Choosing The Right Regulator Style and Features
Choosing the best scuba regulator is not as easy as picking the first regulator you find on-line for the best deal. It is important for you to understand that all regulator do not perform the same, many perform better than others, and your choice will mainly be determined by the environment and conditions that you will be diving in.
For instance, If you are just a recreational diver, only diving in the tropic while on vacation, you choice in scuba regulator is going to be completely different than if you where going to be diving in 40 degrees water at 130 feet.
But, before you start looking for a regulator, it is important for you to know how a scuba regulator works and what feature are available on the modern-day scuba regulator in order for you to make a more informed decision.
How Does a Scuba Regulator Works?
All scuba regulator has one basic function and that is to decrease the high air pressure in the scuba tank to ambient pressure (surrounding pressure) so that we can breathe comfortably under water.
The regulator achieve this through two stages, the first stage and the second stage.
The first stage is the part of the regulator that attached to the dive cylinder. It breaks down the high pressure of the air in the cylinder to intermediate pressure (120 – 150 psi). It then delivers the intermediate pressure to the second stage via hoses.
The second stage is the part of the regulator that you actually breathe from, it converts the intermediate pressure to ambient pressure (surrounding pressure), which make it easy for us to breathe comfortably underwater.
When choosing the first stage there are a few things that you need to consider.
- Whether you need a piston or a diaphragm regulator
- Whether you want a balanced or unbalanced system
- What type of fitting will you need to attached the regulator to the dive tank (DIN or Yoke),
- The number of ports that you will require
- Whether or not we need a seal first stage
Piston VS Diaphragm
Piston first stages generally have the best flow rate and is the simplest design with only one moving part (The Piston).
Many dive manufactures uses piston first stage as their entry-level regulator, because they are less expensive to make (fewer parts to manufacture), and also as their flagship regulators because of the high flow rate a piston regulator can provide..
Because most piston first stages allow water to come in direct contact with some internal parts, they are not generally consider for cold water diving.
However, advancement in insulation technologies and environmental sealing (more on this below) they are becoming more popular in lower temperature diving.
Another, draw back to this type of fist stage is that they generally cannot be adjusted externally in the field, you will need to take it to a certified service technician to get it adjusted.
Diaphragm First Stages has many moving parts, and in the past has been known for delivering lower performance.
However, many advancement in manufacturing technology have made the performance virtually inseparable from those of piston regulators.
One of the main advantage of this type of fist stage is that the internal parts are generally not in contact with water. This reduces corrosion of internal parts as well as reduce free flow in cold water conditions. This makes it the ideal regulator for cold water dividing.
Another great advantage of this type of first stage is It can also be easily adjusted in the field using simple dive tools.
Unbalanced Vs Balanced
The first stage that you choose can be broken down further into two systems, either an Unbalanced system or a Balanced system.
Unbalanced First stages were the first kind of regulator systems ever developed. They gradually lose performance at greater depths and lower tank pressures. However, due to advancement in technology these changes are hardly noticeable at recreational dive limits.
Unbalanced first stage are used by many manufactures are their entry, this is because they are cheaper to manufacture.
I would only recommend using this system if you have a very small budget, and will only be diving in warm waters, at very shallow depth. (To learn more about how an unbalanced regulator works go here)
Personally, I prefer a balanced system because the movement of the piston does not directly rely on the air pressure in the dive tank, you get consistent performance at any depth and at any tank pressure through out the dive. (To learn more about how Balanced regulators work go here).[important]It is also good to note that all diaphragm regulators are balanced by default. Hence, the reason why you normally find them on the mid to higher price range.[/important]
There are Over Balanced or Hyper- Balanced system, these normally fund on diaphragm regulators. Manufactures claim that they deliver better performance the deeper you dive. However many divers report that the second stage tends to free flow on really deep dives, if they don’t make adjustments to the second stage.
DIN Vs Yoke (A-Clamp) Fitting
They are two basic fitting for you to choose from, either Yoke or DIN. Most popular regulator are available in both fittings.
The yoke fitting is the most common of the two fittings and is mostly used for recreational diving. This type of fitting use a yoke clamp that goes over the tank valve, the regulator is then tighten to an O-ring on the tank valve with a yoke screw to form a seal and present leaking.
DIN is the newer of the two fitting and is generally used in Europe. However, the last few year it has gotten more popular for technical diving, and are becoming more readily available at many dive destinations because convertible valves.
DIN fittings is the safer of the two, because the regulator is screwed into the DIN Valve, and the O-ring is on the regulator which makes the seal inside the valve, as opposed to outside like the yoke.
To permanently convert your regulator from yoke to DIN you will need to take it to a certificated technician, but one of the major advantage of a DIN fitting is that you an easy by a screw on adapter to change it to Yoke if you are diving where no DIN tanks are available.
Number of Ports
Another thing that you must consider as well is the number of ports that you will be need. This is normally determined by the type of diving and dive environment that you will be diving in.
Most regulator comes with 2 high pressure ports (HP), and 4 Low pressure ports (LP).
If you will be doing recreational diving in warm water, you will basically only need 3 LP ports and 1 HP port.
