Tank Saver?!?! Is thing for real?

Discussion in 'Tanks, Valves and Bands' started by luckydays, Aug 24, 2009.

  1. luckydays

    luckydays Loggerhead Turtle

    # of Dives: 200 - 499
    Location: San Pedro CA
    1,392
    63
    0
    I was randomly searching ebay for a scuba tank and I came across this "Tank Saver". I understand that the O Ring can fail but I don't see how this "Tank Saver" can fix the tank to save it from being tossed. Plus I can't imagine a tank being thrown away just because it leaks at the O Ring. Replace the O Ring and you are back in action. At least that is what I thought. This seller has sold a few of these with positive reviews. This one is up with an initial bid of $20.

    I do not have AL tanks and the auction only discusses AL tanks so I guess I would not need it but I am curious is this would be useful at all and how would it be useful. Also, I am wondering if anyone here has this sort of device. I am not the seller trying to find another way to sell this device nor am I in any way affiliated with the seller. I am just curious if someone is a swindler and found a way to sell pet rocks to scuba tank owners or if this is a useful tool to have.

     
  2. oxyhacker

    oxyhacker Loggerhead Turtle

    1,314
    28
    0
    The O-ring seating surface on an aluminum tank can corrode or get damaged so that the O-ring can no longer make a reliable seal. Tools similar to this, that reamed the seating surface to get a fresh surfuce used to be sold, but they were illegal under DOT regs because they removed metal from the tank neck, which could potentially weaken it. Also, by removing metal from the tapered seating area they made the O-ring fit sloppier, which could actually increase the chance of leakage. Recently several sources have revived the idea, but modified the design so the tool in theory burnishes the surface - that is to say, smoothes and polishes it - rather than scraping it, so it doesn't remove any metal, and should be legal to use. This appears to be one such tool though from the description it is hard to say for sure.

    It's a specialized piece of equipment to deal with a fairly uncommon problem, so while it might be useful, assuming it works as promised, in a shop, it isn't really something the average diver needs in his or her dive bag.
     
  3. Chugwhump

    Chugwhump Surface Interval Member

    # of Dives:
    Location: SE Florida, the flattest part, I can see Mount Pom
    1,880
    826
    113
    BAH!
    Aluminum Scuba Tanks.

    (I actually have 3, they rot in the garage, (2) 90's and an 80, lol)

    Chug
     
  4. fppf

    fppf Manta Ray

    # of Dives: 200 - 499
    Location: Buffalo NY
    1,166
    1
    0
    Those are pointless
    The sealing surface for the oring is between the bottom edge of the valve and the ID of the tank neck. Not the top of the tank neck, the surface those "polish".
     
  5. oxyhacker

    oxyhacker Loggerhead Turtle

    1,314
    28
    0
    I take it back. I found a better picture, and there's a cutting tool insert on it, set up for shaving the top of the neck , not the seating taper (unless maybe it can be reset for that) as earlier tools did. The idea apparently being to tighten up the O-ring fit by reducing the depth of the recess where the O-ring goes.

    Clever and reasonably priced, but since it removes metal it is of very questionable legality. I'd want to see a letter from the DOT or at least a couple tank manufacturers approving the tool before I used one.

     
    Last edited: Aug 24, 2009
  6. captain

    captain Orca

    6,498
    3,009
    113
  7. beanojones

    beanojones Great White

    3,204
    331
    83
    The bubbling paint under the valve is a frequent cause of leaks out here in the wilds.

    We just use a file though.
     
  8. mksmith713

    mksmith713 Manta Ray

    # of Dives: I just don't log dives
    Location: Jupiter,Fl
    991
    5
    0
    chugwhump, why don't you let me take those 3 tanks off your hands.
     
  9. oxyhacker

    oxyhacker Loggerhead Turtle

    1,314
    28
    0
    I contacted Luxfer and was told that using a tool like the Tank Saver would be grounds for condemning a tank, since it would constitute an unauthorized modification of the tank - according to DOT regulations only the original manufacturer can modify a tank. Oh, I also asked the person selling the Tank Saver on ebay if it had been run by the DOT or any tank manufacturers, and they replied just don't buy it!

    Interestingly enough, the Luxfer rep said that they have not examined or approved the O-Ringer that PSI sells, either.

