If it needs to be serviced, you either vent the helium out (unlikely to happen due to cost of helium thesed days and the volume that will be needed if this beco

If it needs to be serviced, you either vent the helium out (unlikely to happen due to cost of helium thesed days and the volume that will be needed if this becomes a common appliance in households) or move it to another container so you can repurify it at a plant if you are worried about contamination (unsure how much purity those devices need). To refill after maintenance you may also just purge with helium (or another cheaper gas that doesn't impede behavior of the device) then pressurize with helium . So mostly a non issue. And there is really little safety issues with this kind of constant pressure containers containing non toxic gases just a routine inspection should be enough as they can be made of high quality materials and shielded.