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Stupid question without notice... double tanks

Discussion in 'Tanks, Valves and Bands' started by ozJohnno, Mar 30, 2019.

  1. ozJohnno

    ozJohnno Angel Fish

    # of Dives: 200 - 499
    Location: Melbourne Australia
    21
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    Hi there,
    When you are diving doubles, which way do you turn the isolation valve on the manifold to isolate your two cylinders?

    I know this is a stupid question but it had been on my mind since I aborted a 30m dive because I could not confidently Identify that my isolation valve was open.

    so which way is it to fully open the valve on your manifold.... full anticlockwise or full clockwise

    Thanks in advance

    Johnno
     
  2. caruso

    caruso Banned

    # of Dives: 200 - 499
    Location: Long Island, NY
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    I admit to knowing nothing of manifolds and diving with doubled tanks however I would be willing to bet my bottom dollar that turning the isolation valve clockwise closes the valve and cuts off the flow of gas between the two tanks.
     
    Caveeagle likes this.
  3. rhwestfall

    rhwestfall Solo Diver

    # of Dives: 200 - 499
    Location: "La Grande Ile"
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    Clockwise = close
     
    CAPTAIN SINBAD and Compressor like this.
  4. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
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    Same way as on your tanks.
     
  5. ozJohnno

    ozJohnno Angel Fish

    # of Dives: 200 - 499
    Location: Melbourne Australia
    21
    3
    3
    Nice one guys thanks for your advice. Even if I had the isolation valve closed I could have simply switched to the reserve regulator, but by this stage I was getting a bit worked up about it and decided that getting worked up about stuff is unsafe and it was better to be safe than sorry, so I signalled to one of my dive buddies (we were a foursome) and slowly headed to the surface.
     
  6. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
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    Do more valve shutdown drills in shallow water, until it is completely muscle-memory automatic which valve to turn which direction in which order....no reason to have to think about it under stress.
     
    D_Fresh, ozJohnno, divad and 2 others like this.
  7. ozJohnno

    ozJohnno Angel Fish

    # of Dives: 200 - 499
    Location: Melbourne Australia
    21
    3
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    cheers Tursiops, will do
    johnno
     
  8. Compressor

    Compressor ScubaBoard Supporter Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: NYS
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    Yes better be safe than sorry. Routine check list/way of doing things predive is good so when you second guess yourself, you think did I do what I always do? Yes I did but can't exactly remember that part but I know it was not omitted.
     
    ozJohnno likes this.
  9. runsongas

    runsongas Great White

    # of Dives: 500 - 999
    Location: California - Bay Area
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    righty tighty lefty loosey
     
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  10. Scared Silly

    Scared Silly Regular of the Pub

    # of Dives: 500 - 999
    Location: on the path to perdition
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    How can one tell that the isolator is most likely closed?

    1. You start the dive with a reading of your SPG
    2. Sometime into the dive your SPG is still where it was at the being on the dive.
    3. Sometime into the dive you are OOG - isolator was closed, left cylinder was filled, right is cylinder was not.
    4. You have an SPG on the left post and a transmitter on the right and the readings do not agree.


    FWIW My spouse learn #3 the hard way, though successfully dealt with the issue. She was on her backup by the time I deployed mine to her. The dive was aborted and we had a good debrief, first with ourselves, then the captain, then the filler. The reason there was a discussion with the captain is we aborted the dive so a safety issue. The reason there was a discussion with the filler is they shut the valve off. However, the responsibility was on us to check all valves before the dive - complacency kills. Good education for all.
     
    ozJohnno and Compressor like this.

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