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Calypso IV unable to adjust IP

Discussion in 'Vintage Equipment Diving' started by Bingjet, Aug 24, 2019.

  1. 2airishuman

    2airishuman ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Greater Minnesota
    I have three Calypso IV, one with the J mechanism. Two are presently in service.

    The adjustment screw is a fine adjust and will only change the IP by around 15-20 PSI over its entire travel. Coarse adjustment is with shims. Adding shims increases IP.

    If you're getting 170 PSI then I would check for corrosion, unwanted shims, or other foreign material that might be keeping the mainspring from seating on the housing. The shims ordinarily used are very thin, around 0.010", and make around a 15 PSI change in IP, so it does not take much to affect IP. If there are no obvious culprits I would try a different main spring, and failing that, a new piston or housing.

    Used Calypso IVs are abundant so you should have no trouble finding one for parts.
  2. Bingjet

    Bingjet Angel Fish

    # of Dives: 0 - 24
    Location: Ohio
    Update: The regulator now performs correctly after replacing the seat. I also installed the castle spacer per the service bulletin. Thanks for your help.

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