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P-valve not connected

Discussion in 'General Scuba Equipment Discussions' started by giovyledzep, Jan 12, 2020.

  1. guruboy

    guruboy Divemaster ScubaBoard Supporter

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    i think their instructions make sense.

    if the outside is closed, at depth, pressure will go through what I assume is a 1way valve into the balance chamber. On the way up, you’ll need to release this pressure, since gas will start to expand.
     
  2. guruboy

    guruboy Divemaster ScubaBoard Supporter

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    Do you have a “stop valve”?
     
  3. giovyledzep

    giovyledzep Angel Fish

    # of Dives: 50 - 99
    Location: Malta
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    That's what I thought, but nobody I know does that, plus I received an email from the drysuit manufacturer (not the p-valve manufacturer) who said to always keep it closed when not in use.

    If by a "stop valve" the T valve that branches off the main hose is meant, then no. The p-valve has an internal balance chamber. What worries me is not the having to release the pressure, but it's what they say about the system being watertight only when the valve is closed. I really don't want to worry about getting water in the suit. Plus I don't understand how it could be so if we're talking about a one-way valve, how could the water ever enter the suit? Seems like a bit of a contradiction.
     
  4. BabyDuck

    BabyDuck Orca

    # of Dives: 500 - 999
    Location: Winterville, NC
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    On mine, the bolt to outside can be closed but the balance chamber inside my suit is open and does whatever balancing it needs to, hooked up or not.
     
  5. giovyledzep

    giovyledzep Angel Fish

    # of Dives: 50 - 99
    Location: Malta
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    Ok just a follow-up: the manufacturer recommends I leave the valve open all the time, wether connected or not.

    Reason is that the air you put in the suit at depth will go into the balance chamber and is trapped by a one-way valve. To release that pressure when ascending the valve needs to be open, so you might as well keep it open at all times, since water is not going to get in.

    Keeping the valve closed (wether all the time or during ascent) will cause the balance chamber to expand since the air trapped cannot exit the suit into the water and cannot come back into the suit because of the one-way valve.

    I did dive it today as described, always open, and it was great, not a single leak.

    I hope it's useful if any of you have a similar system that didn't come with instructions.
     
    Zef likes this.
  6. Lorenzoid

    Lorenzoid idling in neutral buoyancy

    # of Dives: I just don't log dives
    Location: Atlanta, USA
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    That only makes sense to me IF the tube is connected to you. If the end of the tube is open (i.e., not connected to you), then when ascending the pressure in the balance chamber is released through the open end of the tube or, stated another way, stays the same as the pressure in the suit.
     

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