Air Tanks and Regulators
One of the key aspects that makes underwater diving possible is the fact that divers take their air supply with them. As we learned in earlier lessons, air can be compressed. The air tanks that divers use contains compressed air. This way, they can take air with them on the dive that will supply them with oxygen while they’re underwater. Air tanks come in a variety of sizes, but most are 50, 71.2 or 80 cubic feet. The larger ones hold about as much air as a typical walk–in closet crammed into a space about two feet long and six inches in diameter! Air under this dense can generate a pressure up to 4000 pounds per square inch! Most tanks, however, range from 1800 — 3000 psi.
The device that is connected to a diver’s air supply is called a regulator. A regulator delivers air to the diver at the same pressure as the surrounding water. Thus, a diver who takes a breath at 33 feet (2 ATA) is breathing twice the amount of air that he or she would in the same breath at the surface. Another key function of the regulator is that it reduces the pressure of the air that the diver breathes from the high pressures in the tank.
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Lesson design by Lucas Gillispie.