- 2nd Stage Primary (LP)
- 2nd Stage Secondary (LP)
- BCD inflation hose (LP)
- Pressure Gauge (HP)
However, if you will be diving in cold water, and require a dry suit, the extra LP port will come in handy because they require its own inflation hose.
On most regulator these ports are stationary however, some regulators have swiveling turrets that allows you to somewhat customize how you can set up your regulator, to make hose routing more ergonomic and comfortable to dive with.
This feature is most found on first stage that are rated for cold water diving. Basically, it prevents the surrounding water and its contaminants that might wear internal parts, affecting the performance of the regulator, from entering the first stage.
It also prevent the freezing cold water from entering the first stage, which turns reduces icing and free flows during cold water dives.
The Second Stage
The demand valve does exactly as the name implies, it delivers air only when you it.
As you inhale a diaphragm in the second stage puts pressure on the demand lever opening the valve, allowing air to enter the second stage and you to breathe.
The second stage is a lot simpler in designed to the first stage, however there are a few things you must consider when choosing a second stage.
- Unbalanced Vs Balanced
- Venturi Vacuum Assist
- Adjustable Inhalation Efforts
Unbalanced V Balanced
Just like the first stage, the second stage is also available in balance or unbalanced, and have pretty much the same advantages when it comes to performance.
An Unbalanced second stage will lose some performance at deeper depth and lower tank pressures, whereas a balanced regulator will deliver consistent performance at any depth or tank pressure.
However, one of the major advantage of an unbalanced second stage is it uses a downstream valve. It is simpler in designed, and have less moving parts, and in the event it fails, it is always in the open position allowing you to still breathe from the free-flowing regulator.
Venturi Inhalation Assist
The Venturi system controls the air flow inside the second stage to form a vacuum behind the second stage diaphragm that further opens the valve without any additional inhalation effort by you.
In some regulator this feature can be fixed, however most second stages allow you to adjust the Venturi setting using a knob.
In the Min. or Pre-dive setting the Venturi system directs airflow towards the diaphragm, which helps to keep the valve closed. In this position, it helps prevent unwanted free-flow on the surface and from your secondary 2nd stage (octopus) on your dive.
Whereas, If the Venturi knob in the Max. or Dive position it will deliver the best performance during your dive.
Adjustable Inhalation Effort
This feature is normally found on balanced second stages and allows you to to adjust the inhalation efforts required to open the valve by turning a knob, which increase or decrease the tension on the demand lever spring.
Turned to the Min position, more tension is put on the spring, this in turn results in a lower air flow rate, which is great for diving in would water environment, and helps prevent free flow while swimming against heavy currents.
When Turned to the Max. position, less tension is put on the spring, delivering higher air flow rates, which great from demanding dive conditions, or when you’re tired.
A major advantage to having this system on your regulator is that it allows you to adjust the regulator in the middle of your diving, which can fix simple problems, like a minor free flow or a regulator that is providing too little or too much air at depth.
Secondary 2nd Stage (Octopus)
When buying a new regulator a secondary 2nd stage is not normally included in the package (Only First Stage and Primary Second Stage), however, it is a vital piece of equipment when assembling a proper scuba regulator system.
Generally know as an alternate air source, it is a backup in case your primary fail, or if you need to assist your buddy with air on a dive.
They basically have the same features of the primary first stage listed above, but are generally fitted with a highly visible yellow front piece and/or yellow hose which is longer than the primary.
The general rule of thumb when choosing an Octopus is to get the same model as your primary second stage. However, having a lower performing model is just as good.
There are also Alternative Air Sources that combine your BCD Inflater and Octopus into one unit. The advantage of using this system is that it is very easy to find in the event of an emergency, and it frees up an extra low pressure port for other uses.
However, a major disadvantage to this system is that you will have to give your buddy your primary, and you swap with the alternative air source. Also, because of the shorter hose, movement can be somewhat restricted when sharing alternate air source.
Not all scuba regulators are Nitrox compatible, however most regulators these days are manufactured to be compatible up to 40%. But, it is also good to check you regulators owners manual before attempting to use your regulator with Nitrox.
Most manufactures also offers Nitorx versions of their best selling scuba regulators that are compatible up to 100% oxygen right out of the box. These are normally denoted by bright green on the first and second stage. However, you can take your existing regulator to service centre to have it Oxygen Cleaned.
It is also important to not that all regulator cannot be used with enriched air. Some materials like titanium cannot be use with enriched air over a certain percent due to its heavy carbon content.
The Bottom Line
Many dive manufacturer develop their own specific technology and features into there line of regulators to give them a competitive advance over the others, but the above are some most important feature to look for when buying a new scuba regulator.
It is also good to remember that the regulator that you buy does not necessarily have to have all the features listed above.
For instance, if you are only going to be diving in the shallow warm tropical waters of the Caribbean, then an entry level regulator with out all the bells and whistles should be sufficient.
However, if you can afford a few more feature to make you dive a little bit easier, then by all means go ahead.
Once, you’ve selected the features you want in your new regulator, follow these scuba regulator maintenance tips to keep you regulator working perfect for many years to come.