Question Nitrox considerations when buying regulators

[Rolandisimo]

I am thinking of buying a sidemount regulator set Apeks MTX-R Sidemount Regulator kit . My concern is that it says it is meant for nitrox of up to 40% max but then it mentions 100% oxygen.

I am not clear of what this means exactly, but I have seen that there are nitrox specific regulators even for MTX-R.

My case is that I have Advanced EANx which allows me to use EAN50. Is is ok for me to use the regular MTX-R with a 50% EAN?
What are the issues I might encounter?

Would be happy to learn about the reasons for these differences if anyone knows

Thanks

 

[rongoodman]

From the description it appears that it can be used with mixes richer than 40% following O2 cleaning by a regulator technician.

 

[jeffmg]

https://gue.com/blog/wp-content/uploads/2022/04/Oxygen-Hackers-Companion-Vance-Harlow-Sanitized_01.pdf

some good info on oxygen use, cleaning, etc., this doc probably answers any questions you might have about above 21% o2 use

 

[L13]

Second stages that have been keep clean and only used with clean air and EAN < 40% can generally be used with richer mixes. First stages must be O2 cleaned first before use with rich mixes, and must not containing O2 unsafe materials particularly in their HP path. Primarily this means no titanium in the HP flow path, and some care in valve seat material selection (though extra care can be added in o-ring material selection).

For most non-titanium regulators, this means O2 clean and you are safe.

 

[Lorenzoid]

Dive Gear Express has a nice FAQ that addresses oxygen cleanliness of new-from-the-factory regulators they sell, among many other questions about oxygen compatibility. Obviously, they are not making a general statement about all regulators from whatever source, but it's informative.

 

[Grantt]

I dive the MTX-Rs for my sidemount primaries. I have an Atomic M1 that can be used for 21% - 50% and a dedicated dive rite O2 reg.
The MTX-Rs without any special handling or extra cleaning can run 40% and lower.