Typically, cartridges are changed out when they become plugged and reach a high pressure differential range where the cartridges do not clean down enough to maintain airflow. Usually when the differential pressure reaches 5-6 in. water column, it is time to change the cartridges. Many control panels have a high pressure alarm that can be set to warn that the cartridges need to be changed or that something is wrong with the collector, such as loss of compressed air for the cleaning system.
Many companies follow a routine preventive maintenance program and change out the cartridges no matter what the pressure drop. This is often due to fear that a cartridge may develop a leak and cause downtime.
A good quality cartridge with a reinforced pleat can extend the time between filter change-outs. An open pleat design will extend cartridge life by using all of the media for filtering and not just the outer third of the pleat pack. The open pleat will also increase filter life due to the ease of pulsing the dust out of the wider pleat. Because of the open pleat, you can often recover the cartridges even if they have reached 6 in. or more of differential pressure due to an upset, like loss of compressed air.
A continuous spacer in the open pleat design also helps strengthen and support the cartridge media, also allowing longer time between change-out by preventing cartridge failure.
