The empty weight of a 100 cubic foot steel Scuba tank is approximately 33lbs.
Steel has been used as a tank material since the begining of scuba diving. Extremely durable and useful as a tank material but steel rusts. Buy a steel tank, assume that over the life of the tank it will cost you for a few tank tumbles to remove interior rust. Pay more for a steel tank than an aluminum one. Steel will last (almost) forever if you take care of it. There are steel tanks still in service today that were originally manufactured in the 50s. Aluminium tanks came out in the 70s. It's a softer material, the walls of aluminum tanks are thicker, making them a little larger than steel tanks of the same capacity. The big advantage of aluminum is that it doesn't rust and it's less-expensive than steel. You can find aluminum tanks cheap, for $100-150.
It depends on the size of the tank. The standard tank used at most scuba diving training facilities use an aluminum 80. The tank weighs around 21 lbs. full. As the tank is used during diving it becomes more boyant, meaning that you need to use more weight at the end of the dive then you need at the beginning.
they weight the same if they are both 100 lbs.
the weight of the tank will be about 100 pounds
The diver uses an air tank, which is a tank filled with compressed air. It has a hose that goes from the tank to the mouth, which is held in the mouth by a 'mouth piece'. The tank has a regulator that allows the pressure in the tank to be regulated down for normal breathing.
No. If the water doesn't overflow, then the addition of the fish will increase the total weight of the tank and its contents by 50 pounds.
A very big pool, or a large tank.
the weight of the water above. water in a 1" pipe 100' tall is 43 psi @ base of pipe. water in a 50' tank 100' tall is 43 psi @ base of tank. h x .434 = psi
"A standard 100 lb propane bottle contains 90 litres of propane. " http://www.uniongas.com/business/otherci/techsol/heating/constructionheat/conHeatCostComp.asp
100 pounds per square foot (also denoted 100 psf) is most likely a pressure value. Think of it as having a block of steel 1 ft by 1 ft, weight of 100 pounds, and placing it on a flat surface. The pressure on the flat surface from the block of steel equally distributed over the 1 square foot area is 100 psf.
It depends on the average weight of the steel bars. For example, if they each weigh 50 pounds, then 40 of them will weigh a ton. If they each weigh 20 pounds, then 100 of them will weigh a ton.
Steel vs. Aluminum Scuba TanksThey are both excellent but you need to compare several features. What is the size of tank and the pressure required to get to full capacity. Some dive boats and some stores wont fill past 3000 psi on a tank. I was on one boat that could barely get us to 2600psi. Those divers that required a 3400psi fill on their steel tanks to get to capacity had to shorten their dive times. It used to be a big factor that one tank was more bouyant than another or one less bouyant. Today we have neutral tanks in both aluminum and steel so this is no real factor these days. Even the non neutral tanks dont make that much difference. I both a steel and an aluminum and I carry the same weight either way. Steel is more expensive and can do a 10 % overfill for a period of time. But you need to watch because some say they are an 80 after the overfill. So once you cant over fill you will have a smaller tank. Size for the cu. ft. value I always found the steel to be smaller. So an steel 80 was smaller in size than an aluminum 80. If you were carrying dual tanks this was a great advantage. For the regular sport diver not so much so. Its steel so it can rust. When I inspected tanks it was always the steel tanks I failed because moisture got in, for many reasons, and rusted the tank. Because I cant tell if the rust is new or old and deep they always have to go in and be cleaned and tested with any rust. The aluminum stays at its value start to finish. the 80cu.ft. is standard enough to not worry about some places not filling it and the inspection of the tank rarely finds a fault. Its less expensive than its counter part and comes in more colors. Other than these things I cannot find any reason for one over the other. My preference as an instructor was always to go for the aluminum. Price was better and the look and feel was better. The only people I ever saw benefit from the steel was the deep divers or the dual tank divers. They got more air for the size and the weight difference made big differences at depths beyond the sport diver depths. As for size. An 80 cu. ft. tank can carry most people thru the length necessary for a savfe dive. At 60 feet you have @ 60 minutes time to dive. The 80 cu. ft. will last that long for most people. If you are a heavy breather and can only get 40 minutes at 60 feet then you are a canidate for the 100 or 120 cu. ft. tank. Rent one and see what your bottom times are prior to purchasing. My wife breaths less air than I so I have a 72 cu. ft. tank for her whe we dive together. It failed its testing this year but my aluminum is going strong. Hope this helps. Jonathon, PADI instructor AdditionSteel tanks can always get the "10% overfill" as long as it is requested during its hydrostatic test and if it passes. Steel is a stronger metal than aluminum. It is virtually impossible to put a deep scratch in a steel tank, but it is very easy to do on an aluminum ... which could condemn the tank. Since aluminum is a softer metal, it requires more material to hold the pressure. Because of this, aluminum tanks are bigger than steel (as well as heavier out of the water) to hold the same amount of air. They also have to be pressurized more since the internal valume is less due to there needing to be more aluminum to hold the pressure. An aluminum "80" is not really an 80 and really is more like a 77, so you can not go off of common names to know how much air a cylinder will hold. So to summarize, steel is more durable, lighter out of the water (compared to the same volume aluminum tank), more negative in the water (so you need less weight on your weight belt) and smaller. Of course you can get a steel tank that is larger and holds even more air. The main down side to steel tanks are that they are more expensive, but I find the advantages outweigh the expense. Any rust in a steel tank would be on the inside and only results from bad fills (so go to a good fill station) or draining your tank all the way (so don't do it). The risk of rust is small if they are cared for and any rust can also be tumbled out.