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Regulator list

Discussion in 'Poseidon' started by 'Cuda, May 14, 2013.

  1. USMC_DS1

    USMC_DS1 Angel Fish

    # of Dives:
    Location: Austin, TX
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    Thank you for posting this very informative chart. I recently acquired a new Jetstream Mk3 Regulator so new to how these work. It has the Xstream 1st and Jetstream 2nd stage. Very impressed with how nice and built like a tank it is and got to use it on a recent dive trip to the Hawaiian islands. I'm now trying to mate a Poseidon octo to it. I'm looking at a previously owned Jetstream 2nd stage tuned for an Odin setup (IP 135lbs) so I believe it should work properly with my Xstream 1st stage based on the chart above. The other issue I assume I'll have to deal with is the difference in the LP port threading and the associated hose required: Xstream 1st uses 9/16" vs. Odin's UNF 3/8”. Please LMK if I have this right. TIA.
     
  2. rsingler

    rsingler Scuba Instructor, Tinkerer in Brass Staff Member ScubaBoard Sponsor

    # of Dives: 500 - 999
    Location: Napa, California
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    USMC_DS1,
    You've almost got it right. Some confusing changes in Poseidon threads coming from Sweden.
    The Jetstream has only one threading to attach to the second stage regulator itself. It's that large 1"-ish screw-on to the plastic handle of the second stage. The hose that mates to it comes in two flavors: G1/8 - a European thread that was common to Poseidon years ago, and UNF 3/8" - the US standard for LP hoses. The Jetstream hose does NOT have a 9/16" threading that I am aware of. The HP hose, of course, is larger at 7/16". Below is pictured a body of an Xstream 1st stage currently in my shop:
    Xstream1.jpg Xstream2.jpg As you can see, the ports are standard US threads for both the HP and IP (LP) sides.
    If you have an older Jetstream with the G1/8 threading, you'll need an adapter to thread it into the IP (LP) port.
    The adapter that is pictured below is the opposite of what you'd need. This one is for mating a standard US hose to an old G1/8 body.
    G1_8Adapter.jpg
    In your case, it's possible you'd need a G1/8 female to UNF 3/8 male, but I haven't seen one of those.
    If they aren't easily found, the easier solution would be to get a standard Jetstream adapter and mate it to a US hose with a 3/8" thread.
    They're available from Northeast Scuba Supply:
    Jetstream adapter.jpg
    But then, you said you were contemplating an Odin octo (the American import of the Jetstream) with a 3/8" hose. It should fit right on!

    For interest's sake, it's also worth noting Poseidon's convention when supplying US-threaded port plugs:
    PortPlug.jpg The top two plugs are both 3/8" US standard LP plugs. The top one is US-made and looks like any other plug. The middle one is supplied by Poseidon and has a ring around the face of the plug which indicates UNF thread. For Poseidon, a smooth plug indicates G1/8 thread. Be careful! I have a reg in the shop right now where a 3/8" hose was forced successfully into a G1/8 port. Unfortunately the body is now ruined, as the threads are cross-threaded from the wrong size.

    Tuning your Jetstream/Odin for an IP of 135 is perfect. The factory spec for this regulator is 123-130 psi (8.5-9 bar), but it will tolerate higher IPs just fine. Tuning per the manual includes a step at 145 psi (10 bar) at 300 psi. This was due to the unbalanced old-style 1st stage which used to be supplied with the Jetstream, and which would show a higher IP as the tank emptied. So this factory specified two step process confirms that the Odin is designed to handle at least 123-145 psi IP. You will notice a slight abruptness to onset of flow with this design at shallow depths, which disappears down deep when the air is thicker.

    Also note that the reg will freeflow if IP drops significantly below 100 psi, because there is not enough pressure to keep the bell valve snug up against the housing. That's why, if you follow standard American practice of slowwwwlly opening your tank valve, the reg will freeflow. But this is normal, and the reg will seal as soon as you open the tank valve fully and the IP rises to normal levels.
     
