Many people ask me how often filter cartridges should be replaced. There is no standard answer. I usually tell clients four words: watch the pressure drop.
After installing a new filter cartridge, record the initial pressure drop. When the differential pressure rises to 1.5 times the initial value, it is time to consider replacement. If you continue using it, not only will flow rate decrease, but cartridge breakthrough may occur, contaminating downstream media.
However, in actual operation, there are several other factors to consider. If the material you are processing has high viscosity or contains large amounts of solid particles, pressure drop rises faster. Some processes are intermittent – after long periods of shutdown and restart, special attention should be paid to checking the filter cartridge condition.
Another easily overlooked issue is filter cartridge aging. Even if the pressure drop is not significantly increased, filter cartridges used for more than a year will have progressively declining filtration efficiency. Regular replacement is recommended.
