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My new G250Vs and ramblings

Discussion in 'Regulators' started by buddhasummer, Dec 25, 2020.

  1. Geo7

    Geo7 Contributor

    # of Dives: 2,500 - 4,999
    Location: Los Angeles
    201
    115
    Honest question related to that: Do the 109 and 156 Scubapros that lack a vane usually freeflow if the purge is pressed firmly?
     
    Open Ocean Diver and lexvil like this.
  2. buddhasummer

    buddhasummer Bat sh.t crazy ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Nanny State
    11,701
    4,413
    @couv
     
  3. lexvil

    lexvil ScubaBoard Sponsor ScubaBoard Sponsor

    # of Dives: 1,000 - 2,499
    Location: jamestown, ca.
    4,121
    3,994
    If memory serves mine always did if set to hot.
     
  4. buddhasummer

    buddhasummer Bat sh.t crazy ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Nanny State
    11,701
    4,413
    That is my recollection too but it's been a while and I cannot be positive.

    Same with a Conshelf 14 if hot.
     
    Geo7 likes this.
  5. buddhasummer

    buddhasummer Bat sh.t crazy ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Nanny State
    11,701
    4,413
    Just as a comparison, a G260 will VFF with mouthpiece on even with higher end cracking effort.
     
    Open Ocean Diver and lexvil like this.
  6. rsingler

    rsingler Scuba Instructor, Tinkerer in Brass Staff Member ScubaBoard Sponsor

    # of Dives: 500 - 999
    Location: Napa, California
    5,280
    6,703
    My 156's upgraded to the S-wing poppet usually freeflow just fine with a bang on the purge.

    A 109? Most of mine don't unless tuned lighter than I'm comfortable with a downstream second. I attribute that to the heavy 109 spring.

    216 on top; 109 on bottom
    _IMG_000000_000000.jpg
    Theoretically, it shouldn't make a difference, because the balance forces are added to the lighter spring. But somehow, I don't get the same results with the downstream version.

    @couv ?
     
  7. couv

    couv Instructor, Scuba

    # of Dives: 1,000 - 2,499
    Location: 13th floor of the Ivory Tower
    5,890
    3,683
    A 156 when tuned properly (or a little lower than specs) will definitely VFF. I'll have to double check the 109. But Rob brings up an interesting point. The mechanical spring is stronger in the 109, but if we add the pneumatic force to the mechanical spring in a 156 it stands to reason the total force must be the same-else the IP would overcome the low spring pressure.
     
  8. couv

    couv Instructor, Scuba

    # of Dives: 1,000 - 2,499
    Location: 13th floor of the Ivory Tower
    5,890
    3,683
    If Rob's picture is representative, then (looking at the lower drawing) it could just be a matter of more blade aft directs air further down the mouthpiece shank. Longer fins, like a freediver wears, move water in a straighter line and further back than say a jet fin. Putting the crescent toward the back may relieve the flow-like a spit fin.

    Edit: I'm a little better artist than Rob, so have a look at this picture I just drew. ;-)
    Notice where the air from the aspirator hit the vane?

    VIVA vane.JPG
     
  9. lexvil

    lexvil ScubaBoard Sponsor ScubaBoard Sponsor

    # of Dives: 1,000 - 2,499
    Location: jamestown, ca.
    4,121
    3,994
    I always looked at the balance feature as an assist to closing on these
     
  10. lexvil

    lexvil ScubaBoard Sponsor ScubaBoard Sponsor

    # of Dives: 1,000 - 2,499
    Location: jamestown, ca.
    4,121
    3,994
    This is only my perception but since the BA has a very strong Venturi the viva vane was added to disrupt flow and assist in limiting free flow.
     
    buddhasummer and rsingler like this.

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