     
  10. DCBC

    DCBC NAUI Instructor

    # of Dives:
    Location: Halifax, Nova Scotia, Canada
    4,431
    908
    0
    Good answer oxyhacker. The fact that some of the metal is removed is enough to void the hydro. If however a new hydro was undertaken and it passed, I wouldn't see a problem in using it.
     
  11. oxyhacker

    oxyhacker Loggerhead Turtle

    1,314
    28
    0
    Not void the hydro, void the tank! A hydro doesn't automatically make everything well again. There are many things that can be done to a tank that will render it DOT-illegal, regardless if the tank is rehydroed. Any procedure that removes a more than trivial amount of metal is considered a modification. Doing anything that might weaken the neck is especially questionable, as that is the prime troublespot on aluminum tanks.

    But then we divers are not as concerned with what is legal according to the exact letter of the law, but rather with what is likely to cause hassles for us down the road when we try to get the tank filled. And freshly machined tank top on a very old tank is the sort of thing that attracts questions from fill stations.

    The fact that Luxfer says using the tool would be grounds to condemn the tank is enough to make me avoid it. If pitting is preventing the valve from seating flush against the tank top some careful filing to remove just the high spots as suggested by Beano should do the trick without making is so obvious that the neck has been worked on.


     
  12. DCBC

    DCBC NAUI Instructor

    # of Dives:
    Location: Halifax, Nova Scotia, Canada
    4,431
    908
    0
    DOT's Regulations pertaining to compressed gas cylinders mainly address markings and shipping. They also touch on handling and testing, but the testing regs are limited to hydrostatic requirements. What "legal requirements" are you referring to oxyhacker?
     
  13. mongodives

    mongodives Scuba Instructor

    # of Dives:
    Location: PNW
    335
    2
    0
    I'm guessing Oxyhacker is confusing/mixing legal standards with industry/manufacturer standards.
     
  14. fppf

    fppf Manta Ray

    # of Dives: 200 - 499
    Location: Buffalo NY
    1,166
    1
    0
    Who cares if they make the tank void or not, they are not refinishing the sealing surface. The oring should never be in contact with the TOP of the tank neck. It seals on the ID of the tank neck to the bottom of the valve.
     
  15. Texfrazer

    Texfrazer Barracuda

    # of Dives: 500 - 999
    Location: Knoxville, TN
    349
    13
    0
    Well, DOT regulations prohibit any type of rethreading unless performed by the manufacturer, under the observation of an independent inspection agency. And, all DOT 3 cylinders may only be rethreaded once, and the tank has to be stamped as such.

    Using a tool to carve away part of the neck could be interpreted as a partial rethread (or it might not, depending upon which lawyer you talk with :D ).

    Therefore, it is quite possible that using the tool could be grounds for violating DOT regulations.
     
  16. Randy43068

    Randy43068 Orca

    # of Dives: 100 - 199
    Location:
    5,461
    132
    0
    True, but if pitting on the top surface is preventing the valve from being threaded down far enough to allow the O-ring to do it's job, then taking a little off the top of the tank will let the valve down a little more to crush the O-ring just a little more.

    That's my take on it.
     
  17. Randy43068

    Randy43068 Orca

    # of Dives: 100 - 199
    Location:
    5,461
    132
    0
    Re-threading a tank neck was all I can recall from my PSI training as being forbidden. I should go look it up.
     
  18. fppf

    fppf Manta Ray

    # of Dives: 200 - 499
    Location: Buffalo NY
    1,166
    1
    0
    Pitting makes a depression, not a raised surface, it should not stop the valve from bottoming when torque.
     
  19. Randy43068

    Randy43068 Orca

    # of Dives: 100 - 199
    Location:
    5,461
    132
    0
    I think it's pretty worthless too, but just saying that if one takes a little off the top then the o-ring compresses a bit more. I think filing it is a piss poor idea because if you let a trough, or gap between the valve face and the neck top then the O-ring has a really, REALLY good chance of extruding.
     
  20. krulle

    krulle Angel Fish

    57
    0
    0
    that's true, and pitting is only occuring in dynamic situations.

    Does anyone know the real degrading-mechanism that affects aluminum bottles?
     

Share This Page