydration, waste elimination, etc...) you also need to consider the legal ramifications of any such endevor...

    The advice above about begining a collection for a refurbished chamber or looking into government surplus is the best advice so far. Even new your only looking at between 25,000 and 35,000 for a decently equiped double lock chamber.
     

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