One of the most important components in a self contained underwater breathing apparatus is its air regulator. Scuba diving regulator allows the diver to comfortably breathe in air at ambient pressure while allowing used air to be expelled. This is why scuba diving regulators must be taken care of properly, otherwise, it might fail to function which could be fatal if such malfunction would happen several meters deep underwater. Regular maintenance of this important breathing apparatus component must be performed. Aside from this, periodic examination of its main function should also be done, especially before you swim underwater with it, to assure you that it is still working properly. But how do you really properly care for your scuba diving regulator? One of the most important steps in scuba diving regulator care is ensuring the dust-cap and the seal are dry before you rinse them off the tank. This is because you do not want any water to get into the second stage regulator otherwise, corrosion may result which could definitely damage your lungs. You may want to blow the water off the dust-cap with pressurized air from your cylinder or you can pat its surface with a clean and soft towel. Once it is properly dry, you can now put a tight seal on it so as to prevent any moisture or water droplets to get into the first stage. Then soak the sealed scuba diving regulator in a rinse tank and swoosh it around a little bit so that loose particles will fall out. While it is still inside a rinse tank, try to move the levers back and forth to get rid of any particles which may have adhered to it while you were swimming underwater. However, take care not to push or move the purge button because if you do so, you run the risk of letting water into the regulator's second stage which, in turn, might seep into the second stage and cause some corrosion to form. You definitely would not want that to happen. After this, put the scuba diving regulator under a strong stream of water to take off any remaining particles which you were not able to dislodge in the rinsing tank. Before you do, however, make sure once again that the dust-cap is tightly in place and take care not to touch or push the purge button. Then, take off the excess water residue by carefully tapping it with a soft towel and let it dry in a warm and clean area but never under direct sunlight. Store your scuba diving regulator in a cool and dry place. Also make sure that the hoses are positioned in a way that there are no twisted or bent portions. Habitually giving your scuba diving regulator proper care is a step in the right direction. By doing so, you will be assured that it will always be in good condition.

The basic issue of diving is the pressure of the surrounding water in which we are diving. Dive down to just 10 metres and the ambient pressure is double what it is on the surface. Go down to the 30 metres recommended to Advanced Open Water divers and you are experiencing 4 times atmospheric pressure.

This is a huge variation in air pressure and with just a slight change of air pressure we would be unable to expand our lungs and suck in air. Therefore, the regulator needs to provide air at around the pressure of the water around us.

But on the other hand, at the surface when you test your air supply you could be sucking in air from a tank which is at a pressure of 200 bar - that's 200 times atmospheric pressure. If you were to breathe air at this pressure your lungs would explode.

So the job of a diving regulator is to provide the diver with air at the same pressure as the water around the diver, for comfort and safety.

And this takes place in two stages and the names are the big clues to how this work - with a first stage and a second stage regulator.

The first stage regulator attaches to your tank and reduces the air pressure to a pressure that is higher than you are likely to need, whilst low enough to be safe within the high pressure tubing that goes between the stages.

The second stage regulator takes in the lower (but still too high) pressure air and reduces it to the the same pressure as the water around you. This means that it is perfectly easy to breath in and very comfortable.

But, how does it do this?

Well in each stage there will be a piston or a diaphragm. Whichever is used is probably not really of interest to the diver, but basically the high pressure air on one side pushes it open, whilst it is assisted on the other side to close it when the pressure is sufficient. Therefore, the valve opens slightly to allow some air in, which raises the pressure (or example in the tubing) and once that hits the desired pressure it is assisted to close the valve, until the pressure is reduced (by the diver breathing in), which starts the process moving again.

Both stages use the same basic techniques, with the second stage being opened by the pressure of water pressure, which is what converts the air to a breathable pressure.