How Scuba Regulators Work
Scuba regulators reduce the air pressure from the tank to ambient pressure to allow us to breathe underwater. The regulator is in two stages; the first reduces the tank pressure to an intermediate pressure; the second stage, which is usually incorporated into the mouthpiece in modern recreational scuba equipment, reduces it further so that we can breathe at ambient pressure.
Scuba regulators provide air on demand; that is to say that when the diver breathes in the demand valve is opened to provide air and when the diver exhales the air demand valve is closed and the stale air is vented into the water.
Scuba Diving - Decompression Sickness (dcs)
Getting decompression sickness while scuba diving is not an enjoyable experience. Decompression sickness was encountered when Brooklyn Bridge was being built. DCS affected the workers on the Brooklyn Bridge site who had to spend many hours near the bridge supports in compressed-air filled chambers (caissons) underwater. Upon surfacing, they suffered from abdominal cramps, joint pain, and in some cases death.
Let’s try and understand what causes decompression sickness while scuba diving. As the diver descends, he breathes in the nitrogen in the air through the tank. This nitrogen dissolves in the blood. While the diver is ascending, the lowered pressure causes the nitrogen to come out of the blood, forming small bubbles. To prevent these bubbles from becoming bigger, they need to be either re-absorbed into the blood stream or exhaled out through the lungs.
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