Depth String Wound filters elements at their finer micron ratings rely mostly on Van Der Walls or attractive forces for their small particle capture. With this in mind, using Depth String Wound cartridges or any Depth cartridge, flow is a critical factor in the filter's performance.
A TIE or Ten Inch Equivalent is the way we normalize the operating parameters of cartridge filters. With String Wound depth cartridges, optimum dirt holding capacity and particle removals at the stated micron rating occur at flow rates between 2 and 3 Gallons Per Minute per TIE. Above that flow per TIE, you get reduced life and dirt holding capacity. Other factors include not letting the dirty pressure drop exceed 20 PSI. Unloading of particles occur at higher pressures as flow forces overcome the Van Der Walls forces.