• 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

Tank Equalizer for $2.50

Discussion in 'Do It Yourself - DIY' started by couv, Sep 27, 2010.

  1. raftingtigger

    raftingtigger Divemaster

    # of Dives: 500 - 999
    Location: Woodland, CA, USA
    1,202
    672
    113
    I use 2 old 1st stages connected via the HP ports and a LP BC hose as my pressure relief. Works great.
     
  2. couv

    couv Instructor, Scuba

    # of Dives: 1,000 - 2,499
    Location: 13th floor of the Ivory Tower
    4,678
    1,922
    113
    Raftingtigger,

    If I'm not mistaken, the valve in a low pressure inflator hose is an upstream valve (such as one on a tire and wheel assembly.) It opens against the flow of gas and closes in the direction of flow. Therefore, the pressure in the hose would continue to build until the hose burst.
     
  3. chrpai

    chrpai Great White

    # of Dives: I just don't log dives
    Location: Cedar Park, TX
    3,693
    964
    0
    I had to read this a couple times. I think what you are trying to tell him is that the LP inflator is good enough to be able to purge the system when you are done with the equalization but it's not good enough to protect from runaway IP creep. You'd need second stages or those over pressure gadgets they put on argon bottle regulators.

    Is that what you mean to say?
     
  4. raftingtigger

    raftingtigger Divemaster

    # of Dives: 500 - 999
    Location: Woodland, CA, USA
    1,202
    672
    113
    It is certainly good enough to purge the system. As for a runaway IP creep, The system isn't connected and pressurized for more than a minute if even that. Unlikely to have a catastrophic IP failure of that level. I guess I could install an old 2nd (I have them), but that makes the rig that much bulkier to pack.

    I am interested in the likelihood of, and consequences of a IP leak catastrophic enough to cause a LP hose failure under the above conditions.
     
  5. chrpai

    chrpai Great White

    # of Dives: I just don't log dives
    Location: Cedar Park, TX
    3,693
    964
    0
    I've never built one of these hacked equalizers. I would have assumed it would take more then a minute to transfer any sizable amount of gas due to the size of the passage in the HP hoses. Are you just transferring a couple hundred PSI to top off a tiny pony or something?

    For something smaller look at:

    Over Pressure Relief Valve - Northeast Scuba Supply

    If a high pressure seat fails, the gas as to go somewhere. How likely? Well, I'm going to guess you dedicated a couple of "junk" regs to put this together on the cheap (nothing wrong with that) and that you don't spend money to service them every year. It's not a sure thing, but it could happen.
     
  6. rhwestfall

    rhwestfall Solo Diver

    # of Dives: 200 - 499
    Location: "La Grande Ile"
    12,330
    11,038
    113
    one of the HOG quick shot bag inflators provides the bleed off point, and at "minimal" cost, and minor mass to the device. OPV might be a good idea too.

    Chrpai: I'd reckon that most of the folks making/using one of these are DIY folks, and likely would be servicing the stages as necessary (and we know yearly isn't necessary).
     
    couv likes this.
  7. chrpai

    chrpai Great White

    # of Dives: I just don't log dives
    Location: Cedar Park, TX
    3,693
    964
    0
    Perhaps, perhaps not. I'm not judging.... I'm a cheap arse at heart and was attracted to the "$2.50" headline. That said, I wouldn't want to use my main regs so my first inclination is to go on eBay and look for the cheapest junkers I can find. :)

    I think the paintball adapters and HP hose setup for around $65 is the most practical solution. I have a hard time spending $150 for a "proper" setup.
     
  8. uncfnp

    uncfnp Solo Diver

    # of Dives: 500 - 999
    Location: North Carolina
    5,804
    3,984
    113
    Got the Grainger fitting (turned out they had a branch location 8 miles up the road!). Haven't needed to use it yet but curious about your concern for the regulators. How is using the regulator to equalize pressure between tanks different from using it on the same tank, exposed to the same pressures each time you dive? Is there a reason hooking it up to transfer air through the HP ports will increase the risk of damage? Understand, I am very much a beginner in this DIY stuff! Still lots to learn. Thanks.
     
  9. Mitchell Teeters

    Mitchell Teeters ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Cookeville, TN, (AKA God's Country)
    1,319
    174
    0
    If you are cheap the paintball filler yokes work great. They already have gauges as well.


    Sent from my iPad using Tapatalk
     
  10. couv

    couv Instructor, Scuba

    # of Dives: 1,000 - 2,499
    Location: 13th floor of the Ivory Tower
    4,678
    1,922
    113
    Perhaps this thread has gotten too long in the tooth so I'll try to summarize the reason I started it.

    In response to:

    I should have said the low pressure hose will not act as an over pressure relief valve-unless one considers a blown hose a safety device.

    Please explain why.

    OK, my method takes about 15 minutes (20 minutes including the set up time) to equalize a set of 80 cu ft tanks. The fitting weighs about 50 grams and takes up about 1.5 inches of a spare parts kit and cost $2.50. But time is money, so if you don't have 20 minutes to spare or have a lot of tanks to fill/transfer use one of the $65 or $90 or $150 bulky devices.

    No....but with all the resistance to using this simple, inexpensive method, I would appreciate the input of someone who has found reason not to use it for the purpose I've described.
     
    Six2Life likes this.

Share This Page