Buying and Using Scuba Regulators Tips
Scuba diving requires us to breathe compressed air underwater. Our scuba tanks hold high-pressure air, at about 200 Bars/ 3000 PSI at the beginning of the dive, which is virtually impossible for us to breath. Scuba regulators reduce that high pressure to match the surrounding water pressure, which increases as we descend deeper and deeper. Scuba regulators also deliver air only on demand, meaning it will not deliver air when exhaling and are also known as demand valves.
How do scuba regulators work?
Scuba regulators are composed of two different parts: a 1s stage, and a 2nd stage. The 1st stage connects to the scuba tank and reduces high air pressure from the tank to an intermediate pressure, around 7-10bar/100-150 PSI above the ambient (surrounding) pressure. Air pressure is further reduced, up to ambient pressure by the second stage, which we breathe from allowing us to breathe easily and comfortably
Piston scuba regulators-
External water pressure presses on a piston. Upon inhalation the piston lifts up a valve, which allows the flow of high-pressure air from the tank until the piston is pushed back and closes the valve. External water pressure presses directly on the pistons seal.
Piston scuba regulators are considered simpler and easier to make and maintain as they have few moving parts, though due to the direct contact with surrounding water require careful care.
Diaphragm scuba regulators
To simplify, the main difference is these scuba regulators have a diaphragm that flexes and presses on a rod that triggers movement. As the diaphragm acts as an environmental sealing, these scuba regulators have less chances to get sediments, salt and other contaminating particles in them, thus are less prone for internal corrosion and contamination, and in cold water where water might freeze over the 1st stage. As this type of scuba regulators have more moving parts they might take longer to fix, and might be considered less reliable.
Balanced vs. Unbalanced 1st Stages in Scuba Regulators
Both 1st stages designs can be balanced or unbalanced, which refers to changes in performance as dive time go by and tank pressure drops:
Balanced 1st stage:
the 1st stage performs the same through changes in tank pressure. Makes out for the majority of scuba regulators.
Unbalanced 1st stage:
as tank pressure drops there’s a slight variation in the scuba regulators performance. These scuba regulators are generally cheaper.
Tank connection can be either DIN or yoke, depends on where you dive.
Scuba Regulators 2nd stage
This part of the scuba regulators regulates the amount and pressure of air delivered to our lungs.
Inhaling through the mouthpiece you pull a diaphragm that flexes inwards and pushes on a valve that releases air. A purge button allows you to operate this mechanism manually.
When exhaling air pressure coming from the 1st stage rises, the diaphragm flexes back and the valve closes
Most 2nd stages are designed that way. Some have the diaphragm and purge button on the side or rear. This way there’s no right side up or down, though this design is more prone to drizzle.
What is a complete scuba regulators set?
When buying scuba regulators you buy a 1st stage and a second stage.
To complete a scuba regulator set, a diver needs a SPG (submersible pressure gauge) that allows us to monitor our air pressure and plan our dive according to it. You can add a depth gauge, a compass or a dive computer on a complete console.
Finally, when diving we need an additional air source to provide in the very unlikely event to a diver in need. This may come as an additional second stage attached to your 1st stage, and will normally have a longer hose and is displayed by bright colors to be found easily.
Some divers add a pony tank, a small scuba cylinder with its own regulator that adds additional air supply for you buddy and even for you.
Scuba regulators care and maintenance:
Scuba regulators need to be stored properly:
Avoid dust, sand and direct sunlight. Make sure the hoses aren’t bent- allow gentle curves to the hoses. Finally a regulator is better stored laying flat rather than hanged by its 1st stage.
Scuba regulators and Nitrox:
Generally, scuba regulators may be used with air blends up to 40% O2.
Gas mixture with more than 40% requires regulators to be cleaned to oxygen service specifications and made of O2 compatible materials.
-Follow manufacturer’s guidelines before using scuba regulators on enriched air dives.
Scuba regulators purchasing tips:
-If you dive regularly, have your own, as a reliable regulator makes a huge difference on a divers safety and comfort level.
–Scuba regulators come in a huge array of prices, buy the one you feel comfortable with, even the more affordable ones are highly reliable after all.
-If you dive a lot, especially in cold conditions or ones full of sediments, it’s worth spending a few more bucks and has an environmental sealed, balanced 1st stage regulator.
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