Yet another "What tank to buy?" question

[ckharlan66]

UP,

Thanks for the responce, If I go with the 300 can I not use the replacement fitting. (RF)

If I do use the RF how hard is it to switch back to yolk for vacation?

Chad

 

[large_diver]

No one has mentioned HP on this thread.....

PST makes nice HP tanks as well -- and they are lighter (dry land weight) than LP tanks of the same volume....at the same time they tend to be more negatively buoyant.

Not really DIR (if that matters to you), but assuming you can get good fills...these can be a good choice (especially if you do lots of shore diving).

I wish I could find the prices I see you guys quoting for tanks around here. I was in boith of my LDSs last week asking about PST HP 120s -- Bargain price of $379.00.

 

[The Chairman]

As a safety precaution, valves rated to 300 bar are NEVER convertible to a yoke... the depth of the 300 bar would prevent it anyway.

 

[Lost Yooper]

Originally posted by ckharlan66
LY,

If I get the DIN's is there an adaptor for yolk to din so that I don't have to get a new first stage? At least until I do go to doubles.

Chad

If you get 300DIN valves, you have to buy the yoke to DIN convertor for your reg and actually convert your reg to 300DIN. This is very easy -- takes about 2 mins. You don't have to buy a new first stage. There is no way you can put a yoke reg on a 300DIN valve, you have to convert the reg to 300DIN -- no problem.

Mike

 

[Lost Yooper]

Originally posted by ckharlan66
UP,

Thanks for the responce, If I go with the 300 can I not use the replacement fitting. (RF)

If I do use the RF how hard is it to switch back to yolk for vacation?

Chad

You can switch your reg back to yoke in about two minutes. It's very easy to do.

Mike

 

[ckharlan66]

large_diver,

I had thought about the HP but I don't think my LDS could give me a good fill and there aren't alot of LDS's to choose from. But thanks for the advise

Netdoc,

Thanks, I guess that I will have to get yolk valves for now or buy a different reg (not an option). I will have to convert to DIN in the future.

Chad

 

[roakey]

ckharlan66,

Just to reiterate what others have said but all in one place, they’re three options available to you:

1) Some cylinder valves can be changed back and forth to accept either yoke or DIN regulators. The SeaElite 200 BAR valve is one such valve. This is accomplished by screwing in a “donut” (slang, if there’s a proper word for the part I don’t know it ) into the DIN valve threads and gives you a seating surface for a yoke-equipped regulator. The 300 BAR valve’s threads are too deep (by design) such that the donut would screw in too far and not allow the yoke valve to seat against it. Some of the early SeaElite 300 BAR valves also had a sloped back to the valve so there was not dimple to set the yoke screw into either.

2) There is a DIN-regulator-to-yoke-valve adapter (http://www.northeastscubasupply.com/tanks/images/din_yoke_bg.jpg) that you screw onto your DIN regulator so it will connect to a yoke-valve cylinder.

3) Finally, as far as I know all modern regulators are available in both DIN and yoke configurations, and if you have one configuration, it’s a simple matter to buy the conversion kit for the other. These kits run about $50 or so, unless you’re talking Scubapro which must have some a gold inset in the conversion somewhere and is priced accordingly. As LY mentioned, going from one attachment method to another takes a whole two minutes, so this is the path that most folks take, rather than 1 or 2.

Roak

 

[newton]

Have I missed anything here:

200 Bar DIN valve
-----------------
Pros:
* Can be converted to Yoke with an inexpensive insert

Cons:
* 4 threads less, so is a 'stronger' connection
* Can't be used safey on HP tanks

300 Bar DIN valve
-----------------
Pros:
* More threads, so it has a stronger connection
* Can be used on HP tank safely

Cons:
* Requires DIN regulators
* Requires DIN for tank fills

In my opinion, the two cons for 300 Bar DIN are huge. In particular, the only tank fills I can get around here use Yoke, so if I had a 300 Bar DIN valve, I'd have to get a DIN->Yoke regulator converted just to get a tank fill.

Since I plan on using LP tanks (again, I can't even get a HP fill locally), the 200 Bar DIN valves seem to be the way to go.

I'm not convinced the extra 3-4 threads make that much difference in the safety margin. (Despite what the WKPP guys say.)

The arguments *FOR* DIN are obvious, but the arguments that state 200 are bad and 300 are good are much less obvious.

I consider the 200 vs. 300 Bar valvues to be one of those religious issues, kind of like the 1/2" port on a 1st stage should never be used. (I'm with Uncle Pug when I say that the addition of a *single* static O-ring in the 1/2" -> 3/8" converter isn't going to make any difference. There's a much greater chance of getting hit by lighting as I crash my car into a tree that fell down because of old age on my way to the dive site.)

In my opinion, having a 200 Bar DIN valve is *more* than adequate and plenty safe. I'd be willing to bet my life on a 200 Bar DIN valve in the exact same environments as I'd be willing to use a 300 Bar DIN valve. I don't think there is any significant safety margin between the two. (Again, with the assumption of using LP tanks that are not way over-filled.)

The only caveat I have is that there are rumors of cave divers in FL buying LP tanks, then overfill them to 3500 or 4000 PSI. I would *never* consider doing this safe, so if you plan on having your tanks filled to high pressures, by all means go with the 300 Bar valves. But, for those of us that struggle to get good 3000 psi fills, I'll stick with the more 'flexible' valves.



Nate
ps. I will say that the arguments against the OMS valve have some validity, but I'm not sure how much.

 

[The Chairman]

I guess the apple done fell out of the tree again and gave you some great insights! I heartily concur with each and every statement... and I agree that the O-Ring in the OMS setup is "less than optimal".

 

[Uncle Pug]

Originally posted by newton
Have I missed anything here:

Nate....
Now that you have got that off your chest....
Just go ahead and get the 300 bar DIN....
If you need 'splainin' let me know....