2007-10-27 03:59:35 · 6 answers · asked by Ariel F 1 in Science & Mathematics ➔ Chemistry
The air is compressed NOT to increase volume of the tank (although it does). A diver needs the higher pressure just to be able to breath. If the tank was only pressurized to 1 atmosphere (the air pressure at sea level), once the diver was more than a few feet under water, his lungs would not be able to expand against the pressure of the water. (This is an easy experiment to do in a swimming pool – take 3 foot of garden hose and use it like a snorkel; go down 2 feet and try to take 1 breath – you can’t!)
The second stage of the regulator holds a rubber flap that senses the pressure of the depth of water and equalizes the air pressure from the tank so the diver can breathe.
The tank has to have, as a minimum, pressure equal to the depth he is diving at. A tank that is down to a few hundred pounds might be worthless below 100 feet, but could last some time at 20-30 feet, just due to the reduced pressure of water at that depth.
When I dive, my main tank has 80 cubic feet; my Spare Air (emergency bottle) has less than 2 cubic feet. While their volumes are vastly different, they both work at sporting depths because the tank pressures can overcome the water pressures (until the pressure drops to the point where it can’t overcome the water pressure)
2007-10-27 04:57:18 · answer #1 · answered by Thomas K 4 · 0⤊ 0⤋
It's compressed so that a larger amount of air (NOT oxygen) can be taken underwater. There are several sizes of tanks, and 2 main materials used to make them - steel and aluminum. Steel tanks are pressurized to a max of 2475 PSI when new, and 2250 PSI after they are 5 years old. Aluminum tanks are pressurized to 3000 PSI. Visual inspections are done every year on all scuba tanks, and every 5 years a hydrostatic test is done. In this test, the tank is pressurized to 5/3 it's working pressure. The diameter of the tank around the middle must not expand above a set limit, or the tank is unfit for use, and marked as "condemned".
2007-10-27 04:11:51 · answer #2 · answered by Ralfcoder 7 · 1⤊ 1⤋
1st, it's not Oxygen, it's compressed air.
It is compressed in order to give a much greater volume of air when at the pressure at which it's to be used by the body when submerged. It will last much longer (generally up to 30 minutes or more depending on the size of the tank and the air pressure in it). It's usage is controlled by a 'Regulator' which allows air to the diver as required at the pressure needed governed by the pressure of the water at the level of the diver below the surface.
2007-10-27 04:24:21 · answer #3 · answered by Norrie 7 · 2⤊ 0⤋
Gas is compressed in order to fit more volume into a more compact space. The diver can stay down longer.
2007-10-27 04:06:03 · answer #4 · answered by Anonymous · 1⤊ 1⤋
Because if it were not compressed the tank would only hold enough for two breaths.
2007-10-27 04:04:26 · answer #5 · answered by Michael B 6 · 0⤊ 2⤋
cus its lit
2016-08-30 13:26:58 · answer #6 · answered by Theresa 1 · 0⤊ 0⤋