  3. USMC_DS1

    USMC_DS1 Angel Fish

    # of Dives:
    Location: Austin, TX
    20
    0
    1
    rsingler, thanks for the details. My LP plugs have the rings on them as supplied by Poseidon so my LP ports are the 3/8" UNF thread types. I've also confirmed that the threading fits a standard US 3/8" Oceanic Octo hose. BTW, I've come to understand that the 9/16" reference I've seen posted on various websites for the Jetstream MK3 is in regards to the nut size or wrench size I need to use to tighten the hose onto the 1st stage. Looks like I'm GTG on that 2nd stage I'm keen on procuring. One more query. Is there any difference between standard 2nd stage vs. Octo with Poseidon other than color. Thanks again for all the insight and technical details. That last bit of info re the free flow when I cracked the tank value slowly was spot on... I was puzzled at 1st when it free flowed and resorted to taking a breath off the reg to get it to stop. Will open the tank value more quickly from now on.
     
  4. rsingler

    rsingler Scuba Instructor, Tinkerer in Brass Staff Member ScubaBoard Sponsor

    # of Dives: 500 - 999
    Location: Napa, California
    3,321
    3,683
    113
    No difference at all between black Jetstream and yellow "octo", except color. You are correct.

    Happy to service/tune your new reg for you if you don't have local access to good Poseidon service. Some places, that's an issue.

    Cheers!

    ---------- Post added October 11th, 2013 at 08:55 AM ----------

    For amusement's sake, you might check the post "No air?" in this forum re: how Jetstreams function, as it's not intuitive.
     
  5. divad

    divad Solo Diver

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    I have a few questions about Health Care Insurance............................
     
  6. USMC_DS1

    USMC_DS1 Angel Fish

    # of Dives:
    Location: Austin, TX
    20
    0
    1
    Thanks for the offer... I'll test the "new to me" 2nd stage coming in and let you know if it needs a tune or service. Please PM details or point me to where I can find info re your service offerings. BTW, nice "No air" write-up. One thing I have to get used to was canting the reg to the left and down every so often to keep water out of the 2nd stage.
     
  7. rsingler

    rsingler Scuba Instructor, Tinkerer in Brass Staff Member ScubaBoard Sponsor

    # of Dives: 500 - 999
    Location: Napa, California
    3,321
    3,683
    113
    Just returned from the Poseidon Service clinic at DEMA, and I'm wrong. Although the FAQ for the Xstream first says you "can't" mate it to a Cyklon regulator, this prohibition has only to do with tested configurations. The service manager for Poseidon USA (with reps from Sweden present) confirmed what we've always believed: you can tune any Poseidon first for an IP from 120 (or lower) to 170. My comment about suspicion of plastic deformation of the primary spring with high IP's was an unfortunate conjecture on my part. The spring can take it just fine, it turns out.

    Bottom line: if you have an Xstream first stage that for some reason you want to mate to a Cyklon second, go right ahead. The Cyklon second stage is properly mated with a first stage set to an IP of 167 psi at a supply pressure of 300 psi and then rechecked at full tank pressures (3000-4350 psi). With the balanced Xstream, you shouldn't have much of a change in IP. The Cyklon 5000 second, in any case, is rated to +/- 22 psi from the 167 you started with, which means it can tolerate an IP as high as 189 psi!

    The Xstream first stage is an absolute marvel. The balancing feature is different from every other regulator on the market. In the Xstream, the SEAT shifts position with changing tank pressure, thus affecting the degree of mainspring compression as the tank empties. With the change from a stainless to a ruby ball making the seal, you have a regulator that is now just about impervious to corrosion at this key point.

    The only other regulators that used a shifting sealing point to balance the regulator are some of the Sherwoods with their disc springs that moved the orifice. The Poseidon has done the same thing with the opposite part: the seat. Very cool.

    The Poseidon Xstream is the ONLY regulator that has passed all five of the US Navy's (undisclosed) tests of depth, flow rate and temperature. Can't get a much better endorsement to undercut all the nonsense about that tiny upstream servo valve.
     

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