When learning about diving you are shown the diving equipment and how to use it, but often left unexplained is exactly how each component in you dive kit works. But this knowledge comes handy when you are looking to buy your own dive gear, as it’s not the cheapest purchase and you’d want to make an informed decision to suit your needs. Our Scuba Gear Articles are aimed at doing just that, helping you with all the information you need to Buy Scuba Diving Gear & Equipment.
The most important and key piece of any divers equipment is the Regulator. A diving regulator is the lifeline between the diver and his air source (Scuba tank) underwater. This breathing apparatus that is the regulator and tank, are the only means of a person breathing underwater. In other words they are what makes SCUBA Diving (which stands for Self Contained Underwater Breathing Apparatus) possible at all.
The primary function of a scuba regulator is to decrease the high pressure under which the air in your dive tank is stored, to a much more reduced and safer pressure level which you can breathe at any depth. For this purpose Scuba diving regulators work in two stages-
First stage: Air is compressed and stored in the tank under high pressure, about 3000psi. In order to reduce this pressure, the first stage is a valve or piston that lowers the pressure to about 140psi to let air into the hose. The valve opens to let some air into the hose and then closes again. A regulator compensates the pressure as it decreases in the tank when air is used and as the diver changes depth which causes change the ambient water pressure.
Second stage: The second stage of a scuba regulator is basically the part that goes in your mouth and delivers air upon demand. It contains a mechanism that reduces the intermediate pressure in the hose coming from the first stage to the surrounding water pressure making it comfortable and easy to breathe. Like in the first stage, the second stage also contains a piston or diaphragm construction which starts and stops the airflow. The mouthpiece, an exhaust valve and an emergency purge valve/button are all parts of the second stage. The exhaust valve lets the air escape into the water when you exhale. It is a one way valve and does not let water in. When the purge button is pushed, it forces air to flow continuously into the second stage chamber forcing any water out of the mouthpiece through the exhaust valve.
Diving regulators also come in different types using slightly different mechanisms. They can be balanced or unbalanced, piston or diaphragm and use a yoke or DIN clamp we take a look at these terms and regulators in ‘How to Choose a Diving Regulator’.