The carbon trap should only become saturated if you are working in an area with a lot of solvent fumes, so that one should last a while. The compressors though have seals that will wear out when run constantly. If you turn the generator off when not using the instrument then they will last a really long time, but running 24/7/365 a year to year and a half is the max, and by then they are getting quite noisy. We had one of these units and after a few years of letting the pumps go two years between changes it got to where it just would not make enough flow. I think the particles from the compressors wearing down will eventually clog things up.
We switched to a generator that uses the house compressed air now and the room is so much less noisy
If you do not use the MS often, they at least plumb in a lower flow unit to keep the curtain gas flow over the entrance cone to keep out the room air and shut down the high volume system until it is needed. This will make the generator last longer.