AquaPex and the ferrous issue isolation

[HoracioO]

I'm researching the phased replacement of my hot and cold water supply lines. Currently they 50 year old galvanized pipe, and so I'm going to have to transition to PEX at the outlets (bathrrom) and work backwards over time. Reading about AquaPex is states quite clearly:

AQUAPEX tubing is used in hydronic heating applications where the system contains no ferrous corrodible components or where any ferrous components are isolated from tubing.

I read this as applying only to hydronic heating applications. Correct?

Are there any other issues I should consider before I under take this task? I'd really like to replace in one go, but this is just not possible at this time and there seems to be some easy joins that I can use to get started so I won't need to cut into the pipe...

Cheers

[HoracioO]

Answering my own question... clearly it is for hydronic heating, as the tubing does not have an oxygen barrier and ferrous material in a recirculating (closed) system will oxidize...
Oxygen is already in water so for retrofits this is not an issue, but it is the very reason why we replace the galvanized/iron pipes.