My urge to own a steel tank ...

[BluewaterSail]

Thanks LowViz!

Seems like thats crucial info to know before buying steel tanks!

I have used another diver's 300 bar steel tank before, so I know my reg's OK with it. (Scubapro MK25)

So if someone was going to use a 200 bar steel tank, the only advantage over aluminum would be the extra weight to compensate for bouyant exposure protection. Right?

 

[JustinRochefort]

You need to look at manufacturers specs on any steel tank, Some 8" steel tanks will be positively buoyant at the end of a dive while others will be negative. Also the diameter makes a big difference in buoyancy seeing as a 8" tank will displace more water then a 7.25" tank thus the 8" is more buoyant.

Nice thing about having 200 bar valves is even though you might be din, your buddy who is still yoke can use your tank ( as long as you have the insert.) Plus 300 bar takes forever to screw in. You can also save your 200 bar from getting dented and being useless by putting in the yoke plug after use. I guess you could do the same with 300 bar, but they don't come with the insert so you wont tend to have it handy.

Also consider LP tanks, they are a bigger for the same CF but can be filled by any dive shop and should you happen to get a little over fill you will have even more CF. Over fills on 3442's are rare after they cool down. I wouldn't ever expect more than 10% over fill, and that's on a + rated tank.

 

[lowviz]

...//...So if someone was going to use a 200 bar steel tank, the only advantage over aluminum would be the extra weight to compensate for bouyant exposure protection. Right?

The one answer that always works in scuba diving is "It depends".

Here goes:

Forget the "deco" or "tech" labels in the upcoming link. Here's the deal: Gear tips and recommendations « Doppler's Tech Diving Blog

1) Pool time! Get suited up in <only> exposure protection and fins, dump air, exhale (completely, but "comfortably" so) and figure out how much lead you need to sink to eye level by clipping on (or holding) known value lead weights. Write this number down in your log book noting carefully what you were wearing.

Second exercise:
2) Suck the air out of your BC or wing, attach to tank(s) down to only 500 psi and weigh your rig as in the above link.

3) Done.

#1 tells you how much additional weight you need to hold your safety stop. Compare this to the weight that you come up with in #2.

If the weight in #2 is not enough, the difference is what belongs on your weightbelt. If the weight in #2 is too much, the difference is how overweighted you are.

Starting here, add/subtract weight in two pound increments based on diving comfort. -Spot on in no time.

 

[BluewaterSail]

The one answer that always works in scuba diving is "It depends".

Here goes:

Forget the "deco" or "tech" labels in the upcoming link. Here's the deal: Gear tips and recommendations « Doppler's Tech Diving Blog

1) Pool time! Get suited up in <only> exposure protection and fins, dump air, exhale (completely, but "comfortably" so) and figure out how much lead you need to sink to eye level by clipping on (or holding) known value lead weights. Write this number down in your log book noting carefully what you were wearing.

Second exercise:
2) Suck the air out of your BC or wing, attach to tank(s) down to only 500 psi and weigh your rig as in the above link.

3) Done.

#1 tells you how much additional weight you need to hold your safety stop. Compare this to the weight that you come up with in #2.

If the weight in #2 is not enough, the difference is what belongs on your weightbelt. If the weight in #2 is too much, the difference is how overweighted you are.

Starting here, add/subtract weight in two pound increments based on diving comfort. -Spot on in no time.

Thanks for taking time for the long answer, but thats not what I meant. I did not ask if it could substitute for all of the lead, I asked if there was any advantage to using a steel tank with the same pressure rating as an aluminim tank, besides the extra weight.


Great Steve Lewis article. I loved his book too. Thanks.

 

[lowviz]

Corrosion (constant exposure to marine environment -aluminum supposed to be better if any chance of saltwater entering tank), Overfilling (I'm not going there...), Lifetime (steel supposed to be better) -for the typical diver, weight is the big issue.

 

[Sheri SGR]

If you own all your other gear than having tanks ready to roll at a moments notice makes sense. Buying your own steel tank will also allow you to drop lead (assuming when you rent you get the normal AL80) and that's always a plus. Once you buy it, the annual maintenance/expense is minimal. The HP steel 80 tanks these days are so much more compact than AL80 that the size factor could also make diving more enjoyable for you (no more tanks hit your head and hanging below your butt)

 

[elan]

Thanks for taking time for the long answer, but thats not what I meant. I did not ask if it could substitute for all of the lead, I asked if there was any advantage to using a steel tank with the same pressure rating as an aluminim tank, besides the extra weight.

.

Im not aware of steel tanks at least in NA with the same rating as AL. Can you elaborate?

LP is rated to 184 bar HP to 242 AL to 206. All of them can have a 200ba r valve. Tha "rating" of the valve does not mean it can handle 200 bars only.

 

[Bob DBF]

Im not aware of steel tanks at least in NA with the same rating as AL. Can you elaborate?

Faber still sells a mid pressure tank 3000# service (3300 with +) but is only 71 cuft. Great little tank, I like diving them, would take me back to the old steel 72's except I still dive them as well.

I also ran across Faber mid pressure tanks 3180# service at 100 and 120 cuft but not in person.




Bob
----------------------------------------
I may be old, but I&#8217;m not dead yet.