Apeks ATX40 DS4 Regulator

The ATX40/DS4 features a smaller, lighter, lower profile 2nd stage than the TX40 2nd stage. Includes 74cm regualtor hose

We believe that your regulator should be as flexible as you are. So the ATX40 retains our well proven diver adjustable venturi together with a 'technician-adjustable' balanced second stage and balanced first stage. The combination of this second stage and the DRY SEALED first stage offers an excellent regulator for diving anywhere in the world at a very competitive price. The design of our second stage offers a smooth breathe which enhances your dive enjoyment.

First Stage

• No swivel turret
• 4 medium pressure ports, 4 x 3/8" UNF
• 1 high pressure ports, 1 x 7/16" UNF
• Environmentally dry sealed system
• Polished chrome finish
• Balanced for superior performance

Second Stage

• Pneumatically balanced system - reduces breathing effort
• Heat exchanger for cold water diving
• Integrated Venturi Control
• Micro adjuster
• Extremely efficient exhaust valve
• Compact integrated exhaust
• 25% lighter than TX models
• Comfo Bite mouthpiece - for comfort and to reduce jaw fatigue

Apeks Marine Equipment Ltd (Registered in England 1231692) began manufacturing 30 years ago with one goal - to make the best diving equipment in the world. Our strengths in design, development and engineering craftsmanship produce equipment of such a high standard that they are now the benchmark standards other manufacturers strive for. Through constant innovation and development Apeks has grown into a major player in the diving industry. We now make more regulators for UK divers than any other manufacturer and export more than 70% of our equipment to over 50 countries. Still the only UK manufacturer of regulators Apeks is a respected name throughout the world.

Scuba Diving Regulators

One of the main things to remember when looking to buy your own regulators is that these will keep you alive underwater and, therefore, it's better to buy the most suitable and reliable model you can.
That said, there are plenty of options for divers with a range of budgets and requirements. If you'd like a bit more information about regulators and their different features then keep reading.
If you already know what you want, click here to see our full range of Scuba Diving Regulators
All of the component parts of a regulator set-up can be bought individually or as part of a bundle package.

DIN or A-clamp

One of the first things you'll need to decide is whether to have an A-clamp (or yoke) first stage or a DIN first stage for your scuba diving regulators.
There are advantages and disadvantages to both, so here are a few things to be aware of if you're just starting out.
DIN fitting first stages for regulators are becoming more widespread. They offer a more secure connection to the cylinder valve because they screw into the pillar valve rather than being held in place against it, as with an A-clamp fitting. They are generally regarded to be more durable than A-clamps and are rated to a higher operating pressure (300 bar).
A-clamps are the most widely-used first stage regulator fitting and will be found around the world. This means they are universally accepted, which could be important if you plan to travel. They have a lower operating pressure than DIN (232 bar).
People who choose DIN fittings over A-clamps can purchase an A-clamp adaptor to make them compatible with cylinders which only accept this form of first stage connector.

First Stage Ports

First stages will come with at least one high pressure and two low pressure ports to allow a console or gauge as well as the regulator to be attached.
The number of ports will vary from model to model and it is important to make sure that you have enough on the first stage to cater for the equipment you will be using to undertake your diving safely.
For example, diving in the UK you will almost certainly be wearing a drysuit and will therefore need an additional port to allow air to be injected into the suit.
Low pressure ports are used to attach the second stage of the regulator, Octopus, suit and BCD feeds to the cylinder.
High pressure ports are needed for your gauge measuring the cylinder's contents and will be required if you intend to use a console-mounted computer.
Click here to see our range of scuba diving computers or here to browse our selection of diving gauges.
It's important to take all this into consideration when making your decision about your scuba diving regulator set-up.

Balanced, un-balanced or over-balanced?

In diving and regulator terms, this refers to the airflow from the first stage and into the second stage.
Balanced regulators provide a consistent airflow regardless of the depth or pressure you are diving at. The equipment adjusts to suit the conditions you are diving under. This means that as a diver, you will experience lower breathing resistance at depth.
An unbalanced regulator will not compensate for the decrease you experience in cylinder pressure as you descend deeper. This could mean that at depth, it can be more difficult to breathe from the second stage - although this effect may only be negligible depending on how deep you are going.
Finally, an over-balanced regulator increases the air supply as you descend. This means that it will always be easy to breathe through the second stage regulatorand will considerably reduce breathing resistance at extreme depth. It is certainly worth considering if you are planning to undertake extended range diving.

Temperature Rating

If you dive in the UK then you need to make sure that any equipment you buy will perform in the cold conditions experienced in our waters.
In terms of first stages, this means choosing an environmentally dry sealed unit, which prevents water and contaminants from entering the first stage of the regulator. This should prevent the first stage from freezing when diving in cold water.
Unsealed first stages are available and suitable for use in warm waters, which are usually considered to have a temperature of 10 degrees C or above.

First Stages for Twinsets

If you dive on twinsets, chances are that you will want to reduce the risk of any of your hoses becoming entangled or twisted.
There are several first stage regulators designed specifically for twinset use, in both left and right-handed versions, which usually refers to the location of the ports.
Another option with the first stages for a twinset is to manifold them.

Regulator Second Stages

There are a number of different design features to think about when selecting your second stage for your regulators.
First and foremost is the shape and size of the mouthpiece, which should fit comfortably in your mouth. If you find your jaw is aching after a dive, it probably means that you're having to use too much effort to hold your regulator in your mouth.
Many manufacturers now offer mouthpieces with an orthodontic design, which are intended to provide more comfort to the diver. These can be easily changed once you have purchased your regulator.
You may also want to think about the position of the vents on your regulators. While many models have the vents positioned directly below the mouthpiece, there are some which feature a side-mounted vent.
This has the advantage of discharging bubbles away from the face and mask, providing the diver with less disturbance to their vision.
Another thing to look out for is the diver adjustable inhalation control which is found on many models. This allows you to regulate your own breathing rate and breathing resistance.
For more advanced diving, which specifically requires the use of stage cylinders, you may need to consider left and right-handed second and first stages to ensure that the switch between your back gas and decompression gas is as easy and smooth as possible.

Octopus

An Octo (or Octopus) is your backup regulator. This can be used either by you if your second stage fails or freeflows or by your buddy in an out-of-air situation or in the event that their main regulator malfunctions.
The general rule is that your Octo should be as good as your primary regulator and should be easy to purge and comfortable to breathe off.
Normally, an Octo will come with a long hose to allow a buddy to breathe from it easily. Another feature of Octos are their colour. They will almost always be yellow to allow them to be easily distinguished from a primary regulator and easily seen and will usually be attached to the first stage by a yellow hose.

Weight and Size

Anyone who travels frequently will probably want to reduce the weight of their dive kit. There are a number of compact regulators designed with that in mind to make it easier for divers to take their own kit abroad.
These regulators are often compact and use lighter materials to keep the weight down. They also incorporate features such as BCD inflator hoses which include a second stage regulator that can be used as an Octo to reduce the number of component parts required.

Nitrox and Oxygen Clean Regulators

Anyone who plans to dive using oxygen-enriched air (or Nitrox) will need to make sure that both the first and second stages of their regulators are suitable for this purpose.
They will need to be certified as O2 clean and, as part of their regular maintenance, will need an O2 clean once every year.