• 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

Double Hose Free Flow Question

Discussion in 'Vintage Equipment Diving' started by ScoobieDooo, Feb 23, 2005.

  1. ScoobieDooo

    ScoobieDooo Manta Ray

    1,127
    2
    0
    I have a question...

    When I had my prior DA it would free flow if I floated on my back on the surface. I used it with my Trans Pac with rear inflation (wing). Naturally, with the mouthpiece under my chin it was higher than the box and wanted to free flow.

    Any suggestions to prevent that from occurring while floating / swimming on my back?
     
  2. Danny D

    Danny D Solo Diver

    # of Dives: I'm a Fish!
    Location: MA
    224
    6
    18
    If you saw that mouthpiece that I built it stops free flowing by way of a ball valve. I was running in to the same problem (free flowing) That is another reason why I built the mouthpiece .
     
  3. ScoobieDooo

    ScoobieDooo Manta Ray

    1,127
    2
    0
    How about a picture Danny D?
     
  4. Danny D

    Danny D Solo Diver

    # of Dives: I'm a Fish!
    Location: MA
    224
    6
    18
    The picture is below....
     
  5. DA Aquamaster

    DA Aquamaster Directional Toast ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: NC
    11,460
    1,589
    113
    Interesting mouthpiece.

    We should probably point out though that the tendency for a double hose reg to freeflow when you are on your back is normal and in some cases highly desireable. On the surface, it is a pain and an inconvenience. But under water it is the equivalent of a purge button on a single hose second stage. If you find yourself in a situation where you lack the breath to clear the mouthpiece for what ever reason, rolling on your back and holding the mouthpiece out in front of you (ie: as high above the regulator case as possible) is how you are going to get the reg to freeflow to clear enough water from the mouthpiece.

    A ball valve is probably ok as it is selectable and would not be selected under water, but doing something permanent and non selctable to a double hose reg to prevent a freeflow on your back would be very unsafe.

    Short of modifying your mouthpiece, the solution is obvious - don't swim on your back. Vintage diving is about the only time I actually bring a snorkle along as it is one of the few times when it's actaully convenient to have one along.

    Alternatively you can turn off the tank valve for the surface swim. But this is not always practical as the tank and double hose reg should ride a little lower on your back than with current scuba gear and the valve is hard to reach unless your buddy is handy or unless you undo the waist and crotch strap and hike things up a bit.
     
  6. Bob3

    Bob3 Dive Shop

    4,111
    16
    38
    I vote for the snorkel too.
     
  7. ScoobieDooo

    ScoobieDooo Manta Ray

    1,127
    2
    0
    Guess digging the snorkel is justifiable now!
     
  8. Nemrod

    Nemrod Solo Diver

    11,584
    1,738
    113
    I used to turn the valve off until I reached my place to descend, upon return to shore if it freeflowed some I did not care, the tank was close to empty anyways. If it bothered me I would turn the tank valve off again. Me= snorkel hater. N
     
  9. Danny D

    Danny D Solo Diver

    # of Dives: I'm a Fish!
    Location: MA
    224
    6
    18
    The freeflow should not be a problem BECUASE if everyone remembers the rule of thirds from scuba class you should have enough air to swim back ashore lol. There is your solution hahahah straight from PADI
     

Share This Page