Info How to Choose a Regulator

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How to Choose a Regulator

(an overview of features and their value)

One of the first pieces of equipment that every diver will acquire is a set of Regulators. This is one of the most critical pieces of your gear as it enables you to breathe underwater and are considered to be life safety equipment. A challenge for many divers is there are a huge variety of options to choose from. Beyond taking the advice of your dive shop’s sales staff, how do you make an informed decision? Cost is one factor, but is expensive always better? How cheap is too cheap? What features matter the most?
The sales staff have a compelling argument that you should not be too thrifty when purchasing your “life safety equipment.” This article will attempt to give you some more information about the different regulator designs and features you will encounter, and why those features may or may not have value. I won’t suggest specific brands or models except as examples of the different designs. After you read this article, I hope that you will be better informed about your options and can make an informed choice the next time you need to buy or replace your regulators.

What does a Regulator do?​

A Scuba Regulator delivers air to the diver while underwater and allows them to breathe. What is happening in these devices to make that possible? Let’s break down the components to highlight the requirements of a SCUBA (Self Contained Underwater Breather Apparatus) regulator system.
  • A scuba tank is a cylinder filled with compressed gas at far higher pressures than the 15 PSI (1 BAR) you breathe at sea level. A typical scuba tank will be filled to a pressure of between 2400 – 3500 PSI (165-240 BAR)
  • A 1st stage regulator connects directly to the tank, and its job is to reduce the pressure it contains down to approximately 135 PSI (9 bar) required to operate your 2nd stage regulator. It must dynamically adjust as the tank pressure drops from over 3000 PSI (200 BAR) all the down to just 200 PSI (14 BAR) or less. Once the tank pressure is below 100 PSI (6 BAR) it will be increasingly difficult to breathe, and maybe impossible unless you are near the surface.
  • A 2nd stage regulator connects to the 1st stage and delivers air directly to the diver. The 2nd stage input is at the ~135 PSI (9 bar) delivered by the 1st stage. It needs to further adjust the pressure of the air delivered to the dive to match the “ambient pressure” of the diver. At the surface this will be 15 PSI (1 BAR) and at 100 feet deep this will be 60 PSI (4 BAR), or 4 X sea level pressure. (100 ft / 33 ft) +1 ATM
Regulators need to provide breathing gas at a pressure that exactly and continuously matches the water pressure at your depth. At 100 feet you will have 60 PSI (4 BAR) of pressure squeezing on your chest and lungs. If you had a 100-foot-long snorkel you would not be able to breathe from it as your chest would be crushed and unable to pull in the air. If a regulator delivers more than the ambient pressure, then you would blow up like a puffer fish. Not good. The regulators must be precisely designed and tuned to deliver exactly the right pressure.

Full Regulator System​

A complete regulator system for standard open circuit recreational scuba diving consists of five essential components.
  • 1st stage regulator
  • Primary 2nd stage regulator
  • Backup 2nd stage regulator
  • Submersible pressure gauge
  • Hoses for the SPG, 2nd stages, and BCD/Drysuit
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What Features are Important and Worth Paying Extra?​

There are so many brands with such a wide spread of prices. It can be confusing to know what brand is best and how much should you spend. Within a single brand there can be a spread of prices from hundreds to thousands of dollars.
The reality is that pretty much every regulator being sold by a legitimate dive shop is going to be safe and reliable for standard recreational diving. The most expensive regulator is not going to keep you more alive than the cheapest one. It also may not be more reliable than the cheapest one. It might even be the case that the cheaper one will be more reliable over time than the expensive one.
The same is true with brands. Very often dive shops will have a relationship with a particular brand and might sell that brand more than another, and they probably don’t offer more than one or two of the top selling brands. In general, one brand is not better than another. Most brands have a range of models that vary from basic to fancy. As you scale up in price you get added features. Some are useful, some merely cosmetic, and some that aren’t valuable to everyone. We will cover different options and features in the next section, and I’ll call out some of the more important and useful features that you should look out for.

Serviceability is the #1 Feature 👍

The only comment I will make about Brands in this article relates to serviceability of your regulators. Every single regulator from the least expensive to the most expensive will eventually need to be serviced. After one or two years of use your regulators need to be serviced. If you skip service for a year or two longer you might get away with it for a while. But eventually every regulator will fail and need service. Most brands & models have a 1-3 year recommended service interval. Get your regulators serviced before they fail and start to have problems.
A 1st stage regulator is typically made of a solid chunk of chromed brass and filled with stainless steel springs, synthetic or rubber o-rings, seats, diaphragms, and other plastic parts. Eventually the o-rings will wear out, lubrication needs to be reapplied, and corrosion or grit will build up until the regulator starts to have issues. A regulator needing service might leak, the Intermediate Pressure might no longer be to spec, or could even dramatically blow a seal.
The one feature that you absolutely need to prioritize is: Can I get this regulator serviced, not just from the shop you bought it from, but you get it serviced anywhere in the world?
For most of the top brands of scuba gear, the answer to this question will be Yes. Brands like ScubaPro, Aqualung, Apeks, Atomic, Mares, Poseidon, Oceanic, etc. have parts and service centers all over the world. There are other good brands that might only be serviceable in North America or Europe. Any of these might be great options. Just make sure that you understand how to get your gear serviced wherever you live.
I strongly recommend that you avoid any brands that don’t have widely available service. I’ve seen many divers using regulators I could not identify. There are plenty of cheap regulators available online that are from unknown brands. Many of them are clones of more popular brands or model, and they might work just fine. But eventually they will need service, and if you can’t find a convenient shop to service them you will likely need to buy brand new gear. When a regulator needs service, you need to buy a “Service Kit” from the maker of the regulator. The kit consists of a complete set of o-rings, diaphragms, seats, and seals that experience wear in the regulator. Sometimes other parts break or wear out that are not part of the service kit. If your Brand can’t supply service kits and replacement parts, then no dive shop or service technician is going to touch it.

