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Argonaut Kraken specifications

Discussion in 'Vintage Double Hose' started by Luis H, May 29, 2017.

  1. Luis H

    Luis H Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Maine
    Argonaut Kraken specifications

    Subject: Project Argonaut
    Totally new, vintage style double hose regulator.

    Note: NO Aqua Master or Royal Aqua Master were harmed, sacrificed, or cannibalized for this project… Ok, the cans were temporarily on loan, but all parts are now new.

    Cracking effort: can be easily adjusted to as low as 0.3 inWC, but it is not recommended to be adjusted to less than 0.5 inWC.

    Venturi flow: adjustable.

    Maximum flow rate: more than you will ever need, even with a second diver using an octopus.

    Operational temperature: It is an environmentally isolated double hose like the Aqua Master and RAM. I live in Maine. Ice diving is not an issue, well, at least not for the regulator. Last year we didn’t have any good ice. The regulator has been tested under the ice and I have intentionally push the limit (in a control condition) to see if I could freeze it. I could not freeze in the ice diving condition I dove it in.

    First stage: Balanced diaphragm, similar to Phoenix, but with improved air passages to diaphragm and second stage for improved IP response.

    Second stage: highly adjustable, HPR type with improved volcano orifice.

    This is a totally new regulator based on the cumulative experience of the RAM, the Phoenix RAM and the HPR second stage. It uses many standard components, but it incorporates many improvements, including an improved second stage (based on the HPR).

    The main body also features improved air passages, optimized 3 LP ports and modern HP port.

    It is very hard to improve on the breathing performance of a well tuned Phoenix HPR with the new diaphragm. Mechanically it is almost impossible, but the performance due to the regulator position is always user dependent.

    Some of the improvements of the Argonaut:

    • Ease of service
    • Unitized construction with no gaskets between first and second stage
    • Body is easy to hold, on any vise or with Crescent type wrench.
    • Replaceable first and second stage volcano orifices
    • Better port orientation
    • Lighter weight
    • More compact
    • No need to cannibalize any vintage regulator for parts.
    • Backwards and forward compatibility with parts of the most common vintage regulators. It can be customized with some vintage parts.

    You can find it here:
  2. Luis H

    Luis H Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Maine
    I am collecting and consolidating some of the information I have posted in the past into one thread:

    The Argonaut is a completely new double hose regulator which retains an attractive vintage appearance, but incorporates state-of-the-art modern features.

    1.) 1st Stage relies upon a balanced diaphragm featuring high flow capability. This engineering feature effectively limits intermediate pressure change; thus guaranteeing effortless, consistent performance with any tank pressure or any dive depth.

    2.) 1st and 2nd stages are environmentally isolated to insure absolute reliability in all weather and water conditions.

    3.) The regulator contains 3 low pressure ports for optimal hose positioning. This feature allows the diver to use any variety of low pressure accessories. The ports are industry standard 3/8” UNF sized.

    4.) 1st stage also contains a high pressure port allowing the diver to use either a stand-alone submersible pressure gauge, or a transmitter unit. The port is again, the current industry standard 7/16” UNF size.

    5.) Totally modern 2nd stage design that incorporates features such as: adjustable seat, large ultra flexible silicone diaphragm using a lever geometry designed for optimal mechanical advantage with low friction, and adjustable venturi assistance. The replaceable and adjustable hard seat (volcano orifice) permits ultra-fine tuning.

    6.) Internal parts that are chosen for maximum durability and ease of availability. Food grade silicone utilized for items such as hoses, mouthpiece, and low pressure diaphragms for extra-long life and easy maintenance.

    7.) 1st and 2nd stages manufactured from attractively triple-plated brass alloys, with lightweight, corrosion proof materials used for the housing.

    8.) Main body interfacing surfaces sealed with an O-ring rather than a flat gasket.

    9.) Effortless, natural breathing characteristics due to advanced design vacuum assisted venturi action, and a high flow/ ultra-low resistance exhaust system.

    10.) In essence, a double hose regulator that displays the classic lines of a vintage model with the performance of a 21stcentury design.

