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Double 30s???

Discussion in 'Vintage Diving & Equipment' started by ohonu, Jun 18, 2020.

  1. Sam Miller III

    Sam Miller III Scuba Legend Scuba Legend

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  2. jadairiii

    jadairiii Solo Diver

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  3. Sam Miller III

    Sam Miller III Scuba Legend Scuba Legend

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    @tridacna
    Sam - Explain 90cu ft at 3000psi. Are you talking about the OP's double 30s?

    I see two Al30 cylinders rated for 3000psi usage. I'm perplexed?
    ~~~~~~~~~~~~~~~~~~~~~~~~~~
    Dear Perplexed
    You see TWO 45 US Diver cuft HP cylinders produced especially for the ABS system
    FYI 45 + 45 = 90
    SDM
     
  4. tridacna

    tridacna ScubaBoard Supporter ScubaBoard Supporter

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    Dear Dr Sam,

    I see two Al3000-S30 tanks in the OP’s initial post. How did these become 45s?

    Regards,

    Dr Tri
     
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  5. Boston Breakwater

    Boston Breakwater "Outlaw." Solo Diver ScubaBoard Supporter

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    Good afternoon. I own a set of these. Brand new, never been in water, containing the original factory air. Sorry,the photo is not very good. I can scan, and post the instructions as a P.D.F. this week if it would be helpful. They were attached using a saddle, and hard back plate, or jacket style B.C.D. I believe the born date is 1993....I'd have to check. Part # 2804-99
    Cheers. U.S. Divers Twin 30's.png
     

    Attached Files:

    Andrew Dawson, James79 and jadairiii like this.
  6. Sam Miller III

    Sam Miller III Scuba Legend Scuba Legend

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  7. NAM001

    NAM001 Contributor

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    Just because the dates were in that time window does not mean that they are bad. get them checked. However even if they are good,,you may not get them filled because of shop rules. My understanding is that it was not ALL tanks in the time window just some. Still they are probably not worth much because of that time window.
     
  8. tridacna

    tridacna ScubaBoard Supporter ScubaBoard Supporter

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    I believe that they need a visual eddy before anyone will (or should) fill them. CMIIW.
     
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  9. Scared Silly

    Scared Silly ScubaBoard Supporter ScubaBoard Supporter

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    Correct given the born dates, they would be made from AL6351 which is a bummer but they can still be placed into service when requalified by having the visual eddy performed. And said above a shop still might not fill them.

    That said one can always buy a couple of new AL30s or Al40s and used them with the manifold instead. Or scrap the cylinders, sell the manifold and the OP buy himself and his friend a couple of nice beers.
     
    dead dog and tridacna like this.
  10. captain

    captain Captain

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    New tanks may be a problem, they have a larger diameter than the old AL30's.. I ran into this issue several years ago when I was fabricating triple manifolds for AL 30s using parts from a USD double manifold and a USD single J valve and the old AL30's. The larger diameter of the new AL30's significantly increased the work needed to gain the necessary tank spacing. Pictured are the old AL30's.

    DSC03187.JPG
     

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