• 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

Steel Tank Condemned: Cracks in Threads?

Discussion in 'Tanks, Valves and Bands' started by Barnaby'sDad, Oct 19, 2020.

  1. letterboy

    letterboy Not today, Mr ATF, not today. ScubaBoard Supporter

    49,260
    57,595
    5
    What about taking it directly to a hydro facility?

    I had looked at Eddy current looks like, per wiki, they use it for different steels.

    Could you xray? It would show the fault in the material but at what cost?
     
    AfterDark and rhwestfall like this.
  2. Southside

    Southside Rebreather Pilot

    # of Dives: 25 - 49
    Location: Chicago
    177
    146
    43
    I often get parts x-rayed for work. The local place by me starts at $300 for two images with CR. Might as welwell just buy a new tank.
     
    rjack321, wnissen, lexvil and 2 others like this.
  3. Barnaby'sDad

    Barnaby'sDad ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 50 - 99
    Location: Virginia
    1,128
    898
    113
    I went from diving Asahi HP100’s (I had a set previously) to PST HP100’s. I can’t say that I noticed a difference between the two.

    That’s just it...it’s not worth my time to mess with it. Let’s say I find a place out of the way that’ll certify the thing. Pretty much no facility like this is going to be open on the weekends in my area.

    I’d have to burn a leave day (my time off is important to me) and fuel to get to a facility and who knows how much money to get it inspected. I’d get to do that with this tank every year, because it looks so sketchy that given the responses here...it would be literally a coin toss (from looking at the feedback on the pictures) as to whether or not it would pass or fail the vis. If I found someone that would pass it, I would have to just keep taking it to them.

    I don’t have “nothing” in it, but I’ve got a small enough amount of money in it that I’d feel better about just cutting my losses and condemning it.

    That and regardless of what anyone else thinks...I think it’s cracked. I’ve got no interest in pressurizing this thing and driving around with it in the back of my truck and diving with it.
     
  4. rhwestfall

    rhwestfall Woof! ScubaBoard Sponsor

    # of Dives: 200 - 499
    Location: "La Grande Ile"
    15,185
    16,979
    113
    if you are going to dump it, I'd bet someone like @abnfrog might have an interest in it with his certification class.

    The interesting thing would be to really destructively explore this to see if it was or wasn't a crack....
     
    wnissen, couv and Barnaby'sDad like this.
  5. Barnaby'sDad

    Barnaby'sDad ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 50 - 99
    Location: Virginia
    1,128
    898
    113
    That’s exactly what I’m going to do with it. When the crack was discovered, the shop spoke with a PSI cylinder certification instructor. He expressed interest in getting ahold of it to use as a certification class example if I decided to condemn it. He has examples of cracked aluminum tanks for show and tell, but not steel.
     
  6. Johnoly

    Johnoly ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location:
    2,477
    2,105
    113
    100% agree with you.

    I had an AL80 that passed hydro & vip but was made of the 6351 bad alloy.
    Even though is was a TEENY WEENY TINY chance of a neck/thread failure,
    I couldn't live with the thought I injured someone else over a FEW DOLLARS if it let loose.

    It's just $300 bucks to be safe and sleep at night. If that's too much money for a safety margin, we're in the wrong sport.
    I'm on your side @Barnaby'sDad
     
    Barnaby'sDad likes this.
  7. Rusty Shackleford

    Rusty Shackleford Manta Ray

    # of Dives: 500 - 999
    Location: Port Canaveral Florida
    702
    380
    63
    It's steel, you should be able to magna-flux it.
     
    abnfrog and rhwestfall like this.
  8. shurite7

    shurite7 Dive Shop

    # of Dives: 1,000 - 2,499
    Location: In transit
    1,048
    458
    83
    This is a first for me. Have you sent pic to the manufacturer to see what they about it? A crack in the threads of a steel tank is almost unheard of; I’ve been told by old timers steel tanks will not crack. Then again, a long time ago it was said the Titanic wouldn’t sink.
     
    Johnoly likes this.
  9. rhwestfall

    rhwestfall Woof! ScubaBoard Sponsor

    # of Dives: 200 - 499
    Location: "La Grande Ile"
    15,185
    16,979
    113
    There still seems to be sentiment that this isn't a crack....
     
  10. 2airishuman

    2airishuman ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Greater Minnesota
    2,558
    1,801
    113
    The broader problem at work here is that the packaged gas industry has a fleet of aluminum and steel high-pressure cylinders numbering well into the millions. The steel ones get hydro tested every ten years, for the most part, and the aluminum ones get tested every five years. It is rare for these cylinders to fail requalification, and when it occurs it is ordinarily because of serious external damage, such as an inadvertent hit from an arc welder or corrosion from exposure to salt. Accidents resulting from cylinder rupture are rare enough that it is hard to find reports let alone statistics.

    And yet we have a VIP procedure that was adopted specifically to address the problem of serious internal corrosion resulting from seawater filling dive cylinders at the end of the dive, which was occurring in the late 1960s and early 1970s when it was a common practice to continue a dive until all the air in the cylinder was exhausted. A quick look every year inside the cylinder was enough to solve that because the degree of corrosion involved was readily visible to the untrained eye. PSI and others in the business have turned this into an annual requalification inspection that includes everything except the actual hydrostatic test.

    PSI has made an industry for themselves out of training VIP inspectors to look for "problems" that have never caused accidents. Some dive shops have become paranoid. The 6351 alloy fiasco with SLC hasn't helped matters as SCUBA divers were early adopters of aluminum cylinders. A lot of perfectly good cylinders get thrown in the recycle bin. I would be fine with that if it made diving safer, but it doesn't.
     
    captain, BRT, boulderjohn and 3 others like this.

Share This Page