Aluminum vs Steel SCUBA tanks

Once upon a time, the blogger got a new SCUBA tank. Grady asked me if I wanted it set up for Nitrox or just regular. Truthfully, I didn’t even know the tank was mine, it could have been Mark’s for all I really knew… So I sent Mark a text to ask what his plans were for the tank. As I was typing the text to Mark, autocorrect got me and changed Steel to Steve, so the message went out as, Is Steve supposed to be Nitrox. Instead of is the steel supposed to be Nitrox. With that text, so the tank got a name, it will forever be known as Steve the Tank. And there is the rest of the story I said would come out eventually.

Yes, you read that correctly. My SCUBA tank is named. We’ve actually had a lot of fun with that. I guess people name their cars and chairs and tv’s, etc, why can’t I name my SCUBA tank? So, can anyone guess what we’re discussing today? If you guessed tanks, you would be correct. You get the Gold Star for the day. High Five.

Aluminum Tanks versus Steel Tanks

Scuba Tank 101: Steel versus Aluminum Tanks.

5 Considerations for the best Dive Tank for You

  1. Size. How do you breathe? Sometimes that can be a varying factor when deciding if you want to go Aluminum versus Steel. Another consideration would be the size of the person using the tank. Would you really want to put a petite person in a 120 Steel? But there is no hard, set in stone rule as to going Aluminum or Steel. Sometimes it can be personal preference.
    The typical standard aluminum tank is 80 cubic foot while the standard for steel tends to range at 120 cubic foot. The thing is, you can’t always go by those “standards” either. Are you confused yet? Good. Haha. Let’s just say, many of our diver’s here at Extreme Sports Scuba dive with those standards for the given tank. We’ll leave it at that for now.
  2. Material. As pointed out in the previous statement, SCUBA tanks are either steel or aluminum.
    Aluminum tanks start out negatively buoyant when full and as you consume the air, they become positively buoyant. A diver needs to weight themselves accordingly, especially because that positive buoyancy could create issues when doing a safety stop. But don’t let this be a determining fact either.
    With a Steel, you don’t need as much weight. Steel tanks are heavier than aluminum tanks, to begin with. When a steel tank is full of air, it is negatively buoyant. As you consume the air out of the steel tank, it either stays negatively buoyant or becomes neutrally buoyant. But is that added weight of a steel tank worth not needing the extra couple pounds of weight? Things to ponder and consider.
    Aluminum is a softer metal, which leaves a tank more susceptible to dents and dings. A Steel tank is more susceptible to rust in the presence of moisture.
    Steel tanks tend to last longer than aluminum tanks. Steel tanks tend to cost more. Weigh out all the options and talk to us before you decide one way or the other. We’re here to help!!
    One other point to mention about a steel tank, they tend to carry a higher capacity of air. That may or may not be the breaking point as to which way to go though… Just pointing out facts.
  3. Low Pressure versus High Pressure. The pressure in tanks is measured by pounds per square inch (PSI), in the U.S. anyway. Other countries it is measured in the metric system. Tank pressure tends to range between 2400 PSI and 3500 PSI.
    The low-pressure tanks tend to range on the lower end of that scale, between 2400 PSI and 2700 PSI. The high-pressure tanks tend to range between 3300 PSI and 3500 PSI.
    One drawback to high-pressure tanks is they require more metal to maintain the higher amount of compressed air. This means your high-pressure tanks tend to be Steel, meaning the heavier tank. High-pressure tanks mean high volume in a lower capacity
  4. Valves. In open-water classes, we learn that the valve controls your air flow from the tank into your regulator. There are two types of valves we use, a Yoke and a DIN. Yoke valves are the more commonly used valve of the two. People who tend to dive on the high-pressure tanks tend to convert to DIN valves, but this isn’t a requirement.
    When checking your gear for a dive, if the tank valve is extremely hard or extremely loose to turn, the tank needs to be serviced. It is also good to check the valve connection for leaks.
  5. Oxygen Compatibility. The normal air we breathe sitting here on land is 78% nitrogen, 20% oxygen, and 2% other gases. Air that you breathe in your tanks is 78% nitrogen, 20% oxygen, and 2% other gases. It is the same air that we breathe on land, in a compressed version.
    Except. There’s always an exception, right? Those tanks that are set up for Nitrox. As you know, (or maybe you don’t?) Nitrox is set up with a higher percentage of oxygen. There are classes that teach you all about diving Nitrox and why and when you should. Just know that tanks have to be set up special for Nitrox, as well as those valves.
    Tanks that are set up for Nitrox are serviced by professionals and labeled as such. Otherwise, come take the class and we’ll teach you even more about diving Nitrox!
So Aluminum versus Steel.

Do you know which you should and/or would like to dive with? Have we just made your decision more difficult? Come talk to us. We’ll let you hold one. Holding one might help make your decision. But we can play devil’s advocate. I hope you know that means we’re discussing pros and cons of each versus being the devil. Just throwing that out there.



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