Apeks XTX Series Second Stages

The Apeks XTX series second stage is an ultra-performance pneumatically-balanced downstream design that results in smooth, easy breathing in even the most extreme environments. A metal heat exchanger which surrounds the valve mechanism, dissipates the cold caused by gas expansion while drawing in and retaining ambient heat. The purge button is large and easy to operate and features two-step progressive operation. Press the purge on the side for a lower flow rate, useful where more control is required such as filling lift bags, then press in the center for the full effect of the purge such as when clearing water. The large venturi lever has a soft touch rubber grip, which makes it easier to locate and use. An optional easy-to-grip opening effort adjustment knob keeps the diver in control at all times.

The XTX second stage design supports an Innovative user changeable exhaust tee. This system gives the diver the ability to change between an exhaust tee that makes the second stage more compact and an exhaust tee that offers the best bubble dispersion. The XTX second stages are also a reversible design that can be converted from a standard right-handed hose inlet configuration to an uncommon left-handed configuration. Apeks describes the process of reconfiguring the regulator to a left-handed hose inlet as both quick and simple, however they recommend this be done by a regulator technician; see Product Attachments tab above for more information.

There are several different styles of the XTX series second stages with variations in the cosmetics †, opening effort adjustment, exhaust tee, and mouthpiece.

• XTX50 Adjustable Black - has black cosmetics and includes an opening effort adjustment knob (with hex key micro-adjustment feature), a wide exhaust tee, and the popular Apeks Comfo-bite™ mouthpiece.
• XTX50 Adjustable Yellow - has yellow accent cosmetics and includes the opening effort adjustment knob, a compact exhaust tee, and the Apeks standard mouthpiece.
• XTX40 Non-adjustable Black - has black cosmetics with a compact exhaust tee, and the Apeks Comfo-bite mouthpiece.
• XTX40 Non-adjustable Yellow - has yellow accent cosmetics with a compact exhaust tee, and the Apeks standard mouthpiece.
• XTX40 Non-adjustable Green - has green and yellow accent cosmetics with a compact exhaust tee, and the Apeks Comfo-bite mouthpiece for extra comfort on oxygen accelerated deco with long runtimes.

Regardless, all versions of the XTX series regulators offer identical ultra-performance.

† Just to be clear, the color cosmetics of any XTX Series Second Stage is meaningless in regards to their breathing performance characteristics, cold water tolerance, or oxygen compatibility. All XTX second stage models are literally identical in regards to those specifications: chrome color does not indicate better cold water tolerance; yellow color does not mean a lower performing configuration; green color does not indicate better suitability for oxygen service.

Although your personal preferences will be the best guide, the XTX50 is normally selected for primary breathing applications while the XTX40 is typically selected for alternate applications. However, some divers prefer the simpler XTX40 non-adjustable compact configuration even for primary applications, see our TekTip below for explanation. The XTX50 second stage is typically mated with the DST swivel turret first stage for general sport and technical diving applications. The XTX40 is often mated with the DS4 fixed port first stage for staging, deco and bailout bottle applications.

The XTX series second stages all have the same industry standard intermediate pressure range between {130 psi | 9 bar} and {145 psi | 10 bar} and 9/16-18 UNF male thread hose inlet along with ambient outlet { 1.3 x 0.68 in | 3.3 x 1.7 cm } orifice dimensions. Apeks offers their branded accessories for frequently seen customizations that include: Changing the exhaust tee configuration. Changing the mouthpiece style or color, especially for coding purposes. Adding a bungee necklace to primary backup configurations. Adding a lip shield for diving in freezing cold water. Adding a flow stop to help protect against critical gas loss scenarios.