Title: Scuba Diving Regulators (First and Second Stages)
Headings: How a Scuba Regulator Works
How a Scuba Regulator Works
What a Scuba Diving Regulator Does
The purpose of a scuba diving regulator is to reduce the high pressure air in a scuba tank to a breatheable pressure on demand.
Regulator Terminology
How Regulators Work
The Regulator First Stage:
The Regulator Second Stage:

Content: Since the ambient pressure changes as a diver changes depth, scuba diving regulators must adjust the air delivered to ambient pressure as a diver ascends and descends. How Regulators Work
Scuba regulators reduce tank pressure in two steps. The first step of pressure reduction is from tank pressure to intermediate pressure, and the second step of pressure reduction is from intermediate pressure to ambient pressure. The Regulator First Stage: The first stage reduces air at tank pressure to intermediate pressure and releases the intermediate pressure air into a hose which feeds into the regulator's second stage. The way the regulator first stage reduces tank pressure is ingenious. A first stage consists of two air chambers separated by a valve. When the regulator is not pressurized this valve is open. When connected to a tank, air from the scuba tank flows into the first chamber, through the valve, and into the second chamber. The valve between the two chambers stays open until the air in the second chamber reaches intermediate pressure.