In TOR-5 the adsorbent is maintained based on actual moisture loading, not on a fixed calendar interval. Zeolite cartridges are normally regenerated by controlled heating and purging using dedicated regeneration equipment, and the same sorbent can be reused many times. Replacement is needed only when the zeolite loses capacity due to oil contamination or mechanical degradation. The main indication is rising outlet moisture or water activity despite normal operation, sometimes combined with increased pressure drop. In practice, trend of downstream moisture is a much more reliable end-of-life indicator than operating hours.