Air cylinders

[TheHuth]

Does anyone have a link to a good write up regarding air cylinders? I hear allot of people talk about aluminum 80's, and high pressure steel. Clearly there is some substantial differences between the different sizes, and alloy used. I'd like to educate myself on the topic.

 

[Troyscolwell]

I am quit interested also, that is the last thing I need to complete my kit.

 

[They call me Tater]

Try XS scuba they have a decent one on their Web site. Or seach this site as it has been discussed a few time.

 

[TheHuth]

I just found a pretty good article that sums it up.

http://scuba.about.com/od/equipment...ce-Between-Steel-And-Aluminum-Scuba-Tanks.htm

 

[lerpy]

Dive gear Express www.divegearexpress.com also do good gear write ups, and they have a tank chart showing all the steel sizes, and full and empty weights and buoyancy.

Personal recommendation, seriously consider steel, very nice dive characteristic, the weight allows you to take some weight off your body, and with most being negative when empty make for better buoyancy when completing safety stops, plus you can get more air in which means more dive time ( size and pressure dependant of course)

 

[CuzzA]

The most general way I can explain the two is...

• Aluminum is cheaper than steel.
• Steel will likely last longer than aluminum.
• Steel is typically heavier than aluminum.
• Steel tanks are usually neutral or negative when empty, whereas most aluminum tanks will be positive requiring excess weight.
• Steel has more options for larger volumes.
• Low pressure steel tanks can be safely overfilled increasing the volume of air.

If you're in the market for buying your own tanks a good rule of thumb is 10 cu. ft. per 10 fsw. So if you think most of your diving will be deep I would consider bigger steel tanks. A benefit of overfilled low pressure tanks is you can squeeze more air in and you will rarely ever get a short fill. This of course assumes a dive shop will give you cave fills. Aside from that, the buoyancy characteristics alone were enough to convince me to buy steel tanks.

Personally I decided on Faber 112's. My shop fills them to 130 cu. ft. or 3100 psi. They are slightly negative at the end of a dive allowing me to remove 5 lbs. of lead.

Hope this helps.

 

[The Chairman]

The safety of over filling LP tanks is dubious at best and many would disagree. It is very common in cave country, hence the term "cave fills". Most LDSs will not give you cave fills.

 

[lerpy]

The safety of over filling LP tanks is dubious at best and many would disagree. It is very common in cave country, hence the term "cave fills". Most LDSs will not give you cave fills.

LOL check my post in Cave Diving, have some questions about that.

 

[CuzzA]

Yes, I probably should have clarified that.

 

[The Chairman]

Make no doubt about it: I love me my cave fills. That doesn't make them universally accepted or safe.