300 bar tank

Discussion in 'Tanks, Valves and Bands' started by andy j, May 16, 2009.

  1. andy j

    andy j Angel Fish

    # of Dives: 200 - 499
    Location: england
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    I'm in the market for a tank, idealy i would like a 300 bar 12l.
    My regs are scubapro r190 with a din 1st stage. Will i be able to use these regs on a 300 bar bottle without causing them any damage. I'v connected them to my 3 ltr pony with about 240 bar in and they semed ok.
    Are all din connections the same? i was told some are longer than others?

    I can get hold of a carbon fibre tank realy cheap but was told they cannot be used for diving, is this so?

    Is there a reason most bottles are only 232 bar and not 300, Surely a 12ltr 300 bar will hold the more air than a 15ltr 232bar cylinder and would be more managable?

    I know they are probaly stupid questions but please bear with me as i am a holiday diver trying to convert to some hardcore british summer diving.

    Cheers
     
  2. widget

    widget Manta Ray

    # of Dives:
    Location: South Africa
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    Firstly the cylinders.

    Scuba 12 litre / 300 bar working pressure scuba cylinders are not mass produced. Industrial 300 BAR working pressure cylinders are, but usually in smaller sizes like 7 or max 10 litres. These cylinders will have a differant neck thread to prevent scuba valves been used.

    There are numerous reasons why scuba cylinders in 300 bar are not mass produced, usually its cost, inability of fill stations to fill to 300 bar etc and not ALL scuba regs can operate on a 300 bar system - but purely from a manufacturing point of view because of the above, demand is low.

    That said, Faber dos make them with the standard M25 x 2 scuba neck thread, but usually only on order (ie) when they have sufficient quantity for a run, this makes them relitively expensive and occassionally difficult to get hold of.

    No, not all Din connections are the same, 230 bar din connectors have less threads (ie) are shorter than 300 bar din connectors, the reason for this is obvious.

    I cant comment on the legality of using wrapped tanks in England, you would need to chat to the relevant authorities there, but here, yes, they are not allowed (illegal) in the scuba market.

    Certainly my suggestion is to stick to the commonly available cylinders, 12 or 15 litre cylinders in 232bar working pressure.

    Now the reg.

    I would imagine your reg has a 230 bar din as standard, so in its present format it will not fit a 300 bar scuba valve. Before you decide to buy and fit a 300 bar din fitting I would suggest you discuss the viability of using a R190 on a 300 bar cylinder with a Scuba Pro dealer.
     
  3. WD8CDH

    WD8CDH Manta Ray

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    Most regs sold in the US with DIN fittings have the 300 bar DIN fitting and will handle 300 bar. A few 300 bar regulators came with what is now called the 232 bar fitting. The Cyklon 300 is an example. Either fitting will handle 300 bar, but 300bar tanks usually have the longer valve fitting and the shorter regulator fitting won't fit.
     
  4. maged_mmh

    maged_mmh Scuba Instructor

    # of Dives: 100 - 199
    Location: Egypt
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    simply, if your DIN has 7 threads then it is rated to 300bars; if it has 5 then it is for 200bars.
     
  5. andy j

    andy j Angel Fish

    # of Dives: 200 - 499
    Location: england
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    Thanks for the replies, my din does have seven threads on it.
    A 300 bar cylinder would be more handy for me as i need one to charge an airgun
     
  6. crpntr133

    crpntr133 lost, even with a compass

    # of Dives: 100 - 199
    Location: West Central Indiana
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    Have you looked at the buoyancy of the carbon fiber wrapped tank? I would say that it will be way positive.
    I don't know if this stands in England but in the US if any of the cabon fiber is exposed then the tank is condemned and pulled out of service.
     
  7. roturner

    roturner ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Rotterdam, Netherlands, Netherlands
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    Who told you that?

    In practice the difference in volume is minimal and the difference in weight is also minimal.

    R..
     
  8. WD8CDH

    WD8CDH Manta Ray

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    In the US, most of the DOT exemptions for carbon fiber tanks SPECIFICALLY prohibits SCUBA use. The Luxfer CF SCUBA tank was of course made under a different exemption. I would suspect many other countries have similar standards.

    Interspiro makes carbon fiber tanks specifically for SCUBA that are aproved in some countries.

    Interspiro Divatorlite

    Euro diving zone sells CE certified carbon fiber SCUBA tanks:

    eBay Store - Euro Diving Zone: Carbon Fiber Cylinders: SCUBA Diving Carbon Fiber 6.8 Liters Cylinder 300 Bars

    By the way, most 300 bar steel tanks are much more negative than 232 bar tanks.
     
  9. JonW*Interspiro

    JonW*Interspiro Angel Fish

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    Hi, Jon with Interspiro here...I hope I can answer any questions. To my knowledge, I believe we are the only company that manufactures a fully composite cylinder approved in the European as well as the US market. They have a 300 DIN connection and are rated at 4350 psi. These cylinders are much lighter weight than the standard cylinder, but also more expensive...not really geared towards the recreational market unless you don't mind paying a little more for some really good equipment. Feel free to contact me if you need more info or go to our site at interspiro.com
     
  10. WD8CDH

    WD8CDH Manta Ray

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    Hi Jon,

    What is the exemption number for your US market tanks? What sizes are available?

