The Anatomy of a Regulator

Regulators or Regs are comprised of 3 main components:

The First Stage

As we’ve already mentioned your first stage connects directly to your tank. It was never going to be that simple though, was it?

First Stage Fittings

There are two types of connections used to attach your first stage to your tank

• A-Clamp or Yoke fittings are by far the more common fitting and have been around since the beginning of modern SCUBA. While they’re perfectly safe, A-Clamp fitting are limited to 232 bar tanks and can’t be used with 300 bar tanks at all.
• While A-Clamps have been the prevalent design in diving they’re beginning to be replaced by the more modern and safe DIN fitting. DIN connections are lighter, allow for much higher air pressure and are less bulky and are less liable to small leaks, while can occur with A-Clamps slightly less secure fitting.

Luckily a technician can convert your DIN regulator to A-Clamp and vice versa, so your decision isn’t final. Similarly, you can adapt DIN regs to A-Clamp regulators with an adaptor, and we’d recommend going down this route as it provides the greatest flexibility and performance.

Balanced Versus Unbalanced Regulators

One of the choices you’ll make when buying a regulator is whether to purchase a Balanced or Unbalanced regulator. In this past this used to be a big choice. Balanced regulators were expensive and performed significantly better at depth. These days that gap has been bridged somewhat and should pick whichever you prefer - though most people err towards balanced regs because of their easier breathing.

• Unbalanced regulators are affected by water pressure, increasing breathing resistance as you descend. More significantly, as the gas in your tank becomes depleted breathing effort also increases. Some divers like this as it gives them a heads-up when they are running low on gas (it’s never an excuse to not check your gauges though!)
• Balanced regulators provide a more consistent supply gas regardless of depth or how much gas is left in your tank.
• There is a third option called ‘overbalanced’. These regulators increase the flow of gas as the diver descends further making them ideal for deep diving. These systems can be prone to freeflow due to their increased sensitivity, so like any tool, they take a little bit of adjusting too.
• All current Diaphragm Regulators are Balanced or Overbalanced.

Piston vs Diaphragm Regulators

Most divers shouldn’t get too worked up about whether their first stage uses a piston or diaphragm design to reduce the incoming gas pressure. The difference in performance is negligible - Piston regulators offer minor performance benefits at depth while diaphragm regs can be sealed more easily, making them suitable for cold water diving or in silty, contaminated conditions.

Environmentally Sealed First Stages

We’ve touched upon this very briefly already, environmentally sealed first stages are sealed to prevent water and silt getting in. This prevents the first stage from freezing open in cold water, which results in a freeflow (When your regulator sticks wide open, making it feel like you’re breathing in a jacuzzi). Secondly, it stops silt, bacteria and dirt getting into your system, meaning it needs less maintenance, cleaning and is potentially safer.

Unless you’re flying light with your regulator to dive in tropical waters where none of these issues are a concern we’d recommend an environmentally sealed regulator.

Balanced vs Unbalanced

You might come across the question of balanced and unbalanced second stages, luckily all modern second stages are now balanced in design - that's one thing less to think about!

Opening Effort Control/Cracking Adjust

Opening Effort controls are less common than venturi controls, and if you regulator doesn’t have one, this is set by a diving technician during setup/servicing. Opening effort works by adjusting the spring load of the mechanism within your second stage. In laymans terms this allows you to fine-tune how hard or easy it is to breathe through your regulator.

Octopus

Your Octopus fulfils the role as a backup gas supply should your primary second stage fail (this is thankfully extremely rare!). It functions in exactly the same way as any other second stage, delivering breathable air to your mouth. Unlike your second stage they’re highlighted in bright yellow to ensure they’re visible in low light. They also have much longer hoses allowing your diving buddy to access it easily if they get stuck.

Generally you don’t need a flashy Octopus so they’re typically cheaper, and less highly spec’ed in comparison to your Primary 2nd Stage

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