    Items 3,4,5,6,8,9 in the list above are new. The Phoenix incorporated some of these improvements, but the Argonaut builds on all that previous experience and puts it all together into a well integrated package.

    The flow path between the first stage and second stage in the main body is also optimized.

    Item 5 is basically the HPR second stage with several improvements on the orifice design.


    The case is also new:

    The Argonaut Kraken case is specifically designed to work with many more backpacks and backplates than most other double hose regulators.

    The tapered shape of the front can is intended to reduce the chances for interference and the back can has a large cutout/ chamfer to provide more volume for a variety of different BC bladders/ wings.

    The Argonaut will have a lot less interference with many backpacks and backplates, but you still don’t want a back plate or backpack that separate the tank away from your back.


    During the design process I spent a lot of time trying to improve on a number of details, but I have not had the chance to sit down and write them in one document. Now I have to go back and think about all the details that went into the design.

    The list below is not organize or in any order. I will re arrange it later.

    In addition to the features described above, there area number of other design improvements.

    • The integration of both stages also allowed a much lower profile regulator than the Phoenix.

    Improved seals:

    • The regulator uses no gaskets anywhere (as opposed to the a RAM or DA). It was designed to reduce the number of sealed joint (to minimize possibility of leaks) and only modern designed O-ring seals are used.

    • There is no join between the first and second stage. It is one piece.

    Weight considerations:

    • The integration of the 1st and 2nd stage into one streamlined body also allowed to reduce weight. The weight of the body was reduced as much as practical.

    • With the use of a plastic can the overall weight is about 1/2 pound less than other double hose regulators. I will post exact weight comparison later.

    • The weight is also better balanced and concentrated closer to the attachment yoke. It makes it easier to carry and much less cumbersome when installing on a tank.

    Maintenance considerations:

    • The main body was also designed with two parallel flat surface to make easy to hold on any vise or large wrench (padded surface is recommended to avoid scratches, but it is not essential).

    • The first stage IP adjustment screw can be adjusted with a large screw driver or in the field you can even use a coin.

    • All the edges are rounded (or chamfered) to reduce the chances of damage when hitting something (reduce nicks and dings).
  3. Luis H

    Luis H Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Maine
    Is there a performance difference from a well tuned vintage unit, and the Kraken?

    The simple answer is: yes and no. A lot is going to depend on what you mean by a vintage regulator.

    If it is a truly vintage regulator, the answer is immediately yes.

    If you start talking about a Royal Aqua Master with new silicone diaphragm and an HPR second stage the answer is still yes, but it is not as definitive at this point (and that is not a true vintage regulator anymore).

    For starters, the exhaust in the new Argonaut plastic case has been tested to be better than any previous DH (and probably any SH also), but I seriously doubt that most divers will notice on most dives.

    The Argonaut case was specifically designed to enhance the venturi flow from the second stage. If you look at the venturi jet, it lines up with the horn and the horn is round to match the flow pattern of the yet.

    You can use an Argonaut body (or a Phoenix/ HPR) in a metal can and get very good venturi flow assistance, but sometimes I find that I need to block some of the bleed air ports. With the new plastic cans there is no need to block any bleed air (you actually don’t want to or you get too much venturi).

    The inhalation resistance (both cracking effort and sustained flow) of a Phoenix / HPR can be tuned to perform basically as good as an Argonaut (if everything is working fine). The Argonaut is proving to be very easy to adjust and very consistent in its performance.

    With the Argonaut, both the 1st stage and 2nd stage volcano orifices can be replaced. This guaranties optimal performance at the most critical dynamic sealing interfaces. With a good volcano orifice, a good seal can be obtained without the need of adjusting (increasing) the spring force compression on the soft seat.

    In reality, there is no short answer to that question. I have been working for the last 9 years (actually on an off for the last 42 years) on improving all of my regulators (and this is just a hobby for me). We have come a long way, but when it comes to performance, we have been approaching diminishing return for a while.