    By the way, I have owned several of your older steel tank twin sets. (4400 psi).
     
  11. JonW*Interspiro

    JonW*Interspiro Angel Fish

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    Hi Ron,

    By exemption number, I believe you are asking for the DOT#. It is filed under DOT SP-14209. We currently make 2 twin cylinder packs. One is the larger capacity at 6.7 liters (140 cuft) and weighs 37.5 lbs fully charged minus the buoyancy compensating weight and the smaller is the 3.4 liters (72 cuft) and weighs 20.7 lbs fully charged minus the weight. The advantage to this is reduced weight on the divers back at 95% ready. Other advantages are a more streamlined profile increase kick and less drag as well and easier access to a confined space. Our system is a first of it's kind designed as a complete system much like an scba for the fire service. We base this on safety with the diver in mind.
     
  12. WD8CDH

    WD8CDH Manta Ray

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    Hi Jon,

    I am very familiar with the advantages of slim twin tanks ( see post #5 and others here: http://www.scubaboard.com/forums/tanks-valves-bands/286251-carbon-fiber-tanks.html ).

    I assume the liters figure is per tank and the cuft figure is per set. What is the diameter and length of the individual tanks in those two sizes? What is the neck thread?

    I see that DOT SP-14209 shows a design life of 48 years or greater but a service life of 15 years. Have you thought of having the exemption amended to a service life of 30 years? There is currently a precedence of 30 year service life on a few of the Special Permits for at least one of the SCBA series composite tanks from Luxfer.
     
  13. WD8CDH

    WD8CDH Manta Ray

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    Do you sell tanks individually? I often dive slim triples with the third tank independent.
     
  14. JonW*Interspiro

    JonW*Interspiro Angel Fish

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    Not at this time and I am not sure of any plans in the future. The hardest part to conquer is the buoyancy factor, that is why we have them in the twins. The brass weight slides onto a post in between so that there is even distribution on the divers back. If they come up with something here for the US I will let you know.

    BTW Ron, where are you located? I need help with a general consensus regarding or surface supply system and the application in commercial diving. Any info would be appreciated.
     
  15. WD8CDH

    WD8CDH Manta Ray

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    Hi John,

    Triples would just require 2 weights. At least that is how I did it with titanium tanks or my present set of 7000 series aluminum tanks.

    I am located in NY now but I did most of my commercial diving in the Gulf, in the Midwest and in the Great Lakes. Personally, due to my use of unusual equipment (four AGA tanks (two twin sets) at the same time:shocked2:, 7000psi titanium tanks and rebreathers), I did very little surface supplied air.

    A lot of the surface supplied air that I saw had inadequate bailout. Often the tiny Survivair doubles with only about 20cuft total capacity or nothing at all. I usually used double 30's or double 40's for bailout.
     
  16. JonW*Interspiro

    JonW*Interspiro Angel Fish

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    With regards to bailout, here is where we shine. We have a configuration for surface supply that enables you to use the FULL 72 cubic on you back as a bailout should something happen with the supply line or at the surface! This is much safer than a pony bottle and gives you ample time to return to the surface. Most people relate to it as a J valve on our manifold block, but it is a much better, reliable design. We have a rep in NY if you ever want to see the system in person. Let me know and I will get you his contact info.
     
  17. bacaruda

    bacaruda Angel Fish

    # of Dives: 50 - 99
    Location: Stockholm, Sweden
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    Yes there is a reason. The physics of gas is linear up to around 240 bar, At more extreme pressure, it's getting more complicated. In a 300 cylinder, the last 30-40 isn't "worth as much" as the rest, and the pressure will drop fast when used. If your Dive-shop doesn't "top-off" your 300 bar tank you will seldom see more than 270 bar on the manometer after the bottle cools down after filling. A 12 liter 300 bar bottle will not contain 12x300=3600 litre of air, it will be more like 12x270= 3240 litre.
    A 15 litre 232 bar bottle will in fact hold 15x232= 3480 litre or more (can safely be filled to 250 bar). So with 232 Bar equipment you will get more "air/kg tankweight" that you drag around. On a 300 bar tank you pay for pressure that you realy cant use.
    12/300 and 15/232 has approx. the same weight, but 12/300 will be more negative in the water. the only advantage that I can see is the smaller diameter of the 12/300.
    I dive a 10 litre 300bar, mainly becasue of the extra weight (don't need so much around my waist) and the shorter lenght compared to a 12/232.
     
  18. LouieLouie

    LouieLouie Nassau Grouper

    # of Dives: 100 - 199
    Location: Bergen, Norway
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    7, 10, 12 and 15L 300 bar tanks are available in Scandinavia. 10/300 singles and 7/300 doubles are by far the most common. I've been told the 12/300's are crap, as they are too short and heavy to trim out well. 15/300's are supposedly slightly better but far from good. Most people choose D7/300's instead.
     
  19. WD8CDH

    WD8CDH Manta Ray

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    The 7L tank is a sweet size for doubles but in the US, we can't get them in either 300bar or even 232 bar. We can only get that size in 180 bar (2400psi +10%, 45cf).
     

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