Tanks: HP100's

[beeger]

No, not quite. All tanks sold under the label "high pressure" currently have the 7/8 neck size and will include a 7/8 DIN valve. Examples of this are the Genesis/Asahi tanks and the Pressed Steel HP steels (I think these were called the "sport diver" series, but I'm not sure; I'm not even sure they are still made). The only types of valves that fit the 7/8 neck size are DIN valves. I have never seen a 7/8 neck yoke valve. This is likely due to the higher pressures that the tanks run at (3300-3500 psi) which dictates the need for a more secure connection between tank and reg. Now, given what I have just said consider this: Pressed Steel just came out with a new series of tanks (the "E" series) that runs at higher pressures than their low pressure steels that have been so popular. Some refer to these as HP tanks, some don't. These, however, have a 3/4 neck size. these tanks don't ship from Pressed Steel with a valve (typical for tank companies). I would not recommend getting a yoke valve for this tank. Get a 300 Bar DIN.

Look at the diveriteexpress link below. That is the generic adapter that spins on to any regulator DIN fitting and will allow the reg to mate to a yoke valve. Again, many companies have something like this, but these are very simple devices that all look and work the same. The fill block (as shown in the GMC link) is meant for filling and, strictly speaking, should not be used to load a tank past 3000 psi (but this is done all the time - sometimes the fill station doesn't have a dedicated DIN fill whip and someone wants a >3000 psi fill).

The DIN fitting on the ATX200 is very easy to install and, when needed, switch out for the yoke fitting as needed (for example, a warm water trip someplace). Or get a spin on adapter (again, see the diverite express link above) and its a no brainer. The only disadvantage to the spin on adapter is that it makes the reg stick out a bit more than I like, but it's not a big deal at all.

I would like to offer a piece of unsolicited advice: don't buy just 1 tank; buy tanks in even numbers. Rarely will you do doing a dive outing where 1 tank will be sufficient. Buying 1 will still mean you need to go to the dive shop to rent a tank, or make other arrangements, so no headaches are saved there. Plus having an even number of tanks that are the same size allows you to better plan your dives and track your air consumption. Ideally you and your buddy are diving the same size tanks, but that's a different discusion.

As Jason was saying, don't be scared of the DIN fitting. I own like 9 tanks and have DIN on everything except an old steel 72 that I use for purging my suit with Argon before big dives.

Let me know if I've confused you more or if you are getting a clearer picture.


You lost me on that last reply?

So far I've learned one important thing if going the route of HP100's, Make sure they have a 3/4" neck so a Yoke valve can be directly used (right)?

And no, I don't plan on doing any dives with a DIN->Yoke fill adapter screwed on the tank!

My [albiet quick] search for a primary reg Yoke->DIN converter didn't turn up anything that looked safe/sturdy enough to consider using. I'll keep looking and if anyone comes across such a thing I would be interested.

I believe the item 'beeger' listed was the opposite of what I am looking for unless I missed something here.

If it helps any, I have a decent reg (ATX200) w/Yoke fitting. I think the only way I should even consider using it with a underfilled (3000psi) HP100 is with a directly installed tank Yoke valve.

The alternative isn't that bad. The money needed for (1) HP100 almost buys (2) AL80's. The HP100 just seemed like such a nice all round choice and good long term investment.
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[jasondbaker]

You need to own 2 tanks minimum for local diving. I'd say that 4-6 tanks is the sweet spot. You could dive for a weekend with 4 tanks.

[BLT]

Hi,

I wanted to write a quick note of thanks to David at SD&T. I stopped in Saturday and he took the time to explain (and show me) the different tank neck thread sizes. He also also pulled out the different valves (Yoke, 200BAR DIN and 300BAR DIN) and I was finally able to make sense of the 200BAR DIN -> Yoke insert that several people were mentioning.

Of course there was plenty of info about HP100 vs other tank choices. This information really helped me in deciding what to do in the short term. And now I think I have a good long term strategy when it comes to tank types, valves and regulator connections. Thanks again to David and SD&T. The same goes to everyone here who posted to help out,

- Brad