Scuba Regulator Selection Guide – II

Are you looking to purchase a Scuba Regulator? Choosing a Scuba Regulator is not as simple as it may seem, there are so many different types of regulators to choose from, that we decided to put together a few tips and explanations of commonly used terms in Scuba Regulators to make the selection process a little easier.

Side Vented or Front vented?

While not a serious deal breaking decision, there are some models of regulators out in the market that offer second stage exhaled gas venting from the side of the regulator instead of the front which is usually the case. Side vented regulators prevent exhaled bubbles from obstructing your view during ascents and descents offering divers a cleaner view.

Cressi XS2/AC2 Piston Regulator

Piston or Diaphragm?

The first stage of a regulator may contain either piston or diaphragm mechanisms to regulate the intake of air into the medium pressure chamber and the second stage. The Piston type contains a mechanical piston that sits atop of the air intake valve, and as the diver breathes from the second stage, the piston rises and allows air to enter the medium pressure chamber ready for the diver’s next breath.

Diaphragm type regulators are more complex and are environmentally sealed which is why they are used more for cold water divers and for divers in silty and high particle content waters.  The diaphragm is a flexible cover over the air intake valve that flexes in-ward or collapses as air is breathed in from the second stage allowing air to rush into the medium-pressure chamber of the first stage.

Piston regulators are said to have better flow rates since there is only one moving part, the piston, however performance wise most differences in flow are hardly significant enough to draw up a comparison. diaphragm regs are more suitable to diving in extreme conditions such as dirty water or cold water due to their “sealed” design.

So which one is better Piston or Diaphragm? Perhaps in the past there was good enough reason to select one over the other, but in today’s world, both types of regulators have seen extensive development and as it stands now, there is no compelling reason to select one over the other.

Aeris AT 400 Pro DVT Regulator Diaphragm First Stage

Un-Balanced, Balanced or Over Balanced?

These terms refer to the parts used in the first stage of regulators and mean the following-

An unbalanced regulator uses fewer parts. As a result it sacrifices a bit performance at lower tank pressures and at deeper depths. It’s mainly suitable for very basic diving. An unbalanced regulator will become harder to breathe from as depth increases and or tank pressure decreases. Usually un-balanced regulators are offered on the base models of regulator product-lines.

A balanced regulator uses more parts in the first stage of the regulator to ensure that it delivers the same amount of air at all pressures and depths. So the performance of such regulators is consistent at all times of the dive and in either shallow or deep waters.

An overbalanced diving regulator incorporates a technology that makes breathing easier as you go deeper. These type of first stage regulators is mostly seen in the top ranges.

What should you go in for? Always try and opt for a balanced regulator and an overbalanced one only if you can afford it.  A balanced reg  is all you would need to meet the needs of recreational diving as it makes breathing resistance less and therefore breathing easier. If you are in to deep diving then an overbalanced regulator will adjust to depth offering you more air the deeper you go.

Aeris AT 400 ION Swivel Regulator Balanced

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