• 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

first stage diaphragm

Discussion in 'Vintage Equipment Diving' started by squid.dive@ gmail.com, Jan 27, 2020.

  1. squid.dive@ gmail.com

    squid.dive@ gmail.com Angel Fish

    # of Dives: 1,000 - 2,499
    Location: Poland/Ireland
    7
    3
    3
    Is there anyone who can tell me from what material I can cut the first stage diaphragm? rubber sims to be too delicate.
     
  2. jvanostrand

    jvanostrand Nassau Grouper

    # of Dives: 1,000 - 2,499
    Location: Waterloo, Ontario, Canada
    73
    54
    18
    Most that I've seen have a fibre reinforcement in them. I have seen old rubber ones that are 3mm thick or more that don't seem to have fibres. Aside from being flexible I expect the material has to withstand far more pressure than internal pressure without expanding much at all and rubber needs to be really thick.
     
  3. rhwestfall

    rhwestfall Solo Diver

    # of Dives: 200 - 499
    Location: "La Grande Ile"
    12,942
    12,082
    113
    What brand do you need it for? VDH sells them (new) for some models of double hose.

    I believe @abnfrog used to make them too...

    He might comment on materials.
     
  4. squid.dive@ gmail.com

    squid.dive@ gmail.com Angel Fish

    # of Dives: 1,000 - 2,499
    Location: Poland/Ireland
    7
    3
    3
    This are old types from 70 or 80s, polish or russia made many some other iron courts country, not sure as they belong to friend who wants them restored. The rubber one dried out and broke, was about 1,5mm (Im in Europe) we tryed the aqualung ones but the diam os to small the diary is about 45mm so what reinforced diaphragm material will suit the purpose, or from what the main names made them???
    Was looking for the answer but nothing is sure, many some dive guru here can help???\\
     
  5. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    590
    523
    93
    There are many different types and specifications of the rubber sheets with nylon insertion, including a special configuration specifically designed for diaphragms and capable of repeated cycling without cracking or stretching. This would not improve your day underwater...

    I'm sure there are similar manufacturers in the US, here in Australia one reputable manufacturer is Reglin Rubber.

    Available in 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.65mm, 0.8mm, 1mm, 1.5mm, 2mm, 3mm.
    Full roll width being 1400mm and only for sale in 0.5mt increments
    Nitrile Diaphragm Rubber Sheet - Premium - Reglin Rubber
     
  6. jvanostrand

    jvanostrand Nassau Grouper

    # of Dives: 1,000 - 2,499
    Location: Waterloo, Ontario, Canada
    73
    54
    18
    I never knew that that "diaphragm rubber sheets" was a thing. Thanks.

    We were told that Nitrile wasn't a good material for O2-compatible o-rings. Wouldn't that be a problem with a diaphragm?
     
    Fibonacci likes this.
  7. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    590
    523
    93
  8. squid.dive@ gmail.com

    squid.dive@ gmail.com Angel Fish

    # of Dives: 1,000 - 2,499
    Location: Poland/Ireland
    7
    3
    3
  9. Luis H

    Luis H Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Maine
    2,881
    1,042
    113
    Keep in mind that the diaphragm is not exposed to high pressure gas, only to intermediate pressure (about 9 Bar, or 130 psi). The O2 exposure is very limited.

    I would use the Nitrile (Buna-N) for anything, except maybe 100% O2. And that only because I prefer an unbalanced piston for that application.

    YMMV
     
    John C. Ratliff and Fibonacci like this.
  10. squid.dive@ gmail.com

    squid.dive@ gmail.com Angel Fish

    # of Dives: 1,000 - 2,499
    Location: Poland/Ireland
    7
    3
    3
    Thank you for all the tips learning on the fly, hopefully will get there wiser.
    Any input is more then welcome, I have the aqualung diaphragm from service kit and it looks simple enough greyish material with fiber between the layers about 1.5-1.6 mm and its o2 safe after cleaning. I think that would be the best material anyway digging more.
     

Share This Page