Regulators

Choosing a regulator can seem a daunting task. First comes the shock that the price of the regulator does not include the octopus, gauges and BCD inflator hose that was always included in the rented and school equipment you have been using. However, modern regulators all come up to a very high minimum standard so whichever you decide to purchase, you are unlikely to be disappointed.

For a large range of Regulator and Octopus options for all conditions visit the Regulators section in the The Scuba Doctor Online Dive Shop.

For a large range of Instrument options for all conditions visit the Instruments section in the The Scuba Doctor Online Dive Shop.

General Guidelines

The basic rule of thumb with selecting a regulator is to go for the most expensive you can afford that is most suited to the diving you will be doing. The more you spend the easier the breathe. When purchasing your regulator you will need to buy the three major parts – the 1st and 2nd stage (regulator), the alternate air source (octopus) and the instruments.

As with most purchases, going for major brand names assures a certain level of quality and even though many of us like a bargain, with Scuba equipment, the more you spend the better the equipment you get. So, if you thought your regulator would include an octopus and gauges, take your regulator budget and deduct between 30% to 40% to allow for the basic instruments you will need. Whatever is left is what you can afford for your regulator.

You should always use the same brand of 1st and 2nd stages, plus the octopus you choose should also be from the same manufacturer as your regulator to ensure the intermediate pressures are compatible. Gauges need not be made by the same manufacturer but you should always go for major instrument brands because their accuracy and reliability are much higher than imitations.

Free Assembly

When you have made your choice and ordered your equipment from The Scuba Doctor, we will assemble and test the regulator, octopus, gauges and any hoses, prior to dispatch or collection to ensure they are functioning correctly (unless you request us to do otherwise).

Regulator Choices

There are several types of regulator, piston or diaphragm and balanced and unbalanced systems.

DIN or Yoke (A-Clamp)

The most common coupling in use in Australia is still the International Yoke or A-Clamp fitting (same thing, different names!). Yoke fittings were the recreational diving worldwide standard, but technical divers switched to DIN a long time ago because it's a safer system. Then Europe mandated DIN as the standard for recreational diving.

So today, in most dive travel destinations around the world, the dive operation will certainly have Yoke valve fittings and also probably DIN valve fittings. In fact, the common valves used today are DIN valves that come with an insert to convert them to Yoke valves. Thus they can be easily changed to accommodate either type of regulator. This is now the type of valve used by most dive operators so that they can handle customers with DIN or Yoke regs.

DIN fitting regulators are by far a safer coupling with the regulator actually screwing into the tank valve, trapping the high pressure o-ring so it cannot extrude like it occasionally (and spectacularly) does with an A-Clamp fitting. There are two types of DIN fitting – DIN200 and DIN300 – with DIN200 having 7 threads suitable for use with 232bar/3000psi cylinders and DIN300 with 9 threads suitable for 300bar/4500psi cylinders. Although a DIN300 fitting will attach to a DIN200 valve this is not recommended.

We use and recommend DIN fitting first stage regulators. They're safer and lighter for travel. Plus, if you do end up in a location where they only have valves with Yoke fittings, you can simply use a DIN to Yoke Adapter to quickly changeover.

Balanced/Unbalanced

Simply put, a balanced regulator is always a preferable option. Most entry level regulators are unbalanced whereas the next model up is generally balanced.

A balanced first stage regulator offers consistent air flow regardless of depth and tank pressure.

An unbalanced regulator will become harder to breathe from as depth increases and or tank pressure decreases. That said, modern unbalanced regulators perform very well and the advantage of an unbalanced regulator is that annual service costs are lower as they tend have few moving parts. This does in turn make them exceptionally reliable as are all modern regulators, regardless of type.

However, balanced regulators offer consistent high air flow to the second stages making breathing resistance less and therefore breathing easier.

Cold Water Kit

The definition of cold water diving is in water less than 10 degrees centigrade, which can often occur during Melbourne's winter. There are markings to help you identify regulators suitable for cold water diving such as EN250 but most will say whether they are cold water compatible or environmental sealed in the descriptions.

Do not assume that a regulator is cold water suitable. If you have any doubt please contact us.

Having a cold water regulator does not mean that you will not have a free flow in colder conditions however. High pressure air and water form ice, which in turn can cause a free flow. You should follow the manufacturers recommendations set down in the manual that will accompany your regulator to avoid freeflow and ask your dive instructor, or read one of the many books on the subject.

Piston vs Diaphragm

These terms refer to the way the first stage of your regulator reduces tank pressure to an intermediate pressure.

Piston regulators have a very good flow rate. They generally have only one moving part (the piston) which can make them quite expensive since the machining to make the body must be exact. Piston first stages tend to be more expensive to buy as they have to be manufactured more precisely, but having fewer moving parts makes them even more reliable and less expensive to service. Most deep divers will insist on a piston first stage.

A diaphragm first stage has many moving parts but is much simpler to manufacturer, offering a lower initial purchase cost but lower performance (not generally noticeable within recreational sports diving limits). However, diaphragm regulators tend to offer more protection in colder water against free flow.

Overbalanced

An over-balanced first stage achieves unprecedented performance by increasing your air supply the deeper you go.

Ports

Most regulators first stage will have 1 high pressure port (7/16" thread) and 4 low pressure ports (3/8" thread). Having differing port sizes avoids any error in fitting as a high pressure hose is too big to fit in a low pressure port and vice versa.

Higher specification first stages may have an additional high pressure port which is ideal when you have computerised gauges and require an analogue back up gauge in case of battery failure. Some first stages feature a special low pressure port that is designed for use with the primary second stage as the air flow to that port is higher than the others.

Nitrox

Unless stated by the manufacturer, regulators are not suitable for use with elevated oxygen content mixes. Most leading manufacturers now make their entire range suitable for use with nitrox (EANx) up to 40%. Above this level you need to opt for specially cleaned regulators such as the Apeks Nitrox range of regulators. Titanium regulators are usually not suitable for use with nitrox.

Nitrox regulators need to be oxygen cleaned each year with the annual service or if ever contaminated with unclean air which can increase the on going maintenance costs. You should consult the owners manual of your regulator and speak with your dive instructor for further advice.

Compact Second Stages

A compact second stage is around 75% of the size of a normal second stage but in some cases can be less than half normal size. This design offers a lighter physical weight which in turn reduces jaw fatigue. Some are even smaller offering even more comfort during longer dives. Smaller second stages also have the advantage of less dead air space which in turns helps reduce any potential carbon dioxide build up.

Side Vented Second Stages

The exhausted air from a normal second stage exits the second stage under the mouthpiece. This means that bubbles often come across the face of the divers mask, disturbing the view, especially whilst ascending and descending. A side vented regulator exhausts the exhaled air to one side offering a clearer view. Some side vented second stages also have the advantage that they may be used either way up making them ideal for use as an alternate air source (octopus).


For a large range of Regulator and Octopus options for all conditions visit the Regulators section in the The Scuba Doctor Online Dive Shop.

For a large range of Instrument options for all conditions visit the Instruments section in the The Scuba Doctor Online Dive Shop.

The Scuba Doctor Online Dive Shop