    If you look at single hose regulators, they don’t even publish performance data in their advertising anymore. You are splitting hairs when measuring actual performance. At this point, human perception becomes the more important factor (and that is a very unreliable thing to measure).

    Most of the breathing performance changes are so small that most divers will not be able to notice. One advantage is that this improvement on the Argonaut should be far more consistent than in a converted vintage regulator.


    I have had a few emails (one today) from Phoenix owners asking if they should buy an Argonaut. Below is what I wrote. The link is to this thread.

    Argonaut versus Phoenix:
    • It is lighter, it balances better, can tolerated abuse better without showing scratches.
    • The hose routing is better as it is, but it can be easily optimized for dry-suit, etc.
    • The second stage has a replaceable and adjustable volcano orifice.
    • NO gaskets between 1st and 2nd stage
    • NO issues with port orientation depending on the rotation of the 1st stage (where it stops)
    • lower profile
    • Etc...

    Some of the differences are small, but there is a lot in the details.

    The Phoenix is a great regulator and it performs great, but there is no question that it evolved from available vintage parts. The Phoenix-HPR has been my favorite regulator for years...

    The Argonaut is just what I consider an integrated, elegant design. It takes advantage of decades of knowledge and experience. I designed the entire regulator as complete system. You can even consider the back plate as part of the system.

    I used as many standard of the shelf parts as possible to make it easier for the end used to source replacement parts (if needed), but I took into consideration how it all went together.

    IMO, both the Phoenix-HPR and the Argonaut are great regulators. I will always have a few Phoenix-HPR around, but at this moment, they just happen to be collecting dust.

    The bottom line is that there is nothing wrong with the Phoenix-HPR... If I didn't have my Argonauts, the Phoenix-HPR would be my favorite regulator. I personally think that every DH diver should have at least one of each. :)
  4. Luis H

    Luis H Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Maine


    Argonaut Kraken with optional DIN adapter.



    Argonaut Kraken with optional DIN adapter.


    Argonaut back can and inside view of exhaust valve.





    Argonaut Kraken with optional DIN adapter.



    Looking at the inside during set-up.


    Looking at the exhaust valve. Notice the captive hardware.
    I do not like loose hardware. IMO: loose hardware = lost hardware.



    Below are two cross-section shots of the exhaust can 3D model.

    A huge advantage of this fabrication/ molding process is that it allow me to design the can with thicker material cross section in any of the higher stressed areas. Notice that all the sharp inside corners have a generous radius and the changes in material thickness. It was easy to add reinforcing material were needed.


    It was also easy to design a smooth round to square transition for the exhaust duct-work. Notice the exhaust flow path.


    Notice the reinforcements were the horns transition into the cans. You can see the details from the model in the actual parts (look at the pictures in the previous post).

  5. Luis H

    Luis H Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Maine
    Here I am showing one side blocked


    Other side:






    This gives you an indication of the lever height, but I will expand on this more later. You should not need to do anything with the lever height. It should be fine, but I will explain how to check it later. I am just using the scale as a straight edge.


    I am pressing a bit with my Mistral tool. Again, more later.


    The nozzle points down the full diameter horn. The nozzle flow forms a cone. That is why I designed the can with a full circular tube horn.


    The vintage metal cans are attractive and they work well, but the rectangular horn base is not ideal to develop maximum venturi flow. They are good enough for most flow rates, but the Argonaut can was optimized for all flow rates and the DSV flow diverter is essential to take advantage of the maximum venturi flow.


    This can was optimized for production (with the soldered or brazed horns) not for flow performance. The rectangular horn base is the same as in the early Broxton regulators with no induced venturi flow at all.

    A full sized circular tube horn would have been much more difficult to attach with a clean transition on this can.


    I will be adding more later and I will probably separate this post into a new thread talking about optimizing the overall Argonaut performance, but I needed to provide some advance information.

    I hope this helps.
  6. Bryan@Vintage Double Hose

    Bryan@Vintage Double Hose Instructor, Scuba

    Argonaut Kraken video overview
    tbone1004, couv and lexvil like this.

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