Very Basic Considerations When Buying a Regulator
Under water, your life depends (literally) on the scuba regulator you use. Although all regulators do the same job, not all of them are equal. When selecting the most suitable regulator for your needs, the choice depends on several factors such as your budget, level of qualification and diving experience, and the conditions in which you plan to dive.
There are several different types of regulators depending on the various operating mechanisms and variety of features they have. The very basic designs one should take into consideration when purchasing a regulator are as follows:
Balanced v. Unbalanced Regulators
A balanced regulator is always the preferable option. Most entry level regulators are unbalanced. The more expensive regulators are generally balanced. This sounds significant; however, at depths of 20 meters or less, the difference between the two is hardly noticeable.
Balanced regulators compensate for depth and decreasing air tank pressure by equalizing the air pressure on both sides of the valve. An unbalanced regulator will make breathing harder as depth increases and/or tank pressure decreases.
A question that is sometimes asked is, why are all regulators not balanced? One factor is the cost involved, from the manufacturing perspective, and from yours as the buyer.
If you can possibly afford it, always choose a balanced regulator. It will certainly improve the overall quality of your dives.
Piston v. Diaphragm Regulators
These terms refer to the way the first stage of your regulator reduces tank pressure to an intermediate pressure.
Piston Regulators offer a greater air flow rate and generally have only one moving part. They are normally more expensive, but their overall maintenance cost is lower.
Diaphragm Regulators have several moving parts. They are less costly to manufacture, therefore tend to be cheaper. Diaphragm Regulators are often used in cold waters, as they are less likely to free flow in a cold environment.
There are some other features that should be considered such as the type of coupling fitting that attaches a regulator 1st-stage to the tank and the number of ports to accommodate hoses and other attachments.
There are basically two different types of fittings, yoke type and DIN type. Yoke is perhaps the most common around the world. However, a DIN style regulator can be equipped with a yoke adaptor or a yoke style regulator can be equipped with a DIN adaptor.
Ideally the regulator should be equipped with 2 high pressure ports and 4 low pressure ports.