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Continued in the next post

 
Well done @davehicks. Thanks you.
I've learned mostly that 1-2 year service is unnecess
Can you please elaborate? I am one of those, perhaps uninformed divers, who does services them q2 years as per recommendation from manufacturer.
 
Can you please elaborate?
You regulator will give you signs of when it needs to be looked at...

 
Sorry if this is not where you wanted to go, but you should write a section of basic monitoring..... In my 30+ years, I've learned mostly that 1-2 year service is unnecessary, and can lead to damage... you service when it needs it. There are signs when it is heading toward need...
I totally agree with your opinion. I wrote another article in January, which I may post here, about New Year's Dive Gear Checkup that included a lot of that info. Personally, I service my own gear where I can, and do it when it looks like it's needed.

However, I do have concerns about advocating for "as needed" service in place of scheduled service to a general audience like my dive club. Lots of divers are not DIY type or comfortable with the technicalities of monitor IP and cracking depth in their regs, no matter how simple it is to do.
 
I still don't have the dislike for combo inflator/octo-regulator devices that folks have. There are places they are quite fine. There are however places they just don't belong. I'd use one in a heartbeat bumbling around on shallow warm water reefs, and not give it a second thought. The modern ones are quite good breathers compared to the originals. It takes an understanding/training to safely/properly use them, and the lack of that leads to the vocalized objections.
 
However, I do have concerns about advocating for "as needed" service in place of scheduled service to a general audience like my dive club. Lots of divers are not DIY type or comfortable with the technicalities of monitor IP and cracking depth in their regs, no matter how simple it is to do.
I like the idea of presenting it as an option:
If you are comfortable doing basic DIY checkups (IP, cracking pressure, non invasive checks for corrosion) then service as needed.
If not, then have inspected/serviced professionally on a conservative schedule.

Respectfully,

James
 
I still don't have the dislike for combo inflator/octo-regulator devices that folks have. There are places they are quite fine. There are however places they just don't belong. I'd use one in a heartbeat bumbling around on shallow warm water reefs, and not give it a second thought. The modern ones are quite good breathers compared to the originals. It takes an understanding/training to safely/properly use them, and the lack of that leads to the vocalized objections.
My wife was sold a Combo reg 20 years ago when she started diving and it's still on her original BC. I've serviced it and it still works ok. However, we mostly dive in the Pacific Northwest and not on shallow warm water reefs. Cold water, low visibility, often high currents and offshore dive sites. Shooting a DSMB is common and doing that with a combo reg is not optimal.

I've also been on many remote liveaboard trips with friends who had a combo reg start to misbehave and become a problem. Then you have all the cascade of issues with the wrong hoses, quick disconnects, etc. A couple of them addressed the problem by buying spare Combo regs, which seemed to like a solution that just perpetuates the shortcomings of the original root cause.

My suggestion is to deal with the problem at the point of sale and buy something else.
 
Can you please elaborate? I am one of those, perhaps uninformed divers, who does services them q2 years as per recommendation from manufacturer.

There are a lot of variables but here are two extremes.

Best Case​

Bob Hollis (Oceanic's founder) was on old friend and gave me an Omega regulator when it first came out. He said "beat it up and let me know what fails".

I didn't do anything to it except soak in in fresh water, usually pressurized, and let it dry. I was very careful not to store any dive gear besides tanks in a garage with vapors from vehicles or water heaters. I checked the IP before each dive trip, that's it besides replacing hoses and mouthpieces. The first stage creep was the first failure after 27 years of heavy use.

Worst Case​

Scuba first stages were used on bailout bottles during saturation dives. They would spend 20 plus hours/day 24/7 in the water and the rest of the time in the humid bell atmosphere with nothing but a hot sea water rinse (along with everything else). They required a rebuild or replacement in 3-6 months.

The second stages on hats and masks used in sat diving were only slightly modified versions of the metal can US Divers Scuba regulators. They would go a month or so before being locked out for service — usually for communications but the whole hat was serviced at the same time.
 
Expand with the statement that this is really an "emergency" configuration as many find it moves the first stage away from the valve further, frequently then causing the dreaded "head bang"...


I have always heard this, but never had to use one. So I pulled everything out and found that my adaptor add 3/4” to the reg as a whole. Ouch!
 
I have always heard this, but never had to use one. So I pulled everything out and found that my adaptor add 3/4” to the reg as a whole. Ouch!
I've used an adapter a number of time and it does make the reg stick out further. The issue is if it ends up directly behind your head. If you can lower the tank so it's behind your neck it's a non-issue.

If I am going on a trip where I plan to dive open circuit, I try to ask if the tanks are yoke or have an adapter plug to accommodate DIN. I have yoke fittings I can put on my scuba pro 1st's if that is required. It's quick and easy to swap between DIN and Yoke if you have the parts.
 
https://www.shearwater.com/products/perdix-ai/

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