FX DRS air tube life span

Interesting question. Since moisture corrosion will be the most likely thing to make an aluminum cylinder fail; if you keep the water out of your air Id expect many years. Probably better measured in decades. Thinking about how many pcp are still in service that were built in the 80s and 90s I wouldnt really worry about it too much.

The other thing to think about is the potential energy with a thin walled aluminum cylinder is far less than a CF tank. So even if it does fail, the DRS is probably one of the safer pcp designs.