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Discussion in 'Tanks, Valves and Bands' started by argos59, May 13, 2009.

  1. argos59

    argos59 Captain

    # of Dives: 100 - 199
    Location: Brooklyn, NY
    47
    0
    0
    Can any one tell me the threan size for a HP 3500 psi Norris tank ?
     
  2. NorthWoodsDiver

    NorthWoodsDiver Solo Diver

    # of Dives: 500 - 999
    Location: Florida
    1,314
    8
    0
    It should be the standard thread for any other tank valve of 3/4"X14 Straight thread.

    Only a select few tanks for scuba application (in America) were ever made with other threads.

    Edit: Correction, some 3500psi tanks had 7/8"X16 straight threads
     
  3. jswantek

    jswantek Barracuda

    225
    2
    0
    Wow, not sure on the specific brand. Most tanks are 3/4"-14 NPT. Older tanks sometimes had 1/2" tapered thread, but they're few and far between anymore.
     
  4. NorthWoodsDiver

    NorthWoodsDiver Solo Diver

    # of Dives: 500 - 999
    Location: Florida
    1,314
    8
    0
    Can you provide the tank stamping information?
     
  5. H2Andy

    H2Andy Blue Whale

    # of Dives: 200 - 499
    Location: NE Florida
    29,646
    370
    0
    is there anything that makes you think the tanks would be anything other than 3/4"-14 NPT?

    that's the overwhelming standard in the US
     
  6. argos59

    argos59 Captain

    # of Dives: 100 - 199
    Location: Brooklyn, NY
    47
    0
    0
    Tank is 4 years old DOT E13483-3500 3216355y TP5250 HP100
     
  7. SparticleBrane

    SparticleBrane DIR Practitioner

    5,030
    11
    0
    3500 psi cylinders are 7/8" threading, as far as I know.
     
  8. dannobee

    dannobee Instructor, Scuba

    # of Dives:
    Location: SF Bay Area
    2,479
    50
    48
    If a quarter will fit in the neck hole, it's 3/4"-14 NPS. If the hole is too small, it's 7/8"-16 UNF.


    .
     
  9. argos59

    argos59 Captain

    # of Dives: 100 - 199
    Location: Brooklyn, NY
    47
    0
    0
    I think its 7/8
     
  10. H2Andy

    H2Andy Blue Whale

    # of Dives: 200 - 499
    Location: NE Florida
    29,646
    370
    0
    hmmmm ... you're right:

    When Pressed Steel Tank Company began manufacturing the modern 3500 psi service pressure SCUBA cylinder, they elected to use a more modern thread form for the neck opening known as Unified National Standard Fine. The specific thread form used with the steel 3500 psi SCUBA cylinder is named 0.875-14 UNF, often referred to as "7/8 UNF."

    SCUBA Valves: Regulator Fittings, 200 vs 300 Bar FAQ and Cylinder Neck Threads - Dive Gear Express
     

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