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Porpoise CA-1 regulator

Discussion in 'Vintage Equipment Diving' started by Fibonacci, Jan 14, 2019.

  1. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    535
    440
    63
    Neptune smiled on me at the start of 2019... I stumbled across a 1954 Porpoise CA-1 regulator complete with the original case and twin tank adaptor!

    It is in pretty good condition, quite rare to find in Australia these days... so I'm now having fun trying to source NOS or reproduction parts to restore it back to working condition. The diaphragm had dissolved into goo and attached itself to the inside of the cover plate... but all the other parts are intact.

    I already have a copy of the Historical Diving Society's excellent book detailing Ted Eldred's work developing the Porpoise line of regulators... the world's first commercially available single hose regulator!

    When La Spirotechnique and Aqua-Lung were only producing twin hose scuba and had never dreamed of a single hose system, along came an Australian who changed scuba diving forever. This is the complete story of the engineering brilliance of Australia’s Ted Eldred and the development of his Porpoise scuba, which set today’s world-wide diving standard. Acknowledged by many including HDS US and HDS Australia-Pacific, as the first to mass produce the single hose, 2 stage scuba system as used by scuba divers today.

    PORPOISE-BOOK-COVER.jpg

    The “Porpoise” book reprint

    Porpoise 1.jpeg

    Porpoise 2.jpeg

    Porpoise 3.jpeg

    Porpoise 4.jpeg
     
    JMBL, Boiler_81, undrwater and 8 others like this.
  2. Compressor

    Compressor ScubaBoard Supporter Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: NYS
    2,820
    1,289
    113
    WOW. Amazing pictures. The condition of some of the equipment showing its age. How old is it?
     
    John C. Ratliff likes this.
  3. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    535
    440
    63
    65 years old in 2019... it actually came up quite well after just a brief soak in 50:50 white vinegar and water... I'll post more pics as I restore it... but I think it could do with a new diaphragm as a start :D

    Porpoise 6.jpeg
     
  4. АлександрД

    АлександрД Manta Ray

    # of Dives: 100 - 199
    Location: Moscow, Russia
    673
    972
    93
    WOW! Great!
    Can you make photos of disassembled parts and post it here?
    P.S. see my sign :)

    some years ago I`d seen it on the ebay with very good condition
    fromEbay.jpg
     
  5. АлександрД

    АлександрД Manta Ray

    # of Dives: 100 - 199
    Location: Moscow, Russia
    673
    972
    93
    manual
     

    Attached Files:

  6. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    535
    440
    63
    Picked up a couple of vintage LP tanks (surplus WWII aircraft oxygen bottles I believe) with manifold which should suit the Porpoise if I can find an adaptor!

    Does anyone know the correct thread type?
    Major diameter appears to be OD 22.4mm x 14 tpi so possibly 5/8" BSP?

    Seem sound enough but some surface rust, will put into an electrolysis bath to stabilise it, two-pack prime and then hopefully get them hydro tested and stamped.

    Interesting that back in the day, the initial testing stamp, type and serial number were all on a brass collar shrunk around the neck... no stamps into the shoulder as is current practice.

    Vintage twins valve.jpeg
     
    northernone likes this.
  7. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    535
    440
    63
    The entire second stage has now been stripped down, pickled in 50:50 white vinegar and water then ultrasonically cleaned.
    Sourced a length of the correct ribbed hose, and currently chasing a NOS diaphragm... fingers crossed the Historical Diving Society may have stocks!

    In the meantime, I scanned Ted Eldridge's original sectioned drawing of the second stage, traced it in CAD then scaled and rotated to create a 3D model of the Porpoise diaphragm... be nice to have a reproduction made in silicone rubber!

    Porpoise Diaphragm 3D CAD section trace.JPG

    Porpoise Diaphragm 3D CAD section.JPG
     
    northernone likes this.
  8. Fibonacci

    Fibonacci Manta Ray

    # of Dives: 500 - 999
    Location: Melbourne, Australia
    535
    440
    63
    First tank out of the electrolysis bath, came up pretty well!
    One good thing about the Porpoise is many of the fittings are standard oxyacetylene 5/8”-18 UNF, so rigging up an IP checker via an old LP inflator hose and a new oxygen hose connector took 2 mins and $9!

    D196D5FE-6530-4767-B7FC-538EB8954FEE.jpeg

    B3CB0F0F-243E-43AE-945E-D306FD64BCB4.jpeg
     
  9. АлександрД

    АлександрД Manta Ray

    # of Dives: 100 - 199
    Location: Moscow, Russia
    673
    972
    93
    thread looks like Oxygen thread from Germany. In Russia it known as Сп 21.8х1.81-А or just СП 21.8
    fee8e208de8ef94a3d233e6e7549ef4c.jpg
    or
    2ac3130bedc2d33c44a3708fcfc17bc0.jpg
    Here is drawing for nut.
    Do you have calipers to recheck diameter?

    here is drawing for connector from СП21 to DIN
    a5d82558b4bf5b46428378d22c985ccd.jpg

    ...or it could be Whitworth thread G 5/8 BSPP Whitworth Pipe Thread DIN ISO 228 (DIN 259) aka DIN

    here is some more threads Резьбы и О-ринги: Клуб любителей экзотического дайвинга: Подводный форум больных дайвингом. :)
     
    Fibonacci likes this.
  10. happy-diver

    happy-diver Skindiver ScubaBoard Sponsor

    # of Dives: I just don't log dives
    Location: queensland Melbourne Victoria diver
    841
    492
    63
    It's DIN boys.
    Geeezzz I haven't breathed this thing for fifteen years, or twenty

    full.jpg

    Cough cough bletch spit fart belch yuk
     
    АлександрД likes this.

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