Apeks Regulators – Divers Guide

apeks regulators - divers guide

Apeks make some of the most popular and robust diving regulators available on the market today. They are favoured by Technical and recreational divers due to their performance capabilities and reliability. However, They have such a wide range of models available now that it can be quite confusing to know which regulator is better and whats the difference.

To make your life easier here is the crash course in the Apeks lineup of regulators and their major differences to assist any diver with choosing an Apeks Regulator for their diving needs

Apeks Regulators – First Stages 

All Apeks first stages are designed as a Balanced Diaphragm Valve regulator. Reasons for this are reliability and versatility. All their first stages with the exception of the Flight travel regulator use a common service kit between them. The main differences are with the shape and size of the materials used in construction along with port layouts e.t.c. for these reasons a service centre for diving regulators should have no reason to say “sorry I don’t have the service kits in stock at the moment”.

Here is the list of current first stage models currently made by Apeks with their main differences.

  • US1 – non-environmentally sealed & compact. – Intended for warm Water Use only with 1 LP & 1 HP port. (travel / warm water  pony / bailout set)
  • DS1 – an environmentally sealed US1 for cold water use.
  • ATX20 / US4 – Unsealed and compact like the US1. has an additional 3 LP ports. (travelling abroad)
  • ATX40 / DS4 – Same body as the US4 but has the environmental seal added for cold water diving. (diving in the cold on a budget)
  • XTX20 / UST – The unsealed turret intended for warm water. 2 HP and 4 LP ports as standard with a 5th port upgrade available.
  • XTX50 / DST – The environmentally sealed and most versatile of the lot. same body as the XTX20 / UST featuring 2 HP and 4 LP ports as standard with a 5th port upgrade available. (can be used for normal diving, tekkie diving, deco / stage cylinders and side mounts used – ONE STOP SOLUTION)
  • TEK 3 – Environmentally sealed with 3 LP ports and 1 HP port off one side of the body. Intended for use on a twin set and comes in a left hand and right hand model. In the twinset package you get a left and a right.
  • XTX100 / FST – Environmentally Sealed with 4 LP ports and 2 HP Ports split evenly on either side of the body. Finished with satin chrome rather than shiny chrome. As with some of the new version of this regulator  a 5th port optional extra is available.
  • XTX200 / FSR – same as the XTX100 / FST performance wise. slight different look and more metal used to make the body. Looks nicer and hose routing is improved. As with some of the new version of this regulator  a 5th port optional extra is available.
  • FLIGHT – part carbon fibre, part metal with no environmental seal intended for use in nice warm water. Features 4 LP and 2 HP Ports.
  • XTX Tungsten – Is essentially a nice shiney XTX 200  / FSR First stage finished with a PVD coating which virtually makes it impossible for it to corrode.As with the XTX200 / FSR it has an optional extra upgrade to include a 5th LP port.
  • BLACK SAPPHIRE  – Is an Tungsten on steroids. with further refinement this is its a redesigned XTX 200 FSR with a 5th LP port as standard and a heat exchanger to give itan all new look to and performance factor.

Apeks Regulators – Second Stages

All Apeks 2nd stage regulators are all pneumatically balanced valves, hence the higher base price for all of Apeks regulators.

The primary difference between the ATX and XTX range of second stages is the ability to change the hose feed from the standard right hand side and left hand side. The ATX is right hand feed only so don’t hope to be able to do this. The conversion should only be attempted by a service technician. Two exceptions to this. First is the Egress Octo which is designed to be breathed either way up and with the exhaust on either side. Second is the Flight which is a fixed right hand feed but has a quick detach hose feature to enable more compact storage while travelling.

As with their first stage all second stages except the flight use a common service kit between except the flight.

Here are the list of second stage models currently made by  Apeks.

  • ATX20 – Basic Right Hand feed only regulator with only a venturi lever. The securing nut is made of plastic and is intended for warm water use only.
  • ATX40 – Same as ATX20 bur the securing nut is now metal and is intended for cold water use.
  • Egress Octo – Side exhaust octo with no twiddley bits intended for cold water use.
  • Flight – verry small, lightweight 2nd stage with tool free quick detach hose. Warm water use only.
  • XTX20 – Same features as the ATX20 with the plastic securing nut venturi lever, intended for Cold Water use but the hose feed can be reversed.
  • XTX40 – Same as XTX20 but cold water rated through use of a metal spindle.
  • XTX50 – Based off the XTX40 but features a user adjustable diver inhalation effort knob.
  • XTX100 – Same as the XTX50 but with a label that says XTX100 and utilises satin chrome components and has a slight different front face.
  • XTX200 – Same as XTX50 but slight different front face.
  • XTX Tungsten – Same as a XTX50 with the PVD ultra durable finish and a different front,
  • BLACK SAPPHIRE – Same as the XTX Tungsten with an all metal front purge assembly.

The only annoying thing about Apeks is their naming system for first stage regulators when combined with a second stage or octopus makes it more confusing when choosing what set to go for. For example  the XTX50 Regulator set consists of the XTX50 / DST first stage and the XTX50 second stage. When you want to get just the first stage it is called the DST to add to the confusion.

There you have it the quick summary of Apeks regulators. As you could guess my personal favourite model is the XTX50 first and second stage because of their versatility, features, reliability and the fact they can be used in multiple roles.


Hope this helps anyone out that is looking to purchase a new set of regs and have their heart set on going for an Apeks regulator.

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